Ceriatone Forum

I guess I'll repost what I have done again since my last post is mia

I've have no sound
v1 pin1=193 pin3=1.8 pin6=202 pin8=1.7
v2 pin1=200 pin3=1.9 pin6=207 pin8=1.8
v3 pin1=301 pin3=60  pin6=301 pin8=60
v4 pin3=463 pin4=461 pin5=54 pin6=463 pin8=.039
v5 pin3=463 pin4=462 pin5=54 pin6=463 pin8=.027

I have sound when I plug into power amp in
I have sound when checking volts on v3
I've checked and double checked input wiring and solder joint
all wiring is correct on v1,2 and 3
all solder joints on v1,2 and 3 are nice and shiny
I.ve swapped v1,2 and 3 with 6 different 12ax7 tubes
I have no sound at all even with overdrive section cranked
I've tried to upload pics but everytime I do the thread becomes unreadable
So what would the next step be?
I was asked to check ground on 05 cap on the - side but the cap does not have + or - signs on it. That was one of the pics I was trying to upload
I get a reading from both sides of the cap but I don't see where it would be grounded
thanks for any help

Tim

Hi Tim,

My suggestion was not the check ground on the 05 cap, but instead to check if the cathode resistors (2.2) and caps (5 uF) were grounded. however, judging by your new V1 and V2 pin8 voltages of 1.7 and 1.8 volts. It now looks like the cathodes are grounded, so forget about that.  ;)

Just to make sure the signal is ok......can you hear the noise level (in the speakers) go up, when you engage the OD? From your description above, I would guess you can.

My suspicion is the wiring of the input jack socket, which can be a little tricky, with various connectors and all. For testing purposes, you could try to solder another (simpler) jack socket with a piece of shielded cable direct to pin2 on V1 and ground. Obviously, if that works, your chassis mounted jacksocket is wired wrong.  8)

Yes those pesky input connectors are a bit fiddly - I would double check them.

Hey perhaps one of relays is turned the other way around.  ;D

Or try a line level source into FX return socket.

He said...
So I guess his power section is fine...

Thanks for the replies guys

I have no noise level at all even with volumes cranked and od engaged there is nothing
I do get a audible click or pop when I flick the standby switch on
I will try and hook up a jack to pin 2 and see if that works

I've checked and they are in the correct way
Thanks

Don't talk to me about relays  :D

Ok, hooked up a jack from tip to pin 2 and sleeve to ground and still got nothing, no sound what so ever
so i guess it's not the input jacks
it's kinda fun tracking this down
wish I knew what I was doing
so what do I do next?

Hi Tim,

This is not an HRM right? I know the amp is a bit different than the HRM, but I did a video including the problems I had. It might not actually tell you what your problem is, but you might get some pointers from the stuff I had videod at the time.

My problems revolved around basically the extra little boards (not the main boards). Nik talked about those extra boards being very picky about how much solder to use - too much and they form balls of solder which he said could distort the boards if overtightened and had caused trouble before. Funny thing was, that although my problem appeared to relate to one channel, it was actually there on everything - and when the output 'went off' it became VERY hard to find.

I checked all the connections on all those boards - in my case it did not make a difference, but Nik was very specific about that. All the same, I would check for too much solder, because he was so specific about that problem and the aggrevation it had caused before. Also slack off the non main boards from being too tight and see if the thing works.

Remember its not always wired wrong. In my build I did not have a single wire in the wrong place...

Nik also referred to bad dressing of cables - check that too.

My Power amp also worked perfectly - and I could even drive it with a pedal....  perfect - but the preamp was not.

Check whether this problem is pre-amp or power amp related by pluging a line level input to the FX loop return, this will divide the problem by 2, no output then the problem is topside of your FX return jack, full output then it is the preamp.

Dressing of cables correctly wired will only affect the tone of the output not the existence of output. This is a logical circuit so follow it religiously, checking every wire for correct location and connection. I would recommend an A3 print of the layout and a highlighter pen after each wire is installed. The presence of correct voltages on the test points will tell you whether you have half the circuit right, no output will tell you that your signal circuit is broken or you have a bad valve. Nik will send you a voltage chart that will give you a good starting point for checking, get the voltages right and you are almost there. I think you can safely assume that Niks circuit boards are good until proven otherwise.

Thanks hywelg
I have sound from the power amp input but not from the front inputs
I have emailed Nik for a voltage chart and hopfully you guys can guide me thru the process
Thanks

Tim

Just a quick thought - Could it be a fault with the send/return jacks??
try connecting the two with a jack patch cable

Ok I tried that and still nothing
on the voltage chart v4 and v5 pin1 shows 37 volts
mine are .026v and .039v
the rest are pretty close
would that be the set of (supposedly) matched tubes I bought off fleabay?
And what does HT stand for and where do I measure that?

Since, you have signal from the 'return' jack to speaker, don't waste your time on power tubes and the phase inverter  (v3 + V4 and V5) just yet.
So my suggestion would be to focus on the circuit from input jack to 'send' jack and nothing else.

I agree,...
it looks like you should focus on V1 wiring.
Can you post some photos?

BTW can you hear relays clicking when you flip that switch?

Did you try if PAB works or jazz setting perhaps?

Just to cover all bases.

