I'm tired of anemic guitar amps!

[Chuz Life]

It needs an amp chassis!

With wires coming out of it!

I have at least 5 amps that really need some attention.

Two Fender twins, a Crate, Peavey Bass amp and a Rolan JC-50

That's one reason this thread inspired me want to re-vamp the bench.

If I had time or do overs, I would have built in a 19" rack mount for my rack mounted stuff.

I'll share an image of the first victim, as soon as I can.

 

[Chuz Life]

Looks impressive! You pretty much have just about all the bases covered. I'm envious. If you need anything else (like a big variac?), I guess it'll depend on what you work on, but it would be a real shame to have all that and not use the stuff a lot!

I have a variac, but it is still buried in my heap of stuff I brought home when I retired from my last job.

I have this AC power supply with current limit. . . but I'm not experienced with it (at all) to know how useful it could be with amps and all.

I don't even know if it works.

Edit to add, I like the big knob/ dial of a variac, myself. This thing is probably over engineered for anything I would use it on.

 

[toobfreak]

I have at least 5 amps that really need some attention.
That's one reason this thread inspired me want to re-vamp the bench.

Then at the very least that should entitle each of us to one free bench repair!
If you need anymore work, I have an old 1970s SAE Mark IIIcm 200 wpc bipolar amp which seems to have some sort of fault in one channel which kicks in the protect circuit.

Was my subwoofer amp back in the 1980s.

Thing is beautiful in its solid oiled walnut case with thick-beveled front but there doesn't seem to be any good pictures of the amp in its wood case anywhere on the web, just the bare amp.

 

[scruffy]

Two Fender twins

Twins are easy. Take about 2 hours each, unless you have a bad transformer or something. Scruffy's patented service method is, first remove the tubes, then replace all the electrolytic caps, including the cathode caps. Don't bother testing them, throw the old ones away. Cost you maybe 60 bucks or so, a couple pennies more if you use Sprague Atoms. Then start testing voltages, and if that looks good put new tubes in and bias it up, you're good to go. It's very rare for resistors to go bad, but if there's any residual you'll hear it at this point. Oh and the dreaded death cap, if it has one.

 

[toobfreak]

I have a variac, but it is still buried in my heap of stuff I brought home when I retired from my last job.

Here is a file photo of the variac I use to turn my stereo on. Mind you, it does not turn the WHOLE stereo on at once, it turns on most all of the components one at a time through an elaborate switching system I have.

Here is a picture which kind of shows it in its usual position, on the floor on the far left behind one of my audio racks.

 

[scruffy]

I have a mic preamp to fix, it's a Neve clone, it's called Vintech. It sounded pretty good before it broke. Not sure what's wrong with it. It's discrete transistor. Darn solid state stuff breaks way more than tube gear.

 

[Chuz Life]

Twins are easy. Take about 2 hours each, unless you have a bad transformer or something. Scruffy's patented service method is, first remove the tubes, then replace all the electrolytic caps, including the cathode caps. Don't bother testing them, throw the old ones away. Cost you maybe 60 bucks or so, a couple pennies more if you use Sprague Atoms. Then start testing voltages, and if that looks good put new tubes in and bias it up, you're good to go. It's very rare for resistors to go bad, but if there's any residual you'll hear it at this point. Oh and the dreaded death cap, if it has one.

I was probably going to ask for your recommendations on the caps (Brand) and tubes too. I have no idea what is in my amps right now but one sounds so much better than the other. I've been watching a lot of the techs on YouTube. One female tech is especially easy on the eyes.

 

[Chuz Life]

Here is a file photo of the variac I use to turn my stereo on. Mind you, it does not turn the WHOLE stereo on at once, it turns on most all of the components one at a time through an elaborate switching system I have.


View attachment 1221522

Here is a picture which kind of shows it in its usual position, on the floor on the far left behind one of my audio racks.

View attachment 1221523
View attachment 1221524

Holly shit!

I was told in my classes that using a variac on anything solid state was a no no.

