Amp PCB

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Hi
I want to build a tube amp, and I need a printed circuit board. Does enyone have pcb for fender hot rod deville or simular. Or a marshall 9200 power amp?
friendly regards
jens

― Jens Bjørck, Monday, 10 October 2005 10:41 (twenty years ago)

http://www.valvette.us/ might be a good start. You'll likely find those specific PCBs are closely guarded secrets.

― tissp! (the impossible shortest specia), Monday, 10 October 2005 12:51 (twenty years ago)

if i may ask, why would you want to build those particular amps? the fender is an especially complex circuit, and a better sound (IMHO) can be had with a different design.

you will probably end up paying more to build that amp than to buy it new in the store. the main "market" for building tube amps is for vintage circuits that are either impossible to find or very expensive, and not too complex - not like those recent fenders!

lots of fender tweeds, marshall plexis, etc. I can point you in the right direction if this is what you want to do...

also, PCBs are generally frowned upon, and you'll find that you dont need them for the older circuits.

― AaronK (AaronK), Tuesday, 11 October 2005 11:33 (twenty years ago)

If I have a burned out vintage transistor amp... with schematic... is it feasible for me to rebuild it. It got smoked by someone putting a slow blow fuse in it instead of a fast on and looks pretty damaged. It looks like it was all hand wired in the early 70s.

Also, any idea why plugging it to a stereo chorus (outputting to a crate also) would blow it?

Oh and it has a friendster profile!

http://www.friendster.com/user.php?uid=2800685

― Jonothong Williamsmang (ex machina), Tuesday, 11 October 2005 14:15 (twenty years ago)

something was probably a bit off with it if it was blowing fuses. the different fuse types could damage it, but 2A is 2A and it shouldnt blow regardless.

not sure what you mean about the chorus?

as for whether it's worth it, i dont know. depends on current market value, sentimental value, how good it sounds/plays to begin with.

my guess is probably not :(

― AaronK (AaronK), Tuesday, 11 October 2005 14:23 (twenty years ago)

You not got that thing fixed yet Jon? I think your best bet with that would be to take it to a local tech and ask them to fix it for you.

w/r/t building yer own tube amp, or any DIY w/tubes, I'd avoid it, based on the high voltages some of these things run at. I've built a bunch of analog synth panels from kits, and I'm exposed to mains voltage electricity as part of my work, but I avoid dealing w/anything tube-related personally.

― Pashmina (Pashmina), Tuesday, 11 October 2005 14:31 (twenty years ago)

I haven't had the money nor the time. That blew in fall 2003 I think! It blew when it was hooked to my chorus with another amp and I reached down to fiddle knobs. I felt a current go up from the metal sheath on a cable to the strings of my guitar I think and it blew.

― Jonothong Williamsmang (ex machina), Tuesday, 11 October 2005 15:04 (twenty years ago)

Then I replaced the fuse and it smoked.

― Jonothong Williamsmang (ex machina), Tuesday, 11 October 2005 15:05 (twenty years ago)

xxpost - yeah, upwards of 250VDC, usually 300-450. kinds of insanely lethal. You do it at your own risk, as anyone will tell you. In fact, anyone decides to get involved in it, it's often good to start off by

1. first reading up tons on safety, grounding, and how to do things like safely discharge capacitors

2. build something small, non tube. something like a guitar pedal, that will give you the feel for musical electronics, what can go wrong, and the debugging process. yur first build *will* *not* *work* the first time.

jonothong, that sounds nasty. sounds like there's something seriously wrong inside. something shorting mains to something else in the signal path. ick. where are you located?

― AaronK (AaronK), Tuesday, 11 October 2005 16:03 (twenty years ago)

New York City

― Jonothong Williamsmang (ex machina), Tuesday, 11 October 2005 16:39 (twenty years ago)

there shoudl be lots of repair shops around, but if you cant afford it, i dont see the harm in opening the thing up and seeing if you can *see* anything bad about it. If a transformer is smoking, for example, I would probably consider it a total loss and not worth replacing.

do you know how many watts it puts out?

― AaronK (AaronK), Tuesday, 11 October 2005 16:51 (twenty years ago)

40?

― Jonothong Williamsmang (ex machina), Tuesday, 11 October 2005 17:03 (twenty years ago)

Hey Jon, does one of the amps have a three-prong grounded plug, and the other a two-prong ungrounded?

― John Justen (johnjusten), Tuesday, 11 October 2005 17:35 (twenty years ago)

ok. yeah, fuck it, just open it up and see. my guess is the transformer is shot. that or some big filter capacitors. These will be big cylinder looking things, usually either black or blue and somewhere near the power transformer. Look for leaking, blisters on the sides (where the wire comes out), or black sooty crap around them. what's the smell of the smoke when it smokes too?

