Recent Posts

41

Tube Amp Building - Tweaks - Repairs / Re: Classic 50 volume reduction

« Last post by stratomaster on September 04, 2025, 07:33:15 pm »

Put a 250k audio pot wired as a voltage divider in an enclosure with 2 jacks. Send that to him and have him place it in the effects loop. He'll now have a master volume control.

Alternatively, a passive volume pedal or an EQ pedal run flat will work with the gain slider being the volume control.

42

Tube Amp Building - Tweaks - Repairs / Re: Classic 50 volume reduction

« Last post by shooter on September 04, 2025, 05:03:27 pm »

I wouldn't recommend it, time/money better spent finding someone that can do the work, especially some 'ol guy that's just in it to keep his skills sharp.
Those amps are already problematic, tend to flame-out just because they can 

43

Tube Amp Building - Tweaks - Repairs / Classic 50 volume reduction

« Last post by proaudioguy on September 04, 2025, 04:19:05 pm »

A friend in another state has a classic 50.  Its too loud.  I do not see an adjustable bias.  He is not competent to be inside the amp.  When pulling 2 tubes on a twin and disconnecting 2 speaker, I have always rebiased but I
Never noticed if I needed more negative voltage or less.  I’d like to tell him to pull 2 el84s, and disconnect one short one speaker.  My question is if he would be in danger of too hot a bias (too low neg voltage).


What do you all think?

44

Other Topics / Re: Meme of the day

« Last post by shooter on September 04, 2025, 03:15:48 pm »

 


I don't miss those days, and at this stage in life, don't even miss the paycheck
now basing which monkey-view of me based on the memes......

45

Tube Amp Building - Tweaks - Repairs / Deluxe 5E3 tone stack

« Last post by Lectroid on September 04, 2025, 02:55:16 pm »

I'm looking at rebuilding my Bell&Howell Deluxe-ish clone.  I built it with a standard 5E3 tone stack, with the interactive Volume and Tone controls.  But then I got to wondering:  What if the volume and tone controls were wired one after another, in series instead of in parallel?

Anyone know the reason the Fender 5E3 controls are wired together like they are?  What's the reasoning?  It seems like they might be separated into two consecutive circuits, but Leo Fender didn't and he must have had a reason.  Usually it was to save a few beans but I don't see any lower parts count no matter which way you do it.   

Here's the original 5E3 Deluxe-like tone stack and the new separated method I'm wondering about.

46

Other Topics / Re: Meme of the day

« Last post by SEL49 on September 04, 2025, 02:28:57 pm »

...

47

Tube Amp Building - Tweaks - Repairs / Re: Questions about Rehabilitating a 65 Super Reverb

« Last post by Lectroid on September 04, 2025, 02:24:54 pm »

Get the entire book...

https://trinityamps.com/ForumGallery/trinity/resources/Jack_Darr_Handbook.pdf

^^^  What he said.  Jack Darr Handbook is a treasure of tips and tricks for the new builder.

48

Other Topics / Re: Meme of the day

« Last post by shooter on September 04, 2025, 01:45:43 pm »

...

49

Tube Amp Building - Tweaks - Repairs / Re: Bias Wiggle Tremolo with 7591?

« Last post by dwinstonwood on September 04, 2025, 12:49:55 pm »

I used a Princeton Reverb trem with a 7591 PP fixed bias power section. It works very well.

Interesting, my initial "schematic-sketch" resembles a PR front end. I didn't intend it to.

50

Tube Amp Building - Tweaks - Repairs / Re: Hum and Buzz in Cordovox Build

« Last post by scstill on September 04, 2025, 09:40:04 am »

Thanks for the ideas, I will check these ideas next week as I'm off to the mountains for the weekend.
yes signal lines shield are only grounded at one end.