Search found 602 matches

by maxkracht
Wed May 08, 2024 6:35 pm
Forum: Technical Discussion
Topic: Bad power?
Replies: 9
Views: 167

Re: Bad power?

I was referring to a single wire transmission line, not a lack of a ground wire. I don't think they typically fluctuate so much to give an audible voltage drop, but might under certain circumstances. Not an expert, I've just heard of some weirdness in rural areas. https://en.wikipedia.org/wiki/Singl...
by maxkracht
Wed May 08, 2024 6:29 pm
Forum: Technical Discussion
Topic: ID this tube?
Replies: 4
Views: 82

Re: ID this tube?

Sometimes if you pop the tube in the freezer for a bit, the condensation will show an impression of the worn off screen print when you take it out.
by maxkracht
Tue May 07, 2024 9:10 pm
Forum: Technical Discussion
Topic: Bad power?
Replies: 9
Views: 167

Re: Bad power?

Not sure what your cabin is like, but assuming it is more rural than your house you could have some power distribution weirdness. Maybe low or inconsistent voltage from the utility, maybe the correct voltage from the utility but you have a single wire earth return system or some other oddity. Can te...
by maxkracht
Sat May 04, 2024 10:09 pm
Forum: Technical Discussion
Topic: Two 20 watt amps in one chassis - layout/grounding
Replies: 10
Views: 265

Re: Two 20 watt amps in one chassis - layout/grounding

+1 for using a toroid. I'm not sure what benefits there would be for having separate power transformers, but you can stack toroids on top of each other. You could also do one transformer with seperate windings. Something like this would work if you're ok using a SS rectifier. https://www.antekinc.co...
by maxkracht
Sat May 04, 2024 9:55 pm
Forum: Technical Discussion
Topic: Light bulb limiter tured bright at power on
Replies: 6
Views: 201

Re: Light bulb limiter tured bright at power on

I'm probably conflating memories of solid state bass amps and powered mixers, or some other category of things I try to avoid working on which glow brightly and sometimes won't turn on all the way with a lightbulb limiter...
by maxkracht
Sat May 04, 2024 3:30 pm
Forum: Fender Discussion
Topic: Conductive boards again.
Replies: 14
Views: 520

Re: Conductive boards again.

One caveat with the scrubbing, heating, alcohol method; I have seen a few where the backer board gets charred. Sometimes you can lift the top board slightly and pull the backer board out without disassembling everything, then scrape off the carbon, add some fish paper, etc., or just replace the boar...
by maxkracht
Fri May 03, 2024 5:50 pm
Forum: Technical Discussion
Topic: Light bulb limiter tured bright at power on
Replies: 6
Views: 201

Re: Light bulb limiter tured bright at power on

Your mixer is going to glow brighter faster than most tube guitar stuff. Presumably, everything is solid state, so there isn't much warmup time before it pulls full current, and the reservoir caps are going to be massive compared to what were used to in tube amps.
by maxkracht
Wed Apr 24, 2024 1:02 am
Forum: Technical Discussion
Topic: Does anyone recognize this amp design?
Replies: 10
Views: 518

Re: Does anyone recognize this amp design?

All of the caps look West German. Think I spot F&T, Siemens, Frako. I wonder why they put the power tubes by the input and the preamp tubes in the middle?
by maxkracht
Tue Apr 23, 2024 5:54 pm
Forum: Technical Discussion
Topic: Illinois brand capacitors still bad?
Replies: 12
Views: 590

Re: Illinois brand capacitors still bad?

I don't think temperature rating necessarily means anything in isolation, it's not a hard limit. It's that temperature at a specific ripple current and voltage for a certain amount of time. An 85c cap with otherwise better specs will probably outlast the 105c cap at 105c. No idea how much you need t...
by maxkracht
Mon Apr 22, 2024 11:19 pm
Forum: Technical Discussion
Topic: Illinois brand capacitors still bad?
Replies: 12
Views: 590

Re: Illinois brand capacitors still bad?

I don't think I have seen 105c axial electrolytics from Illinois but I could be mistaken. Haven't worked on a fender with prematurely bad IC brand caps in the past year or so but I used to find them somewhat regularly and not just hotrod series. Guessing many of the premature failures end up being w...
by maxkracht
Fri Apr 19, 2024 9:40 pm
Forum: Technical Discussion
Topic: 0.003uf or 0.0033uf?
Replies: 8
Views: 397

Re: 0.003uf or 0.0033uf?

That extra 3 is probably just a typo. Usually people would be asking “.003 vs .0003” (big difference) not “.003 vs .0033” (no difference). Not a typo. There are different standard values of components depending % tolerance. You need enough values allowing 5%, 10%, 20% or whatever in between without...
by maxkracht
Fri Apr 19, 2024 4:45 pm
Forum: Technical Discussion
Topic: Broken 5E3 for sale locally - worth checking out?
Replies: 11
Views: 466

Re: Broken 5E3 for sale locally - worth checking out?

Not sure if it's a good deal or not. If $800. is the cost of a new kit, just buy the kit and avoid the frustration. The fun stuff is done, the annoying stuff remains. Solving the stated problem is likely easy, finding the remaining problems is likely more difficult and could turn into rebuilding the...
by maxkracht
Tue Apr 16, 2024 4:25 pm
Forum: Fender Discussion
Topic: Octal Tweed Princeton
Replies: 9
Views: 589

Re: Octal Tweed Princeton

Lots of different champs throughout the years and I think the B+ was creeping up higher in the CBS era. Same power transformer was used for princetons, so maybe they were going for a compromise between the two, maybe they were trying to sell tubes so they didn't bother to rebias to compensate for th...
by maxkracht
Sat Apr 13, 2024 9:35 pm
Forum: Fender Discussion
Topic: Octal Tweed Princeton
Replies: 9
Views: 589

Re: Octal Tweed Princeton

6v6 running at 14w isn't unusual for a champ, cathode biased amps are usually close to 100% at idle, somewhere around 90-95% is a good place to shoot for if you are being conservative. I often see stock champs that have been used for years in the 115+% range without issues. This isn't ideal, but som...
by maxkracht
Sat Apr 13, 2024 4:25 pm
Forum: Fender Discussion
Topic: Octal Tweed Princeton
Replies: 9
Views: 589

Re: Octal Tweed Princeton

I would suspect a damaged pot and/or a bad solder joint. You shouldn't lose the ground reference at max volume if everything is wired as it should. Easy enough to measure, with the amp off, what resistance you get at max volume. Could be an oscillation, but my guess would be a bad connection. You co...