The AudioExMachina’s Echorec Bible

The ultimate reference for Binson Echorec owners. The AudioExMachina’s Echorec Bible is constantly revised and updated to cover every Echorec model ever produced. To my knowledge this is the only complete catalog of Echorec units available anywhere.

This page is © 2012/2016 by AudioExMachina. Please link to this document instead of duplicating content, thank you.

Table of Content

• 1. Models and Features
• 2. Echorec Models and Pink Floyd: Timeline NEW
• 3. Echorec Models and Pink Floyd: the Adam Ritchie photo sets
• 4. Panel Labels in Various Languages
• 5. Trimpots
• 6. Magnetic Drum
• 7. Magic Eyes
• 8. AC and DC Motors
• 9. Dedicated Preamp Models and Features
• 10. Audio and Foot-Switch Connectors
• 11. Official Echorec Maintenance Instructions NEW
• 12. Echorec, PreMixer and Power Amp: the Binson 7 NEW
• 13. Echorec and PreMixer Integration: the EM6
• 14. Strangest Beasts: Mod. G7
• 15. Strangest Beasts: EC-10 2×10
• 16. Binson and Hagström
• 17. Binson and Guild
• ??? (coming next)

1. Models and Features

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	Model	Front Panel	Year	Type	Meter	Heads Play+Rec	Tone Ctrls	Inputs	Selectable Feedback Heads
Binson Echorec : Small Frame Models
	Baby Echorec	SilverPlexi	1960	Tube	EM81	4+1	0	1	N
	T3F-A	BlackPlexi	1960	Tube	EM81	4+1	0	1	N
Binson Echorec : Large Frame 4-knob Models
	B1S	BlackPlexi	1960	Tube	EM81	4+1	0	1	N
	B2	BlackPlexi	1965	Tube	EM81	4+1	0	3	N
	T5E (B2)	BlackPlexi	1965	Tube	EM81	4+1	0	3	N
	B2 Export	BlackPlexi	1971	Transistor	EM81	4+1	0	3	N
	1A (rebranded as Guild)	BlackPlexi	1965	Tube	EM81	4+1	0	3	N
	Echomaster1 (rebranded as SoundCity)	BlackPlexi	1971	Transistor	EM81	4+1	0	3	N
Binson Echorec : Large Frame 6-knob Models
	Ecorec (note: ECO, not ECHO)	GoldPlexi	1955	Tube	EM80	4+1	0	3	N
	T5E Echorec	GoldPlexi	1957	Tube	EM81	4+1	0	3	N
	T5E Echorec2	GoldPlexi	1958	Tube	EM81	4+1	1	3	N
	T5E Echorec2	BlackPlexi	1960	Tube	EM81	4+1	1	3	N
	T6FA	BlackPlexi	1961	Tube	EM81	4+1	1	3	N
	T6FA (rebranded as Guild)	BlackPlexi	1961	Tube	EM81	4+1	1	3	N
	T7E Echorec2	BlackPlexi	1962	Tube	EM81	4+1	1	3	N
	T7E Echorec2	BlackPlexi	1971	Transistor	EM81	4+1	1	3	N
	Echomaster2 (rebranded as SoundCity)	BlackPlexi	1971	Transistor	EM81	4+1	1	3	N
Binson Echorec : Studio Rack Models
	PE-603	BlackPlexi	1967	Tube	EM84	4+1	2	1	N
	PE-603-T	BlackPlexi	1969	Tube	EM84	4+1	1	1	Y
	PE-603-TU	BlackPlexi	1969	Tube	EM84	4+1	2	3	Y
	PE-603-TE	BlackPlexi	1969	Tube	EM84	4+1	1	3	N
	PE-603 STEREO	BlackPlexi	1970	Tube	2 x EM84	2 x (4+1)	2 x 2	2 x 1	Y
	PE-603-M	BlackPlexi	1971	Transistor	EM84	4+1	1	1	N
	PE-603-T	BlackPlexi	1971	Transistor	EM84	4+1	1	1	Y
	PE-603-TU	BlackPlexi	1971	Transistor	EM84	4+1	2	3	Y
	PE-603-T-6	BlackPlexi	1972	Transistor	EM84	6+1	1	1	Y
	PE-603-TU-6	BlackPlexi	1972	Transistor	EM84	6+1	2	3	Y
Binson Echorec : Slim Red Head Models
	A-601	RedPlexi	1969	Transistor	Mechanical	4+1	1	3	N
	A-601 (rebranded as Guild)	RedPlexi	1969	Transistor	Mechanical	4+1	1	3	N
	A-602	RedPlexi	1969	Transistor	Mechanical	4+1	1	1	N
	A-605	RedPlexi	1969	Transistor	Mechanical	4+1	1	1	Y
	A-606	RedPlexi	1973	Transistor	Mechanical	4+1	1	3	Y
	A-606 (rebranded as Guild)	RedPlexi	1973	Transistor	Mechanical	4+1	1	3	Y
	A-605 TR-6	RedPlexi	1973	Transistor	Mechanical	6+1	1	1	Y
	A-606 TR-6	RedPlexi	1972	Transistor	Mechanical	6+1	1	3	Y
	A-606 TR-6 (rebranded as Guild)	RedPlexi	1972	Transistor	Mechanical	6+1	1	3	Y
Binson Echorec : Desktop Models
	EC-3	Black	1975	Transistor	Mechanical	4+1	1	3	Y
	EC-6	Black	1975	Transistor	Mechanical	6+1	1	3	Y
	EC-8	Black	1975	Transistor	Mechanical	8+1	1	3	Y
	EC-10	Black	1975	Transistor	Mechanical	10+1	1	3	Y
Binson Echorec : Portable Models
	E4T	Black	1981	Transistor	LED	4+1	1	1	Y
Binson Echorec : Modules in Larger Systems
	Binson7 Amp with Echorec	Silver	1972	Transistor	Mechanical	4+1	12	6	Y
	EM6 Silver	Silver	1974	Transistor	Mechanical	4+1	12	6	Y
	EM6 Black	Black	1974	Transistor	Mechanical	4+1	12	6	Y
	ME-8 Mixer with Echorec	Black	1982	Transistor	Mechanical	4+1	16	8	Y

2. Echorec models and Pink Floyd: Timeline

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The British band Pink Floyd had Binson Echorec devices as part of their equipment for more than a decade, since their early works up to the 1977 Animals album. This section presents the first accurate study of available visual material (stage/studio photos and videos) with the goal of identifying and catalog Binson Echorec units available on stage during Pink Floyd performances.

