LC,
I'll like to try linear supply first. I have two transformers I could use: 39V AC 440VA and 30V AC 600VA. Which one would "work better"? Speakers are fairly efficient at 90 dB... Thanks
I'll like to try linear supply first. I have two transformers I could use: 39V AC 440VA and 30V AC 600VA. Which one would "work better"? Speakers are fairly efficient at 90 dB... Thanks
I have a 10 kilo amp that I would like to fit with your VSSA. The PS rails are +/-70V, what do I need to change on your boards to use this PS? How stable is the VSSA? Have you measured its phase margin?
Probably First One was on your mind, not VSSA. Well you would have to unwind some turns from transformer's secondary to get +/-63 V DC on smoothing capacitors as this is also max. recommended voltage for the First One module.
Closed loop phase margin is less than 1 deg at 100 kHz.
Thanks. Yes. by the speed I am building the amp, there will be a new SMPS champ when I am ready 🙂
Late hours by last answer. Phase shift was measured as stated, open loop phase shift only simmed and by this phase margin resulted in less than 80 deg at 0 dB as I remembered. Stability checked by capacitive Zload alone from 0 to 10 uF without causing any oscillations.
No, I think I remember reading still4given (Terry) say he was using +/-70V supply on a VSSA but I could be wrong. Maybe it was a slewmaster.
Transistor's Vce is the limit. BC559 for example can only withstand approx. 30V
As VSSA amplifier (all versions) author I can assure +/-45 V is an absolute maximum for PSU to deliver. Anyway VSSA's front-end could be adopted to higher voltages without any problem, but that is not genuine VSSA anymore.
Which Mica Isolators?
What kind of transistor isolators are people using?
Looking at eBay, you can find ready-cut ones from Hong Kong with thickness=.2mm
For thinner ones, 0.05mm they come in sheets from Bulgaria.
What kind of transistor isolators are people using?
Looking at eBay, you can find ready-cut ones from Hong Kong with thickness=.2mm
For thinner ones, 0.05mm they come in sheets from Bulgaria.
Yes, you're right Lazy Cat, he probably used another input stage so it was not your VSSA. My mistake. Can you point me to a project with similar performance numbers using a 70 supply?
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Thanks. The closest one I could find (Mouser) are for rectangular TO-3 0.07mm. One can cut to fit but the center holes in the mica insulator may not cover some of exposed metal of the power transistor. There would be an air gap of 0.07 mm though.
Would this be a problem?...Thanks.
Hello, please check your PM/email. I'm looking for the status/tracking# on this order. Thanks.
Thanks for the order, First One modules v1.3 prepared and send in a few days.