Super Regulator

[dahlberg]

Yes but the drop to 4.8V is strange. At which points do you measure the output voltage? What do you use for the ref and what in series with opamp output. What opamp?

Jan

The voltage drop was with the opa604, the ad817 and the LT1641 does not show a voltage drop 👍
Voltage reference is 4040/2,5v and a 2,5v zener at D2

 

[dahlberg]

Measures where done right at the outputs with sense connections shorted to output at the bottom side of the board.

 

[jan.didden]

According to the specs and data sheet, the OPA604 needs at least 9V supply and is not rail-to-rail out so no wonder it doesn't work correctly.

Jan

 

[dahlberg]

Well I had them right in front of me so I thought I might just as
well try and drop one in. I was surpised that it did (kind of) work 😏

 

[jan.didden]

It didn't. It didn't regulate 😏

Jan

 

[dahlberg]

You pick the device which is believed to be most susceptible -- it makes a difference for the Borbely "All FET" preamp with poor PSRR, other discrete designs, probably not as effective with an op-amp design with high PSRR.



Assume for a moment that you have 100 milliOhms of "resistance" in between the SR and the DUT. If you don't use the Sense terminals you've taken a high performance engine and turned it into a two-banger. This illustration was done using the AD825 error amplifier. With the AD797 Z out will be a couple microOhms! (But "simulated" phase margin @1.3MHz is inadequate with the AD797).

That graf was most helpful so, thanks 🙂
(It's on page 100)

This is a resistance calculator I found that might come in handy as well.
So for a 5cm long / 1mm thick copper wire there should be no need for
sense wires, right ? That's 1 micro Ohm.
https://www.omnicalculator.com/physics/wire-resistance

 

[jan.didden]

Agreed.

Jan

 

[iplayforme]

Is there a build guide. I want to try to save myself sine embarrassing questions. Thank you.

 

[dahlberg]

These will cover the basics, and then there is 137 pages so.... 😎


https://linearaudio.nl/sites/linearaudio.net/files/superreg V2.3.pdf

https://cdn.shopify.com/s/files/1/1...tions_for_Resistor_Values_v5.pdf?v=1619915284

 

[iplayforme]

This helps a lot. Thank you

 

[jan.didden]

The diyaudiostore has also a build guide for it.

Jan

 

[felipeunix]

Maybe use a green LED and 1n4149 in series for D5 and D2 - much quieter

Have you already tried this change?
I believe that "maybe" there is a difference in D2 only.
The noise from the voltage reference (D5) is mitigated by the RC (R4+C9), even a noisy reference should not be a problem.

* at least that's what I understood following the topic in the last few days.🙃

 

[ticknpop]

also see Walt's GLED 431 article for a low noise 2.5 volt reference.

https://refsnregs.waltjung.org/GLED431_An%20Ultra%20Low%20Noise%20LED%20Reference%20Cell%20_Walt's%20Blog%202014_092418.pdf

 

[4shane]

Does anyone know when boards will be available again?, or where I can buy a completed 5 volt version.

 

[jan.didden]

Ask Jason, he should know.

Jan

 

[4shane]

Jason, do you know when boards will be available again?, or where I can buy a completed 5 volt version.

 

[4shane]

Does anyone have experience with the Super Regs on eBay?

 

[redjr]

Does anyone know when boards will be available again?, or where I can buy a completed 5 volt version.

Did you try the DIYAudio store? I received 2 PCBs just yesterday. Ordered about 10 days ago.

 

[4shane]

Does anyone have experience with the Super Regs on eBay?

I just checked, they're still out of stock. You must have got lucky.

 

[jan.didden]

I'll nudge Jason to order more.

Jan