Methodology. The devices listed below are included only in those cases where visual proof of presence exists: this means that even when the use of additional Echorec devices may be inferred from acoustic cues, only visible units are listed. Also, due to camera shooting angles, in some performances the Echorec(s) used by a band member may be not visible: even in this case, no inference is made and the device(s) is/are not listed.

During this study, it happened more than once that when some Echorec was reasonably suspected to be present but not visible, the search for extra footage or photos from a different sources/angles, when successful led to discovering additional units.

Echorec models and Pink Floyd: Legend
Icon	Description
	Echorec Baby. There is a single model.
	Echorec 1. There is a single model.
	Echorec 2 T5E, T6FA or T7E. In general, without a close picture, it’s impossible to tell one model from the others.
	Echorec 2 T6FA. The T6FA for the American market has chicken-head knobs and some minor differences that can be told at some distance.
	Echorec PE 603 series. At least one of the PE603 units has been identified in several different locations/dates as a TU.
	Album related event (such as the first day of the first recording session or the album release day)

Echorec models and Pink Floyd: Timeline
	Date	Location	Event	Notes
	19661015	Roundhouse,London,UK	International Times First All Night Rave (launch of the underground newspaper International Times)	First Echorec Baby appearance. First Echorec 1 T5E appearance.
	19661216	Architectural Association,London,UK	Student Party
	19661223	UFO club,London,UK	Opening night
	19670111/12	Sound Techniques Studios,London,UK	Recording of Interstellar Overdrive for Tonite Let’s All Make Love In London soundtrack	First Echorec Baby appearance in studio. First Echorec 1 T5E appearance in studio.
	19670127	UFO club, London, UK	Granada TV documentary, ‘Scene Special’
	19670221	Abbey Road, London,UK	The Piper at the Gates of Dawn recording sessions, first day
	19670512	Queen Elizabeth Hall, London, UK	Games for May-Space Age Relaxation For The Climax Of Spring
	19670705	Abbey Road, London,UK	A Saucerful of Secrets recording sessions, first day
	19670805		The Piper at the Gates of Dawn released
	19671021	De Lane Lea, London, UK	A saucerful of Secrets recording sessions
	19671217	Mike Leonard’s House,London, UK	BBC Tomorrow’s World ‘Lights’ documentary	Last Echorec Baby appearance on video. Last Syd Barrett appearance on video as member.
	19680629	Abbey Road, London,UK	A saucerful of Secrets released
	19690201	Pye Recording Studios, Marble Arch, London,UK	More soundtrack recording sessions, first day
	19690414	Royal Festival Hall, London, UK	More Furious Madness From the Massed Gadgets Of Auximenes	First Echorec 2 appearance.
	19690613		More soundtrack released
	19690427	Mothers, Erdington, Birmingham, UK	Ummagumma live recording sessions, first day
	1969 summer	Biggin Hill Airport, UK	Ummagumma read cover photo session
	19691025		Ummagumma released
	19691025	Mont de l’Enclus,Amougies, Belgium	Actuel Festival
	19691116	International Recording Studios, Rome, Italy	Zabriskie Point soundtrack recording sessions, first day
	19700301	Abbey Road, London,UK	Atom Heart Mother recording sessions
	19700329		Zabriskie Point soundtrack released
	19700429	KQED TV Studios, San Francisco, California, USA	An Hour with Pink Floyd (TV show)
	19700516	The Warehouse, New Orleans, Louisiana, USA	Concert
	19700628	Kralingse Bos, Rotterdam, Netherlands	The Holland Pop Festival 70
	19700718	Hyde Park, London, UK	Blackhills Garden Party
	19700808	St Tropez, France	St Tropez Music Festival
	19701002		Atom Heart Mother released
	19701204	Paris, France	ORTF TV show
	19710104	Abbey Road, London, UK	Meddle recording sessions, first day
	19710225	Grosser Saal, Musikhalle, Hamburg, Germany	European tour
	19710515	Crystal Palace Bowl, London, UK
	19710615	Abbaye de Royaumont, Royaumont, France
	19710619	Palazzo delle Manifestazioni Artistiche,Brescia, Italy	Concert	PE603 series first appearance. David Gilmour’s dual Echorec stack (PE603+Echorec2) first appearance.
	19710620	Palazzo dello Sport, EUR, Rome, Italy	Concert
	19710701	Stiftshoff, Ossiach, Austria	Internationale Musikforum Ossiachersee
	19710806	Hakone, Japan	Hakone Aphrodite Festival
	19710815	Randwick Racecourse, Sydney, Australia	Australian tour	One of the Echorec 2 (Roger Waters) is identified as a T6FA with 60% probability
	19710104	Pompeii, Italy	Live at Pompeii recording sessions
	19711004	Pompeii, Italy	Live at Pompeii: live performance	One of the Echorec 2 (Rick Wright) is identified as a T6FA with 90% probability
	19711030		Meddle released
	19711213	Studio Europa Sonor, Paris, France	Live at Pompeii: studio performance	One of the Echorec 2 (Rick Wright) is identified as a T6FA with 70% probability
	19720223		Obscured by Clouds recording sessions first day
	19720304	Château d’Hérouville, Hérouville, Île-de-France, France	Obscured by Clouds recording sessions
	19720522	Olympic Stadium, Amsterdam	Concert
	19720601		Dark Side of the Moon recording sessions, first day
	19720602		Obscured by Clouds released
	19720629	Brighton Dome, Brighton, UK	(Peter Clifton film)
	19720902	Edinburgh Film Festival in Scotland	Live at Pompeii released at the Edinburgh Film Festival
	19730301		Dark Side of the Moon released
	19730518	Earls Court	Earls Court Concert
	19750106		Wish You Were Here recording sessions, first day
	19750705	Knebworth Park	Knebworth Park Concert
	19750812		Wish You Were Here released
	19760415	Britannia Row	Animals recording sessions, first day
	19770123		Animals released	Last Pink Floyd album featuring Echorec devices

3. Echorec Models and Pink Floyd: the Adam Ritchie Photo Sets

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Early evidence of the Pink Floyd using Echorec devices on stage is due to the works of British photographer Adam Ritchie. The year is 1966 and band is composed of Sid Barrett, Roger Waters, Nick Mason e Wright.

