what about pt15?

[dsdn.]

Hi
I'm new, in this forum. I'm french, and my english is not fluent any more, because I didn't practise ennought since i was at school. I saw few thread were some people talk about pt15. I have a quad, and I would like to use them for making a push pull in triode connection. I'm not so experiment to create all the staff, and I have never seen a push pull with tese tubes on the web. Is someone, have seen something like that, or have an idea?
I have already made three amplifiers: a pp of 845, an SE of 845 driven by an r120, and a se of 6b4G.
Thank you.

DAvid

[James D]

David,

Welcome to the forum! And your english is miles better than my written french which is horrible

I have built a PT15 PP amp. Circuit is below. I used a Aikido front end and a parafeed IT phase splitter to drive the push-pull output stage. The output stage has the WE harmonic equaliser and by adjusting the pot a 20dB or so reduction in third harmonic distortion can be acheived.

ciao

James

[dsdn.]

ok thank you, it will help me, I do not found the way to calculate the final transformer impedance. I don't tink I will use a transformer between the final stage and the driver. But it's a good begining for me. I don't think the pt 15 needs a really "strong" driver.

DAvid

[James D]

PT15 Ra is about 2.6K so Ra-a should be between 5-10K... 10K works very well.

The Aikido driver is a superbly neutral and open driver but Iagree its not necessary to have such 'drive' for the PT15. IT phase splitting is the only way for me. I really don't like the sound of other methods but everyone has their own opinion on this

Please keep us informed of your designs and building progess

ciao

James

[dsdn.]

Well, I will have two transformer 8K left. These J L Chrétien's Construction, so could it be abavailable for the project?
How much watts offers your schema?

DAvid

[James D]

8K is fine, each side will see a 4K load in Class A which is fine. WIth Ia=60mA through each PT15 and Va=400V you should get an honest 10-12Watts from the amplifer.