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ACP+ Preamp/HPA for Yarra Preamp

Founder of XSA-Labs
Joined 2012
Paid Member
Vunce and I have both built the verification boards for the Pass ACP+ preamp / headphone amplifier in Yarra daughterboard format. This format also is compatible with the M2X amplifier front end bolt holes. Requires +24v supply and can be used as a standalone preamp/HPA.

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The design is basically a miniature Aleph based output stage with a Aleph J or J2 front end (?). It sounds super and is very powerful with deep bass authority. A very nice sounding preamp that has tons of headroom. You will enjoy the sound immensely.

It is a mostly SMT layout in order to make it small enough to fit in the Yarra/M2X board format. However, the small tight layout contributes to an exceptionally low noise and great sounding design.

Thanks to Mr Pass for giving us the go-ahead to make this design for the Yarra/M2X. Thank you to JPS64 for another superb layout.

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Please add your name, number of boards, and country to the interest list below if you would like to see a GB for this happen. Boards will be the usual price of $12 each and 1.6mm thick 1oz copper, ENIG finish. Green solder mask.

GB Interest List:
For example...
JohnDoe / 2 boards / USA

Edit Dec 24, 2020: BOM is here https://www.diyaudio.com/forums/attachment.php?attachmentid=904464&d=1608844039
 

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Founder of XSA-Labs
Joined 2012
Paid Member
I’m sure it wasn’t meant to offend you...

I was just going to offer the prepopulated SMT option as $100/pair You still need to put in the through hole stuff. I will need at least 10 pairs of prepopulated to be viable. I am not doing it myself but having an expert do it for me. This is all manual no robot.

You will basically get something like this: all MELFs and SMT caps, the opto, and the JFET. All genuine Mouser BOM.

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Unraveling a mystery ...

Thanks for deleting GBA, nice touch, what was it about God Bless America was offensive? You didn't type it, but thought you should sensor?


Cancel mine X I know it wasn't you, but this crap just chaps my ***.


JT

JT

I just realized that I am the offending party. I assure you that I have no interest in censoring you. The reason that you disappeared is that I failed to refresh my browser before adding my name to the list. Your addition had been slipped in during that window of time and as result, you were skipped over. Please add back your name. No fowl was intended.
 
JT

I just realized that I am the offending party. I assure you that I have no interest in censoring you. The reason that you disappeared is that I failed to refresh my browser before adding my name to the list. Your addition had been slipped in during that window of time and as result, you were skipped over. Please add back your name. No fowl was intended.


No worries, I had a bad moment besides if you had, "sensored." my post we should having some form of reading, or measurement...? :). Have to stop posting after that second drink. :p


JT
 
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Founder of XSA-Labs
Joined 2012
Paid Member
ACP+ GB Interest List

Name / Type of Board / Qnty / Country

MShipmanPE / SMT Prepopulated / 2 boards/ USA
Carl_Huff / bare PCB / 2 boards / USA
mnichols30030 / bare PCB / 2 boards/ USA
Thompsontechs / bare PCB / 2 boards / USA God Bless it in these trying times!
Aljordan / SMT Prepopulated / 2 boards / USA

I appreciate the support for getting this preamp going! Especially the SMT prepopulated ones - they are time consuming to make.
 
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