Rewiring the basement "Studio". All drum machines are in there place, rejects are now in the filling cabinets.

losthighway wrote: Sat Jan 28, 2023 7:41 pm ^ I sent a mic into them once. It wasn't the cheapest thing but it wasn't the most expensive either. In a value of unit vs cost of repair ratio I imagine your 4060 will fair a little better than my 4047 did.

Thanks, that kind of confirms what else I’ve read about the cost for Audio Technica to refurbish their stuff. I quite liked it when it was working so hopefully it doesn’t turn into a money pit

tallchris wrote: Wed Feb 01, 2023 4:41 pm

Nate Dort wrote: Wed Feb 01, 2023 4:37 pm Whoops, bought a YBA-3A for $100

https://reverb.com/item/65475958-trayno ... 970s-black

Goddamn!

Hard to tell from the photo--does it have the power tubes?

Picked this up today. Apparently it had been used as a PA, then given to the previous owner after it stopped working. PO had received a quote from a tech of $500 to fix it back up, but didn't want to pay that much so he threw it on Reverb. Guy knew it was a 3A even though he listed it as a 3, and knew it was worth way more than he was asking.

First things I noticed:

• Missing two of the output tubes. The remaining ones (6KG6A) look original, branded RCA. I've already ordered a set of Russian 6P45S to see if they'll work.
• Two of the three 12AX7s were broken. All of them look original, branded Philips.
• Not sure what the date of this thing is, it's missing the serial number plate on the back. The schematic pasted to the large sheet-metal lid is rev 4, dated April 15, 1970, so it's after that. A couple of the big wirewound power resistors are dated 10th week of 1970 and 34th week of 1969, so it's probably in the first half of 1970. Either way, it's the non-MV version, before they had redone the gain control to be between the first and second gain stage, rather than using the second triode as a follower.
• Somebody had been in there before, as it looks like C25 had blown its guts all over the inside at one point. It had been replaced with what looks like a late 80s or early 90s Sprague cap (the orange dude in the photo).
• It's pretty filthy. Gonna give the case a good scrub.

I ordered a set of caps for it and a reproduction logo for the front.

More YBA-3A work:

• Washed about 50 years of bong resin, nag champa, and nicotine off it. Used a mixture of TSP and Oxiclean and a magic eraser, then polished the tolex with some leather conditioner I had laying around.

• I soaked all the metal bits, including the steel top cover, with rust remover. Scrubbed the rust off with an abrasive pad, then hit the chrome parts with some polish.

• Cleaned the knobs in the ultrasonic cleaner with more TSP/Oxiclean.

• Replaced the rubber feet.

• Cleaned the fan.

• Polished the front and back panels with some Novus 2.

• Recapped it.

• Added an extra RC filter stage to the V1 plate supply, per the later YBA-3A schematic.

• Added extra 47 ohm screen stopper resistors to the two output tubes that didn't have them, to prevent oscillations.

• Cleaned/lubed the pots and switches.

• Added grounded power cable, cut out the death cap.

Still waiting on new output tubes, probably won't show up for a few weeks since they're coming from Ukraine.

Nate: One of the first things I remember reading here was how difficult it will eventually become to source these 6KG6A tubes (& once they're gone, they're GONE gone with zero chance of these EVER getting reissued let alone getting "matched sets" or whatever) so they had their tech mod the amp for individual bias on each power tube. IDK if you feel there's value there w/ this info or not but if there is, might wanna consider that? And if so, probably will drop mine off at some point for same procedure.

I also have a small cache of unmatched soviet era tubes I could mail you if there's some concern about the wait from Ukraine.

Garth wrote: Mon Feb 13, 2023 7:37 am Nate: One of the first things I remember reading here was how difficult it will eventually become to source these 6KG6A tubes (& once they're gone, they're GONE gone with zero chance of these EVER getting reissued let alone getting "matched sets" or whatever) so they had their tech mod the amp for individual bias on each power tube. IDK if you feel there's value there w/ this info or not but if there is, might wanna consider that? And if so, probably will drop mine off at some point for same procedure.

I also have a small cache of unmatched soviet era tubes I could mail you if there's some concern about the wait from Ukraine.

This isn't a huge concern for me, considering that JJ makes a new production EL509-II with the same specs. However, it's an octal socket as opposed to the 6KG6A magnoval socket, so it would require some surgery to swap the sockets. Less work than adding individual bias pots though.

It would make tube rolling 6550s or KT88s or KT90s or something else easier in the future also.

And thanks for the tube offer. The two original 6KG6As I pulled out appear to work. Or at least they're not shorted. Haven't passed any real current through them yet, but they're probably sufficient for testing to make sure this thing passes audio.

Nate Dort wrote: Thu Jan 19, 2023 10:37 am Grabbed a Music Man 115 sixty five from CL for $450. Actually had the trem/reverb footswitch with it.
No idea what speaker is in it. Need to pull it out and look, but I don't have high hopes just looking at it. Might be a radio shack jawn. I may make a baffle adapter and throw one of my extra 12s in there.

Found one of the main filter caps was visibly leaking, so I did a full recap. Also replaced the speaker with a Warehouse G15C. Sounds way better now. Bass is tighter, treble isn't as piercing as it was with the Eminence PA speaker that was in there.

Only thing I need now is a new bottom cover for the footswitch. Looks to be the same size as the old Fender oval ones. I'm not having any luck finding just a replacement cover though, only entire knock-off footswitches. May have to go that route.

llllllllllllllllllll wrote: Sat Jan 28, 2023 6:24 pm Audio Technica AT4060

Great mic I bought a while back

Had a little noise I could see on the daw but couldn’t really hear. I probably should have returned it at that point

Now that thing spits out so much white noise you can’t use it. I replaced the tube with a NOS Amperex and it’s still doing the same thing.

Someone on the internet recommended keeping it in tupperware with silica packets. I found a couple and tried it for the hell of it, but its still doing the same thing. I’ll reach out to Audio Technica next week as I’m not sure what else I can do other than just sending it in

RIP Tom Verlaine!!

Yeah that repair bill stung, but perhaps not as bad as a $600 paperweight. It was the element.

Anybody using professionals for mic repairs these days? Guitar equipment I basically never bought new unless it was Balls or EGC, but for studio stuff I am thinking I might be better off buying something with a warranty.

YBA-3A is pretty much done. Quad of 6P45S tubes arrived from Ukraine today, but unfortunately two of them were broken in shipping. I installed and biased the other two and it works fine with just those. Still loud AF at half power. One of the original RCAs it came with is toast, I'll keep the other for a spare.

Got a repro front logo from a guy in Kazakhstan. It's some sort of laser engraved / 3D printed plastic jawn, but it looks pretty good after I filed some rough spots off the edges.

Bass boost switch doesn't seem to do anything. I might look at that at some point, but I don't feel like opening it up again right now.

I installed 1 ohm cathode resistors' and external banana jacks on the back panel for biasing. Also removed the ground switch on the back and replaced it with a recessed bias pot. Taking the chassis in/out and aligning the mounting screws and the top sheet metal plate is quite a chore, so I'm not keen on having to take it apart every time I change tubes.

Some shots before/after I cleaned it up:

I wanted to ask - I’ve got a couple vintage guitars that had their trems removed and were converted to hardtail. Good for me because it was cheaper. Unfortunately the stupid groundwire is just flopping around in there.

Any ideas for grounding these things without routing a hole to the bridge? I expect it wouldn’t hurt the value that much considering, but I’d like to know my options.

Unfortunately one of them had a lyre vibrola, so finding another one would run around $300 or so, which is too much for a prop