Emotiva source thread, BasX / XPA / ERC / XDA

Admin note: edited to include all emotiva gear, not just A100

I think we all know this amp, right?
Low cost, somewhat small simple speaker amp.

Well, mine has an issue where the volume pot causes a bunch of crackling when changing the volume. Screwdriver in hand and wrist strap grounded, I opened mine up.

To get the front panel off, there are 5 screws: one on each side and three on the bottom (flip the unit on its side)

…and swing the front panel to the right.
:warning: Mark the cable↔connector :warning:

Front panel and the two PCBs on their own.

And the money shot!

It is a nicely designed and made PCB. Just a single side is all they needed to have two color LED control and an Op-Amp to give the signal a boost.
So, A-100 Op-Amp rolling when? :stuck_out_tongue_winking_eye:
Comes stock with a TI TL072CP

And the reason for this entire endeavour: 20k Ω pot of unknown brand.

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Are you thinking of replacing the pot? That might be quite an interesting mod to do. Also opamp rolling it might be hilariously entertaining!

That was the initial idea.

Seeing how the front panel is done, I am thinking of replacing the entire board with a custom one.
That way I am free to pick any Poti I like instead of one with that specific footprint.

The other idea is changing the LEDs out so my A-100 glows red when on, warm white in stand by.

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That sounds like a cool project. I like the idea of custom leds a lot. I was planning to build my own custom passive preamp to use in front of mine as that frees me up from needing to mess about with that board.

That board being active in the audio section is a bit of a PITA.

To make it worse, the amp has no ground so probing in there definitely requires a differential probe before sticking oscilloscope probes on the Op-Amps output to see what level it puts out.

That does make things complex. I guess it depends how much you want to risk something catastrophic? What options do you have for a like for like pot replacement?

Depending on circuit layout in the A-100, using the RCA inputs for ground would work. Problem is that that failing would mean capacitive coupling through the transformer windings for an easy 340V p-p, wich is, bad.
Grid voltage and stuff related to it is no joke.

Have not looked yet, just taken measurements.

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Noisy volume potentiometers… I think I have 2 or 3 doing that currently, It happens and I just deal with it. Good on you for opening it up👍

Found a Poti that may fit the bill:
Piher PC16 in the “D H - 10 I P06 223 A 2020 MTA” variety (yes, that is the part name).
The “D H - 10 I P06 223 B 0505 _ 3D _ _” version would be better, but that is special order and I need 1 or 2, not >1000.

Part Number Decoder

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