Calling all amp gurus..

[WORMDIRT]

So a friend gave me a half finished amp..
A can of worms for shizz...
so what I have is..
2 superlead turret boards, already populated, no connected
a chassis with a hammond 272jx, a mystery OT, and a smaller hammond transformer with 115v on the primary and 36v on the seconndary, already connected
a C1999 choke, not connected
2 100-100-175uf caps, and 2 32-23uf caps all wired up.
4 Power tubes sockets wired up
no preamp tube sockets, and no pots.

everything is on a TCM 100w "Tube Top" chassis.


Really I'm trying to figure out what this beast is.
I assume the OT is from the donor amp, but the PT is only rated for 50-60w amps
I guess I can make it into a 50w superlead clone, but I need some help on that front.

Will the OT work with a 50w amp build?

I'm cleary in over my head here haha.
Pics can be posted if needed.

[crochambeau]

Will the OT work with a 50w amp build?

Didn't you just say the OT was a mystery? There's NO WAY of telling.. That said, I've seen LAUGHABLY small output iron on amps that claim 50 or even 100 watt output, just don't expect much love below 100 hz.

Pictures would be huge. There is absolutely no way of second guessing someone's line of thinking based on a half finished circuit. It sounds like ambition directed the design phase and overwhelming did follow. Was this your friend's build? What other information did you receive? (other than the expected "get it the fuck out of my sight!")

[WORMDIRT]

I'm assuming the OT is 100 watts because it looks like its from the donor amp.
Its not his build, he did a CL trade and some old dude gave him a bunch of parts and shit, and the half finished build came with it. The old guy said it was a Hiwatt build, but the boards it came with say otherwise.
I'm not a builder, but I know my way around a tube amp, mostly, so I was not gonna take it but, curiosity took over haha

[crochambeau]

Sounds like fun, any numbers on the OT?

[WORMDIRT]

Images are currently uploading

[WORMDIRT]

Sounds like fun, any numbers on the OT?

OT is blank

[WORMDIRT]

pics
http://imgur.com/iqpROdy,CasMnMV,cKLDHW ... WP,DXHkLzi

[crochambeau]

Looks like quality work. Wire ends also look like they've been installed and then pulled. Could be due to a wiring error, or poor lead dress (oscillation) maybe? Hard to say, but I would start by testing the iron and making sure it's in good working order.

With that level of completion I'd suggest trying to follow the original plan, starting at PSU and working your way from there.

That OT could also be a PPP 100 watt, are you able to measure out the ratio?

[WORMDIRT]

Looks like quality work. Wire ends also look like they've been installed and then pulled. Could be due to a wiring error, or poor lead dress (oscillation) maybe? Hard to say, but I would start by testing the iron and making sure it's in good working order.

With that level of completion I'd suggest trying to follow the original plan, starting at PSU and working your way from there.

That OT could also be a PPP 100 watt, are you able to measure out the ratio?

I don't have a variac or anything, to put AC into the OT, so no.

The OT is the biggest obstacle here..
I have the OT and PT from a Peavey windsor I just might use instead.

[crochambeau]

I don't have a variac or anything, to put AC into the OT, so no.

Do you have a multimeter or an AC voltmeter and a way to create a constant signal? Does not need to be a variac, could be an amplifier output being fed with an oscillator. Remember, you don't need a HUGE signal to read. You're just after a ratio, the secondary speaker outputs should be color coded to give you a reference point there, but historically people couldn't settle on a format. Just look for similar AC voltages from CT at B+ inlet to each plate feed (I'd strap the signal across the plates, then measure from plate to CT on each side, followed by whatever is on the secondaries). Identifying the ground/common on secondary is hopefully as easy as grabbing the black wire (sometimes they are a different color).

Ultimately, a 50 watt push pull is going to want to reflect a higher turns ratio that a 100 watt push pull parallel, but there's gobs of slop and it's easy to reassign 100 watt outputs to reflect proper ratio on a 50 watt circuit (I don't recommend going the other way around).

Apologies if this post reads like nonsense, I like to obfuscate a little bit when talking about power (for safety sake), I think everything you need to sort the OT mystery is in there...

[WORMDIRT]

I don't have a variac or anything, to put AC into the OT, so no.

Do you have a multimeter or an AC voltmeter and a way to create a constant signal? Does not need to be a variac, could be an amplifier output being fed with an oscillator. Remember, you don't need a HUGE signal to read. You're just after a ratio, the secondary speaker outputs should be color coded to give you a reference point there, but historically people couldn't settle on a format. Just look for similar AC voltages from CT at B+ inlet to each plate feed (I'd strap the signal across the plates, then measure from plate to CT on each side, followed by whatever is on the secondaries). Identifying the ground/common on secondary is hopefully as easy as grabbing the black wire (sometimes they are a different color).

Ultimately, a 50 watt push pull is going to want to reflect a higher turns ratio that a 100 watt push pull parallel, but there's gobs of slop and it's easy to reassign 100 watt outputs to reflect proper ratio on a 50 watt circuit (I don't recommend going the other way around).

Apologies if this post reads like nonsense, I like to obfuscate a little bit when talking about power (for safety sake), I think everything you need to sort the OT mystery is in there...

Officially in over my head. I think I'm going to get a 50 watt classictone OT and do this build right.

[crochambeau]

I don't want to come off as a dickhead here, but I'd suggest keeping your eyes open for a variac - they are an incredibly useful tool for doing what you propose to do.

[WORMDIRT]

I don't want to come off as a dickhead here, but I'd suggest keeping your eyes open for a variac - they are an incredibly useful tool for doing what you propose to do.

I've been on the hunt for one on CL and at swap meets for a while. Trying to "fall into" one if you know what I mean. Just kinda stingy

[crochambeau]

Just kinda stingy

I've seen unwired variable auto-transformers in surplus electronics / recycling shops. They are sometimes not presented as a variac (which was a trademark of GenRad, so it's useful to arm yourself with more search terms) depending on how informed the seller is, they often look like JUNK, and can be found much cheaper that way than as a self contained unit with your mains outlet and fuse protection, etc. built in. Of course, then you're responsible for your own safety..