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Recommendations for SE UL OPT, greater than 6K primary, over 30 watts?

Is anyone aware of changes with Antek's models? The previous three vendors were dead ends with no response from Hayboer. Perusing options again and considering a 5k transformer run off the 4 ohm tap I noted the Antek specs apparently changed. My recollection is the original transformer showed severe HF drop below 20 kHz. The current spec is flat. Any experience with their latest? Thanks.
 

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I wouldn’t be surprised if they have reworked them to get full range response to be more in line with other brands. I use their power transformers but haven’t tried the outputs yet. Have you looked at Toroidy yet? They are big in Europe but sell in NA too. They have some nice looking transformers and some with cases to finish them off nicely.
 
The associated project is based on an Antek PS transformer. So far I find them mechanically quieter than Plitron. No complaints here.
I did look at Toroidy but questioned the high primary Rdc of their 7K model, especially given the high current rating. A UL tap is also custom. The 6.5K UL Hammond available locally is much cheaper with lower power losses but I might still reach out.
Not lying the low Antek pricing is also very appealing.
 
My Antek PS transformers are dead quiet and you can’t beat the price! I’ve never used a toroidal output transformer so I’m kind of hesitant but one day I will just to see if they are any good. I haven’t been willing to gamble on any of my projects so far. It’s too bad Electra-print and Transcendar are gone, they would be good choices for you.
 
I’ve never used a toroidal output transformer
I tried a pair of Ebay SE toroids that weren't even air gapped. Threw them out.
Contacted Antek and they recommended a 7.5K model to be released next week. Spec sheet below. A tiny bit of HF drop at the very top of the range but this amp will utilize ~20 dB of feedback anyway. If it's priced with the rest of the range I'll buy a pair.
 

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It’s strange that Hayboer didn’t respond to you. I emailed them a question two days ago and I heard from them today! I might get another pair of their really nice outputs for my next project, a deal at $160 each for a heavy 30W 3.5k single ended output transformer with dual output impedances. No UL tap but I doing triodes of late. They usually deliver in less than two weeks!
 
Can't really say. Maybe a 10K high power SE UL transformer was too niche to bother. Or the web form was just missed. Currently though Antek recommended this transformer based on the voltage and current operating parameters, provided a full set of specifications with response graph, and shipping excluded is far and away the least expensive option. From an engineering perspective those are strong incentives.