Saturday, 29 September 2007 15:40

This time we’ll take a look at what was probably the most successful solid-state delay created: the Electro-Harmonix Memory Man series.

EH debuted their legendary line in about 1976. The whole idea behind the MM was to create an echo/delay unit which would produce the same effects without tape or other mechanical parts and at a lower cost. The delay was accomplished by using a bucket brigade delay IC (BBD), the heart and soul of each unit. This IC receives a signal and passes it along in stages to the IC’s output pin. BBDs were (and still are) available with anywher from 68 to 4096 stages. The more stages, the more delay available. A tradeoff was that as more delay was used, distortion in the delayed signal increased.

The first model to be released was the standard Solid-State Echo/Analog Delay Line model. Designed by Irwin Kornfeld, this no-frills model was as simple as could be. It was in a plain metal box (actually the first to use this style box) and had controls for BLEND, FEEDBACK, and DELAY as well as a BOOST switch for greater signal strength. In addition to the INPUT jack, there were also jacks for DIRECT and ECHO outputs. The early chassis were very gray in color and stand out easily among other MMs, but these were only in use for a short time before the now standard brushed metal chassis were used. Delay time for these early models could be set from 5ms to 320ms.

When you’ve got a good thing going, improve it! Presenting the 4 knob Deluxe Memory Man! This model added a LEVEL control to the Solid State Echo/Analog Delay Line MM to prevent clipping of the input signal and also added noise reduction circuitry. EH claimed a delay range of 15ms to 400ms. They also added a SQUELCH switch in place of the BOOST switch to further control unwanted feedback.

Not content to rest on their laurels, EH eventually upgraded the Memory Man to include a chorus feature. By doing so, they were forced to remove the BOOST switch and put an ECHO/CHORUS one in its place. The DIRECT output jack became a BOOST input jack to give that little extra volume you may have needed. Chorus was enabled by setting the switch to the CHORUS setting and setting the BLEND and FEEDBACK controls to points indicated by stars on their dials. The chorus in these models is actually quite good.

Well, it wasn’t too long before another change was made. This time the pedal became the Memory Man Stereo Echo/Chorus. Gone was the BOOST input and in its stead another OUTPUT jack was placed, which provided a clean output. They also added a STATUS light to indicate the effect’s on/off condition. EH claimed that the addition of special circuitry created a full, spacious sound as well as lowering the noise level. This is probably one of the most common models seen today.

The top o’ the line, though, was the Deluxe Memory Man Echo/Chorus/Vibrato. This model had 5 knobs, 4 of which were the same as the earlier Deluxe model. The 5th knob was a CHORUS/VIBRATO control which could be turned either way to the desired sound. The SQUELCH switch also became a CHORUS/VIBRATO switch. This was truly the ultimate Memory Man and was also the highest priced of the Memory man series then as well as today. This model is being reissued today by Sovtek/Electro-Harmonix.

Here’s a handy dandy chart to identify the various models:

Version Description.

1) Echo/Delay w/BOOST switch

2) 4 knob Deluxe

3) Echo/chorus

4) Stereo echo/chorus

5) 5 knob Deluxe

The original Echo/Analog Delay Line and 4 knob Deluxe both used the Reticon SAD1024 delay IC. From my understanding, EH decided the chips were noisy and started using the Panasonic MN3005 delay IC instead. This was the reason the later models were quieter and had better delay effects. Most of the 4 knob Deluxes I’ve heard make a high-pitched whining noise in the background on the delayed signal. With proper setup, you can reduce this to a minimum, but it’s difficult to remove it completely.

Memory Man effects have held their value well in the vintage market. Originally listing for $149.95, the Solid State Echo/Analog Delay Line costs about the same today. The same holds true for all the Memory Men. The biggest concerns you should have is:

(A) The delay IC going bad (you can still buy the out-of-production SAD1024 on Ebay and elsewhere. Beware chinese counterfeits!!. The MN3005 is out of production as well but Xvive makes a compatible and reasonably priced version that you can purchase here)

(B) The voltage regulator IC used in some models going bad (replace with a positive and a negative 3-terminal regulator).

Any other problem is standard. and should be easy to fix. Go get yourself one and throw that nasty ol’ Echoplex away. Better yet, send them to me for safe disposal!

Saturday, 29 September 2007 15:45

Most everybody is familiar with the Memory Man series of pedals made by EH, but just as many may be less informed about other delay units that EH made in their heyday. Some of these are fairly scarce but they’re all great sounding delays and very useful to the average guitarist. Most of them also take up less space on a pedalboard.

