LunchBox Instrument Amplifier

I was using the Quark Minor amplifier a lot and with the ToneBack selector switch in the center which basically means no Tone control, only Volume. I was thinking of a Combo that would work more due to the stupid Covid Virus…. so low wattage, all in one combo that is smaller, but could do so much more if required.

I took the Quart design and instead of a 6V6 or even a 6AQ5 (7pin version of the 6V6), I thought of the EL84 to make it more chimey. I remembered back when I did audio of a 5686 tube which was like a smaller version of the EL84 and so I looked into that and sure enough there are tons of them out there. I used the same rectifier the 6ZY5G and the same gain dual triode the 6072A/12AY7A because those are the best sounding. I started to think a little more and added the optional transformer coupled DI. Heck why not think bigger like coffee shop. Hell I remember going to a show back stage and all these massive amps were not even plugged in and a small Champ sized amp had a mic in front with a cage around it. That is what was being played.

I then thought why not have a 9V stomp box supply as well. Really how cool would it be to walk into a place with a couple of cables a single power cord and you are ready to go!

Since I was using the Warehouse Alnico 10” and people and magazines were raving about it, I asked about an 8” version and they were already working on it and it sounds fantastic.

I would classify this amp as an instrument amp. It would work great with any instrument, Harp, Guitar, Fiddle anything with a pickup. It is full range and wide open, nothing specific to guitar. But it really is killer for guitar!

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There is the standard version which uses Nichicon Audio Capacitors for the high voltage and bypass, Mial coupling capacitors and Mercury Magnetics output transformer.

SuperCharged model has the following upgrades:
1) MagneQuest custom over wound output transformer, limited quantities.
2) Black Gate capacitors for high voltage and bypass, look them up on eBay, current price there is $1122.00.
3) V-Cap ToneCap used for coupling.
4) Analysis Plus Speaker Harness cable.

Either version can be fitted with an optional transformer coupled DI. This version shipped with a TRS to XLR cable.

Tolex colors: Tweed, Red, Black, Black swirl, Carolina Blue, Pink, Dorthy Red Sparkle, Orange and Seafoam Green. Others available by request, see all the colors at

Each amp is shipped with a 2.1mm extension cable and a 1->5 2.1mm splitter for the on board 9V/400ma stomp box supply. Also shipped is an IEC heavy duty power cord.
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The main circuit board assembly:
Red capacitors are the Black Gate in the SuperCharged model.
Green is the transformer coupled DI.
Light Blue is the DC supply for the heater for the 6072A/12AY7A
Orange is the constant current source biasing used on the 5686
Dark Blue is the isolated 9V regulated supply with OSCONS and dedicated CMC inductor, with 9V regulator.
Purple you have never seen this in a guitar amplifier, we bias the input triode (6072A/12AY7A) with an LED, super quiet and fixes the input for really high head room.