Adam’s photos document Pink Floyd gigs at three locations: the concert at the Roundhouse for the launch of the underground newspaper International Times, the student party at the Architectural Association, and the famous friday nights at the UFO club.

Adam recalls: “I was there taking pictures because I had previously shared a flat with Hoppy who started the UFO Club in Tottenham Court Road (and the International Times and the London Free School and the Notting Hill Carnival (with Raunie Laslett)). “

[AExM] “The look of your images is awesome, any detail about the shooting technique?”

[Adam] “I took the pix on a Minolta 35mm SLR without flash because you can’t take pictures of a light show with flash. I probably used Ektachrome X film. All my pictures were taken hand held at about 1/2 to one second exposures because the light levels were pretty low. The ones that are sharp are sharp because someone else was taking a flash picture while my camera was open.”

Adam has been so kind to provide a set of nine previews (three shots for each location) of this very important material, for inclusion in the Echorec Bible. I’d recommend everyone seriously interested in Echorec devices to visit his site at www.adam-ritchie-photography.co.uk for browsing his full catalog. You’ll find other gems there.

Roundhouse,London,UK 1966 Oct 15

Syd Barret, Echorec Baby, Roger Waters, Echorec 1 (behind Roger)

Syd Barret, Echorec Baby, Roger Waters, Echorec 1 (behind Roger)

Echorec Baby, Roger Waters, Echorec 1 (behind Roger)

Architectural Association,London,UK 1966 Dec 16

Roger Waters, Syd Barrett and Echorec 1 on the floor

Roger Waters, Echorec Baby and Syd Barrett

Roger Waters, Syd Barrett, Echorec 1 on the floor and Echorec Baby in the background

UFO club, London, UK 1966 Dec 23

First gig at the UFO, Syd Barrett playing guitar and Echorec Baby behind him

More UFO: Pink Floyd, Echorec1 behind Roger, Echorec Baby behind Syd. Two go-go dancers in the front of the stage

UFO: Echorec1, Roger Waters, Echorec Baby, Syd Barrett

4. Panel Labels in Various Languages

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Being a product made in Milan,Italy, for the national market, the language for panel labels on early units was Italian only. With new orders coming also from abroad, and production increasing, French language versions were offered starting with the Echorec1 model. English and German panels followed soon after. Eventually, with the introduction of the Studio Rack line‌, English became the only language used for every Echorec.

Labels : Large Frame Echorec1
Functionality	Italian	French	English	German
main switch	interruttore spento/acceso/moto	interrupteur eteint/allume/moteur	control off/on/motor	[no german version]
mode: echo/bypass/swell	selett. eco-alo eco/normale/alo	selettionneur echo/normal/son	echo swell selector / echo/normal/swell	[no german version]
rec level	volume reg.	vol. enregistrement	input control	[no german version]
feedback	lungh. alo	longueur de son	length of swell	[no german version]
wet level	vol eco-alo	vol. echo-son	volume echo swell	[no german version]
delay patterns (heads)	ritardi	retards	echo/swell switch	[no german version]
rec level display	livello reg.	niveau enreg.	level indicator	[no german version]
I/O channel selector	selettore canali	selectionneur canaux	channel selection	[no german version]
Labels : Small Frame and Large Frame 4-Knob Models
Functionality	Italian	French	English	German
main switch and rec level	vol. reg. / spento	interrupteur / eteint	control / off	schalter / aus
feedback	lung. alone / eco	longueur de son / echo	length of swell / echo	schall-lange
wet level	vol. alone / ec	volume echo/son	volume echo/swell	lautst echo-schall
delay patterns (heads)	ritardi	retards	echo/swell switch	verzögerungen
rec level display	livello reg.	niveau enreg.	level indicator	aussteuerungsanzeige
Labels : Large Frame 6-Knob Models
Functionality	Italian	French	English	German
main switch and rec level	volume reg	vol. enregistrement	input control	aussteuerung
feedback	lungh. alo	longueur de son	length of swell	schall-lange
wet level	vol eco-alo	volume echo/rep/son	volume echo/rep/swell	lautst echo-schall
tone	tono bassi/alti	ton bas / aisu	bass/treble	tonelange – tonblende tief/hoch
mode: echo/bypass/swell	selett. echo-alo	selett. echo/rep/son	selector echo/rep/swell	wahler echo/wied/schall
delay patterns (heads)	ritardi	retards	switch	verzögerungen
rec level display	livello reg.	niveau enreg.	level indicator	aussteuerungsanzeige
I/O channel selector	selettore canali	selectionneur canaux	channel selection	kanal wahler

5. Trimpots

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Trimpots (miniature potentiometers) are contained in every Echorec model, in order to control several parameters. They are meant to be properly set at the factory, and possibly re-adjusted by technicians as part of the servicing procedures. As a user interface design decision, parameters controlled by trimpots are hidden to the end user by making them adjustable only from the inside of the device.

Echorec2 T5E Trimpots

Trimpots are individually presented below: each one is associated with a short mnemonic, starting with letter “T” (for [T]rimpot).

TD – Dry Level

what: controls the amount of dry input signal that passes-through to the output. The trimpot acts at the output of the first tube/transistor, thus you can either attenuate the input signal or boost it above unity gain, as desired.

when: since the first 1955 Ecorec prototype.

who: every model (excluding the final version of the PE603-T Tube and Transistor, PE603-M Tube and Transistor, PE603-T6, A602-TR, A605-TR).

TF – Feedback Level

what: controls the amount of wet delayed signal coming from the magnetic drum that is re-injected toward the recording head. This trimpot is of paramount importance when tuning the machine for auto-oscillation.

when: since the first 1955 Ecorec prototype.

who: present on every model ever produced.

TM – Magic Eye Sensitivity

what: controls the amount of dry+wet signal that is routed toward the Recording Level Indicator. The indicator is an EM80/EM81 tube for any small-frame or large-frame machines, an EM84 tube for the PE603 rack models, and a mechanical VU meter for later models.

when: introduced with the Echorec2 and Baby2 families and derived models.

who: every model (excluding the Ecorec, Echorec1, Baby).