Let’s start with the Slap-back Echo. This was EH’s first foray into the smaller delay unit. It was designed to give 80ms of delay and featured a BLEND control for mixing with the straight signal as well as a FILTER switch for cutting out high end noise. It was available in 2 versions: the standard unit and the rare Stereo Slap-back Echo, which also featured a DIRECT OUT output jack and a power indicator LED, one of only 2 small EH pedals with LEDs. Any guesses as to the other one? (answer at the bottom) Both units used the Reticon SAD1024 delay IC.

Just a short time later, EH redesigned the Slap-back Echo and reintroduced it as the Full Double Tracking Effect. Same case, but now the delay was switchable between 50 and 100ms. The BLEND control was retained and the FILTER switch was replaced by the MS DELAY switch. It was produced around 1979 and used the Panasonic MN3005 delay IC, which EH had replaced the Reticon chip with in nearly all of their effects. The Panasonic chip was capable of doing the same delay effects, but with better bandwidth and less noise.

(The other small EH pedal to feature an LED was the Small Clone. Unlike the Stereo Slapback Echo, it was used to indicate the on/off state of the effect.)

Saturday, 29 September 2007 15:53

In this article we’ll take a look at other EH delays that are AC-powered. For battery-operated units, go Here

Here’s an oddball EH delay: the Echo 600. Imagine a 7 knob Deluxe Memory Man pedal, but with slide pots instead of rotary controls. I have only seen a bare handful of these units over the years (as I’ve also done with the Stereo Slapback Echo). You can control the input and output volumes and blend, speed and depth of the chorus/vibrato, and delay and feedback of the echo. There’s also a SHORT/LONG switch for setting overall delay times. It probably came out in the late 70’s or very early 80’s and featured 600ms of delay.

EH Designer Howard Davis came up with the AMBITRON, a unit to synthesize a stereo effect from a mono input. It was available in at least 2 forms: the floor unit made for guitar use and a rackmount stereo unit for home stereo use. Howard says he designed the Ambitron to get a stereo effect from his mono jazz LPs. Good show, Howard!

Another rarely seen delay is the Solid State Reverb also known during it’s development phase as the Reverbatron. Basically, a Memory Man with very short delay, it uses a difficult-to-find-and-expensive-when-you-do delay IC, the MN3011. Notice the plugged hole near the FEEDBACK control. Every one of these units I’ve seen (all 3 or 4 of them) has had this. According to the schematic the pedal was going to have a 5th knob, labeled Sustain, but EH apparently changed their mind shortly before production.

Saturday, 29 September 2007 15:58

This month’s pedals of old are the Pulse Modulator and its Siamese twin brother, the Stereo Pulse Modulator. These are very similar to the Harelip Microphone Echo we looked at several months back in that they provide a tremolo effect. These 2, however, took the effect several steps further.

The Pulse Modulator, at first glance, looks like a Big Muff on steroids (fig 1). The first thing you notice are the 8 knobs on the top. Then you see the giant Big Muff style box (8 1/8″ x 6″ vs the Big Muff’s 6 7/8″ x 5 1/2″). As if that’s not enough, there are 3 jacks on the end! Left to right, the jacks are labeled INPUT, BOOSTED OUTPUT, and PULSE OUTPUT.

Now, here’s what the Pulse Modulator does. It is THREE tremolos in one box! Not only that, but it has a control to boost your sgnal as well. The upper three knobs are PULSE SPEED, which sets the speed of the effect. The second row of knobs are labeled PULSE VOLUME. These set the relative volume of each tremolo. The knob at lower left is the BOOST VOLUME, with the on/off switch on it as well. This controls the level of the boosted signal. The last knob, at lower right, is the PULSE ATTACK, which sets the strength of the pulses. Your amp is connected to the appropriate output jack, depending on which effect you’re using.

You’d think that with all these knobs, this would be one versatile pedal. The fact of the matter is: It’s not the greatest thing in the world. The tremolos are “clicky” or “thumpy”, depending on your particular unit, like the Harelip and when you hit the footswitch, your entire signal is turned off. This can be easily fixed with a minor rewiring job. The boost feature is always on, but your output must be connected to the BOOST OUTPUT to use this feature. What it boils down to is this:

1) You can have tremolo

2) You can have boost

3) You can’t have both at once (unless you use 2 amps)

4) You can’t bypass the effects (except for turning your entire signal off in the tremolo section)

I’ve seen some Pulse Modulators with circuit boards and some older ones with the circuit laid out on perfboard.

