The Amp Garage

The volume jump is certainly an issue, particularly if you want to footswitch it in (which sounds like your intention). ... To rectify the volume drop issue, I put a 500k pot in series with the master volume ground reference (wired as a variable resistor). In saturation mode, it kicks in and you se...

I have just added a Jose style clipping circuit to my Metro 50w Plexi (now 2204 / Bogner Blue circuit). Coming out of the cathode follower and in parallel with the tone stack, add a 10k resistor > 100nf cap (high voltage) > clippers > ground. For the clippers, I have 2 options: - Friedman style wit...

FET won't affect input impedance. You can set the impedance as you want, just tweak the gate leak resistor. Also with a pulldown resistor on the FETs input and a solid relay switching scheme you won't have any popping. Don't look at the ODS FET boost for ideas, it's not that great. I'd look at runo...

That is why I used the term "distortion" in the title. I understand diode clipping does not give more gain, rather it limits headroom. Fun thing, I did a little experiment in the meantime with a small amp that only has 1 preamp stage before a LTPI. I first added a pair of LEDs between signal and gro...

So picture a 2204 type build. Adding an extra pre valve is not an option. The 2204 sound must remain intact, but I need a more "metal" tone available on a footswitch. I've thought of two options: a FET input (Dumble style), or diode clipping. FET input (aka built-in booster) PROS: No "fake" distorti...

try the classictone PT with dual taps for high and low voltage. and use a standard 103 8k OT. this way you can use 6v6s and lower voltage or kt66s and higher voltage (I prefer the latter) Ohhhh, Classictone 40-18054, 625 and 690 taps! Hadn't seen that one. They say around 379V with a 5AR4 recto on ...

I like the Magnetic Components Inc iron and I think you should give this company a try. They offer a variety of PTs, you should be able to find your target voltage there. Btw, what is this Hammond PT # with the 600VAC secondary? My experience is they don't make one in a 200ma + version. ?? Did you ...

statorvane wrote:I would think springing for an 18watt x-frmr set and running cathode bias - well you have a 6V6 18 watt - not a JTM45.

Except it will be fixed bias, and have the cathode-follower driven stack.

So it won't be a 6V6 18W, it will be... something else (not a JTM45 per se either of course)

Like I said , the Trainwreck express Trannys would be perfect all around. I do not care for the JJ 6v6s( not a true 6v6 more like a older 6l6) the New Tungsol 6v6s have been excellant in tone and durability. RJ has a good price on them too. Where can one find more information about those "RJ transf...

no! Biuld a normal JTM then move down one click on the selector for 8 instead of 16 with the same speakers and bias it for whatever tubes you want back and forth from normal to 6v6. But with the typical 6K6 Z of a JTM45, that puts it at 13k2! Might not be the best zone for tone. Considering the usu...

billyz wrote: Why are you stuck with Hammond iron , there are several better options.

I can get them locally for cheap, being in Canada.
And I really like the amps I've built with them (a 2204 and an AC30).

That said, their JTM45 set is actually quite expensive for some reason.

So my initial goal was to build a 20W-ish JTM45 using 6V6 power tubes. I was thinking about using a 18W set of transformer to get a lower voltage (350-ish) and a higher output Z (8k) compared to your typical Marshall, in order to get lower power (I want to DRIVE this thing with the band, and 15-20W ...

Always found the specs on that choke a bit baffling. Interestingly, it's not listed on Hammond's website anymore. When I built my JCM800 clone, although I used their "replacement" line for the PT and OT, I went with a generic choke (159Q, 7H, 150ma rating) which seemed more in line with the original...

Really really loved that amp, for the first time a small amp that sounds just like a big amp when cranked except quieter (instead of smaller). I don't want to clone it (buying it would be cheaper), but I want to study it as a basis for a build. Although Ampeg does not publish schematic, they do have...

Love my 2204 clone, it's got some mods of course: less NFB, Presence circuit modified to Recto style (effectively a pre-PI cut control), smaller coupling cap after 1st stage, hot-biased 2nd stage (2k7 IIRC instead of 10k), I think that's most of it… and a Metro loop kit. I'm rebuilding it as this wa...