TSC1,…,TSCn – Shunt caps

what: control each playback head’s high-frequency roll-off. On the Baby, B1s Tube and Transistor, B2, PE603-TE, PE603-M Tube and Transistor, A601-TR, A602-TR there’s a single trimpot for the summed signal coming from all heads. On every other model there’s one tripot dedicated to each individual head, named TSC1,TSC2,TSC3…

when: since the first 1955 Ecorec prototype.

who: present on every model ever produced.

TSW1,…,TSWn – Swell Playback Levels

what: control each head’s playback level ONLY in swell mode. Allow to choose a reverb tail shape (ramp down,
ramp up, etc..). Do not affect echo or repeat modes. There’s one tripot for each individual head, named TSW1,TSW2,TSW3…

when:introduced with the Echorec2

who:every model (excluding the Ecorec, Echorec1, Baby, B1s, B2 Tube and Transistor, PE603-TE, PE603-M Tube and Transistor, A601-TR, A602-TR).

TI – Input Gain

what:controls the input level, before the first tube/transistor. Note that here we refer to the device’s input level, while the dedicated input knob on the front panel adjusts the disk (recording) input level.

when:introduced with the PE603-T final version.

who:every PE603-x models (excluding the PE603-STEREO), every A60x-TR (excluding the A601-TR), every ECx model, EM6, ET4.

TO- Output Gain

what:controls the output level, after the last tube/transistor.

when:introduced with the PE603-T final version.

who:every PE603-x models (excluding the PE603-STEREO and the PE603-M Tube and Transitor), every A60x-TR (excluding the A601-TR, A605-TR6, A606-TR, A606-TR6), every ECx model, EM6,ET4.

Echorec PE603T Trimpots

The amount and function of trimpots installed onboard varies depending on models. A detailed table is presented below. When the amount of trimpots is different from the typical value as described above (eg. a single TSC trimpot instead of one for each head), this amount is displayed as a number.

Trimpots: Small Frame Models
Model	TD	TF	TM	TSCx	TSWx	TI	TO
Baby	+	+		1
T3F-A Guild	+	+		1
Trimpots: Large Frame 4-knob Models
Model	TD	TF	TM	TSCx	TSWx	TI	TO
B1	+	+	+	1
B2S	+	+	+	1
B2 Export	+	+	+	1
1A Guild	+	+	+	1
Echomaster1 TR SoundCity	+	+	+	1
Trimpots: Large Frame 6-knob Models
Model	TD	TF	TM	TSCx	TSWx	TI	TO
Ecorec	+	+		+
T5E Echorec1	+	+		+
T5E Echorec2	+	+		+	+
T6FA	+	+		+	+
T6FA Guild	+	+		+	+
T7E Echorec2	+	+		+	+
T7E Echorec2 TR	+	+		+	+
Echomaster2 TR SoundCity	+	+		+	+
Trimpots: Studio Rack Models
Model	TD	TF	TM	TSCx	TSWx	TI	TO
PE 603-T		+	+	+	+	+	+
PE 603-TU	+	+	+	+	+	+	+
PE 603-TE	+	+	+	1		+
PE 603-STEREO	2	2	2	8	8
PE 603-M		+	+	+		+
PE 603-M TR		+	+	+		+
PE 603-T TR		+	+	+	+	+	+
PE 603-TU TR	+	+	+	+	+	+	+
PE 603-T6		+	+	+	+	+	+
PE 603-TU6	+	+	+	+	+	+	+
Trimpots: Slim Red Head Models
Model	TD	TF	TM	TSCx	TSWx	TI	TO
A601 TR	+	+	+	+
A602 TR		+	+	+		+	+
A605 TR		+	+	+	+	+	+
A606 TR	+	+	+	+	+	+
A605 TR6	+	+	+	+	+	+
A606 TR6	+	+	+	+	+	+
Trimpots: Desktop Models
Model	TD	TF	TM	TSCx	TSWx	TI	TO
EC3	+	+	+	+	+	+
EC6	+	+	+	+	+	+
EC8	+	+	+	+	+	+
EC10	+	+	+	+	+	+
Trimpots: Portable Models
Model	TD	TF	TM	TSCx	TSWx	TI	TO
E4T	+	+	+	+	+	+

6. Magnetic Drum

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The magnetic drum, heart of the Echorec’s recording subsystem, is a metal component shaped as two stacked cylinders with a central axle. The lateral surface of the top cylinder is covered by an additional aluminium ring. This ring is an early visual hint about the age of drum assemblies. Early generation rings (for the Ecorec prototypes, the Echorec1, the T5E first generation Echorec2) extend from the border torward the center of the top drum face by 0.5in/1.15cm while later more common models just by 0.2in/0.5cm.

In the rest of this section, when two alternative measures are reported, the former is from early generation drums, the latter from later ones. Figures are provided in two units of measure: inches (in) and centimeters (cm).

Echorec Magnetic Drums: early generation (left) and later ones.

The top cylinder has a diameter of 4.7in/12cm and is 0.6in/1.45cm to 0.8in/1.95cm tall, depending on version. The aluminium ring surface exhibits a recessed zone, 0.3in/0.8cm wide, fitted by an ultra-thin iron wire accurately wound around. The result is a smooth metallic tape loop that gets magnetically written and read by the recording, playback, erase heads, according to the wire recording principles (the main difference here being the substantially wider audio track substrate on the Echorec, compared to typical wire recorders).

The top flat surface of the drum is decorated with a beautiful psychedelic motif. The effect is obtained by adding 0.4% liquid silicone into the paint mixture. The very last generation of drums, late seventies, exhibit a solid-black finish instead.

The bottom cylinder, smaller, is 4.4in/11.15cm to 4.5in/11.5cm in diameter, and 0.3in/0.8cm tall. The external surface of this component is the end-point of the motion transmission chain whose starting-point is the Echorec electric motor. Early generation drums are much heavier (2.82lbs/1.28kg) as the bottom cilinder is solid-metal. Later models feature an hollow bottom cylinder, the total drum weight being just 0.99lbs/0.45kg.

Echorec Heavy 1959 (left) and Light 1967 (right) Drums

The drum axle extends up to 2in/5cm below the top surface of the drum. Axle’s diameter is 0.3in/0.8cm cm. Near the lower end of the axle (in the pictures the drum is turned upside down and the lower end is the one facing up) there’s a milled zone where the diameter is reduced to 0.2in/0.5cm.

Echorec Drum Shaft

The milled zone at the bottom of the axle is meant to inhibit vertical axial movements of the whole drum assembly by means of a locking screw inserted into a dedicated threaded hole located on the drum shaft sleeve.

