Sjöström Audio DIY forum

I found something that looks odd. There were some more SSR01 boards lying around. It looks like the others have the AD825 rotated 180 degrees. It looks like this one is up side down. I e-mailed you a pic, dunno how to upload it into this thread. Does it look right to you?

They are there.

Tin drops on J1 and J2?

Hi. I'd much appreciate some help on the 13V SSR01 I'm trying to build. I can't get it to work.

I am feeding it rectified / smoothed DC @ 21-22V, so well above the target output of 13V. The output of the SSR01 is not quite stable at around 18.2V. It looks like it's not going into regulation.

The build is using the LM431 as voltage ref. It has the AD825 that you soldered on the board. I used the 12V SSR01 version as I found it in the documentation. The only change to the BOM / schematic is adding 15K @ R17 to get 13V output.

Just now I have meticulously double checked each component against the schematic and the BOM. Everything is right where it should be.

I tried 13V (or 13.2V to be precise) in a different configuration: I removed R17 and changed R8 (1k) out for 1k2. Same thing: still not quite stable at around 18.5V.

What could I be missing? Are other changes to the schematic needed when adding R17 @ 15K?

Thanks for looking into this.

More pictures...

https://postimg.cc/gallery/B2YSLtd

QSXM2 from Slovakia :-)
Very nice sound.

I'm sorry I forgot to answer you. The regulator has up 120 dB PSRR so it means 1 v ripple ends up with 1 uv ripple out. The only thing you must pay atttention to is min and max voltage in. If you use the preregulator then min voltage is 4 volt more in than your output voltage. Without preregulator it's 2.5 volt.

In the end I was happiest with a 100uF smoothing capacitor. That is not a typo. (Measured load was 40mA rather than simulated 18mA.) It leaves a significant ripple for the SSR01 to deal with, but with 10V headroom in unregulated DC input this was no problem to eliminate for the super regulator: there was no measurable AC on the SSR01 output. The turntable sounded better with each reduction of smoothing capacity. Lower than 100uF probably won't be useful but I may yet try 56uF so see what happens. The super regulator is a weird and wonderful device.

Your SSR04 uses 2200uF. I started out with around double that, but it didn't sound right. Too slow and heavy. At around 2000uF it's already much better. I'd like to try and reduce it further, but ripple will keep increasing. I have an LTSpice model of my rectifier bridge and smoothing caps that sit before the SSR01. By varying the load it is quite easy to see the resulting amount of ripple. Can you give some guidance of the maximum amount of ripple that you'd recommend is okay for the SSR01 to receive?

I'll take a look. The current consumption looks like it's around 15-20mA.

Rephrasing the question, how much ripple can I feed the SSR01 (30V version) before the SSR01 begins having trouble rejecting it?