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Availability of 10K/8K 30W+ pp output transformers

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Joined 2021
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There seems to be a lack of reasonable priced 10K/8K push-pull 30W+ output transformers. There are plenty for 10...20W, but slim pickings (other than in China) above that. There are plenty of cheap and good valves like GU-29, GU-50 and the likes that enjoy high anode voltages.

Any reasons for that?
 
Thank you! I had a look, definitely interested. I mailed them because they do not list the UP as a delivery destination, got a very nice and fast reply.

I'm a bit puzzled about the valve recommendations for the 50W 8K OPT, surely one would not be able to get near 50W from a couple of EL84s?
 
Hi, I've six of them in a custom version with 23% UL taps.
I use them for EL84 and 6V6. They declare them for EL84 because it's the tube that usually uses that Raa, but those toroids can easily manage higher wattages than what you can squeeze from a pair of EL84. Share with them your intentions, and they will give you their comments.
 
Hi, I've six of them in a custom version with 23% UL taps.
I use them for EL84 and 6V6. They declare them for EL84 because it's the tube that usually uses that Raa, but those toroids can easily manage higher wattages than what you can squeeze from a pair of EL84. Share with them your intentions, and they will give you their comments.

Thank you, great to hear good feedback. The transformers look great in photos, glad to hear they work well too!

I told them about my setup, fingers crossed. Delivery costs from mainland Europe to the UK have shot up after Brexit, and most of UK OPT suppliers are gone.
 
In attach the photo of pp EL84 OT trafo I have developped with help of a little company in Italy
Double C core laminated 0,1 mm

In thid link you can see the test lab, not simulation as I see normally here.
EL84PP, a simply circuit

Walter
It looks really good!
I'm planning to use the transformers with a GU-29 (829b) as output tube. My goal is to reach 30W+, 450V. Curves show I may be able to get around 33W with 10K, or 30w with 8K (400V). That's 6L6GC territory with a single tube.

I'm still nursing my fractured left arm though, the good one, no soldering for me at the moment, had to stop my current built just when I was going to start wiring the heaters 🙁
 
It looks really good!
I'm planning to use the transformers with a GU-29 (829b) as output tube. My goal is to reach 30W+, 450V. Curves show I may be able to get around 33W with 10K, or 30w with 8K (400V). That's 6L6GC territory with a single tube.

I'm still nursing my fractured left arm though, the good one, no soldering for me at the moment, had to stop my current built just when I was going to start wiring the heaters 🙁


I have same double C, laminated 0,1 mm for p-p EL34/KT88; no UL .

to Artosalo
in this link (italian) there is my friend who sell some stuff for DIY
Kit MILLENIUM AUDIO

Please ask me if you have questions

Walter
 
There seems to be a lack of reasonable priced 10K/8K push-pull 30W+ output transformers. There are plenty for 10...20W, but slim pickings (other than in China) above that. There are plenty of cheap and good valves like GU-29, GU-50 and the likes that enjoy high anode voltages.

Any reasons for that?

Heyboer makes a very good copy of the Peerless S-265-Q, 10K p-p, 40 watts. They're about $250 each. Not cheap, but a bargain compared to anything else I've investigated. I use them in classic Williamson builds with excellent results. You can specifiy the screen taps. I use 50% like the originals for "ultralinear" Williamsons. The only downside is the lead time, which can be months right now because they are very backed up and short-handed.
 
Heyboer makes a very good copy of the Peerless S-265-Q, 10K p-p, 40 watts. They're about $250 each. Not cheap, but a bargain compared to anything else I've investigated. I use them in classic Williamson builds with excellent results. You can specifiy the screen taps. I use 50% like the originals for "ultralinear" Williamsons. The only downside is the lead time, which can be months right now because they are very backed up and short-handed.

Thanks for the tip! I'm afraid that's way above my budget though.