Some one gave me parts from an old Leslie 122 ?? guitar amp maybe

[copperheadroads]

1 ohm resistors are installed on the powertubes , the -29 i got from the bias test point in the preamp board . never tested the bias off the pin 1/8 to ground from the Power tubes .

[copperheadroads]

I just changed C1 to a .1 uf & now i get so much more than i need .

[copperheadroads]

The bias is in range now but when i fire it up with tubes i can hear sound coming through the speaker but when I turn it up the dim bulb starts to light & the pilot light goes a little dim . did some reflowing of solder of some joints & checked a bunch of stuff
b+ 412 v
Filiments are reading 5.9vac
v1
1 207v
2 0
3 1.99
6 178
7 0
8 1.83

v2
1 266
2 .019
3 3.01

v3
1 206
2 40
3 63.0
6 211
7 37
8 63.9

v4
1 -.038
3 414
4 391
5 -30

v5

1 -.038
3 412
4 391
5 -30
6 397

[Enzo]

As is expected with the bulb. The bulb is not intended for operation of the amp. The bulb is there to prevent blowing fuses. The harder ANY amp works on the bulb, the more it will light the bulb.

[copperheadroads]

Thanks for everything , I've been working on this trying to get it right , It seems to be working but not sure if all the controls work as they don't do much & it don't get any louder past about 3 on the volume ,It's not really loud & its an unpleasant distortion right from 1 up.

[mozz]

You don't have the dim bulb tester hooked up while you are trying the amp do you?

[copperheadroads]

Not using the dim bulb any more
The bias of the tubes seems to be working correct as well as the power section , heaters have correct ac current on all the tubes
I noticed in the layout there is no ground from the pots or preamp . only the bus wire & i guess grounded through the pots to the chassis ,just to be sure I've added a ground wire from the bus wire to a bolt in the chassis under the pots ,but it did not help

[mozz]

I asked about the dim bulb because i thought i read filaments were at 5.9vac. Those voltages look ok so that thing should be cranking.

[copperheadroads]

filaments were lower with the dimbulb , Filaments were up in the 6.5v area but this thing is not loud by any means more like a 5 watt amp or even 1 watt (being the trannys are for a 40 watt tube amp ) & not any clean headroom & it gets gainy right away & turning up the volume don't do much past 3 only gets more compressed (that maybe how the train wreck works )

[copperheadroads]

Ok it's alive & loud now , I was thinking maybe the output transformer secondary's were wired wrong
These are a direct replacememt for leslie OT (same color wires & everything )
http://www.classictone.net/40-18044.pdf
this Output transformer only has an 16 ohm tap so it's wired directly to the jack
In this build i'm using cliff jacks which are isolated & i wanted to see if the common/ sleeve needed to be grounded so i removed the ground & it squeals a little without it being grounded. But when i removed the negative feedback wire it came too life .loud !!! clean & all controls seem to work fine . so i grounded the common again & it's still loud but it breaks up more & sounds good , I wonder why the Negative feedback was dragging her down & what should i do with it ? it had the correct values & wired correct .

[g1]

Which schematic for power amp and NFB circuit?

[copperheadroads]

pretty much these which is quite similar to this one also
TW Express Schem 12-4-08 (2).pdfTW Express Layout RLW 1.8.pdf

[g1]

That schematic has the NFB coming off the 8 ohm tap. You have only a 16 ohm tap so the NFB circuit won't work the same. You will have to play around with the value of R22, the NFB series resistor.

[copperheadroads]

Ok thanks I will do some testing . I didn't understand how negative feedback could effect an amp like it did . it can restrict the volume & controls wow .

[loudthud]

Going from the data sheet, Grey on the layout should go to Brown on the transformer, Pink on the layout should go to Blue on the transformer. Ground the Green wire on the secondary an connect 16 Ohm load to Green/White on the transformer. Do not connect to the Black wire. Change the feedback resistor to 140K or 150K and connect to the 16 Ohm tap (Green/White).

If you have a good place to solder the Black wire, you can take the feedback from there and use a 75K feedback resistor.