vacuum tubes type 10 and UX201A

[mos57]

Hi, see the attached files for informations:

201 and 301 are pretty the same, i remember

Francesco

[mos57]

The datasheet for the original 00 and 01 tubes:

Francesco.

[andyjevans]

I have been building with 10 and 01A for a while. These are two great tubes - in the top ten with 26, 300b, 2a3 etc.

10 makes a great preamp tube, and doesn't need to be run full on to sound good - it sounds good even with 5ma through it. It is a full rich sound, very dynamic. It is also a GREAT driver tube - maybe even the best. If I had two (well, I have about 60) I'd use them as a driver for a SE 300b amp. And then use the 01A as the input tube. That's one of the best sounds ever - hard to beat.

Don't worry about filaments - they are very easy. Just use Schottky diodes, a nice big capacitor like 15,000uF and then a LM1084, 1085, 1086 depending on the current requirements. you use that as a current source - negative to the filaments goes from the capacitor negative. Positive goes from the positive of the capacitor to the input of LM1084, then the output to the filament positive comes from the adjust pin. Put a resistor between the adjust and output pins. 1 ohm at 12 watts for 10, and 5 ohm at 3W for the 01A. small heatsing for 01A, and large heatsink for 10. Secondary voltage of transformer would be 6v for 01a and 9v for the 10. You need one filament supply like this for EACH tube.

To get some confidence working with DHTs, try a preamp with 01A. Then go on and build an amp with 01A, 10 into what you like - 300b, 2a3, whatever. 10Y has quite a high plate resistance so as has been suggested, you could use two in parallel. i wouldn't because they're expensive! Use as a driver or preamp tube where it really shines.

andy

[45]

Originally Posted by andyjevans

If I had two (well, I have about 60)

andy

Do you have 60 10's?
Would you sell 4 to me?

Cheers,
45

[Norris Wilson]

Hello,

While we are on the subject of 10 type tubes.

I have a NOS pair of VT-52, and am wondering what could be done with them? I was thinking along the lines of possibly a preamp, or low powered SET?
I understand that the VT-52 is a ruggedized version of the 801A?

Not meaning to thread jack here, just looking for some guidance and possible circuits.

Thanks for any advice

[Norris Wilson]

I made a mistake in the above thread of identifying the VT tubes that I have as VT-52.

They are VT-51 vacuum tubes instead.

Sorry for the confusion.

Thanks

[45]

Originally Posted by Norris Wilson

I made a mistake in the above thread of identifying the VT tubes that I have as VT-52.

They are VT-51 vacuum tubes instead.

Sorry for the confusion.

Thanks

Hi Norris, VT-51 is the military equivalent for the 841. This can be used as Class B push-pull power amp or as Class A RC coupled voltage amplifier.
The 841 has hi gain and high internal resistance. It can be an excellent choice as input tube in high power/high voltage SE amps with 211's and 845's.
with 1000V supply voltage it can swing 450 V peak-to-peak with low distortion!! However must be used with high effective anode load (250K).
It has thoriated tungsten filament like 211, 845, 10Y/801A.

Cheers,
45

[transformator]

Thank you very much for everyone who has given me advice.
Sorry i didn't give comment on the advice because iam still studying it.
So my conclusion :
1. It's not easy to make because of humming. Pease give me a solution !
2. For the heater supply have to with battery or not ?

So for all problem :
1. How should the circuit be to make good sound (frequency range reached 20hz-20khz flat, not only the middle sound is more clearly heard)?.
2. What is the best type circuit for UX201A (single ended, SRPP, or cathode follower, or the other circuit) ?.
3. What kind of tube rectifier for UX201A ?.

Thank you very much for every advice that I have and I will recieve .
A. In other to make with tube UX201A of good sound guality.
B. For power with tube type 10 use really good .

[Bandersnatch]

hey-Hey!!!,
US retail for type 10 and its relatives( 10Y, 801A, VT25, VT62 ) is ~$75. Some care will get you lower prices on ebay. they are not so rare as to be long to wait for.
cheers,
Douglas

[andyjevans]

<<<So my conclusion :
1. It's not easy to make because of humming. Pease give me a solution !
2. For the heater supply have to with battery or not ?>>>

I wouldn't agree with either statement. A good filament supply with a ccs or something more sophisticated like Rod Coleman's supply sounds as good to me as a battery.

A good filament supply should not hum if the tube is in good condition and you keep magnetic componants and AC well away from the filaments and tubes. The problem with SOME small signal DHTs is microphonics - airborne and vibration borne through the chassis. These may be OK when used in well damped chassis and well damped rooms, but in a flimsy chassis and a lively room (wood floors etc) they can howl. The worst culprits are the tubes with low filament current. From 250mA up things start to go better.

andy