kevin gilmore

its zero feedback or super symmetry. can't be both. a couple of people have made relay switches that switch from one to the other. all SS jumpered for SS all zf for zf mode.

by matching the tubes. its +/-5 volts typically.

you can expand the picture and read it NOT Felista Audio OTL Push-Pull Electronic Headphone Amplier For the record this is not a push pull amplifier.

i would check this real hard to make sure i did not introduce any errors. cfp3smt2 - CADCAM.ZIP

done and ready to ship

IT FUCKING WORKS. makes music and everything. transformers stone cold after 1 hour.

my latest is kgdynalobal9-cadcam which is version 1.2 i can't find anything with .4 on it if you are talking about kerry's board, that is not my property and i don't have the gerber files for that. or supply a link to a picture.

increase the voltage value of the zener.

i think the last remaining problem is that the batteries don't discharge evenly. but its highly likely that many other products out there have the same problem. kerry will get to it when he can. chassis etc is all done. i still think that we can make a more efficient power supply but that requires someone with extensive flyback transformer knowledge and someone that can make prototype transformers. want +/-300 with 2.5 watts of power. plus the bias. i received a miniature hv supply for the bias from Tajikistan and with modifications it works fine.

i will let kung explain if he wants to, but it is highly likely that this chinese product does not yet exist. evidently hvrv is also pretending to sell T2 and KGBH.

there are corncob led lights with up to 1kw equivalent output. i have a 500 watt equivalent one in my garage, was the biggest at the time, lights things up real nice.

this is what dukai has done.

so here is what is going to happen. birgir will use his contacts to purchase one of these if it exists. Then he will determine if he likes it or not and will publish pictures etc. He has yet to publish pictures on the other 2 (or is it 3) stax portables. If he likes it, and if its really $400 then i will buy one. Because there is no way i can build one for $400.

here is my original schematic from january 2021. there are minor changes in the production version. Might as well let everyone steal it. electrostatportable.pdf

Absolutely not. Stax D10 uses apex high voltage opamps and is class a/B with limited voltage swing. other amplifiers out there use class D amp driving transformers. birgir has a couple of them. they suck. If your amplifier is indeed $400 then i want to buy one NOW. Since the design is virtually identical to my design there is no reason for me to build one when i can buy yours.

that looks very close to my design. no surprise i guess.

nope, not mine but may be close. definitely want more information.

ciss of 1350pf work, yes. sound good, unlikely.

NO, the incident with the T2 was a real original T2. The fake siemens tube made on RFT equipment arcs over when you use it in the cascode position. Then it shorts out the gain tube and puts 200 volts on just about everything in the front end including the volume pot. Lots of damage. I've never tested with lower voltage rated parts. probably they will eventually blow up as the 2sk216 definitely sees about 200 volts on it.

6922 and el34 only. the pinched waist siemens tubes on ebay for stupid amounts of money are all fakes that blow up as soon as you put 75 volts on the grid.

DO NOT ROLL TUBES on a T2. Definitely do not roll fake siemens tubes as they cause the amp to blow up many expensive parts.

take them completely apart and use male xlr pins to open up the socket pins

i've noticed that anything after 8.9 will only open gerber files that it created. also has something to do with gerber vs gerber x2. gerber seems to always work. one recent file i sent to jlcpcb as x2 failed with all sorts of errors yet the gerber version of that file was fine and the resulting circuit boards were perfect.

got the second batch of transformers from SumR. Now the filament voltages are 14% too high, but transformers run cool. 7.3448 volts on the 6.3v line (zoom in) in other news the 300v regulated power supply with the appropriate fixes works great.

i have been told that the new vendors supplying to92 parts have acquired the semiconductor lines from the previous manufacturers, so they should be identical. but i have not tested this. it is certainly a pain in the ass.