Personally I keep all my drums unlocked for easier manteinance and access to internal parts. WARNING: if the unit is moved, an unlocked drum might fall to the ground and be severely damaged. Be careful if you unlock your drums.

Echorec Drum Shaft Sleeve: Threaded Hole for Locking Screw (right).

The magnetic drum is actuated by a rubber wheel, which in turn is actuated by the Echorec electric motor shaft. The wheel freely rotates around a static axle. Friction against the static axle is controlled by a metal ring placed at the center of the rubber wheel.

Rubber wheels of different Echorec models may have different inner metal rings. The difference is in the profile and depth of such rings.

A wrong wheel/axle pair displaces the wheel vertically, resulting in the rubber surface being unable to reach the drum’s bottom cylinder and impacting against the top cilinder (the one devoted to recording). This happens also when mounting an otherwise correct wheel/axle pair with the wheel’s bottom surface incorrectly facing up (reverse mounting).

Echorec Rubber Wheels with Different Inner Rings

The rubber wheel is mounted on a slide that is pushed torward both the motor shaft and the magnetic drum’s bottom cylinder by a spring-loaded mechanism. The wheel is secured on its axle by one of two methods, depending on model: a screw and washer or a metal collar.

Echorec Slide with Screw and Washer on Top (and a Collar in Foreground).

7. Magic Eyes

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A magic eye is a special tube whose purpose is to provide visual indication about voltage levels. Electrons leaving the cathode hit a luminescent area inside the tube, called the target. As the amount of voltage applied to the grid (the voltage to be measured) changes, the glowing area of the screen changes in shape accordingly.

In the Echorec the magic eye displays the level (voltage) of the audio signal sent to the recording head for being recorded on disc.

This signal is the mix of the dry input and wet (delayed) feedback. The dry input is controlled by the “input level” knob (and TI trimpot when present). The wet feedback is controlled by the “length of swell” knob (and TF trimpot, always present). The level of the sum of both signals is measured by the magic eye indicator.

The magic eye sensitivity is adjusted by the TM trimpot.

Excluding a limited use of EM80 magic eyes in early units built, the standard luminescent tubes for the Echorec are the EM81 (compatible with the EM80) and the EM84.

EM81 (left) EM84 (right) rear view

The EM81 luminescent screen is an elongated half-oval. Visual feedback is provided by two bright green wings that rotate close to each other as signal level increases. Electrons hit the front face of the screen in order to emit green light.

The EM84 is a micro back-projection device. Electrons hit the back side of a phosphoric strip to obtain green-blue light. Visual feedback is provided by two bars that move close to each other as signal level increases.

EM81 (left) EM84 (right) front view

Magic Eyes
Tube Model	Year of Introduction	Sensitivity Range	Visual Range	Echorec Models	Datasheets
EM80	1953	-1V , -14V	45 degrees (angular)	Prototypes	pdf
EM81	1956	-1V , -10.5V	60 degrees (angular)	Small Frame and Large Frame (all)	pdf
EM84	1957	0V , -22V	21 mm (linear)	Studio Rack (all)	pdf

8. AC and DC Motors

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Since early prototypes dating mid-50’s, Echorecs have been powered by an AC electric motor. AC electric motors rotate at a fixed speed, proportional to the mains frequency (60Hz in North America, 50Hz in Europe,…). Proper gearing ratio reduces this speed to a value appropriate for the Echorec’s disc (just above one turn per second).

In disc delays, given non-movable heads, disc rotation speed determines delay duration. While other manufacturers of similar mechanical devices experimented variable-ratio gear (e.g. Meazzi), every tube-based Echorec features a fixed gearing ratio (that is, fixed speed and delay durations).

After the development of transistor-based models, Binson introduced versions equipped with a DC electric motor, starting 1971 with the T7E Echorec2 Transistor.

DC motor rotation speed is proportional to supplied DC voltage, rather than frequency, making it easier to possibly implement a variable speed control (the purpose of such a control being to obtain variable delays).

Actually, Binson never released a variable speed Echorec, however retrofitting a DC motor (replacing the original AC motor) and controller into existing AC Echorec models is the standard route followed nowadays by technicians aiming at implementing variable delays as a custom modification.

For the reason explained above Echorec models that come stock with DC motors are especially interesting. After the Echorec 2 TR, more DC models were introduced in the 1971/1973 period, both in the PE603-X and A60X lines. Below is a detailed table.

Echorecs featuring DC motors
Year of Introduction	Echorec Model	Echorec Type	Notes
1971	Echorec2	Transistor only. Tube version fitted with AC motor.	4 Heads
	PE603-T	Transistor only. Tube version fitted with AC motor.	4 Heads
	PE603-M	Transistor only. Tube version fitted with AC motor.	4 Heads
1972	PE603-T6	Transistor only. Tube version fitted with AC motor.	6 Heads
	PE603-TU6	Transistor only. Tube version fitted with AC motor.	6 Heads
	A606TR-6	Transistor. No tube version.	6 Heads
	Binson 7	Transistor. No tube version.	4 Heads
1973	A606TR	Transistor. No tube version.	4 Heads
	A605TR-6	Transistor. No tube version.	6 Heads
	A602TR	Transistor. No tube version.	4 Heads

A note from John Hamley (Brunswick Amplifier LLC), Echorec servicing specialist in Cleveland, USA:
“Wanted to share an issue that one of the units was having after a rewire by someone else. The unit was brought in with the motor spinning very slowly. Careful listening revealed that the motor was “slipping poles,” that is the magnetic field in the motor was outracing the spindle. You can hear this as a warbling sound and vibration coming from the motor. The reluctance motors in the Binsons (without the start cap) are synchronous motors. With two poles, they should spin at 3600 rpm in the US. 2500 in Europe with 50Hz power. It appears that the Guild branded devices have 120V motors built in. The Euro models are 220V. Wiring the Euro model for 120V results in poor startup and poor speed control. (If it ever gets there) Using the 220V tap for the motor on the power transformer on the Euro models obviously fixes this problem. I cannot recall seeing a difference in the motor. Safer to start with the 125V tap if you are not sure. If the motor does not run well, try the higher voltage tap. This of course assumes that the shaft spins freely by hand and there are no bearing issues.”

