“new old stock” stuff 
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I don’t know yet if I will invest time to trace the PCB of the Darkglass Vintage Microtubes. might be interesting … but long … but interesting … but long … 
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I contacted the Shalltechnik guy to ask him for the schematics. he explained me that his hands are tied regarding to the particular case of the GUMA pedals … what I understand is that there are legal considerations. so, even if I trace the schematics I won’t be able to share it publicly here.
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I swear I have seen them somewhere.
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the B3K schematic is available but I was unable to find it for the Vintage Microtubes. I guess those are pretty close, that’s exactly what I want to determine … well at this point I’m almost sure I will trace the PCB.
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I finally found some time to finish this preamp yesterday evening. So, it’s the Shalltechnik Growling Krizzly Deluxe, which is the full reproduction of a Gallien Krueger 400RB preamp (with footswitchable boost and effect loop, and all the voicing switches).
It works perfectly and sounds great.
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So cool. Post audio samples! 
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yeah I have to find a bit more time for this 
but yeah it sounds pretty much like a 400RB
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Dude that’s awesome! You even made it look really cool. I’m more than a little jealous right now.
Did you make any modifications to the original design?
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I modified the label sheet but from an electronic perspective it’s 100% the original design. That’s what I wanted : a pure GK 400RB preamp.
That said, if I had to re-build one, I’d change one small thing : the location of the “Boost” LED and the way that the LEDs are wired. the anode circuitry is not very logical for the Deluxe version (but it is for the Basic one, with only one footswitch). nothing very important.
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quick and (very) dirty record, just between the 2nd and 3rd morning coffee 
I might have been on the agressive side, setting-wise … … but that’s for that chainsaw-attack that I love those GK. the preamp doesn’t lack gain, I’m only at 5 on the volume (gain) and 5 on the boost.
Played with Greenie and a pick, obviously. The cab sim is the Ampeg SVT 8x10 from Line6 POD Farm. The preamp is connected to the DAI with the XLR DI.
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Man, that sounds good!
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Yep, that’s a G-K all right
Sounds awesome.
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I like those kits from MusicDing. not crazy expensive (at least here, close to Germany, where the shipping cost are low), really high quality and with a lot of choice.
now I have the Guma Antique (Darkglass Vintage Microtubes) kit to build … and after that I plan to eventually build :
- the Acapulco overdrive (for guitar)
- the MadBox in the dual blendable parallel loops version
- probably the Guma Drive (Darkglass B3K)
- possibly the Muff Green Russian , a copy of my favorite Big Muff version (the russian made with military parts)
nice little projects, I liked to build the GK during random spare time and with no deadline. by the way the GK is by far the most complicated projects on the list (except maybe the Guma Antique because of the SMD components).
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It looks like that SMD component is available pre-soldered to an IC socket adapter board? Or do you have to solder it? I couldn’t quite tell from the instructions.
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I have to solder all the SMD components. but that’s fine … I modified a few Nintendo Game Cube in the past, and this Guma Drive can’t really be more complicated, I think
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I think they sent you the torture version 
. Unless we are using the term SMD differently, this one only has one chip …
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Ah, missed those. Ugh. SMD scares me.
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Plus the chips are socketed
Still sad I had to cancel that kit. Looks super fun. I really liked Musikdings, the customer service there was really helpful.
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