The Stereo Pulse Modulator (fig. 2) was similar in concept. This pedal was actually designed to be used with your stereo! The jacks on the rear are RCA jacks, perfect for hooking up your 8-track player to it. The pedal (or effect, since it doesn’t really qualify as a pedal) has 9 knobs and an on/off switch. You have a MASTER VOLUME, which of course controls the overall volume of the effect. There are also 2 groups of 4 knobs, 2 PULSE VOLUME and 2 PULSE SPEED for each channel of your stereo. Here’s what EH claimed in its literature:
“WE GUARANTEE YOU’LL GET STONED!!!…. Two pulses of existing music are continuously re-generated per channel, each with a separately adjustable speed and volume control. It is the mix of these 4 pulses with their intermittent beat frequencies that will give you a new high or reinforce one you already have……. Every object and sub-object has a resonant frequency. The high achieved by the Stereo Pulse Modulator is a result of tuning in to your own resonant frequency.”
All I can get it to do is make my stereo sound weird.

The Stereo Pulse Modulator is a technician’s nightmare. All the parts are hard-wired together and crammed into a small space. I had to replace the electrolytics on each PULSE SPEED control and nearly went mad in the process. Why couldn’t they use a circuit board? Who can tell?

If these were your thing, you could have bought them new in the early ’70’s for $49.95 for the Stereo Pulse Modulator and $59.95 for the Pulse Modulator. Prices now seem to be $200 and up for either of them. The Stereo one seems to be a little rarer.

Thanks to Kevin Macy for his help in procuring both these effects.

Saturday, 29 September 2007 16:19

In The Different Drummer, Part 1 we briefly looked at EH’s first drum machine offering, the Rhythm 12. Here’s a more in-depth look at this odd little drum machine.

The Rhythm 12 was actually made by Soundtech, a company in England, and relabeled for EH. They were available in the late 70’s. At around the same time EH had released the DRM series of drum machines so the question is: why did they need to rebrand another company’s unit when they had their own? With a list price of $189 for the DRM-15 and $269 for the DRM-32, it may have been a cheaper alternative that was offered or was available only for the short period until the DRM series was released. This is possible since I’ve been unable to locate a price sheet or catalog that lists both the DRMs and the Rhythm 12.

I’ve picked up another Rhythm 12 and was surprised to find that it was slightly different from the other one in my collection. In the full pics, you can see that they’re basically the same.

The upper left panels show the most obvious differences. The first unit has the “Electro-Harmonix Made In England” sticker and DISCO for the 3rd setting. On the 2nd unit, Electro-Harmonix is screen-printed on the unit and the 3rd setting is WALTZ 2 while WALTZ becomes WALTZ 1. The screen printing is also a little sloppier on the relabeled unit than the EH unit.� There are also units that have the “Electro-Harmonix” screenprint but still have the DISCO setting.

On the circuit boards, another oddity is found. The first unit actually says “EH” on the board while the 2nd unit says “S Tech”. Which was first? I’d be more inclined to say that the EH sticker unit was first simply because of the sticker. It’s also possible that the Soundtech company was distributing the box under their own name in England at the same time and, in order to get a shipment out to EH, slapped a new sticker on the front of some of their units. It doesn’t explain the circuit boards, though or the change in setting 3. I doubt we’ll ever know for sure. Maybe someone in England can help shed some light on this mystery?

Saturday, 29 September 2007 16:45

This is the EH RTG or Random Tone Generator. It was definitely one of the weirder things EH made in their heyday.

 Designed by Bob Bednarz, the RTG was a Random Tone Generator.  It makes electronic beeps and boops, either in normal mode or you can use the GLIDE switch to make it glide up and down to the note. Other than the Glide, the only other control was for the Rate of the tones. They’re not really random as you can hear it start to repeat itself if you listen for a couple of minutes or less, depending on the speed.  Just connect it to an amp and go!! 

One of these sold recently on Ebay for $850!!  Contrary to the auction hype, they were not prototypes; they were actual production units that appeared in EH price lists circa 1980. Pic follows and sound samples below the pic.

sound samples: (coming soon)

• First, the RTG in standard mode.
• Second, the RTG in glide mode. I adjusted the speed slightly at the beginning.
• Third,  the RTG running in standard mode thru a Deltalabs Effectron echo.
• Finally, the RTG inglide mode w/ echo. This is the coolest thing you can do with it, at least in my opinion.

Saturday, 29 September 2007 16:56

The Sovtek Big Muff: A History In Pictures

You think the EH Big Muff and other EH pedals went through a lot of changes over the years they were in production? Brother, it’s nothing compared to the changes the Sovtek Big Muff has gone through since it’s Russian reissue made the scene. Following are some pics showing the changes it’s made in graphics, knobs, color, construction, and other minor details. If you’ve got one that’s not like any shown here, by all means, send a pic and I’ll add it in!

I’ve made some attempt to arrange these in chronological order when possible.

