Yet another Priboi thread...

[Wavebourn]

Originally Posted by tchiwam

Interesting, could he expand a bit on the setup ? It is true that the GU-19 are really quality made tubes, ceramic insulators around each leg etc etc and they look good. They work as is in a Priboi at -15VDC but I know I need to adjust more than that. I now have the OPT values...

Some people use them as is, some use 4 Ohm tap for 8 Ohm. What is really needed, some heatsinks on anode pins.

Oеhers prefer GU-29.

Also, I know about triode connected GU-50 used there.

[tchiwam]

Originally Posted by Wavebourn

Some people use them as is, some use 4 Ohm tap for 8 Ohm. What is really needed, some heatsinks on anode pins.

Oеhers prefer GU-29.

Also, I know about triode connected GU-50 used there.

110W in those transformers, lets assume they are the same as in the 75W version, that is still a lot more than designed for. I know Russians didn't have a shortage of copper but I still don't want to grill them.

And yes these are quite low impedence transformers for the output...

[Zen Mod]

Originally Posted by Wavebourn

.......

Also, I know about triode connected GU-50 used there.

yes , your fave .....

mind to share your schematic of Priboi with ГУ-50 ?

[Wavebourn]

Originally Posted by Zen Mod

yes , your fave .....

mind to share your schematic of Priboi with ГУ-50 ?

It was not me; it was Sergey Sergeev, from Irkutsk, Siberia



Sergeev's site about Priboy modifications

[Zen Mod]

tnx W.

[Wavebourn]

Originally Posted by Zen Mod

tnx W.

You are W., but he got 25W from it only in triode mode!

I would use, of course, in pentode mode with parallel feedbacks around output tubes. Or, stick with GU-19 or GU-29. GI-30 is another option, it is GU-29 with higher cathode emission. The story is, after new equipment was designed for Hall of Congress in USSR, around GU-19 and GU-29 tubes, then Minister got an order to design civil version of the tube. 6R3S-1 was born as the result, birth defected.

[soundbrigade]

Originally Posted by Wavebourn

Let's agree to disagree. I can make a nice amp from Priboy using EL34 tubes.

This old discussion has been mostly about replcement tubes in the Priboi amp, like the GU-19.
I have a few questions that is too related to this thread to require a new thread.
Under my bed, I have stored my Priboi (in good company with a Dynaco PAS3 and some hundred tubes - I sleep good at night ). Many years ago I modified it to Likhnitsky's schematic, but as I have ended up with loads of amp projects around or below 10W I started to consider do a new remake, getting som more watts from it.
So, IF I am to switch to other tubes, what tubes can be used? Likhnitsky mentioned that he had tried EL34 with good result before redesigning.
And what's the maximum power that the components (power transformer + OP transformers can provide)?
I have been thinking of EL34 or 6L6, or even parallell 6L6, but I also have a pair of EL156 and KT120 - could these be used? Or is maybe KT88 or KT90/KT100 a better choice?

There was a Priboi-UM75 with 6R3S in parallell, that, according to the name was capable of 75W/channel, but I dunno if there were other and heavier transformers for that model.