9. Dedicated Preamp Models and Features

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	Model	Front Panel	Year	Type	Echorec Send Faders	Echorec Send Return Channels	Channel Strip: [B]ass [M]id [T]reble [V]ol [S]end	Input Channels	Power Supply
Dedicated Preamp Models and Features
	PreMixer HiFi	GoldPlexi	1959	Tube	0	3	B T V	6	N
	PA3MN	BlackPlexi	1961	Tube	3	1	B T V S	3	N
	PA4MN	BlackPlexi	1961	Tube	4	1	B T V S	4	N
	PA6MN	BlackPlexi	1961	Tube	6	1	B T V S	6	N
	PA602	BlackPlexi	1967	Tube	8	1	B T V S	6+2AUX	Y
	PA602-M	BlackPlexi	1969	Tube	4	1	B T V S	4	Y
	PA602-4	BlackPlexi	1969	Tube	4	1	B T V S	4	Y
	PA602-6	BlackPlexi	1969	Tube	6	1	B T V S	6	Y
	PA602-8	BlackPlexi	1969	Tube	8	1	B T V S	8	Y
	PA602-S	BlackPlexi	1968	Tube	8	2	B T V S	4+4 STEREO	Y
	S600	BlackPlexi	1968	Tube	2	2	B M T V S + Rvrb + Vbrt	1+1 STEREO	Y
	A607TR4	RedPlexi	1971	Transistor	4	1	B T V S	4	Y
	A607TR6	RedPlexi	1971	Transistor	6	1	B T V S	6	Y
	A607TR8	RedPlexi	1971	Transistor	8	1	B T V S	8	Y

10. Audio and Foot-Switch Connectors

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While standard TS and TRS connectors are mounted on the Studio Rack and later product lines, several Small-Frame and Large-Frame Echorec models (see table below) feature special audio connectors made by Geloso, an italian electronic components and devices manufacturer.

Echorec Models with Geloso sockets (models not listed here mount always TS/TRS sockets)
Echorec Model	Notes
Echorec Baby	all units have Geloso sockets
B1S	early units: Geloso sockets – later units: TS/TRS sockets
B2	early units: Geloso sockets – later units: TS/TRS sockets
T5E Echorec	all units have Geloso sockets
T5E Echorec2 GoldPlexi	all units have Geloso sockets
T5E Echorec2 BlackPlexi	all units have Geloso sockets
T6FA	all units have Geloso sockets (Guild versions: TS/TRS sockets)
T7E Echorec2	almost all units have Geloso sockets (some later units: TS/TRS sockets)

Geloso sockets and plugs are listed as parts N.398 and N.396 in Geloso catalogs. On the Echorec, the N.398 socket is used in audio I/O ports and also in the Premixer port for connecting (if model offers this feature) to the dedicated Premixer PA-3/4/6 MN external preamps.

Binson Echorec N.398 and N.396 connectors from Geloso parts catalog

The connector’s three silver-plated pins handle voltages up to 300V RMS. Insulation is granted up to 500V RMS. Max current: 5A. A dent on the plug grants correct pins/holes matching after insertion.

Geloso plugs for the Echorec

While replacing Geloso sockets with functionality equivalent TS sockets is a common restoration/upgrade practice, some owners prefer to preserve the original parts as this results in an higher collectible value. In this cases, adapter cables can be built with a Geloso plug on one side, and a TS female plug on the other one.

On the Echorec, of the three pins in the socket two are grounded and one (the pin diametrically opposite to the dent) carries signals. The adapter is an unbalanced cable that maps a two-contacts TS to the three-pin Geloso scheme.

Adapter cables for Echorec models with Geloso sockets. Note the alignment dent on the plug’s surface.

Echorec footswitch sockets and plugs are Geloso parts too. They consist in a jack connector with reduced diameter (5mm) compared to common 6.3mm parts. The 5mm plug and sockets correspond to Geloso parts N.9008 and N.9004.

Binson Echorec – Geloso audio (top) and foot-switch (bottom) connectors

11. Official Echorec Maintenance Instructions

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Official maintenance instructions from the original Binson documentation.

Official Echorec maintenance instructions, pag1.

Official Echorec maintenance instructions, pag2.

Official Echorec maintenance instructions, pag3.

12. Echorec, PreMixer and Power Amp: the Binson 7

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The Binson 7, also known as Amplificatore 7, is an unique device consisting of a cabinet that houses a PreMixer unit, a power amp and an Echorec. The external shape reminds more a personal computer tower case than a vintage analog musical device. Another easily recognizable feature is its cyan/silver livery, later used also for the 1974 EM6 Echorec.

BINSON 7 – front panel.

BINSON 7 – rear panel.

The project dates 1972. Despite being the first step torward the integration of a multi-channel mixer/preamp and an Echorec, the Binson 7 still presents well separated user interfaces for the mixing and echo functionalities. Complete integration will be reached two years later, with the 1974 EM6.

The presence of a power amp section is no surprise as Binson started making tube amps in the early 50’s, before the Echorec was invented. Since 1967, beside tube amps, Binson manufactured also transistor amps.

The Binson 7 is a fully solid-state design, available in two flavours: 100W and 200W. The 100W model drives 1x8ohm speaker cabinet, the 200W 2x8ohm or 4x4ohm cabinets.

BINSON 7 – top, disc cover.

BINSON 7 – top, Echorec controls.

The mixer section features six or eight channels (depending on versions), each with a switchable input transformer. Each channel strip contains the following controls (from top to bottom): echo level, channel level, treble, bass, input impedence selector.

The input sockets for all channels are on the front panel, excluding an additional AUX input (available on most Binson PreMixer models) on the rear pannel,

BINSON 7 – top, front.

BINSON 7 – top, rear.

The Echorec section is based on a four-head disc memory module. For each playback head two push buttons allow to send the disc signal to the output bus and/or the echo feedback bus. This set of buttons, known at Binson as the “keyboard”, was used for the first time on the PE603-T (T stands for “Tastiera”, Italian for “keyboard”).

BINSON 7 – side.

BINSON 7 – rear.

The unit is powered by an unusual (compared to the typical AC motor in previous models) DC motor at 9V. Electronics are exclusively solid-state, no tube versions, following the trend started with the A60x (Slim Red Head) series.Also from the A60x comes the mechanical VU meter, however the Binson 7 has a couple of them (Echorec level and mixer level).

