Electro-Harmonix EH 3003 Big Muff π V5 (Op Amp Tone Bypass) 1981 USA as used by Andy Martin-Reverb

Electro-Harmonix Big Muff π V5 (Op Amp Tone Bypass) 1981 USA in very good condition and full working order. All original except for battery clips.  Screws and all other parts are original.

Please note that the " EH-3003 " in the description has bearing on the model numberfication by EHX ". It has no bearing on the PCB used in the fifth version.

THE OP-AMP ”TONE BYPASS“ BIG MUFF π - VERSION 5

Quote from Kitrae website :
Circa 1978-1980 (Pots typically date as early as 1978 and as late as 1981, though some have dates as early as 1976)
Model Numbers: EH1322, EH1322B, EH3003
Circuit Designer: Howard Davis and Michael Abrams
Edition Versions: 1
True Bypass: No
Power: 9V battery or AC power jack. Jack is 1/8" (3.5mm) plug tip positive. This is reverse polarity of typical pedals so use an E-H power supply or use a converter adaptor like the 1 Spot C35 3.5mm Converter
Enclosure Size: 6 7/8 " x 5 1/2" x 2 1/4"(short end) x 2"(long end) / 174mm x 138mm x 35mm(short end) x 57mm(long end)
Packaging: Brown or white corrugated cardboard box with red printing. Box graphics matched pedal graphics.
Place of Manufacture: Manhattan, New York, USA
Replacement Parts

The V5 tone bypass version and the V4 on/off switch version (listed above), were made and sold simultaneously. They both share the same circuit boards and similar pot dates. The V3 transistor based Big Muff with tone bypass switch was also made at the same time as this version, making it appear E-H had three version of the Big Muff Pi on the market simultaneously! The tone bypass mod was added point-to-point on the back side of these three circuit boards. Note that this is a "tone bypass", not "true bypass" which is something completely different. None of the vintage Big Muffs were true bypass. The tone bypass function gave a flatter EQ with more mids, more volume, but completely disabled the tone control.

GRAPHICS - Identical to the V4 Big muff, except “TONE BYPASS” was labeled on the top of these V5 units instead of "OFF ON".

CONTROL KNOBS - The Daka-Ware style knobs that had been used since Version 2 were changed during production of the V5, and are also seen on tone bypass V3 models. After years of using knobs from other suppliers, E-H decided to invest tooling money to make their own injection molded knobs in Taiwan. These were the familiar flat-topped, hockey puck shaped knobs with white indicator marks that are still seen on the V9 NYC reissue versions being produced since 2001, and many other E-H pedals. Both knob types were used for the V5 version.

CIRCUIT - The on/off switch seen on Version 4 was also made to be a tone bypass switch for Version 5 of the Big Muff, which was likely in production at the same time as the V3 tone bypass trasistor version and the V4. Howard Davis' orignal circuit design for the V4 op-amp Muff included the tone bypass function. Switching the bypass on disabled the tone circuit. The tone knob had no effect when in bypass mode. Otherwise this was practically the same unit as the Version 4 Big Muff.

There were four different circuit board layouts used for the V4 version, and three of those were used for this tone bypass version, indicating that both the V4 and V5 were offered for sale at the same time. Note that three of the four circuits required a .22uF/224k cap and two 47k resistors to be soldered point-to-point on back side of the circuit board for the tone bypass mod, but the fourth circuit layout incorporated this complete schematic into the circuit design so all components could be mounted on the populated side. It is interesting to note that Howard Davis thinks the tone bypass feature was already in use on the V3 when he designed the op-amp V4/5 version, which explains the V3 transistor Big Muffs I have seen that included this feature. This circuit design was also morphed into the Deluxe Big Muff circuit, also using op-amps rather than transistors.

To economize production, all three V5 circuit boards included extra pads for another volume pot position. The extra pot pads were to allow the circuit board to fit sideways in the Little Big Muff pedal enclosure, which used the same circuit, but only had one control knob for volume.

There was NO LED light on this version. Power was from a 9V battery or an AC power adaptor jack. The top had to be removed to change the battery. These had four rubber feet and shipped in a corrugated cardboard box. Most of the pots I have seen are dated 1978, though I have been told these were still being made and sold as late as 1980.

CLONES OR SIMILAR PEDALS - The Deluxe Big Muffs from the late 1970s also used a nearly identicals circuit, as well as some of the Little Big Muff pedals Electro-Harmonic made in the same time period. Later replicas are the Euthymia ICBM, Stomp Under Foot Op-Amp Fuzz. See DiscoFreq's Effects Database for a thorough listing of all the Big Muff clones and variants throughout the years.

THE V5 SOUND - Practically identical sound to the V4 op-amp Big Muff described above. This version included a 'tone bypass' switch (not true bypass). With the bypass switched on it removes the tone circuit, making a huge, peircing distortion. The bypass also allows a flatter EQ that makes it have brighter mid tones. I think the tone in non bypass mode sounds better as the tone control is key to the Big Muff sound, but some people like the bypass. There is a slight 6-7 decibel boost when in bypass mode. This is the most common of the two op-amp Big Muffs.