5B6 started

[telentubes]

I'm going to make one more adjustment then possibly shelve this thing till more inspiration comes along.
Ran through 4 6SC7s, 3 6SL7s, 6 6L6s and 3 5U4s (including a SS) to get a combination that "kinda" works.
My voltages are within a volt or two of spec except B+1 which is high by 8 to 15V, depending. I used the Fender 180V for V2.
Here's where I'm at with tweaks...
V1 cathode bypass dropped from 250uf to 100uf to try and tame some bass.
V1 plate dropped from 270K to 178K to raise voltage.
V1 couplers dropped from .1uf to .05uf to tame bass (changed all caps to 6PS Orange Drops)
V2 plate dropped from 270K to 240K to raise voltage.
V3/V4 cathode resistor raised from 250 Ohm to 300 Ohm.
1st dropping resistor raised from 10K to 22K
2nd dropping resistor raised from 10K to 12K
First filter caps are two 80uf/450v in series with 200K bleeders. The start-up voltage spike was around 512V.
All of the tweaks helped, and it has some nice tones, but not nice enough to keep. Kind of a one trick pony. Any thoughts about what I might try next, or what I could turn it into? The PT is 700V.

[Blackburn]

If you want more help with the bass, go down to .02uf for the first couplers. I did this with my first attempt at this amp and also did it PTP. It was a mess, but it could be played dimed, sitting on the cab I was using in its chassis without a head cab and would only make a slight rattle from the bass, but other than that, was problem free. I also kept a 220uf bypass cap. Really miss that amp.

However, I just got that chassis running again as something else now.

[telentubes]

Blackburn.
I went all the way down to .01 with the first couplers. Also reduced the V1 cathode to 47uf. Still too much bass. Tried the .1 snubber on the 6L6 which was terrible. Took that off. Added a 270pf snubber on V2. Helps a little with the high treble.
I'm wondering if the transformers I'm using are not well suited for this amp. (???) Who knows. But I'm done at this point so will move on to something else. I've been screwing with this thing for weeks. There is only a very small window at a certain volume and tone setting where the amp sounds OK and is balanced and fun to play. Kinda disappointing after hearing others reports of glorious tone. I like the cab.

[M Fowler]

The tube store sells 6SL7 and 6SN7 by Northern Electric that have great reviews but they are not cheap.

http://www.thetubestore.com/Tubes/Northern-Electric

[telentubes]

I went back in and rewired this thing PTP. Went back to all stock values. Fired right up.
Tweaking looks like a nightmare so I probably won't. Voltages aren't perfect, but it sounds way better, kinda like an amp. Whodathunkit?

B+: 409, 359, 341
V1: 154, 1.8
V2: 201, 2.4
V3/V4: 406, 358, 29.9
V5: 409, 354AC

[Firestorm]

Wow. That looks like it was wired by somebody from the 1940s. How old did you say you were? Glad it sounds like an amp.

[M Fowler]

Congrats on the PTP rebuild.

I play Les Paul's so since the 5b6 is a dark amp I use Vintage 30's.

The longer the amp burns in the better it would sound, with a reverb like quality.

[Blackburn]

Very nice PTP!

[dreric]

I went back in and rewired this thing PTP. Went back to all stock values. Fired right up.
Tweaking looks like a nightmare so I probably won't. Voltages aren't perfect, but it sounds way better, kinda like an amp. Whodathunkit?

B+: 409, 359, 341
V1: 154, 1.8
V2: 201, 2.4
V3/V4: 406, 358, 29.9
V5: 409, 354AC

So.................. I've been watching all the 5B6 threads. Glad your's is sounding better, nice work.

Is it fair to say that there is a consensus that PTP builds more in the vein of Tino's book sound better and are more stable that a more modernized approach with eyelet boards etc??

[vibratoking]

Nice build...look at all those bits of heatshrink. You've got patience.

[Blackburn]

I went back in and rewired this thing PTP. Went back to all stock values. Fired right up.
Tweaking looks like a nightmare so I probably won't. Voltages aren't perfect, but it sounds way better, kinda like an amp. Whodathunkit?

B+: 409, 359, 341
V1: 154, 1.8
V2: 201, 2.4
V3/V4: 406, 358, 29.9
V5: 409, 354AC

So.................. I've been watching all the 5B6 threads. Glad your's is sounding better, nice work.

Is it fair to say that there is a consensus that PTP builds more in the vein of Tino's book sound better and are more stable that a more modernized approach with eyelet boards etc??

I can say from experience that PTP should be done for this circuit over boards of any kind. I'm sure some have had success with them, but I didn't. With a tube as microphonic as a 6SC7 can be, PTP is a much better for stability. Mine was fine at first, very ugly, but fine. It could be played directly on the speaker cab in just its chassis and was great. I wanted to make it a nicer build internally and did the boards and all. Basically oscillated itself to death. Octals don't like long leads. Luckily, I salvaged the trannies for something that I'm digging now, and isn't microphonic at all.

[telentubes]

I'm doing a little tweaking. I dropped the V1 coupling caps from .1 to .047, and will probably go down to .01 tomorrow. I also put the snubber back on V2 to cut some of the brittle highs. I'm not going to mess with any voltages.

I had a Vintage 30 in there (good choice Mark) but yanked it to put in my Princeton Reverb, where it sounds really good. The Eminence that is now in the 5B6 sounds surprisingly good (inexpensive speaker), although not quite as good as the Vin 30.

I like this amp OK. The distortion and wolf notes that were present when there was a circuit board are gone, so PTP has prover to be the way to go for this circuit (for me at least) but the octals are sensitive to any vibration, and kind of a PITA. There are some great tones, including the natural reverb Mark mentioned, but I'm not sure if this thing will end up a keeper or not. I'll play it for a while and see how it breaks in. I may try different transformers, just to see.

Blackburn, What did you turn yours into? I might take the same path if this thing doesn't do it for me.

[Blackburn]

Well, after some very interesting configuring with these http://www.cedist.com/products/P-SH12-1-31 I was able to affix my 9 pin sockets in place of the octal holes that were there. I don't think I used them the way the manufacturer intended. I only used two of those things and had a third hole that was fine. That amp is now a 6G16 Vibroverb without the verb. I love it. Same trannies and RCA 6L6GCs that were in the 5B6 are now kickin in there. I think of it as a dedicated clean amp with really thick vibe. Very interested tapped treble pot on that schem. I wired it up just like that and it has a very intense sweep after around one o'clock on the dial. No choke used.

[M Fowler]

I haven't seen that plate offered before.

[telentubes]

Thanks Blackburn. I will have a look.