The Amp Garage

Poplar is similar to pine/spruce without the nasty resin and no tendency to warp. I used it in a narrow panel build with 2 x 10" speakers; floating baffle of 1/2" ply. Sounded fine. The floating baffle was intended to improve bass response in open cabinet designs. I found it can eliminate the boxy s...

Very cool amp! I am surprised you had trouble with the New Sensor 6V6s. They had been advertised to handle up to 450 volts on the plates, right? Not sure about the screens. I had a pair of JJ 6V6S in a 1987 clone a few years ago. They handled 425-430 volts no problem. I liked EL34s better so swapped...

Yes, C11 and C16 - sorry for the confusion - where C11 may be a "Death Cap".

The smoothing in Merlin's s article concerns smoothing the DC voltage of the power rail - "downstream" of the rectifier. C12 through C15 are snubbers for the diodes in the rectifier. If you use UF4007 you can eliminate them. C1 and C2 I am not sure. I think C1 may reduce or eliminate a "pop" when sw...

I found a champ schematic with a solid state rectifier (below). This rectifier uses ultrafast swtiching diodes, so you can dispense with the snubber capacitors. I would ignore the rest of the modifications shown on the schematic. This will get you going replacing the tube rectifier. If interested, y...

Other than the value of C2, this is the same as the Fender 5F6-A and Marshall 1986 bass amp tone stacks. I believe Duane Allman played the Marshall on the Fillmore East recording.

Oops, I misread your note, thinking you said bass was too much. Increasing R1- the slope resistor shifts more of the signal to the treble frequencies. On my 1987 clone I increased the slope resistor to 56K to tame the bass response. It may be that your low bass response is the result of a preamp cat...

Looks like R12 is the slope resistor in a typical MFV tone stack (R1 in the Tone Stack Calculator below). I'd try bumping that up from 22K to 33K (Marshall 1987) for starters.

Might want to try a 12AY7 in V1.

I have no clips. I recently put in a SS effects loop. I'll have to get some. 100_4496.JPG 100_4504.JPG For all things SE there is a pretty good forum here: http://www.sewatt.com/forum Initially it focused on mods and upgrades to the Epiphone Valve Jr., an off=-shoot from https://www.18watt.com/ . So...

You want loud? Go parallel single-ended.

Ditto. Best amplifier I ever built.

Sixteen years here for me, if I did my math right. Now where's that slide rule? Oh rats, I forgot the batteries. Wait... it is solar powered as long as the lights are on - superior technology. Who knew? When I was 13 Hendrix died, Beatles broke up, Hawkwind released their first album. Black Sabbath ...

I could have sworn that I read somewhere (but cant find it right now) that making the suppressor grid negative helps limit max plate current in extreme situations, Mark, maybe you are thinking of Tone Lizard's Marshall Myths page. Something about connecting the suppressor grid to the bias voltage r...

There are some really good SE resources on SEwatt.com. Free to register, this was originally an offshoot of the 18watt.com website which was centered around modifications to the Epiphone Valve Jr amplifier. There are two broad sets of forums - SE and Push Pull each with sub forums. http://www.sewatt...

I've been very happy with a pair of Tung Sol 6L6GC in my Supro 1688 clone. They roar.