Electro Harmonix Frequency Analyzer – Modern version

EHX Frequency Analyzer AD633 e8feaaf4c0bf

 The modern version of EHX Frequency Analyzer. The ICL8083 IC is obsolete but there is still some vendors that have it in stock. Came out taller than expected since I wanted the bipolar voltage doubler circuit on the same board as the main circuit. But it will fit sideways in a BB enclosure… Schematic is … Read more

Dunwich Amplification Olde Dirty Bass – Big box version

Dunwich Olde Dirty Bass big box version a96517c870bc

   Update 2 210514 Both schematic and layout is now corrected. A big thank you to Vince who traced the later 125b version which revealed how the active Mid control really works.   Update 1 210514 Caution! There was a mistake in the trace. The Mid control have a different setup than the schematic and … Read more

Dunwich Amplification Modified HM2 – “Left Hand Path” version

Dunwich HM2 Hand 30cc452554fa

 Traced by AlexS and Fuzzhead, this is a quite tweakable and heavily modified HM2 variant with more gain on tap, more volume, two on/off/on diode switches and a very flexible four band eq.  It is a quite noisy beast when Gain and all eq controls is maxed out though but a buffer up front helps … Read more

Electro Harmonix V2 Big Muff Ram’s Head “White Can version” 1974

EHX Big Muff V2 Rams Head 1974 White Can 0cc780dd28fa

 It is Pie Day so here is a layout of an old Ram’s Head variant. Rarely cloned and some cap values is not found in any of the other vintage EHX variants. 220pF/680pF caps replaces the standard 470pF/500pF values and the tonestack has less mid scoop. Still added a Mid switch for some sligtly boosted … Read more