Best carbon comp supplies?

[azatplayer]

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[ToneMerc]

I have some NOS Erie carbons, I'll have to check to see how far they have drifted.

TM

[diagrammatiks]

man I love how clean those old voxes are.

everyone always talks about hiwatt but vox was way cleaner then just about everyone else from the get go.

[LeftyStrat]

Damn, look at all those old mustards.

That is one sweet sounding amp. I've been wanting to do a Vox clone, along with a hardwood cab like Vintone made:

[azatplayer]

ANyone used little demon 1 watters?
Just checked Nebraska surplus too for some old carbon, plenty to choose from but gees that stuff is exxy.

[chopstuck]

Wow, that AC-10 is now on my radar.

I could play that for an hour and not heat the whole house, like my old AC30 does.

Sometimes the amp would heat by convection, other times combustion.

[TheHandsomeOrk]

ANyone used little demon 1 watters?
Just checked Nebraska surplus too for some old carbon, plenty to choose from but gees that stuff is exxy.

Nice shots. Threw out a box of those old white resistors a couple of years ago, wasn't confident using them in a new build, oh well how was I to know.
Are you in OZ? if so I could send you some allen brads 1&2 watt ( got boxes of 'em kicking around here some place) and maybe some mustards (if I've got the right values). post a list of values needed and pm an address.
cheers

[rp]

My clone had the screens 10V higher than the plates too and IIRC like 340V and I messed a lot trying to 'correct' that, should have just let it be as I'm sure that's how the original ran. The way they are tied together while weird must be a part of the great sound.

I would love to see this amp get more attention here and maybe someone can get a really fine clone going. Like I said my orig reminded me of a Vox 5E3 the way it took off. Real nice vibrato too.

Finding the right OT might be tricky, IIRC I first used an Audio Note 8K then used a Hammond 1600 8K 10W w/o much luck but it may not have been the OTs fault. MAybe the orig was closer to 6K like the AC-15? I used a 5Y3 too. It was an early attempt by me and it came out very dark, also odd as I used MFs and MIT caps. Might have had a parasitic as it ran hot but it was ptp so that's unlikely. My vibrato was never as big, I believe caused by the lack of correctly tappered RA pot. There was no TAG to ask for help.

Maybe it's just a tricky build, which is not uncommon when trying to capture the loose, warm, organic quality of old amps. And I think the right speakers are critical but that's usually true w/ Voxes too.

Thanks for the info Azat. IMO my AC-10 was the best 2xEL84 amp I ever heard. Future cloners get to work and report back.

[azatplayer]

Resistor values are, 100R x 2, 820Rx1, 1K2 x 1, 1k5 x 3, 22k x 2, 47k x 1,
68k x 4, 100k x 3, 150k x 1, 330k x 3, 470k x 2, 750k x 1, 1M x 9.
Caps are all 400V .0047 x 5, .047 x 3, .01 x 5, .1 x 1, .022 x 1.
Two of the old schems ive seen state 8K primary and 8 henry 120ma choke.
I meant to pic the trannies but didnt. The OT was replaced on this amp, so its hard to say how much is that. It fit in the same mount holes tho and looked to be original, same lams as the PT, maybe was a rewind. Was the differing new looking wires that gave it away as a replacement. Size wise, it was at least as big as some 18watt iron i have, tho is laydown style.
I have a few to choose from, hope i get somewhere near it, im sure i will, tho will surely have some differences.
I really wanted to get it thru some 12's too, but didnt get the chance, im sure thru a single greenback or celestion blue would be pretty killer. Had a look around for some G10L-35's, bit thin on the ground, killer speakers in this amp. Seems Marshall used them in their 4x10's. Very sweet tones.

rp, i was thinking of using a 5Y3 too. I have one in my 15W/zwreck build and have a SS switch for the rec, far and away prefer the 5Y3's dynamics.
PT has 2 taps that give it the exact same voltage either SS or tube rec, was an interesting experiment. Friggin loud amp that one!

[groovtubin]

Ahh yes i did measure a few resistors and the drift is massive. I intend to document the values before it gos home. They look really shabby too, some of the bands are near gone. It started out just a recap, but ended up the old re-al jacks were brittle and the spring contacts were moving around where the jacks had chipped away, one channel was staying open with the jack empty. So i had to replace them, using cliffs. Of course needed to relic the chrome bezels
In rewiring the jacks i realized they created an attenuation at the input deliberately crippling the amp to a supposed ten watts. That and smaller trannies and lower B+, kept it under the AC15, but essentially the same amp power wise. I rewired the jacks in a standard hi lo config and that opened the amp up immensely, also took away the crappy buzzy distortion the divider created.
It had 220k grids on each hi and lo input with a 1meg to ground. Thing is the inputs are in parallel with each other and the 1meg, with each grid resistor to ground when the jack is closed. So using either input gives you a divider of 220k-180k (220k*1meg/220k+1meg) giving a massive attenuation.
Also they ground one side of the cut control which gives much less cut control! So i lifted that as well as swapping lugs to make it more a tone control as thats what it is marked as.
Basic reversible stuff, which i think he will like.
The thing was wired wrong impedance too, luckily had not damaged the OT, running a 4ohm load from the 8ohm tap. Ended up sounding just great

to get a higher value from new comps, just dremel/shave off the resistor til you get the right value, with a METER connected of course!

jim

[TheHandsomeOrk]

to get a higher value from new comps, just dremel/shave off the resistor til you get the right value, with a METER connected of course!

jim[/quote]

Can you explain how that would work.
I've read that it's an old Ham radio trick but doesn't make sense logically.
CCs are a mixture of clay and carbon and prone to moisture which can cause them to rise in value as does high heat. Shaving or removing material
from the resistor would affect the wattage value but not the composite value.
Hence 1/2 watt resistor small, 1 watt larger, 2 watt larger again, I guess if removed enough material from a 1 or 2 watt you could end up with a 1/2 watt but can't see how it would effect ohms value. Too lower a value you may have better luck by drying a resistor on a sunny day to remove any added moisture then coating with a clear poly gloss to stop re-absorption, makes them look purdy as well

[groovtubin]

to get a higher value from new comps, just dremel/shave off the resistor til you get the right value, with a METER connected of course!

jim

Can you explain how that would work.
I've read that it's an old Ham radio trick but doesn't make sense logically.
CCs are a mixture of clay and carbon and prone to moisture which can cause them to rise in value as does high heat. Shaving or removing material
from the resistor would affect the wattage value but not the composite value.
Hence 1/2 watt resistor small, 1 watt larger, 2 watt larger again, I guess if removed enough material from a 1 or 2 watt you could end up with a 1/2 watt but can't see how it would effect ohms value. Too lower a value you may have better luck by drying a resistor on a sunny day to remove any added moisture then coating with a clear poly gloss to stop re-absorption, makes them look purdy as well[/quote]Ok, would you agree that a potentiometer is a resistor with a wiper? IF so, try shaving off the trace w/sandpaper, and pls report back to me what your results are!

peace, jim@Omegaamps.com

[TheHandsomeOrk]

Oops your right Jim I shouldn't drink and drive a keyboard. I've done that with new pots myself in the past to raise the value to where I want it.
Forgot about Ohms law, more carbon = less resistance: less carbon = more resistance. I remember trying to scrape a 2watt CC many years ago and didn't succeed, never went deep enough through the 1mm jacket to hit carbon thinking all I'm gonna do is turn a 2watt into a 1watt.
O.k any tips for going in the other direction.