13. Echorec and PreMixer Integration: the EM6

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The EM6 is a special Echorec model from 1974, the first and only example of full integration between an Echorec memory module and a PreMixer unit. The Binson PreMixer, initially introduced in 1959 and produced up to the 70’s in several different generations, is a multi channel mixer with input transformers and sends dedicated to the Echorec.

See further details about the PreMixer in the PreAmp section.

EM6 – Echorec memory module and PreMixer unit integrated into a single device.

Actually, the Amplificatore 7 (seventh generation of the Binson amp) designed two year earlier already featured several devices mounted on a single chassis ( an Echorec, a PreMixer, a 100W power amp), however these modules were still well separated entities interfaced together.

With the EM6, for the first time a seamless control surface exposes knobs and faders for operating both the Echo and the PreMixer. This unique design won’t be replicated in later products but in the early 80’s Binson resumes the concept by proposing their larger mixing consoles (ME and M12/18/24) with onboard Echorec units.

EM6 – note the unusual cyan disc cover.

EM6 – disc uncovered.

The EM6 reprises the cyan-silver color schema from the 1972 Amplificatore 7. This unique livery was briefly used for just these two models. Side panels are an unusual electric blue. A cyan-black EM6 was also available.

The following EC series, launched shortly after, shifted to a total black look, with wooden side panels. Cyan won’t be seen anymore in Echorecs.

It’s interesting to note how the extremely rare EC10 2×10 (only one unit is known to exist at the moment), a transitional device from the EM to the EC series, reprises some components and the unusual cyan and electric blue colors from the EM6.

See the EC10 2×10 section for further details.

EM6 – Echorec controls, details of the “keyboard” on the right.

EM6 – closer view of the disc.

The Echorec EM6 is based on a four-head disc assembly. Each head can be independently selected for feeding the feedback loop by a set of push buttons. This set of buttons, known at Binson as the “keyboard”, was used for the first time on the PE603-T (T stands for “Tastiera”, Italian for “keyboard”).

The unit is powered by the classic Echorec AC motor at 110/220V. Electronics are solid-state only, no tube versions, following the trend started with the A60x (Slim Red Head) series. Also from the A60x comes the mechanical VU meter, however the EM6 has a couple of them (Echorec level and mixer level).

EM6 – rear panel.

EM6 – details of the side panel finish and power switch (both same as in the EC10 2×10).

The EM6 was proposed by Binson as part of a larger sound system based on PF100 and PF200 power amps.

The unit presented in this section was photographed by Tom Hughes of For Musicians Only, East Haven, CT (USA).

14. Strangest Beasts: Mod. G7

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In January 2014 Izy Holvoe from Belgium sent some pictures of a strange Echorec model he acquired years before. Those images were a big surprise: the depicted object was a kind of Binson Echorec I’ve never seen before. Izy anticipated he never found any info anywhere about his device.

What follows below is a technical analysis based on pictures displayed in this section, on additional pictures not published here and on a brief Q & A session with Izy about the state of the device before some reversible modifications he made to convert it to a B2 and about some physical properties of the materials.

Technical analysis: Amplifon Mod. G7

At first sight the device looks obviously like a large frame Echorec. Shape, proportions, size, painting color and method, structure match perfectly those used by Binson for their early series.

No Binson logo is present on the front panel. The left side plate (displaying the serial number, the Binson logo, the model name) was not mounted or was removed.

NOTE: while there is a single case of Echorecs not featuring the Binson logo (the Sound City rebranded Echomaster1 and 2) every model ever produced displays the Echorec patent number, and this includes the Sound City case were the Echomaster is not explicitly identified as an Echorec.

Mod. G7 – No Echorec-style left-side plate (the mains connector is a modern replacement)

The front panel exposes just two control knobs, unlike large frame models which always feature either four or six knobs. The two knobs are placed in the same position of the two most external knobs  on any large frame Echorec. It looks like the remaining knobs were not mounted or removed.

NOTE: Binson proposed the 4-knob series (B1s/B2) as an intermediate line of products placed between the small-frame devices (Echorec Baby/T3F-A) and the large-frame 6-knob ones (Echorec1/2). The 4-knob series was designed as a hybrid solution, featuring the electronics from the small-frame series and the chassis from the large-frame models. Sharing the same chassis, the four knobs on the B1s/B2 are aligned with four of the six knobs of the Echorec1/2 (specifically, their outer pair and the inner pair). The middle pair of knobs, not present on the B1s/B2, corresponds to two empty round holes in their chassis. In the Mod. G7 unit even the inner pair is not mounted.

Analysis of the internal circuitry (pictures not shown here) tells that this is a tube device designed according to the Binson 3+1 tube architecture, as used in the 4-knob large-frame Echorecs. This is either a B1s or a B2.

NOTE: The 4-knob series is based on the 3+1-tube architecture as featured on the Echoerec Baby. 6-knob series is mostly based on the 6+1-tube architecture of the Echorec 2, an evolution of the 4+1 scheme originating from the Echorec 1. The “+1” term refers to the Magic Eye tube.

Despite the lack of a channel selector on the front panel, the right side of the chassis exposes 3 inputs and three outputs. This is a modified B2 (the B1s is single channel).

Mod. G7 – 3+1 tube architecture from the Echorec B2. See, behind the grid, tube caps on the left, the motor in the middle and the power transformer on the right.

Mod. G7 – 6 I/O connectors, B2-style. The 2 TS connectors are a modern replacement of the original Geloso. The chicken-head knob is a modern upgrade that extends the internal feedback trimpot to the outside.

A red logo on the front plexi reads Amplifon. The model name reads: Mod. G7.

Amplifon is an earing aids manufacturer located in Milan, Italy, the hometown of the Echorec. The company was founded in 1950 by Algernon Charles Holland, a former Major in the British Special Forces. While company logo changed over years, the one adopted in the 50’s/60’s is the same depicted in the front panel of the G7. Incidentally, at the time, Amplifon’s head office was less than 3 km. away from the Binson factory.

Text on the front plexi is in Italian. The device is described as “Dispositivo per la voce ritardata”, which translates to “Delayed voice device”. This suggests that instead of being a sound processor, this is rather a speech processor.

Further text reads: “Sistema Azzi” (“Azzi system”). This is the most interesting part.

Dr. Azzo A. Azzi (Hear-nose-throat Clinic – University of Milan – Italy) in the 50’s was involved in research about methods for discovering deafness simulation (malingery). He extended the work of Bernard S. Lee on delayed speech feedback as a cure for voice stutter.

