PS Transformer find: OK or not?

[Guitarist]

Basically, to run a small amp or perhaps bigger. Would these run a 3 tube preamp and a pair of KT88s or, ok, smaller output tubes?

I was from the Antek website: http://www.antekinc.com/trans.html

Sure would be nice to lighten things up a bit and have less hum. Less interact ion with a MM OT.

They might have a preamp only transformer as well.

[tubeswell]

These PTs are Transistor amp type trannies. They aren't powerful enough for a tube amp.

Tube Amps PTs have a different secondary windings from these - a High-voltage (280VAC to 350VAC is common) winding that is center-tapped, and a 6V heater winding, and if you want tube rectification, they also need a 5V (or 6V, depending on the type of rectifier tube) recto winding. The high voltage specs usually mean that they need to be made out of something more substantial than plastic.

[Guitarist]

Yes, i hear what you're saying. It seems the centre tap may be the #1 issue. But, the full wave bridge's -'ve should be fine, no? I just referenced an Ampeg V4 schematic and it has no center tap. The B+ voltages are low but might be high enough for a Blue Angel brown sounding output. I don't want a 540 Volt supply but 300-400 would rock well enough, if the current capacities are present.

One can happily avoid a tube rectifier. It seems that the filament windings look adequate though. Send the 6 Volts to the outputs and the 12'vs to the preamps.

These toroids are popping up in a few amps these days: Traynor, Ibanez, Laney. Thus if I'm going to buy an OT I'd lean that way BUT a beefy unit is a must, hence the post. Also, if you saw my hum inducing wiring mayhem...!

It it appreciated that you as a senior poster offer your comment, thanks. Next model up maybe?

[Albert Kreuzer]

Should work according to the specs. Just as you said, a full wave bridge will put you in the 400V range (HV secondaries in series). 6.3V/3A is fine for a pair of EL34 or 6L6, a bit narrow for KT88 (1.6A each).

Cheers,
Albert
www.albertkreuzer.com

[Enzo]

I agree, it should work that way.

Toroids are showing up all over. yes, but they are not all alike. The ones you see in guitar amps were made directly for that purpose.

if you saw my hum inducing wiring

You realize, I hope, that the transformer itself will have zero effect on the hum from wiring. 6VAC is 6VAC, and when it flows through wires in the amp chassis, it has no idea what transformer put it there.

[Guitarist]

Thanks gents,

I'm sort of hoping that under load that 400V will strain down to 385 Volts so as to use those cool JJ filter caps : http://www.newsensor.com/ProductHigh...aspx?ProId=784

and just one of them for once- meaning, without two in series to ensure adequate Voltage handling.

(meanwhile back at the ranch/edit)
I just got off the phone with John and these units are freakin only $29 and have 120% rating. $10 shipping. They can also add custom tweaks to the units. Man, a bias tap would be sweet. The guy knows tube amps as he used to repair them over his 50 years.

It will be nice installing these things, drilling only one hole and mounting it plain anywhere.

Albert, if one did be tempted to use those KT88s and the voltage dropped a bit, is that a deal-breaking issue? The PT looks fairly robust. A guy could go with the "200" transformer, the next unit up from the catalogue, but then we're in V8 territory again. Also, the amps are the same anyways. Actually, I plan on designing for individual bias to encourage tube mismatching.
That is bringing in the idea to blend the two side (PI) so as, if using a KT88 and a 5881 for example, that the levels a match. Kind of a quasi-crossover-fader. AND that solves the "thin current" scenario. Yay!

Albert, you're quite the musician over there in Deutchland, sehr gutt. Ich kann ein bissien deutch gesprechen Du bist der jazz konig.

Enzo, you've helped me out so many times man, thanks.

[Albert Kreuzer]

Originally Posted by Guitarist

Thanks gents,

I'm sort of hoping that under load that 400V will strain down to 385 Volts so as to use those cool JJ filter caps : http://www.newsensor.com/ProductHigh...aspx?ProId=784

and just one of them for once- meaning, without two in series to ensure adequate Voltage handling.

Maybe not such a good idea. What if you have to test the amp without tubes? You don't need 550µF anway - 50 or 100 @ 450V will be enough.

Originally Posted by Guitarist

Albert, if one did be tempted to use those KT88s and the voltage dropped a bit, is that a deal-breaking issue? The PT looks fairly robust.

You'll probably be OK with that, as you plan to go with three preamp tubes (.45A@12V), so you won't exceed the total power rating.

Originally Posted by Guitarist

Albert, you're quite the musician over there in Deutchland, sehr gutt. Ich kann ein bissien deutch gesprechen Du bist der jazz konig.

Oh, vielen Dank
Actually, I'm in Austria, which is not quite the same

Cheers,
Albert
www.albertkreuzer.com

[tubeswell]

Originally Posted by Guitarist

It it appreciated that you as a senior poster offer your comment, thanks. Next model up maybe?

Oops sorry! lazy me - I looked at the link instead of at your attachement and then I only looked at a couple of trannies at the top of the table and couldn't see anything remotely powerful enough - didn't look properly - my bad

[Satamax]

http://www.amplimo.nl/index.html?lan...arget=d19.html