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Per-Anders Sjöström

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Power supplies / Re: SSR03 (AD825, LM431, +-15V...
Last post by peranders - March 12, 2020, 08:57:12 PM
The AC voltage should be a few uV but this must be measured with special equipment. Check first the incoming voltage. It should be at least 4 volt more than the output voltage, in your case 19 volts. Measure at the input of the LM317/337.
Power supplies / SSR03 (AD825, LM431, +-15V BOM...
Last post by minionas - March 12, 2020, 07:41:09 PM
Got transformers and hooked it up to SSR03 (AD825, LM431, +-15V BOM). Final result +15.19V / -15.09V. If i would like to trim it down a bit, to 15V exactly, what needs to be done?

I measure 10-11mV of AC on outputs on cold, and 9mV on stable working unit. It is normal in my case?

Thanks in advance.

Power supplies / Re: Changing output voltage on...
Last post by peranders - February 04, 2020, 05:51:52 PM
If you check the documentation you can find the 6 V version, both BOM and schematics.
Power supplies / Changing output voltage on SSR...
Last post by zidor28 - February 04, 2020, 02:45:51 PM
Am sure (and sorry if) this question has been dealt with before. I would like to change the output voltage of the SSR01 from 12V to 6V. I would just want to validate which resistor(s) needs to be changed and what kind of values would work. Thanks for this.
Headphone amplifiers / Re: QRV-08 gain reduction
Last post by peranders - September 12, 2019, 07:30:03 AM
Headphone amplifiers / Re: QRV-08 gain reduction
Last post by Hodgin - September 11, 2019, 03:42:45 PM
Do 330 ohms impact anything else besides the gain?
Power supplies / Re: SSR03-15V LM431 Volt too l...
Last post by eloes51 - September 08, 2019, 05:16:26 PM

Thanks for the tip.

I did not think that the AGND have no mass !!!
Power supplies / Re: SSR03-15V LM431 Volt too l...
Last post by peranders - September 08, 2019, 04:14:04 PM
Are the sense inputs connected? Have you tin drops on J1-4?
Power supplies / SSR03-15V LM431 Volt too low
Last post by eloes51 - September 08, 2019, 11:42:53 AM

SSR03 board with OP, the rest soldered itself.
Plus volts 13.4V, minus volts 10.4V.
OP From PIN6 + V -6.5V
OP from -V + 3.5V.

All components checked twice.
Maybe components defective?

Please help!! :-(
Headphone amplifiers / Re: QRV-08 power up
Last post by svarthvitt - June 13, 2019, 09:11:47 PM
E29 is fine. Have a look at a thermal photo of the amp. Does it look fine?

What can I measure to confirm that it is working properly now, amd how do I adjust the pots correctly?

Thank you again, it would have been really great to get this amp working properly.