― AaronK (AaronK), Tuesday, 11 October 2005 17:35 (twenty years ago)

WHY YES JOHN JUSTEN. The blown one isn't even polarized IIRC.

― Jonothong Williamsmang (ex machina), Tuesday, 11 October 2005 17:57 (twenty years ago)

Well, at least now you can boast to your freinds that at least once in your life you have functioned as an electrical ground. You also probably used up one of your nine lives...

My guess is that when you touched the chassis, you completed the ground between the two amps. I assume that you've re-fused it and the fuse has blown again (without being connected to the other amp)?

― John Justen (johnjusten), Tuesday, 11 October 2005 18:10 (twenty years ago)

yes.

― Jonothong Williamsmang (ex machina), Tuesday, 11 October 2005 18:21 (twenty years ago)

It's probably not the transformer, which generally would be the last thing to go...any bulged caps?

Hell, if you want to, take a couple of pictures of the inside of the amp and post them here or email them to me and I'll see if I see anything odd...

― John Justen (johnjusten), Tuesday, 11 October 2005 18:30 (twenty years ago)

http://photos.friendster.com/photos/58/60/2800685/1051999229995l.jpg

This is pre blowout. I saw a large black resistor smoking when I plugged it back in.

― Jonothong Williamsmang (ex machina), Tuesday, 11 October 2005 18:39 (twenty years ago)

I got a new digital camera so I'll take a picture when I see it next.

It sounds soooo sweet.... built in tremolo. It weighed like a pound, tops.

― Jonothong Williamsmang (ex machina), Tuesday, 11 October 2005 18:45 (twenty years ago)

What the hell is that? I've seen one of those before...a Sano?

― John Justen (johnjusten), Tuesday, 11 October 2005 18:56 (twenty years ago)

"Norma"? I can't figure out if it is from Italy or Japan.

― Jonothong Williamsmang (ex machina), Tuesday, 11 October 2005 19:29 (twenty years ago)

If you bought this, you could be all matchy-patchy!

http://cgi.ebay.com/VINTAGE-OLD-NORMA-STRAT-GUITAR-MIJ-60S-70S_W0QQitemZ7355971558QQcategoryZ2384QQrdZ1QQcmdZViewItem

― John Justen (johnjusten), Tuesday, 11 October 2005 19:45 (twenty years ago)

ha ha, holy shit. You HAVE to buy that guitar!

― walter kranz (walterkranz), Tuesday, 11 October 2005 19:56 (twenty years ago)

Its pretty badass, but I don't play guitar much anymore.

― Jonothong Williamsmang (ex machina), Tuesday, 11 October 2005 21:29 (twenty years ago)

john - thought it might be the tranny because if something was shorting secondary leads together it could start to smoke.... happened to me once :) the smell is somewhat pleasant. it wouldnt be a bad way to die.

― AaronK (AaronK), Wednesday, 12 October 2005 01:17 (twenty years ago)

Yeah, it still could be the transformer, but I rarely see solid state supplies go berzerko...I'm thinking the exploding cap is more likely.

BIg exploding caps are unpleasant, smell like acrid death, and shower the unfortunate tech with all manner of nasty crap.

Speaking of which...Jon, do you remember a really sour, acidic smell when it blew up? If so, I'm thinking the black capacitor you mentioned above that was smoking is the culprit.

― John Justen (johnjusten), Wednesday, 12 October 2005 05:36 (twenty years ago)

Jon you have to buy that guitar!!!

― Pashmina (Pashmina), Wednesday, 12 October 2005 07:29 (twenty years ago)

I would really love it, it looks so fucking cool...

― Jonothong Williamsmang (ex machina), Wednesday, 12 October 2005 13:00 (twenty years ago)

I'm bidding on it right now!

― John Justen (johnjusten), Wednesday, 12 October 2005 20:50 (twenty years ago)

And losing. Fuck.

― John Justen (johnjusten), Wednesday, 12 October 2005 20:51 (twenty years ago)

My Norma is the best sounding amp I have ever owned.

― Jonothong Williamsmang (ex machina), Thursday, 13 October 2005 02:24 (twenty years ago)

Old solid state stuff is often just as cool as vintage tube stuff, if not more so.

(Across the globe, tube loyalists begin sharpening their knives...)

― John Justen (johnjusten), Thursday, 13 October 2005 04:23 (twenty years ago)

eight months pass...

JON WHAT HAPPENED TO YOUR AMP?

― John Justen, Bataan death march of dimes. (johnjusten), Sunday, 2 July 2006 01:05 (nineteen years ago)

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