SSL 9k5 - Alternative Input Gain Selector - Thoughts/Ideas?

[frejo89]

Even if it was a fake, but functional, the offset would not be so huge.

That seems wrong to me.
Since I have never built a 9k nor have one available to measure, I can't be of more help.
I would suspect some resistor value; can you certify the values of resistor pairs R106/R70, R105/R69, R109/R73 ?
Also check C82/C58, one may be leaky. It happens with styroflex.

It shouldn't matter.

Thanks!

The resistore values are all alright, the C82/C58 are fine too.
They are WIMA MKS.

But I already checked alle the values before.
.. strange issue so far

 

[Rob Flinn]

Firstofall thanks for your time!

I got a MAT02 EH - the offset is the already at 20mV there. thats to much... Could it be a fake one? (Photo attached)

When I got the correct 5534s, than yes, they do vary.

IC22 (to R73) goes from -2,07V to -2,79V
IC29 (to R109) goes from -2,02V to -1,2V

I recognized that already my (filtered) 3-Rail PSU by DIYRE had a little offset:
+15,76V against -15,84V

The MAT02 EH you are using look similar to a fake I got from ebay. The original ones I got directly from AD had all the details laser etched on the top, which made me suspicious of the ones you have. This was compounded by doing a simple Hfe test where the real device should be +600 or somthing like that & the type you have measured less than 100 on the one I bought. The other thing is the case just doesn't look right for an AD device. I complained to the vendor (who was in Manchester U.K, I forget their name). He offered me a 50% refund, I insited on a full refund. I replaced that device with an AD394, which seems to work well.

 

[frejo89]

Got it!
After I had done a visual inspection and measured the values again,
I simply soldered all the points of the resistors and caps from the inputwith the soldering iron.

The MAT02 EH you are using look similar to some fakes I got from ebay. The originl ones I got directly from AD had all the details laser etched on the top, which made me suspicious of the ones you have. This was compounded by doing a simple Hfe test where the real device should be +600 or somthing like that & the type you have measured less than 100 on the one I bought. The other thing is the case just doesn't lok right for an AD device. I complained to the vendor (who was in Manchester U.K, I forget their name). He offered me a 50% refund, I insited on a full refund. I replaced that device with an AD394, which seems to work well.

Thanks for your answer.

Just the hint makes me want to order this one here:

https://www.banzaimusic.com/MAT02FH.html


away from the eBay stuff...

 

[Rob Flinn]

Got it!
After I had done a visual inspection and measured the values again,
I simply soldered all the points of the resistors and caps from the inputwith the soldering iron.


Thanks for your answer.

Just the hint makes me want to order this one here:

https://www.banzaimusic.com/MAT02FH.html


away from the eBay stuff...

I also seem to remember that the fake had a kind of white plastic star thing underneath in the middle of the legs. The AD devices the case just looks much more precision than the device you have.

 

[frejo89]

I also seem to remember that the fake had a kind of white plastic star thing underneath in the middle of the legs. The AD devices the case just looks much more precision than the device you have.

OK

this was the one:

https://www.ebay.de/itm/192069952557

 

[Rob Flinn]

OK

this was the one:

https://www.ebay.de/itm/192069952557

That actually doesn't look bad. the one I had was shiny silver with a kind of slightly lumpy, not smooth finish. The screen printed info on the top was very blotchy & it had this whote plastic former underneath. The ones I got from AD were slighty matt & the writing I think was etched, the case looked very precise. Unfortunately I don't have either in front of me to check.

 

[frejo89]

That actually doesn't look bad. the one I had was shiny silver with a kind of slightly lumpy, not smooth finish. The screen printed info on the top was very blotchy & it had this whote plastic former underneath. The ones I got from AD were slighty matt & the writing I think was etched, the case looked very precise. Unfortunately I don't have either in front of me to check.

The one I got differs from the one on the photograph. Print is shiny. I cant remember the legs.

 

[abbey road d enfer]

https://cabintechglobal.com/as394h
You may want to have a look at it. From a 4 yo thread, so may still be active.

 

[Rob Flinn]

The one I got differs from the one on the photograph. Print is shiny. I cant remember the legs.

Well the one in their pic looks legit but the one ofn your pcb looks fake.

 

[Rob Flinn]

https://cabintechglobal.com/as394h
You may want to have a look at it. From a 4 yo thread, so may still be active.

That's actually what I used for one channel that I built & it worked well.

 

[frejo89]

Well the one in their pic looks legit but the one ofn your pcb looks fake.

yes - you are right =)

That's actually what I used for one channel that I built & it worked well.

thank you.

Maybe will try both

 

[frejo89]

I installed the original MAT02 (see picture attached).

It not only looks better.
There are no cracks or hiss anymore and the offset is as low as it should be.

Thank you all =)