Ceriatone Forum

Nothing.  ???

Ok the light came on and the tubes have power to them, but no sound came out.

My first thought is the pre-amp tubes I have are pretty old and I'm not 100% certain they actually work at least up to full power. All of the pre-amp tubes barely get warm; I can actually touch them and there are warm, but not hot and this is after about 5 minutes of being on.

I'm going to pull those tubes and put them in another amp I built that I know works. As I said they are old - they are mullards that I pulled out of some sort of old amp years ago (amp is long gone).

Any other thoughts?

This is the amp which worked before, right?

Measure the voltages just to make sure everything is fine under the hood.
If you send some signal into your RETURN input... any sound from your power amp?

Check your voltages against this chart then you can rule out that as being a problem

This is a new built amp so it has not worked before.

I need to find a thread that instructs how to read the voltages and then I'll compare them. I'll be investigating later this evening after work.

FYI: I did put tubes in that I know work and I can see these glow.

Ok I just checked the voltages and this is where the trouble is. Oh by the way this is the first time I've ever checked voltages.


       Pin 1       Pin 3         Pin 6     Pin 8
V1:  7.38         0.1             009.     0
V2:  30.8         .24              35.      .2
V3:  263          52.1           254      51.6


                      Pin 3     Pin4     Pin5     Pin6     Pin 8
V4:                 455      452      -43.3    -1         21.6
V5:                 453      452      -43.2    -1          22.7

The power tubes are TAD 6L6 WGC

I had to adjust my multimeter between V1, V2, and V3 on Pins 1,2,3 between VDC 20, 200, and 1000: V1 only read on 20, V2 would only read on 200 setting and V3 I used the 1000 setting.

Also when checking V3 I did hear crackling from the speaker.

I know there are problems now how to fix them.

Ok, so its clear that the problem is between the phaseinverter V3 and V1+V2.

Check your power dropping string 'point L' and 'Point M' on the Ceriatone schematic, to see if the problem is in the PSU, somewhere.
Also check very carefully, that you have wired V1 and V2 correctly.

I will check those.

Let me make sure I'm taking a reading correctly. I put my multimeter on ACV 200 and place the black to ground and the read on the 120v connection from the PT to the on/off switch and I get a reading of 1.2

Yet when I do the same thing on the connection from the PT to the rectifier board it reads 50 (multimeter at the same setting). Does that sound right?

I'm sure I understand what you mean. You want to measure the AC voltage to/from the transformer??

Please remember that you are dealing with lethal voltages inside a tube amp. Leave it alone if you feel insecure and take it to a qualified technicial!!

Remember that after you get past the recifier you are measuring DC volts, though I guess you must have got your multimeter set right to get the 450 B+ on V4 and V5.

You should be seeing around 200volts DC on V1 and V2, if not then your wiring is amiss somehwere.

Yes I wanted to measure the AC voltage from the transformer. I was confused about the labeling on the PT because it was different from the wire diagram; there is another post about this showing pics of the PT label.

EDIT: Here a link to that post http://ceriatoneforum.com/index.php?topic=1267.0 (http://ceriatoneforum.com/index.php?topic=1267.0)