Ceriatone OTS build problems

[Bruciep07]

Hi all,
I decided to cross the tracks from the trainwreck side and build a 100W ceriatone OTS kit. I used Hammond iron (290FX PT, 1760W OT, and a 194B choke). I pretty much built it to nik's layout with the exception of the half power switch being like #124. I get whisper quiet sound out of it, that's it. I've gone over it 100 times looking for a problem but I can't find one, figured maybe someone with fresh eyes might catch something I missed... The very little sound that does come ou is very distorted, but like I said it's almost whisper quiet. The preamp volume, bright, deep, and rock/jazz switches have an affect on the sound, T-M-B have no apparent affect, OD level/ratio have no apparent affect, and master volume does very little... Any suggestions on where to start? There are no obvious cold solder joints, but that doesn't mean there isn't one. I'm going to spend the rest of te night checking solder joints unless someone has another suggestion. Some pics for your viewing pleasure...
[IMG:800:600]http://i23.photobucket.com/albums/b355/ ... 3c5e35.jpg[/img]
[IMG:800:600]http://i23.photobucket.com/albums/b355/ ... 7b2f98.jpg[/img]
[IMG:600:800]http://i23.photobucket.com/albums/b355/ ... 8ef88e.jpg[/img]
[IMG:600:800]http://i23.photobucket.com/albums/b355/ ... 24ef68.jpg[/img]

[talbany]

First thing... Check all your voltages cathodes included and post them...This will help us find a problem..Then check all your grounds..

Tony

[stelligan]

if you have a preamp out and power amp in jack, plug a pod or other preamp type device into the power amp in to see if power amp is working. Likewise if you have an amp with a power amp in that you know is working, plug the preamp out of your ceriatone into it. This will tell you which half is working or not....

[ChrisM]

if you have a preamp out and power amp in jack, plug a pod or other preamp type device into the power amp in to see if power amp is working. Likewise if you have an amp with a power amp in that you know is working, plug the preamp out of your ceriatone into it. This will tell you which half is working or not....

+1

Also check your sheilded cable. Make sure the sheild and conductor arent shorting.
Set your controls to max then use the continuity function of your DMM to test.

[David Root]

WTF is a "Holy Grail Cap"??

[ChrisM]

WTF is a "Holy Grail Cap"??

Two Weber caps inclosed in a orange foil.

[aToneMint]

WTF is a "Holy Grail Cap"??

Two Weber caps inclosed in a orange foil.

Is this true???

If it is I have an OTS that will be getting an overhaul.

[ChrisM]

WTF is a "Holy Grail Cap"??

Two Weber caps inclosed in a orange foil.

Is this true???

If it is I have an OTS that will be getting an overhaul.

It was a joke.

[Bruciep07]

WTF is a "Holy Grail Cap"??

Two Weber caps inclosed in a orange foil.

I hate you guys, don't even mess around
I've been so concerned with all the other caps I have being fakes...

OK, here are the voltages...
V1 190 Plate1, 194 Plate2
V2 325 Plate1, 328 Plate2
V3 408 Plate1, 408 Plate2
V4 423 Plate, 32mV Cathode
V5 423 Plate, 31mV Cathode
V6 423 Plate, 31mV Cathode
V7 423 Plate, 42mV Cathode

That 42mv follows that tube BTW...

Ive gone through and checked solder joints and continuity since the first post, I haven't found anything out of the ordinary...

[Deric]

Check all your voltages cathodes included and post them...

Get the cathode voltages.... V2 and V3 plates are very high. Double check the cathode grounds for both V2 and V3.

[Bruciep07]

Check all your voltages cathodes included and post them...

Get the cathode voltages.... V2 and V3 plates are very high. Double check the cathode grounds for both V2 and V3.

OK, so cathode voltage on V2 and V3 are both WAY high, around 390V... The ground side of both cathode resistors/caps are tied together, then tied to the speaker out negative which is tied to the OT negative and effects loop jack negatives, all of which are isolated from ground because of the cliff style jacks. Stupid mistake, I didn't ground any of that ... I'll fix that in the AM, swap out the cathode caps to be safe and report back... Think I could have harmed the OT by lifting the ground? Thanks...

[67plexi]

Bruciep07, Try this, http://www.diyguitarist.com/PDF_Files/j_darr4.pdf

It will help you to know what steps to take and save you time.

B+1(plates)
B+2(screens)
V1 Triode
V1 Plate, Pin6=
V1 Cathode,pin8=
V1 Plate,pin1=
V1 Cathode,pin3=

V2 Triode
V2 Plate,pin6=
V2 Cathode,pin8=
V2 Plate,pin1=
V2 Cathode,pin3=

V3 Triode
V3 Plate,pin6=
V3 Plate,pin1=
Cathodes, pins 3,8=
V3 Grid,pin7=
V3 Grid,pin2=

Heaters voltage
Bias voltage-
B+1,B+2,B+3,B+4,B+5 voltages

Double check grounds
On preamp tubes start with V-3 and work back to V-1 when the probe contacts each pin you should hear a pop from the speaker.

Follow this order
1-Test tubes
2-Power supply
3-Components read all values, triple check wire.
4-Test cables
5-Transformers-Power,Output,Speaker.

I hope this will help.

Steve.

[Bruciep07]

Thanks Steve, that's a pretty good read... I thought I had a pretty good handle on this build, it's by far the most complex amp I've built yet. I'm hoping once I install the missing ground that I'll be in business, I figured it was something obvious that I missed. I'll find out tomorrow, my brain is spent for tonight...

[M Fowler]

WTF is a "Holy Grail Cap"??

Two Weber caps inclosed in a orange foil.

Chris I am still laughing over that one, thanks

[glasman]

WTF is a "Holy Grail Cap"??

Two Weber caps inclosed in a orange foil.

I hate you guys, don't even mess around
I've been so concerned with all the other caps I have being fakes...

OK, here are the voltages...
V1 190 Plate1, 194 Plate2
V2 325 Plate1, 328 Plate2
V3 408 Plate1, 408 Plate2
V4 423 Plate, 32mV Cathode
V5 423 Plate, 31mV Cathode
V6 423 Plate, 31mV Cathode
V7 423 Plate, 42mV Cathode

That 42mv follows that tube BTW...

Ive gone through and checked solder joints and continuity since the first post, I haven't found anything out of the ordinary...

I would check the grounds on V2 and V3, neither tube is conducting if you were measuring the plates (Pins 1 and 6). Specifically the ground on the cathode resistors of V2 and the point were the presensce cap ties to the PI tail resistor. To ground that should be 0 ohms.

Gary

Gary