I gave you a clear description how it's working. Your assumption is wrong. Start tracing the circuit and let me know where you are wrong or where I'm wrong...

Fabulous; start studiyng your stuff again.
Bias is the amount of current regulated through the power tubes. In this design it regulates the current for 2 or 4 tubes , not to balance them. You have to use a matched set of power tubes.

The pot for the phase inverter tube balances the signal between the 2 triodes which are sending their signal to their respective sides of the power tubes

The EVM12L is a completely different speaker. It has way more highs and less low end compared to the G12-65.
F.e. cleans with EVM12L has a different tonal pallette; it's like playing a completely different amp.

Hi Riverman; If your amp is after summer 2008 I won't bother. If it's before check: http://ceriatoneforum.com/index.php?topic=981.0

You now have a tuned racecar amp...

HI Marin,

Hope you're doing well with your recovery. That was a nasty drop you made.

Excellent explained vid. Even for noobs about this amp it will sure help to get a good picture.

One note: Maybe you can try setting your IN control on the Clator to the max. The compression varies than more with the pick attack and the tone becomes rounder. In addition you can set up your amp brighter if that's your taste.

Greetz Erwin

Hi Nik,

The parts on your OTS kit are overall good.

However you should take a look at your electrolytics. They were all off spec in my OTS. F.e; One 4,7uF electrolytic holy grail cap was measured 2,8 uF! For a cathode bypass cap that's very bad.

The OT in my OTS(may2008) was dark sounding. A MM was much better, however: I did some mods on several Ceriatone OTS  and noticed that later production OTS have other OT's?  The Ot's for the OTS from summer 2008 till now are good sounding OT's they can hold up easily with the MM's.

One other thing to mention for building the OTS: keep the grid, cathode and plate wires away from the heater wires. It kills tone. I mentioned it before but modding several OTS I keep seeing this wrong wiring.


Hope this helps,

Greetz Erwin

Try raising the value of the 3K3 resistor to 3K9. Raising the value of that resistor drops the voltage for your pre amp tubes.

When using a wire stripper for the braided shield; only do the cut and move it up so there is a small part uncovered. That's were the teflon wire is soldered. Then put a small piece of heatshrink to cover it.
Added is a picture without the heatshrink added.

I always work with both schematic and layout. With a schematic it's easy to check if the wiring is correct and understand/ calculate in case you want to debug or mod.

Attached is a schematic; some values are probably different from Ceriatone. Also the relay for OD switching might be a little different.

Hi Steven, Setting you fx to the max reduces noise. (it's minor)
The available signal level has effect on the recovery side of the dumblelator.

Because there is a Local Negative Feedback(LNFB) circuit. It's acting a bit like a compressor but only with a high frequency roll-off. The high level signal peaks will roll off highs. With low signals the effect of the LNFB is minor.

So; With a pick attack the signal enters the LNFB and will roll-off highs, when a signal is decaying the highs will become more prominent because the the LNFB isn't working much.

That's why signal levels matter and also the middle knob of your dumblelator is part of that.

Hope this will help, I tried to xplain it as non-technical as possible

The outer foil is marked because it can be used as a shield against electric field coupling into the capacitor.
It looks like this: plate voltage-->>cap(outer foil-->other side;inner foil)-->>to next gain stage.

When done the right way your amp can be considerably more quiet.

For further info on this subject visit: http://www.aikenamps.com/OutsideFoil.htm

Hi ToneQuest:

I think I use these: http://www.tubeampdoctor.com/product_info.php?cPath=21_60_63&products_id=390

I don't care what the recomendations are; they are v1 and PI in my OTS and fender amps.

The OTS doesn't have a cathode follower at v2. For other amps; I never tried them in a cathode follower/recovery triode setup.

Don't mind the sales pitches on the TAD website.
Only thing I noticed they don't draw much current so the plate voltage is higher in comparison to a JJ ECC83.

Yes I do; 7025 high grade selected, one of the best new production tubes around!

You can also go with a normal OTS and evm12l speakers. EVM12l is the way to go for cleans IMO. I tried; G12-65, Emenince RWB,Celestion v30 and EVM12L.