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6 Cool Germanium and Silicon Switchable Fuzz Pedals

AmptweakerBig Muff Style FuzzFuzzFuzz Face Style FuzzFuzz-Drive and FuzzstortionGermanium FuzzJDM PedalsKeeley EngineeringPaul Trombetta DesignSilicon FuzzSpaceman EffectsTone Bender Style FuzzVFE Pedals+-

This article has come about really because of one single fuzz pedal that I’ve coveted for a while now - the Spaceman Effects Gemini III which was released back in 2012 in limited batches as follows:

  • 50 x Black Edition - $359
  • 15 x Blue Edition - $359
  • 20 x Copper Edition - $389
  • 90 x Silver Edition - $349
  • 40 x White Edition - $359

So 5 limited runs of a total of 215 pedals. Of course all those pedals were sold within a matter of weeks I understand, and the way Spaceman Zak Martin works - he unfortunately never creates the same pedal twice - to a degree because of limited component availability but also I suppose because he gets quickly bored of making the same units over and over. Zak is quite different to other boutique pedal maker brands where most of his pedals seem to be sold within a sort of bun-fight scenario (limited numbers, auctions etc.), and they mostly go to high-end collectors rather than proper players and musicians. Some people buy one of each variation or at least the more rarefied ones - as financial investment vehicles. It’s obviously a strategy that works well for Zak, but it also kind of annoys the heck out of me at times.


If you want a Gemini III you need to wait patiently until one shows up on at a reasonable price - which isn’t going to happen any time soon. Here are the last 4 units sold this year:

  • 21 March 2018 - Condition Excellent - £813
  • 11 March 2018 - Condition Excellent - £891
  • 26 February 2018 - Condition Mint - £930
  • 6 February 2018 - Condition Very Good - £562

Nearly all of those sold are either Excellent or Mint - indicating pedal collectors rather than players! The priciest model - $389|£292 has shot up to over 3 times the value or thereabouts in these 6 years.


What is unique about the Gemini III is that it has separate Germanium (NOS AC128) and Silicon (BC109?) Transistor circuits which you can each set at 3 different gain levels and mix the output together controlling that with a central mix dial - a pretty simple but genius idea! And the only pedal produced to have done this? I have informally asked Joel Korte to do a Brothers version in a similar fashion - with separate Germanium and Silicon Channels in place of the current JFET / Integrated Circuit version - or a Brothers GeSi / MKII!


In the meantime I’ve been looking for suitable substitutes, and it pains me to say that there are no proper near matches available. The other 5 pedals in the above listing all have Germanium | Silicon / Ge | Si or G | S switches but these are mostly one OR the other - except in the 2 gain-stage VFE Fuzz Duo where you can select either G or S on each of the first and second stage - meaning 4 combinations are possible - GG / SS / GS / SG. Moreover I believe the Amptweaker is simply just a Silicon or Integrated Circuit Fuzz which uses some kind of DSP or EQ switching to change the tonal profile from Silicon to Germanium style.


All the other pedals feature both Germanium and Silicon Transistors as far as I can tell although the majority here are discontinued / unobtanium.


Pedals are listed alphabetically by brand:

Amptweaker TightFuzz Jr - £169

The details on the internals of this unit are somewhat scant, and I can't tell whether this is simply an Integrated Circuit, DSP or some sort of Silicon Transistor model. It does seem though that there is some sort of signal processing which goes on here and that the Germanium / Silicon switching is simply achieved by EQ modulation rather than actually separate circuit switching. This is a reasonably priced pedal, but not necessarily fully in the running here - as it is most likely neither Germanium or Silicon, let alone both! It sounds good though!

JDM (Joe Doc Music) Union Fuzz - $139 (Joe Doc Music)

This is purportedly a genuine Germanium and Silicon pedal with separate circuits that can be switched back and forth. These are hand-made in Germany, but no details are given of which Germanium and Silicon Transistors are used and in which quantity - i.e. single or dual. The pedal features the Si | Ge switch, alongside a separate Treble | Lo | Hi 3-way voicing switch, and then Volume, Pregain and Texture dials. It sound pretty good to me - see above video, and as reported is a one or the other circuit type of pedal, rather than a mixable Germanium and Silicon pedal - pretty good value though regardless. I've long considered this, but it's not quite close enough somehow to what I want - so still undecided here.

