Search found 501 matches

by romberg
Fri Mar 08, 2024 10:04 pm
Forum: Marshall Discussion
Topic: Marshall 5010 rebuild
Replies: 6
Views: 222

Re: Marshall 5010 rebuild

Nice! Is the new circuit a 2204 ish sorta thing?

I'm guessing the extra 12ax7 is for either an effects loop or more gain stages?

Mike
by romberg
Fri Mar 01, 2024 3:48 am
Forum: Fender Discussion
Topic: New to me Deluxe Reverb
Replies: 12
Views: 401

Re: New to me Deluxe Reverb

Does the crackle go away if you pull out the reverb driver tube? The fender design hits this tube VERY hard. On my build (which was an AB763) the reverb driver tube started to overdrive around 6 or 7 on the dial. But the important thing was that when it was in overdrive, it polluted the upstream sig...
by romberg
Thu Dec 21, 2023 3:15 am
Forum: Technical Discussion
Topic: - The Woefully Misguided Turretboard Stiletto Ace Thread -
Replies: 11
Views: 4822

Re: - The Woefully Misguided Turretboard Stiletto Ace Thread -

Whilst I absolutely understand the impetus for doing so, building something like a Champ, from an existing layout isn’t really going to teach me what I want to know. Rather than diving into the deep end of the pool with an amp at the extreme end of the complexity scale, I'd argue that there would b...
by romberg
Thu Dec 14, 2023 3:44 am
Forum: Technical Discussion
Topic: New Amp Build
Replies: 22
Views: 15669

Re: New Amp Build

Very nice work! I'd love to see a schematic or just a description of the topology of each of your three channels. Is one of the channels a gain stage added? I'm kinda guessing based on the controls.

Mike
by romberg
Tue Oct 31, 2023 1:40 am
Forum: Fender Discussion
Topic: mod AB763 to include Vibro Champ tremolo
Replies: 11
Views: 17486

Re: mod AB763 to include Vibro Champ tremolo

ab763 tremolo is just too square wave for me and I never vibed with it. ... I dig slower smoother tremolo tones. Unless you are dead set on playing around with a bias tremolo circuit, you may want to first try out slucky's Trem-o-Nator: https://sluckeyamps.com/trem/trem.htm It is a fairly simple mo...
by romberg
Sun Oct 08, 2023 2:03 am
Forum: Garage Talk
Topic: Tom (Structo)
Replies: 33
Views: 12875

Re: Tom (Structo)

Hi Tom! Your posts always seem to be in all the old interesting threads that keep rising back up to the top. I'd see them and miss you around here. Glad to see you are back! Life is never easy and I'm glad to hear you are making progress overcoming the latest obstacle in your path. Keep at it! We ar...
by romberg
Sun Oct 01, 2023 5:49 pm
Forum: Trainwreck Discussion
Topic: Late to the Trainwreck party, gonna build one anyway.
Replies: 43
Views: 60806

Re: Late to the Trainwreck party, gonna build one anyway.

I'll include, at the very least, a preamp out jack. Thinking about an effects loop, too. Not committed to it by any means. I'd see if I could use a Metropoulous zero loss loop. On an express having a preamp out and or an effects loop is mostly a waste of time. The reason why is that the express pre...
by romberg
Fri Jul 28, 2023 2:33 am
Forum: Technical Discussion
Topic: Amp Crackle
Replies: 16
Views: 2153

Re: Amp Crackle

Got an odd issue to run by you all. My amp it has a weird crackle as soon as I drive it into distortion. Literally on the edge of breakup it will crackle when I hit certain chords. Back off and it’s perfectly clean. The amp has two channels, a TW songwriter preamp and a Fender normal channel preamp...
by romberg
Wed Jul 19, 2023 7:17 pm
Forum: Technical Discussion
Topic: Master Volume - am I doing it wrong?
Replies: 8
Views: 762

Re: Master Volume - am I doing it wrong?

The only problem with it is that I'm loosing quite a bit of treble with the pot at low settings. Perceiving less highs (and lows) is a common and expected thing with all volume changes. It is not the circuit. It is your ears. The human ear's frequency response changes with volume levels. At lower v...
by romberg
Thu Jul 13, 2023 5:32 pm
Forum: Technical Discussion
Topic: cold clipper
Replies: 13
Views: 1609

Re: cold clipper

I can't remember if it was Mike Soldano or Dave Friedman who said this, but I heard that they were playing with values and kept going until the waveform was symmetrical and that's how they ended up with 39k. It was on Friedman's Tone Talk youtube channel. Dave asked specifically about the 39k and M...
by romberg
Wed Jul 12, 2023 8:27 pm
Forum: Technical Discussion
Topic: Midpot to 50k and a question
Replies: 11
Views: 1061

Re: Midpot to 50k and a question

I'm horrible at reading resistor colors. But, it would make a whole lot of sense for it to be a 47k resistor. When the 50k pot is all the way up, the circuit looks just like (or very very close to) a stock 25k pot. (47k in parallel with 50k).

Mike
by romberg
Wed Jul 12, 2023 7:39 pm
Forum: Technical Discussion
Topic: Midpot to 50k and a question
Replies: 11
Views: 1061

Re: Midpot to 50k and a question

The resistor will make the pot look like a 25k (or very close to it) value at one extreme and then modify the taper:

https://www.amplifiedparts.com/tech-art ... ifications

Mike
by romberg
Wed Jul 05, 2023 8:30 pm
Forum: Technical Discussion
Topic: Fender The Twin Red Knob reconstructed
Replies: 7
Views: 798

Re: Fender The Twin Red Knob reconstructed

Very impressive amount of quality documentation! I'm sure anyone working on the insides of one of these would find your document to be extremely useful. I wish something like this existed for some of the amps I've been inside.

Mike
by romberg
Mon Jul 03, 2023 5:45 am
Forum: Technical Discussion
Topic: Octal preamp 2204 build questions
Replies: 25
Views: 10613

Re: Octal preamp 2204 build questions

Yoda wrote: Thu Jan 12, 2023 1:21 am Yes I fabricated the chassis myself, knobs recessed on top for a unique look. Just need to build a head shell for it.
Cool look. Different is good.

Mike
by romberg
Mon Jul 03, 2023 2:34 am
Forum: Trainwreck Discussion
Topic: Yet Another Express...
Replies: 14
Views: 3597

Re: Yet Another Express...

Very nice build. How do you create the faceplate labels? I've been looking for alternatives to laser etching and your builds always have good looking labels.

Mike