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!