Search found 125 matches
- Tue May 28, 2024 10:25 pm
- Forum: Technical Discussion
- Topic: Cathode follower for compression
- Replies: 18
- Views: 1553
Re: Cathode follower for compression
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...
- Tue May 28, 2024 4:30 pm
- Forum: Marshall Discussion
- Topic: My first experience with Mullard reissue 12AX7’s
- Replies: 4
- Views: 152
Re: My first experience with Mullard reissue 12AX7’s
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...
- Mon May 27, 2024 3:30 pm
- Forum: Marshall Discussion
- Topic: soliciting input re: resistor brands for my first Marshall build
- Replies: 12
- Views: 7819
Re: soliciting input re: resistor brands for my first Marshall build
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...
- Sun May 26, 2024 11:43 pm
- Forum: Technical Discussion
- Topic: Common anode mixer and Brown Fender trem operating points
- Replies: 3
- Views: 455
Re: Common anode mixer and Brown Fender trem operating points
- 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...
- Sat May 25, 2024 1:23 pm
- Forum: Marshall Discussion
- Topic: Modding 2204: Background noise help
- Replies: 4
- Views: 729
Re: Modding 2204: Background noise help
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...
- Sat May 25, 2024 12:50 pm
- Forum: Technical Discussion
- Topic: Strange pilot light experience
- Replies: 8
- Views: 362
Re: Strange pilot light experience
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 ...
- Fri May 24, 2024 10:05 pm
- Forum: Technical Discussion
- Topic: Common anode mixer and Brown Fender trem operating points
- Replies: 3
- Views: 455
Common anode mixer and Brown Fender trem operating points
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...
- Tue May 21, 2024 1:38 am
- Forum: For Sale/Trade
- Topic: Amp parts for sale
- Replies: 21
- Views: 6949
Re: Amp parts for sale
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...
- Sat May 18, 2024 5:22 pm
- Forum: Fender Discussion
- Topic: Micro Brown Bassman-Princeton hybrid build
- Replies: 2
- Views: 1144
Re: Micro Brown Bassman-Princeton hybrid build
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...
- Sun May 12, 2024 9:15 pm
- Forum: Fender Discussion
- Topic: Micro Brown Bassman-Princeton hybrid build
- Replies: 2
- Views: 1144
Re: Micro Brown Bassman-Princeton hybrid build
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...
- Sat May 04, 2024 7:16 pm
- Forum: Technical Discussion
- Topic: JTM45 Build, looks alive but no sound,
- Replies: 7
- Views: 435
Re: JTM45 Build, looks alive but no sound,
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...
- Sat May 04, 2024 11:26 am
- Forum: Technical Discussion
- Topic: Two 20 watt amps in one chassis - layout/grounding
- Replies: 17
- Views: 739
Re: Two 20 watt amps in one chassis - layout/grounding
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...
- Thu Apr 25, 2024 11:39 pm
- Forum: Fender Discussion
- Topic: Micro Brown Bassman-Princeton hybrid build
- Replies: 2
- Views: 1144
Micro Brown Bassman-Princeton hybrid build
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...
- Sat Apr 20, 2024 3:03 pm
- Forum: Technical Discussion
- Topic: Broken 5E3 for sale locally - worth checking out?
- Replies: 11
- Views: 755
Re: Broken 5E3 for sale locally - worth checking out?
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...
- Fri Apr 19, 2024 10:05 pm
- Forum: Technical Discussion
- Topic: Broken 5E3 for sale locally - worth checking out?
- Replies: 11
- Views: 755
Re: Broken 5E3 for sale locally - worth checking out?
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...