Ceriatone Forum

Hello to all. I am having some issues with my 183 build and any help would be greatly appreciated. I am getting some sound out of the amp, but it is very week and sounds like a bad fuzz pedal. I have done the usual checking tubes, and making sure inputs are wired correctly. Have gone through the layout and wiring several times. I plugged a cord in the power amp input, and I am getting a good signal from that.
Here are my voltage readings.
B+ around 458
V1 and V2 high voltage-198v, grids pin 2&7 is 0v, cathodes 1.8v
V3 pin 1 and 6 300v, pins 2 & 7 38v,  and pins 3 & 8 62v
I am assuming my problem is in the preamp section.
I can get more info if needed. Any ideas from the above information?
Thanks to all in advance.

Is your clean ch working OK?

Have you tried replacing V1,V2 tubes?

The clean channel is doing the same thing. I have changed the tubes also. Do the voltages look to be good?

Voltages look OK to me...

I would say you have a fault at V1, maybe tone stack, maybe input if your power section works fine.
Can you post some pictures?

Yes I will get some pics up asap. I went back and did some checking, and I now have the normal channel working. I think it was a grounding issue, but now I do not have an overdrive channel. Again, I am getting some signal, but it is very very weak, and extremely distorted. Just to make sure, I went through all the preamp tubes again, and made sure they were all good. So now where do I start to troublehsoot? Pics coming

So V1 is fine, troubleshooting V2 should be even easier...

Let's assume all resistor and caps are fine... I would say you have a wiring issue. Check everything again.... maybe you have a cold solder somewhere. At least you could re-solder all V2 connections.

Cool. I think I will start there and see what I get. Thanks so much so far with the help. It is greatly appreciated. By the way, I have been checking out your builds, and they are extremely well done!!

Here are the pics of the amp. Not the order I wanted but oh well.. I know I am missing something stupid.
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183011.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183011.jpg)
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183009.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183009.jpg)
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183006.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183006.jpg)
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183003.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183003.jpg)
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183002.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183002.jpg)
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183004.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183004.jpg)
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183005.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183005.jpg)
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183012.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183012.jpg)
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183009-1.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183009-1.jpg)
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183008.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183008.jpg)
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183007.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183007.jpg)
(http://i91.photobucket.com/albums/k320/kadswan/dumble/th_dumble183001.jpg) (http://s91.photobucket.com/albums/k320/kadswan/dumble/?action=view&current=dumble183001.jpg)

Can't spot anything from here but just one thing you can check. 100K pre OD pot... check if it's touching chassis... usually there is very tight fit and if you're not careful you can have a short there.
If I were you, I would use my multimeter in continuity mode and check everything for shorts.

Check your cathode resistors at the phase inverter. Those voltages at the v3  grids and cathode are too high.

Real 183 had 59V on V3 cathode side... that's not to far from what Ken has.

I don't think he has a problem with PI section.... after all Clean CH  works fine for him.

Yeah you're right my bad.. To the OP; Check your wiring for the od trim pot on the back.  measure in Ohms. Sometimes when heated too much, the insulation of the shielded wire is touching the leads.
It is also good to go through the whole schematic and measure each connection. Work yourself from relay Od input to PI input.

Well I checked all the conections and solder joints with the MM in continuity mode, and all seem to be good. I'm thinking maybe the problem might be in the overdrive relays, or the voltage regulator. Like a dummy a broke a pin off of one of the relays, when I was checking the conections, so can't do anything until I get that replaced. I'll report back, and again thanks for the help so far, and keep it coming if you think of anything. Cheers

Here is the update :(. I basically spent the whole weekend going through the circuit, again checking all the voltages, and continuety. Everything is coming up as it should. I rewired V2 just to make sure all the connections were good, and also checked the relay boards to make sure I am getting 12 volts to both of them. I purchased a new relay for the overdrive board, installed it, fired it up and I am getting the same thing. The normal channel works great, barely any output from the overdrive channel unless it is cranked up. By the way, the PAB is working, so it has to be in the overdrive relay board. I moved the relay on the board with a chopstick, while it was in overdrive mode and I got a very loud pop, and then it blew the small 4amp fuse. The 1A fuse is still in tact. I'm beating my head against the wall, any ideas?Could the socket for the relay on the relay board be bad? I checked all my connections on top, and underneath on that board, and all seem to be good. I even reflowed the solder joints on it.

have you checked the wiring on the override switches on the back of the amp? they could be inadvertently wired incorrectly or shorted. also are both switches in the right position?


Gregg

I thought I did, but I could have missed something. I will check that again. Yes both switches are down in the pedal mode.

Also try without pedal in manual mode.... just to be sure it's the amp and not the pedal.

The amp is finally up and running ;D. Once again, thanks to all of you who took the time to help me out on this project. After nearly rebuilding the whole amp, I plugged the guitar in it, and started to check connections with a chopstick. Turns out that the overdrive relay wasn't making a good connection with the socket. When I would push on the relay the amp came on in overdrive, and when I let off of it the sound would dissapear. I am going to put it back together, and retension the socket for the relay. Thanks again for all the help and support. You guys are a great bunch.
Cheers!!

One final comment. I emailed Nik and he gave me a great little tip, that I thought I would pass along, so no one else goes through the same frustration I did. He said that they cable tie the relays right to the board, then mount them to the chassis. Seems simple, and academic, but it works like a champ. I have been playing the amp for a good two hours with no glitches. ;D ;D

Very cool!!! glad you got 'er goin!!!

Gregg

Good to hear that... normally these things are something stupid... and as such hard to detect. Take it as a great learning experience as now after all this activities you know more about amps don't you.

So it like... tanks God for this, as it made me better.
 ;D

amen :)