The Amp Garage

Im havin a helluva time with this little guy. Came in with "it just stopped working, it needs new tubes". Customer kept mentioning something about "I hope my Swart attenuator didn't fry something..." He was getting no sound at all upon failure. After I replaced and biased the outputs, I got sound, b...

Hi Tom Been wondering about the Kelley non reverb models. Can you remember if there were any major differences in the preamp compared to the reverb models? Did it have two or three preamp valves? Wondered if it still had four stages before the cathodyne inverter or only three. Be interesting to see...

wow what a beautiful build! What value of trim pot did you use for the bottom of the CF? lastly are the 220K resistors off v7's plates tied to the grids? its hard to tell in the drawn schematic. Im using a different circuit for the LTPI and CF and I want to try this setup out. Sorry, just seeing th...

You guys R crazy! I've only become interested in playing amps with reverb and tremolo recently. I've always played quite dry, but I've been enjoying my reverb pedal someone gave me, as well as some bias modulated trems I have in a few of my amps. So, though I've built some for others, I've never bui...

Indeed! Very nice, tidy work. You've developed quite an original style of layout that is very cool.

That looks killer!!

Here's a picture

I dug up a mojo deluxe chassis the other day, mounted some shit, and got a raw cab. My plan is to stain it reddish, build a single channel Deluxe + 1 stage, make it switchable, and gig with it. I'll clean this fresh build up, but here's a clip of the mule I'm gonna draw from. This one has a 33K slop...

Iso transformer seems to be doing OK. I turned the amp on 20min ago and left the room. Just checked and it's gotten a little warm, but I keep my hand on it indefinitely. I ordered a Jensen MOD 8" speaker 4ohm for it, so I'll revisit in a week when I get it. Only thing that's buggin me a little is th...

Alright I think we're good here. Shorting the 270K//5n to ground kicked up the 50L6 plate from 105VDC to 145VDC, and quieted the hum considerably, as well as adding some life to the tone, probably mostly from the preamp voltages coming up too. For the heater voltages, I've got: 35Z5 : 37VAC (spec 35...

I reattached the floating ground system, and connected the secondary leg to it, and installed a shiny new 270K/.05 from all that, and I've got sound...granted the most primitive amplified guitar sound you've ever heard, through a damaged speaker, and some hum, but I'll address that tomorrow. I've go...

Ok so looking at it, all my grounds are entirely floating and have no reference to any voltage, it looks like
Do I need to ground that bottom leg of the secondary?
Or prop up the heater string/secondary with that damn 270K/5n to ground?

Thanks for the input Lou! I'll adress that when I get to it, but I'm starting to think that network may have some other effect, lending to my current confusion, now that I just finished wiring, and ready to crack a beer... I'm throroughly confused at this point. I got everything wired up, and am not...

I don't know what to make of the original schematic as drawn. I've seen the "floating ground" with the parallel cap and resistor between circuit ground and the chassis before, but I don't see how the first stage could operate with that between the bottom of the cathode resistor and circuit ground. ...

Here is my proposed schematic for the rebuild of this Supro Bantam 1611 with the isolation transformer. I sure could use some extra sets of eyes before I start to go at it. I'd like to continue to use the 35Z5 rectifier, but it's half-wave, so I've got a solid state bridge rectifier before it. Still...