Mainly because of regulators and the (ohm law) drop in voltage can result in increased current (unless the current is also being limited.)

Beautiful pics!

 

[Chuz Life]

I have a mic preamp to fix, it's a Neve clone, it's called Vintech. It sounded pretty good before it broke. Not sure what's wrong with it. It's discrete transistor. Darn solid state stuff breaks way more than tube gear.

If you ever want to get into troubleshooting solid state, you should invest in a "Huntron Tracker" (ideally a model 2000 for component comparisons)

 

[toobfreak]

Holly shit! I was told in my classes that using a variac on anything solid state was a no no.

I don't use the variac to bring up any solid state devices. Then again, the only place I have any solid state in my audio chain is for frequencies below about 120 Hz, mid-bass, bass, and subsonics.

 

[Chuz Life]

Here is a file photo of the variac I use to turn my stereo on. Mind you, it does not turn the WHOLE stereo on at once, it turns on most all of the components one at a time through an elaborate switching system I have.


View attachment 1221522

Here is a picture which kind of shows it in its usual position, on the floor on the far left behind one of my audio racks.

View attachment 1221523
View attachment 1221524

Is that a DAC on top?

 

[toobfreak]

I have at least 5 amps that really need some attention.

I just found this picture on line of Chuz hard at work at his work bench.

 

[toobfreak]

If you ever want to get into troubleshooting solid state, you should invest in a "Huntron Tracker"

Wow, haven't seen one of those in a long time. Closest I ever came to that was the component tester in my Fluke 867. It created a similar graph display of I vs. E, which you can set up at different frequency excitation to stimulate various reactances. This doesn't show any of that but is the best file photo I have:

 

[scruffy]

I was probably going to ask for your recommendations on the caps (Brand) and tubes too. I have no idea what is in my amps right now but one sounds so much better than the other. I've been watching a lot of the techs on YouTube. One female tech is especially easy on the eyes.

What are the years? Which one sounds better?

 

[Chuz Life]

Wow, haven't seen one of those in a long time. Closest I ever came to that was the component tester in my Fluke 867. It created a similar graph display of I vs. E, which you can set up at different frequency excitation to stimulate various reactances. This doesn't show any of that but is the best file photo I have:


View attachment 1221530

I've never seen that model Fluke!

And will that laptop (386?) handle Windows 11?

That thing looks pristine.

 

[toobfreak]

Is that a DAC on top?

Not sure where you mean, but is there a D/A converter there? No. That is my Sony ES model 77 CD player on top, I'm not sure, but I think you can separate the D from the A if you want, but there is no need to. In today's money, new, it would probably cost $4,000 to build a CD player like that now.

 

[Chuz Life]

What are the years? Which one sounds better?

They are both 70's silverface with push pull master volume. The better sounding amp has chrome dome PYLE speakers than I doubt were factory. The newer cleaner looking amp has (I believe) celestion speakers. The newer one also has mixed tubes for finals due to one falling out and breaking at a gig. Though I can't remember the brands. One is a Sovtech, I think.

 

[toobfreak]

I've never seen that model Fluke!

I actually helped a guy at Fluke write some of the technical papers on it. The meter you see in the picture (big, fat, yellow thing) was actually used to troubleshoot a problem in Atlanta and saved the 1996 Olympics in Atlanta to go on in time.

And will that laptop (386?) handle Windows 11?

Nah, I just run an old OS on that because it needs to run old software for special testing aps I use that originally came on a 3.5" floppy.

 

[Chuz Life]

Not sure where you mean, but is there a D/A converter there? No. That is my Sony ES model 77 CD player on top, I'm not sure, but I think you can separate the D from the A if you want, but there is no need to. In today's money, new, it would probably cost $4,000 to build a CD player like that now.

Back in the late 70's to early 80's there were "DAC's" which radio stations relied on for recorded audio with no tape.

I thought that was a DAC

 

[westwall]

Not knowing better, I destroyed so many valuable radios in my youth.

I wish I had do overs.

I have one of those Transoceanics with a B-17 on its face.