The Amp Garage

I'd be lying if I said I wouldn't be interested in sound clips of two otherwise identical amps with different resistors. You could even just build two preamp boards with the different resistor sets and alligator clip them in. I've been searching for clips to try and see if I can hear a difference, b...

- I'm struggling to get my head around the operating point of the splitter/mixer stage from the Brown harmonic tremolo circuit. If I re-conceptualize that stage's shared 4.7k/2uF shared cathode as a split cathode arrangement, I think it'd have 9.4k cathode resistance with a 1uF bypass capacitor. Th...

Does the amp make these weird noises with no guitar plugged in and with the volumes at maximum? Could be a tube issue, but I'd also want to rule out some unforeseen oscillation. If you don't have extra tubes to roll and rule out a tube fault, it couldn't hurt to just shuffle the 12AX7s you already h...

Do you know if the pilot light was as bright as it usually shines during the last incident? I'm tempted to say your mains AC may have dropped if you were playing during the day. If the weather there is warming up (it certainly is here in AL, but then again I've never visited Massachusetts), you may ...

I'm working out an upcoming build that'll be a small two-channel Brown Fender style amp for my wife. She really likes the 6G2 Princeton circuit, so that'll be one channel, and I wanted to add a second channel borrowing from one of the bigger Brown Fenders (originally planned on the bass channel from...

Everyone, I thought I could handle selling stuff but that proved impossible with my health. My heart has decreased Left Ventricle ejection fraction at 36% so not getting enough air, of course medication increased so breathing a lot better now. Next is to tackle my blood sugar levels so I don't slee...

Maybe this would be better to ask under Technical Discussion? Edit (5/19/24): here's a schematic with the design as it stands so far. Still wondering if this makes sense in terms of adjusting the splitter/mixer stage for the harmonic trem. I thought maybe keeping the common anode mixer stage unbypas...

Been thinking this design over and making some progress. I've been mining rootz's thread on his 6G2 build (https://ampgarage.com/forum/viewtopic.php?t=36749) to learn as much as I can. There are a lot of solutions to design problems I've identified in my build which mostly pertain to keeping the res...

Looking over your voltages, something's definitely not right on V2. The cathode follower should have significantly more voltage on its plate than the preceding gain stage's plate since there is a plate load resistor feeding the preceding gain stage versus the cathode follower's plate being connected...

I built an amp like this and second TUBEDUDE and didit's suggestions. The amp I built had a single shared toroidal transformer feeding to completely parallel, dissimilar amps (a Brown Princeton and an AC15-ish preamp each feeding an ECC99 push-pull output section). Beyond the PT, there are no shared...

After wrestling with some hum issues in an older build, I decided to just start over with a clean slate. The old amp is a 6G2 Princeton using an ECC99 push-pull output stage, but it was a really early build of mine and there are a whole host of grounding issues that I haven't been able to resolve, a...

It's your decision, but since I think I was probably the most optimistic poster previously, I feel obligated to underscore that I would strongly recommend walking away if you can't get information on part sources. At that point the only things I'd trust would be the speaker and cabinet, and even the...

That price is ridiculous. You can buy a quality kit new for that price. Of course, that's no speaker and no cabinet. Still, buying someone else's problems for that price? You should pass or offer $250. I agree and forgot to mention that if you're looking at buying this you still shouldn't pay anywh...

Since ghosting is a power supply issue and the amp seems to have been essentially rebuilt (except for the PT, which I think is likely fine), I'd want to know how everything measures in the amp currently. Are you getting any AC current anywhere without anything plugged in? All B+ and cathode voltages...

Others have covered that it can be a losing game to pick up other people's mistakes, especially when you're starting out, but I did want to add that it can be worth picking up depending on what parts it has. I'd specifically want to know what cabinet, transformers, speaker (you already know V30), an...