Keeley Fuzz Head (discontinued) - c$150 (

There are 8 of these currently listed on ranging from £84 to £162 - with a sort of median value of around £150 for those in decent condition. These very simple twin dial (Fuzz | Head) Si/Ge switchable pedals that have been discontinued for a while. They are either / or mode pedals with a lot of range for overdrive also, and use of which Germanium and Silicon Transistors is not specified. This is one is kind of in the same are, but not exactly the same as the others here, in fact deep down really all these pedals are quite distinct, and the only thing they have properly in common is a Germanium/Silicon switch! Still sounds great though.

Spaceman Effects Gemini III (discontinued) - c£900 (

I've already said pretty much all I need to say about this pedal in the intro above. It's the one I still want out of all of these, although I would also quite like a Bone Machine GTX. Both are rather 'unobtanium' at the moment, and there are no other similar competing products as far as I am aware. I'm a sucker for versatile compact fuzz pedals, and I automatically gravitate towards the more feature-rich models. Would love it if Basic Audio, Monsterpiece, Skreddy or SolidGoldFX or one of those Fuzz specialists could do something similar - i.e. a pedal with independent but mixable Germanium and Silicon channels. I've already said also that the Chase Bliss Audio Brothers format would be perfect for such a pedal - it does not have to be an exact copy of the Gemini III - I could see the 3-way toggle switches being replaced by dials for further fine-tuning. Someone please rise up to the challenge!

Paul Trombetta Design Bone Machine GTX (discontinued) - c£550 (

Last one sold on 28 October 2017 for £542! So not quite as lofty as a Gemini III, but still plenty lofty enough, and I believe those Bone Machine GTXs are really very rare, with only one or two showing up for resale each year. These are truly swiss-army-knife fuzzes with 4 dials - Volume, Gain, Bore (Skinny/Fat) and Mood (Bias), and 4 toggles - Normal/Bright/Dark, Si/Ge, T for T Cap and Lo/Hi Mood Range. You get a few extra Socketed Caps for experimenting with the 'T Cap Switch to get to slightly different tonalities. And there are two high grade Silicon transistors and one Germanium, although not specified. Paul has decided he no longer wants to engage in waiting-list-manufacture as typified by Analog.Man etc. Instead he makes what he wants and puts in on sale on his website - currently there is nothing in stock. There are a few other Trombetta models listed on Reverb - such as the Mini Bone, but as I stated, years can go by without a GTX - which first launched in 2014.

VFE Fuzz Duo (discontinued) - c£100 (

These sell for around £100 currently for Mint/Excellent examples, although 2016 is the last year listed for when 3 of these were sold. The pedal is available in a variety of looks, and I prefer the more minimalist original ones. This is the only one that comes close to the Gemini III in allowing you to mix together Germanium and Silicon circuits. You have two different Gain Stages on this pedal, and can select either Germanium or Silicon for both making 4 combinations possible - GG / SS / GS / SG. Unlike the Gemini you cannot vary the degree or mix between the two circuits, but you can nonetheless mix things up. You have 4 further dials to sculpt the tone - Fuzz, Bias, Level and Filter. I am a huge fan of VFE pedals with 3 of theirs already in my collection - all acquired second-hand off as most of these are now discontinued.

Final Thoughts

I am still really holding out for a Gemini III - although that is likely an impossible pipe-dream as I don't really want to part with the best part of £1000 for a single pedal - so I will likely hold out until I am a millionaire or otherwise someone else finally launches something similar. As for the others I still would like a Trombetta Bone Machine GTX and VFE Fuzz Duo - with the last mentioned the most likely to happen. The Trombetta pedals are still somewhat dear, although not as ludicrous as the Spaceman ones. I'm not adverse to pricey pedals - having both an Origin Effects RevivalDrive Custom and Eventide H9 Max in the collection - but those have a lot more technology onboard and far higher versatility and use cases. Here is a call out to all those boutique builders in UK, USA, Athens and Croatia - you know who you are! Someone make me a decent / improved Gemini III clone for around about the same price those original ones were issued at - should be doable within the £350-£400 mark - using NOS high quality Transistors of course!

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Stefan Karlsson
Stefan Karlsson
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