The earliest unit was actually called the Mike Matthews’ Red Army Overdrive. Except for the name, it’s the same as the first Sovtek Big Muff, with a somewhat golden green color, although it also adds a cool star graphic to the top. Like later early SBMs (Sovtek Big Muffs), it’s in a case with a separate cover that must be removed before you can actually get at the real casing. The jacks are also held only by the solder holding them to the board!

Note the neat military-style wiring harness used in these early SBMs

Following closely was the first SBM. This is an amazingly clean example from my collection. For some reason, these early pedals had paint that was not very resistant to scrapes and abuse. As a result, many of these early SBMs look as bad or even worse than the Red Army Overdrive shown above.

Next came the first color change. Gone was the green-gold and in was the blue & gray. Should this be called the Civil War model? Also, note that at some point the knobs were changed to the black, round ones. These seemed to be the mainstay until the black Muffs arrived on the scene.

Eventually, the SBMs had had enough and went with the military green color. They would keep this color for several years so we’ll just note the changes in the graphics of the various models. Note also that the second picture shows a SBM in a new 2-piece chassis without the overlay (as evidenced by the 6 screws as opposed to the 4 screws of the earlier models).

Finally, EH decided on an update in the color, switch, and graphics. They changed the color to basic black and later on the knobs became “chicken head” knobs. The chassis remained the simple 2 piece affair. The switch became the standard footswitch found in many pedals:

Ooops!! Must have gotten caught in the middle of the change. Here’s a pic of another black one. I purchased both of these new from Sovtek at the same time. The first black unit has the new switch and the old labeling while the next unit has the old switch and new labeling. You can also see on the second pic that the DISTORTION control was changed to the familiar SUSTAIN control.

Eventually, EH/Sovtek redesigned the chassis so that the black SBM was now about half the height of the early ones. You can see in these pics the difference the redesign made. They were also made a bit lighter in weight.

This last pic is an overhead view of the early black SBM alongside the newer, shorter version. Note also that the knobs are now pointer knobs and only 4 screws are used to hold the 2 halves of the chassis together.

Saturday, 29 September 2007 18:48

This is a prototype Electric Mistress pedal, one of approx. 5 that were made in Russia in 1994. The prototypes were given to EH salesmen on the company’s move from their Manhattan offices to the new offices around 2000. Reportedly, at least one prototype does not work. This one works, but is hissy. You can see from the pics below that it’s a pretty standard Russian pedal construction, much like the Sovtek Big Muffs and Small Stones.

Saturday, 29 September 2007 18:54

Last Updated on Friday, 20 August 2010 06:13

Not content to change just the sound of your guitar or other instrument, EH also ventured into the realm of stereo for a brief time.

Nearly all of their stereo products can be found on a single flier dating from the early 70’s. This sheet showcased their line of boosters and sound enhancers specifically designed for the stereo systems of the time. While most of their stereo products were designed to actually enhance your listening pleasure, there were times when they just couldn’t help themselves.

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First off, there were the Linear Stereo Boosters (LSB) models 1 and 2. Both units were simple boosters utilizing 2 transistors per channel. The difference was that the LSB-1 had a non-adjustable output while the slightly larger LSB-2 included an output level control for each channel. Simply hook them up inline with RCA cables and get a nice boost to your input signal, be it from a tuner, 8-track, or other device. Switching them to the OFF position bypassed the boost effect.

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The Stereo Tone Expander was similar in build, but allowed you to adjust the tone of each channel via a TONE control. According to EH literature, the controls had the effect of extending the existing preamp tone controls one extra rotation.

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We looked at the Stereo Pulse Modulator in another article, but a recap is called for here. Imagine two tremolos for each channel, each with it’s own VOLUME and SPEED controls, along with a MASTER VOLUME and you’ve got stereo insanity! EH claimed that by tuning in to your resonant frequency with the SPM you could get stoned electronically. Presumably, there are no laws to prevent this.

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Finally, we come to the Stereo Ambitron (also mentioned here). Basically, it was a rackmount delay unit designed to convert mono recordings to stereo and was designed by Howard Davis for use with his mono jazz recordings.

EH’s stereo products came and went pretty quickly. It seems that they lasted for only a year or 2 at the most and all are rare items today. Not really usable to most musicians today, but nonetheless they’re an interesting chapter in Electro-Harmonix history.

Friday, 05 October 2007 18:18

Last Updated on Friday, 20 August 2010 06:14

Here’s a series of photos taken in 1972 to advertise the new EH Freedom amplifier. While at least one of the shots was initially rejected by publishers (guess which one), all eventually appeared in magazine ads or EH literature. Featured in these ads was the famous “Miss Band-Aid”, who was also available on her own 6 ft poster, and Mike Matthews in his finest 70’s regalia. The Black gentleman is unknown, but may well be EH employee Willie Magee. The slogan at the bottom sums up the Freedom amp campaign.