Sovtek 5Y3 rectifier

[Buddha's Guitar Tech]

Anyone have any long lasting success with a 32uF filter cap off a modern 5Y3 tube? 20uF is the 'classic'.

i had a scare a while back and i'm looking for any success stories

Thanks

[Bierschinken]

Some say the Sovtek 5Y3 is a GZ34 with the wrong label - possible!

I use mine in a Champ style Circuit and the difference between the Sovtek and a NOS 5Y3 is about 20 Volts at 325V AC and about 40mA current.

If you have any concerns using a bigger loadcap, than just add another filterstage to your power supply.

22µ - 100Ohm - 22µ - Anodes

This is by far more efficient than just embigger the loadcap.

Cheers,
Swen

[FYL]

Some say the Sovtek 5Y3 is a GZ34 with the wrong label - possible!

Not exactly, it's a 5Z4M, a Russian indirectly heated recto quite close to a 6106, rebranded as a 5Y3GT.

[FYL]

Anyone have any long lasting success with a 32uF filter cap off a modern 5Y3 tube? 20uF is the 'classic'.

Up to 40 µF can be OK depending on the actual source Z and current demands, 32 µF is usually OK - but do you need it?

[Bear]

Does it spec any closer to a 5V4? In my lazy thinking, it's always been a bit closer to that than a 5Y3. Bigger market for the 5Y3, though, so what else they gonna label it?

[FYL]

Does it spec any closer to a 5V4?

The 5Z4M is quite close, but with slightly lower max ratings (for instance 375 mA max current vs. 525 mA).

[Buddha's Guitar Tech]

Up to 40 µF can be OK depending on the actual source Z and current demands, 32 µF is usually OK - but do you need it?

want to to minimise power supply hum - single ended 6V6 champ.
Not awful, but you know...

i'm sure it will work, but just wondering what happens when you crank it and play for a good while.

EDIT:

So far so good.

1 ohm resistor in series between the 5Y3out and the first cap, measured 72mVAC / 7.2mVDC - i presume then 72mA AC is the ripple current? (i know plate current is around 40mA)

That was at idle, went to a bit over 100mA cranked up almost all the way (babysteps!)

[FYL]

want to to minimise power supply hum - single ended 6V6 champ.
Not awful, but you know...

Single ended amps are class A, with a constant current drawn by the power tube(s). Using a valve is inefficient and doesn't bring any sonic benefits. Try a solid state recto, then you can add real stiff filtering and nearly totally curb the hum.

[Buddha's Guitar Tech]

Single ended amps are class A, with a constant current drawn by the power tube(s). Using a valve is inefficient and doesn't bring any sonic benefits. Try a solid state recto, then you can add real stiff filtering and nearly totally curb the hum.

i like the idea, and i do have SS diodes in there to experiment with.

but they give off too much voltage, which leads to too much current in the tube. i could put a larger cathode resistor in, but then plate and screen voltage go up again. (over 400VDC with SS rectos)

(having said that, i could experiment with different power supply configs... who knows)

i COULD use a different PT but screw that. This champ sounds better than my store-bought Champ-600, so i'm happy so far.
And the 32+32 gives me noticeably better filtering than the 22+22, so as long as it holds, i am happy happy happy

[FYL]

but they give off too much voltage, which leads to too much current in the tube.

You may play with a CLC (cap - choke - cap) first section, that'll bring a ruler flat DC response. The choke R will lower B+ and you'll be able to fine tune voltages by playing with the first cap value (you may do some nice sims using Duncan's PSU Designer II).

[Bierschinken]

As I´ve already said; add another filterstage!

5Y3 - 22µ - 100R - 22µ - 1k - 22µ - 10k - 22µ

6V6 connected to the second cap.
General Voltage is dropped by roughly 4Volts; hum is reduced by more than a half!

If you have a choke, you can use it instead of the 100Ohm resistor.
That will decrease hum too, or embigger the second cap conntected to the 6V6.

Cheers,
Swen

[Buddha's Guitar Tech]

May have to experiment, thanks.