Should I just give up?

dartanion · Post by **dartanion** » Fri 03/16/07 10:20 pm

There is no guaranty that it will work at all with the pots wired all cockeyed. Easily remedied as has already been suggested.

When you are checking voltages, do you hear any pops through the speaker when touching the plates or grids of the power tubes or PI? If you are, it's the preamp/tonestack/inputs. If you've got good voltages and no pops when doing this, then check your speaker jack/OT wiring. Remember to ground the OT too.

steveh · Post by **steveh** » Sat 03/17/07 6:54 am

Are you sure those input jacks are wired to the contact and not the switch side (ie the connection which is disconnected with a jack inserted - these should all be grounded so the grids get grounded with no jack inserted.)

I could be thinking upside-down, but they look wrong to me.

As already mentioned, you don't need a signal generator, just carefully probe with a multimeter probe, you can trace back from the power tubes by tapping the probe on each tubes grids, listening for the pop/buzz until the noise from the speaker stops, then you've isolated which stage has the problem.

andrew7667 · Post by **andrew7667** » Sat 03/17/07 10:09 am

I've heard no sound from this at all. No pops from touching the plates or grids...nothing.

All my voltages looked fine the other day, but I'm starting think the 5y3 isn't supplying adequate voltage. It looked a little low, but nothing I was worried about. It did cause my PT to heat up after about half an hour though. Would a rectifier do that (I'm using 6L6's right now instead of 6V6's...the design I'm using is supposed to be able to handle both) if the power tubes were pulling too much current than the rectifier is able to supply?

andrew7667 · Post by **andrew7667** » Sat 03/17/07 10:55 am

Here are my current voltages with an RCA 5Y3 and a matched pair of GE 6L6's.

V5
Plate: 334v
Screen: 334v
Grid: -27.78
Cathode: 57mv
Cathode w/ respect to heater: 21v

V6
Plate: 337
Screen: 337
Grid: -27.76
Cathode: 55.6mv
Cathode w/ respect to heater: 21v

I also saw 2v at the 8 ohm speaker jack. Still no sound though.

andrew7667 · Post by **andrew7667** » Sat 03/17/07 11:27 am

steveh wrote:Are you sure those input jacks are wired to the contact and not the switch side (ie the connection which is disconnected with a jack inserted - these should all be grounded so the grids get grounded with no jack inserted.)

I could be thinking upside-down, but they look wrong to me.

As already mentioned, you don't need a signal generator, just carefully probe with a multimeter probe, you can trace back from the power tubes by tapping the probe on each tubes grids, listening for the pop/buzz until the noise from the speaker stops, then you've isolated which stage has the problem.

You were absolutely correct. I switched over to the other side and heard something when I touched the tubes. There's still no sound from the input, but hey...it's a start. I'll rewire my pots and see if that clears anything up. Good eye.

andrew7667 · Post by **andrew7667** » Sat 03/17/07 11:34 am

With my volume all the way up, my guitar is starting to make some sound through the amp. It's very quiet and extremely distorted. By what would this be caused?

marty1776 · Post by **marty1776** » Sat 03/17/07 11:52 am

Like others said, also scrutinize your output jacks. If you used shorting style jacks on the output, or wired them wrong, this could give you what you're seeing.

andrew7667 · Post by **andrew7667** » Sat 03/17/07 12:02 pm

I did use shorting style jacks on the output, but I rewired them correctly. They were wired wrong the first time, but I'm getting sound through them now. It's just very quiet and highly distorted. Should I get a different type of jack or can I use the shorting style, so long as they're wired on the correct side?

andrew7667 · Post by **andrew7667** » Sat 03/17/07 1:16 pm

I already figured that out and corrected it. I changed the 8 ohm jack, but not the 4 ohm. I never use the 4 ohm anyway.

andrew7667 · Post by **andrew7667** » Sat 03/17/07 4:12 pm

Does anyone see anything wrong with the voltages I posted?

Could the lack of volume be a blown OT since I've been running it without a load all this time? Besides checking all my wiring, what other checks should I run to see where I'm losing volume? Would the tapping still be a good idea to see where the sound dies down?

andrew7667 · Post by **andrew7667** » Sat 03/17/07 4:35 pm

Too bad that voltage chart is for EL84's. The CD uses 6L6's or 6V6's.

I'll certainly use it for the 12AX7's though. Anyone have one for 12AT7's or 6L6's?

marty1776 · Post by **marty1776** » Sat 03/17/07 9:50 pm

Either you're missing what we're saying about the ouput jacks, or I am. You need to use non-shorting jacks for the output, no matter if you're using that jack or not. Otherwise your signal will be shunted to ground.

andrew7667 · Post by **andrew7667** » Sat 03/17/07 11:24 pm

He's using 6V6's where I'm using 6L6's. I'm considering ordering a pair of 6V6's just for testing purposes, but for now I don't have any. Well, I do, but they kind of gave out when I jumpered over the diode in the bias.

They were just some Groove Tubes anyway. No big loss.

I'll definitely go through and check my preamp voltages though. They should be similar, though not exact, seeing as how I'm using a different version of the Dreamer. Should my voltages be drastically different using 6L6's or would it be safe to expect everything to be about the same, save for the bias voltages?

marty1776 · Post by **marty1776** » Sun 03/18/07 11:25 am

Sorry, Kenny, you are right, I just figured if he was using them, they were hooked up.

andrew7667 · Post by **andrew7667** » Sun 03/18/07 1:33 pm

Naw, I just happened to order four of the same jack rather than ordering two shorting jacks and two non-shorting jacks.

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Should I just give up?