Dr. Azzi invented a test, the delayed speech test, also referred to as the “Azzi test”.

From International Journal of Audiology Jan 1962, Vol. 1, No. 1, Pages 134-144 – Hearing Test in simulation (A.Azzi)

"..The introduction of a time delay in the speech feedback loop with apt electronic devices
 produces a more complex interference in phonation. The test, based on a phenomenon observed
 by LEE, has been developed by Azzi for application in detecting simulation of deafness or 
 psychogenic deafness."

From International Journal of Audiology Jan 1962, Vol. 1, No. 2, Pages 191-193 – Malingering Tests (A.Azzi)

"..[delayed speech test"].. It is based on the interference caused by a disturbance brought
 to the ear during speech. This disturbance is the voice of the subject played back to his 
 ear with a delay of some tenths of a second.[..] The test is highly reliable[..] It requires
 a special and costly instrument."

Dr. Azzi’s work is also cited in the book “The Ear and the Voice” by french otolaryngologist Alfred A. Tomatis (which, by the way, is a really interesting reading about various aspects of sound and psychoacoustics).

The test prescribes using a delayed signal with a single repetition at a pre-determined level.  which means that if an Echorec were to be used as the “special and costly instrument” referenced above, then just the recording level control and the delay selector (the two outer knobs) would be required. The feedback knob and the echo volume knob (the remaining two inner knobs in the B2) wouldn’t be needed.

Is the Mod. G7 the instrument referenced by dr. Azzi in his works?  Is this a prototype for later production or was it intented to be one-of-a-kind?

At this point it is not known who manufactured the Mod. G7, whether Binson was directly involved, whether dr. Azzi himself was involved too. The investigation continues.

15. Strangest Beasts: EC-10 2×10

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The EC-10 deserves a special mention as it is the Echorec model featuring the largest amount of magnetic heads ever: 10 playback heads, 1 recording head and 1 erase head composed by 3 rare-earth magnets. Independent playback and feedback switches for each head allow to choose among more than one million echo patterns.

Echorec EC-10 Magnetic Drum

The EC line dates 1975 and is composed by the EC-3 (four playback heads), EC-6 (six playback heads), EC-8 (eight playback heads) and the EC-10 (ten playback heads). All models are solid state. While circuits works at 24V voltage, the motor is 110V/220V AC (see the motors section for a detailed list of other solid state series that use 9v DC motors instead).

Echorec EC-10: internal view

Echo patterns are controlled by 10 dedicated push buttons for enabling playback on each head and another set of 10 for enabling each playback head’s feedback to the recording bus/head. You can see them on the right side of the control panel when looking at the official EC10 product picture by Binson. Notice the 4 rows of 5 buttons each.

EC-10 Official Binson Picture

As if the EC-10 weren’t intriguing enough, Giorgio Montagna (Montagna Hi-end Audio Systems, Italy), provided a set of photos depicting an even more interesting EC10 unit. As you can see by comparing Giorgio’s Echorec with the official EC-10 picture by Binson, the control panel layout is different, side panels are different, cover colors (cyan and blue) are different.

Echorec EC-10 : rare cyan version

Echorec EC-10: rare cyan version

Magnetic head push-buttons are arranged in 2 long rows of 10 elements each. This unusual layout required moving the on/off switch and fuse from the lower panel to the top panel, something that never happened on any EC model.

Echorec EC-10: note the unusual location of the (blue) on/off switch (top right corner)

Side panels, finished in blue, are the same used in the earlier Echorec EM6 model. The cyan metal covers reproduce the livery of the Amplificatore 7 (1972) and the EM6 (1974).

Echorec EC-10: blue side panels and cyan cover

Echorec EC-10: rear view

It is unclear if this device is a preproduction unit or a custom built one produced later. My opinion is that this is an early EC-10 unit due to the fact that the Binson logo is drawn with an outlined font, as used up to early 70’s, while the EC series always present a Binson logo drawn with a solid, italicized, font, introduced in mid 70’s.

NOTE: The hypothesis is further confirmed by an analysis of images of an early EC-8 unit. Pictures tell us that the EC-8 too was initially introduced with the older Binson logo and a layout consisting of 2 long rows of 8 elements each (stock Ec8 models have 4 rows of 4 elements). In this case however, side panels are brownish and no cyan part is present suggesting that this EC-8 was close to the final design used for the EC series up to the 1980.

This EC-10 is tentatively dubbed EC-10 2×10 to distinguish it from the less rare EC-10 4×5. At present only one 2×10 Echorec unit is known to exist, this one.

NOTE: the EC-8 as well should be considered available in two forms: EC-8 2×8 (old logo) and EC-8 4×4 (new logo).

16. Binson and Hagström

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Hagström, famous instrument and amp manufacturer from Älvdalen, Sweden, became the official Echorec distributor for Scandinavia in late 50′s.

Karl-Erik Hagström jr (from HagstromParts.se), grandson of the founder Albin Hagström, kindly provided the Echorec Bible with high resolution scans of brochures, magazine ads and manuals from the 60′s. This is a beautiful gallery of rare images, never seen before on the net. Thank you Karl.

Thanks to Janne Olofsson-Godman (from hagstrom-vintage-guitars.se) for additional help with Hagstrom-related researches.

17. Binson and Guild

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Guild, the american guitar manufacturer founded in 50’s, started distributing Echorecs in USA in mid 60’s. The agreement between Binson and Guild stipulated that Echorecs shipped from Italy for the North American market would be rebranded as Guild Echorec by Binson.

Below is a page from the 1966 Guild catalog depicting two tube models presented as Model1 and Model2. Observant readers will recognize them as the small frame T3F-A and the large frame T6F-A. Interestingly the pictures were displaying pre-production models as the knobs are the same typical kind used on Binson Echorecs. Guild Echorecs are always equipped with generic black chicken-head knobs, with no Binson logo.

Guild Echorec by Binson: Model1 and Model2 ( T3F-A and T6F-A)

The partnership continued in the early 70’s, with more models available, namely the A60x red-head series. These units were solid-state only, and the rebranding scheme changed to Binson Echorec by Guild. The PE-603 studio rack series, developed in the same period, were never released with the Guild logo. A60x flyers below.

Guild Echorec by Binson: A-606-TR-6

Guild Echorec by Binson: A-606-TR and A-601-TR