The Amp Garage

Truly, truly appreciate the follow up on this! So it seems like the cold bias on that stage could be based on stability concerns then, which would make sense to me. Given that I'm planning on a miniature output section anyway, the lower gain doesn't bother me a ton, but I did want to ensure I wasn't...

I remember seeing or reading somewhere that in some cases they were used to energize coils on speakers. Not sure if that was the OT or choke, though. I apologize for the vague answer, but I do know in some cases transformers mounted to speaker frames played a functional electromagnetic role in addit...

(clever circuit btw) I forgot to comment on this initially, but I'm also really enjoying looking over this circuit. Thanks for posting, tictac! I'm looking over the ICL8038 datasheet now. I'd love to see how you configured your power supply and regulated the oscillation frequency if you're willing ...

Really like that grille in the cabinet!

I think you're right that the increase in bias voltage likely is the culprit. Your oscillator's amplitude didn't change, so with the larger overall bias voltage, the proportion of swing for trem is lesser. How did you settle on a 100k drain resistor? I've typically seen larger for trem oscillators, ...

Does anybody know if this ’Direct DC coupled cathode follower’ setup for compression can be done with transistors instead, with the same compression result? That is, ’direct DC coupled emitter follower’. Was thinking of trying this for a pedal.. If I understand RG Keen's Mosfet Follies article (htt...

I've broadly had really positive experiences with JJ's, though I know the sound isn't for everyone in terms of the treble roll-off. Pretty rugged tubes that have put up with some butter-fingered moments and have stood up to abuse in high voltage DCCF applications. I have heard the long plate 12AX7 J...

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...