YL-1200 for audioamp

[flatheadmurre]

Hello everyone

I recently got my hands on some YL-1200 tubes and the question is if anyone got some experience of using this as output tube?

I want to make an SE amp of this and use the 5692(6sn7) for driver.

All help are welcome

[flatheadmurre]

The total silence can mean 2 things either i´m totaly wrong about using this tube for audio output or it´s a rare tube.

I got a few of these from a industrial aplication thats discarded they came with a lot of RCA 5692 thats why i want to use it for driver.

I´m aiming for good power at no budget.

Yes i now it´s a hard combination.

[SY]

Well, I can tell you about 5692...

[Knarf]

It is a rare tube from what I can tell, looks to be a Philips creation.

The catch is that the cost of an amp isn't really in the tubes but in the other parts, most notably the transformers. So even if you do find a datasheet for the YL-1200, then you will still need the transformers. And if you do build an amp around some rare tubes, then you better have a few as spares, unless you don't plan on using it a whole lot.

For 'good power' you usually need 4 tubes, two for each channel. So say 8 in total if you want one spare for each your amp needs.

Better start the other way around IMHO. Find a good set of cheap iron [1], and buy the tubes to match.

- Frank.

[1] Generally doesn't happen unless you are really, really lucky.

[flatheadmurre]

Knarf in my case iron isn´t the main problem patience and my old old AVO winder will solve that, i was thinking PSE, for tubes i got enough for me and for someone else to build an amp.

I now this tube is a transmitting tube and the question is if it´s at all suitable for an amp or if i should donate them to someone with an old transmitter in need of tubes.The old Specs i found indicates LF use so there should be some hope for it.

Perhaps someone with an old tubechamp(read they were used in thoose want to trade me a good audio tube)

In the lot of tubes i got there was a few E130L and EL34 this is of course more natural choises but there are just a few.

So if it´s a bad choice or there are some people out there throwing darts at my picture cause they need it for transmitters let me know and i take this projekt in a different direction.

[Knarf]

Well, the problem is that without knowing exactly what you are considering, and having access to a detailed datasheet, then it is hard to say anything definitive. Some of your requirements are a bit counterproductive.

I could find some data, but no anode/screen grid current curves so far. Basically this is a power pentode with 45W anode dissipation. That would mean on the surface it has the same capability for audio as a KT88 or a similar tube. In triode strapped SE class A service you can expect about 7-8W per tube, more with true pentode or UL.

The catch is that some of the 'better' transmitter tubes has a fairly low, maximum allowed screen grid dissipation. This *may* mean the tube isn't suitable for either triode strapping or UL, but must be used as a pentode with g2 at a fixed voltage. Tubes like the EL84 and EL34 are designed to be triode strapped and run in UL, so they have a comparatively high maximum screen dissipation. All the data points I saw suggests that Vg2 = 250V is considered normal for the YL-1200.

Running the tube at above maximum g2 dissipation may mean death fairly quickly or just reduced lifetime. This may or may not be acceptable to you, depending on how many of these you have.

So it may be a great tube for push-pull class AB with fixed screen grid voltage, while being a lousy choice for a SE class A amp. Or it may also be great for class A SE. Just no way of telling without the required data.

- Frank.

[flatheadmurre]

Here´s a link to some data on YL-1200 PE1/100

http://www.mif.pg.gda.pl/homepages/f.../p/PE1-100.pdf

[TheGimp]

Loooks like class B at 600V you can get 82W from a pair with a 6K p-p transformer. That does not sound like it is any too strange on iron requrrements.

Knee of the curve is kind of high up at 200V, so AB1 I would expect you will get a good bit less than 82W, but might be interesting to play with.

[Knarf]

Originally Posted by TheGimp

Knee of the curve is kind of high up at 200V, so AB1 I would expect you will get a good bit less than 82W, but might be interesting to play with.

Look at the screen grid current for 600V class B service, it is already seriously high at full sine wave drive. 50mA @ 250V is 12.5W, and Pg2,max is 7W. You are going to fry the screens if you increase the idle current by much.

This does unfortunately look like it is one of those tubes, which was designed for either class B or C service. The ratio between screen grid and anode current for Vg1 = 0 V shows this. Compare for instance with KT88.

KT88: 280mA/20mA = 14 for Va > 200V, Vg2 = 200V, Vg1 = 0.
PE1/100: 400mA/70mA = 5.7 for Va = 400V, Vg2 = 250V, Vg1 = 0.

Too bad really, looks to be a fun tube otherwise.

[flatheadmurre]

So back into the dark hideaway the YL-1200 goes.

Just finding a socket for it could have been a challenge !!

I´ll dig deeper in my industrial leftovers.

This far i have a LOT of 5692(6SN7), 20more EL34, 8 E130L, 2 handfulls of 5693(6SJ7) there are some LM Ericson tubes i can´t even identify what is a 6761 for an example. Loads of strange rectifiers/voltage controllers in oversized models, A box of 807 seems to be a safest bet this far.I even think i got 2 PP irons for 807.

What to do with 30more YL-1200 start a radiostation

Some suggestions on a good working schematic on 807 or E130L