Ceriatone Forum

It has been awhile since I posted here. I am hoping one of you can steer me in the right direction. My Power tranny fried on the low voltage winding....brown wire. This is the second tranny I have put in it. I doubt it would be covered by any warranty so I have to buy a new one and not necessarily one from ceriatone. I cant't believe it happened again but it did..any suggestions on a tranny for this amp are appreciated.  ??? ???

I don't think you will be able find a drop-in replacement. The Ceriatone tranny has a winding for the 12vdc supply for the relays and the voltages are slightly different that most stock power transformers. I think the only choice is either to have some one custom wind a transformer or use a separate tranny for the relays and use a standard tranny for a Twin or similar Fender. You may have to adjust some resistors to get the same voltages. Honestly, I would contact Nik about a new one and explain your situation. But I wonder about a few things?

Was the second tranny a Ceriatone tranny?
When you say "brown"wire, which are you referring? (voltage wise) Just to be sure we're talking about the same thing.
Is this the same failure spot of the first tranny?
If so, it may be a good idea to check a little deeper into things to see if there's something in particular stressing the tranny.

Thanks SoundPerf
It's the low voltage wires 3.15b volts. I don't remember what happened last I replaced it. But I will take your advice it may be something else causing this so to a tech it goes. Just for information I will post what he finds. I will get a hold of Nik if there is a problem getting a tranny.
t/u
Burnie

Hmm, those are your filament/heater leads. It's hard to say for sure. They are carrying AC directly to the tubes and wouldn't be an unusual failure zone. Yeah, talk to Nik and a Tech for sure and yes, let us know. If this was the second time for the filament secondary I would be suspect.

Are you using anything unusual as far as tubes?

Yeah the heater/filament secondary may be low voltage, but its high current.  Tubes draw a lot of current, if that secondary burned out, the tubes may be drawing more current than spec'ed.

You are using stock tubes? And not substituting EL34's, 6CA7's or KT66's for the 6L6GC's? Which brand 6L6GC's? No preamp tube substitutions?

This is also a common secondary for a short-circuit to fry a PT, especially somewhere overlooked like the lamp wiring.

Mercury Makes a Drop in replacement for the OTS Series. It's a lil pricey, though.

Ive used a fender bandmaster tranny on a  couple with no issues?

Although pricey, Mercury Magnetics has the best warranty, something like 10 years I think.

Might be worth the extra $$.

Worth extra? No.

That's like paying extra for an extended warranty, something that has become a litmus tastes for saps.

It's ten years against defects that 99% of the time show up within the first few months, after most transformers last for 40+ years.  That's not a bad deal, but not worth extra money.

However, in this case, because of IC secondaries, pickin's is slim, and MM is viable option.

But my guess is, after burning out two PT's, the issue is elsewhere.

@ wyatt I agree. sounds like there is a short somewhere. Maybe a bad solder job shorting out on one or more of the tube sockets, maybe a bad ground on the center tap, or like you said, in the pilot light wiring. Could also be shorting if there was a bad solder on the little junction post just south of the tranny where the taps run into the heater and pilot wires. Could also be a tube shorting out intermittently.

@Burnie  Did the HT fuse ever blow? Did you pilot light ever flicker or did you get any scratchy popping sounds while the amp was playing?

It does kinda suck that there are limited options as far as replacement trannys go. I often thought if i ever had to replace it i would either get one from Nik (most preferable), or if time was an issue, get one from hammond that had all the required taps with rthe equired current except the 6 volt for the relays and then mount a seperate 6 volt tranny also from hammond, rather than get the overpriced mercury. that's how i feel about mercury.

i've often thought about asking Nik if 5 volts is enough for the relays to work properly too as you can usually get a tranny with 345-0-345, 3.15-0-3.15, 60-0, and 5-0, the 5  which would be used for a tube rectifier. 5 volts prolly isn't enough, though, unfortunately.


Gregg

I ordered my OTS kit without transformers. I will be using a Hammond 291DEX PT, and Nik said it'd be fine to use the 5v tap for the relays. The Hammond isn't a drop in replacement though (nor are the Hammond choke and OT that I'll be using), so I had to drill new mounting holes.

I was able to get the transformers for my bluesmaster directly from MM at wholesale through Nik - he's a dealer - you paypal him the cost, and he sets it up so MM sends you the transformers. Got them for a great price that way! Although it does sound like you need to find the problem first.

There was a loose connection found at on off light, I was running el34's at a hot bias, I pulled the effects loop cables out with it on standby. It could have been anyone of those causes with a combination of 1 or more or it could have been something I am not seeing. I replaced it again and would have used a mercury magnetics tranny if I had thought of that. I didn't know he had a drop in replacement. The tech, who broke my faceplate at that on/off light and told me to get a new one and he would install it for free..how nicer of him ha ha, last time I take anything to him, put a fuse on the low voltage lead on the tranny so I won't have this problem again I hope..I feel cursed. I just posted this to let you all know what happened..I take responsibility, I am sure I did something wrong :)

Ive since found that there are other transformers but I have already put in the stock one. I wanted to say thanks to all of you. I have another topic (overtone) and my on going quest to get the sound right. So thank you I really appreciate the input.

There is one more possible cause for failure of OT and that is my ohm setting which I had on eight and my speaker, A G12-65 which is 15 ohms ooops. My understanding now is that I can set selector at say 16 ohms for an 8 ohm speaker but I shouldn't go the other way and set an 8 ohm at 4, or a 16 ohm at 8. There is no point in doing this, that I know of. I have no idea why I set the amp at 8 ohms for a 15 ohm speaker but it is the wrong thing to do. So like I said my bad..operator abuse.