I'll try and post pics in a new thread so it doesn't kill this one

Yes I can hear the relays clicking and yes I have tried all the settings and nothing
I'm trying to post some pics but it won't let me

Ok thanks, I will try and figure out the path on the layout if I can

Hi Tonym
Just watching your video's,in video #44 you mention the ground wiring is wrong
I have wired it just as it looks on the layout with the ground wire from the tip of the jack
is this wrong?
the ots is a bit different than the hrm and I don't quite understand what you mean
Do I have both jacks wired in reverse or just the ground wire?
Can you have a look at the layout for the ots and let me know?
Thanks

Hi Tim,

what I really meant was that if you look at the layout on the ceriatone website for the HRM, it can be interpreted two ways, looking at the back, or looking at the front of the jacks. I remember it was a bit weird at the time. If you watch further I think I said, ok thats right.. it  was just confusing to see the tip appearing to go to ground.

I removed both inputs from the chassis and checked them against the diagram where I could easily see and fix them.

I have copied what I did in a more viewable pic.

see attached

Ok thanks
I got it right then

Ok guy's I tried everything
Spent all day going over solder joints and checking wiring and still nothing
I did a continuity test from the tip of a chord in the input to ground just out of curiosity and it is continuous
Is this correct or do I have it wired wrong?
I have it wired just as it looks in the layout
All my voltages are good
so now I'm stumped
What would be the next step?

I think you might have wired your relay switches incorrectly.

Compare yours with this http://www.ceriatone.com/images/completeAmpsPic/Overtone_100/b18B.jpg
 (http://www.ceriatone.com/images/completeAmpsPic/Overtone_100/b18B.jpg)

Can you have a look at the layout and confirm the the photo you showed is correct?
It doesn't make sense to me
Maybe there is some kind of mod on this amp?

It appears thepwebsite photos don't match the layout. I've checked my layout and I built to an earlier version which is the same as the photos so I guess he didn't update the website photos when he changed the layout.

It seems yours is correct to the layout.

Ok I unhooked two wires from the relay board and one from the star ground so I could have a look underneath the main board to see if there was a problem underneath
I found nothing wrong so I hooked everything back up
Now when I hit the power switch I get a low hum and v5 is red plating
What would cause this?
All wires were reconnected to there proper places

a wrong bias setting (the Powertubes should read anything from 29mv - 35 mv)
and/ or a bad output tube.

Do you still have signal from the 'power amp in' jack?

Found it, I pinched a wire between the standoff and mainboard
I built listening probe
(a pair of aligator clips, a 1/4" jack, a .047uF/400V (or more) cap and some wire. You connect a wire from an aligator clip to the ground connection on the jack, the cap to the other clip and the other side of the cap to the hot lead on the jack.)
then hooked that jack via 1/4" cable to another amp
Plugged in a tone generator to the OTS input and tried to trace the sound
but I could not get a signal from the tip of the input jack on the OTS
The listening probe worked fine when the tone generator was hooked directly to the aligator clips but not thru the input jack of the OTS
sssoooo unless I've wired the input jacks wrong which I've checked several times and even rewired again there must be a short to ground on the inputs
Is this correct?
I'm just guessing......remember I'm a newbie

Tim

Yes, with not jack plug connected to the input, the input jack (22k into V1a, pin2) is shorted to ground.

Whats the current status ?? is the amp operational ?

Sorry just got back from a ZZTop concert
No the amp has no sound as of yet
Nik say's that the input is wired correctly
so I'm stumped

Time to take it to a tech?

+1

+1 from me as well

However, I have one small suggestion you could try.

For testing purpose, as per the attached picture, solder a wire direct from V1 out to the power amp in. This way you will find out if the problems are related to the relays or send/return jacks. Just an idea.

closest amp tech is probably 300 miles from where I live
I've been talking to Nik and he asked if the tip of the input jack was shorted to ground
With a 1/4 inch cable inserted I have continuity to the chassis

Solder an alternative jack direct to pin 2 on V1 (and disconnect the existing input wire)

If this doesn't work, use the 'yellow wire' mod I've pictured above.

Well I feel kinda dumb
I have all the wires that are spliced into the shielded wire hooked up to the main conductor wire instead of the shielding
I'll redo them after work and let you know how it goes

Ok
Fixed all the wires and we had sound
Played it for about ten minutes and it just quit suddenly
all the voltages are good and the bias
Any ideas?

What wires??

From the post above

"Well I feel kinda dumb
I have all the wires that are spliced into the shielded wire hooked up to the main conductor wire instead of the shielding
I'll redo them after work and let you know how it goes"

It was working good , all the switches and pots did what they were supposed to
It did have an ac hum that wasn't that bad, not sure if it is from this old building I live in or wire placement
Fuses are good, all the voltages are good
it just quit working
I used to get a small click or pop when I turned the standby switch on but now I get nothing

blown fuse?

Fuses are good
Here's something I noticed
When I turn up the ratio and level I can here an ac hum coming from inside the chassis
sounds like it's coming from the pots themselves but I'm not sure
and when I touch one of the output tubes it get louder

Check your socket wiring, what about all the checks you made initially have you redone them? ie line level in at FX loop, FX loop out to another amp, bias still OK etc. trouble shooting is just a matter of being thoroughly methodical and breaking the testing down into bits to eliminate various possibilities.

I'd hesitate to suggest it but consider chopsticking various signal path connections, based on your results from the fx loop tests above. If you don't know what I mean then you probably shouldn't do it, it is dangerous.

figured out what the problem is
the new speaker cabinet I had made has a faulty jack
Replaced it with a new one and away she went
I'd like to thank everybody for all your help
bluesfendermanblues, hywelg Nik and everyone else
I couldn't have done it without you guy's

The amp sounds awesome
gonna let it burn in now

Thanks so much

Tim

 :)