AKSA's Lender Preamp with 40Vpp Output

Founder of XSA-Labs
Joined 2012
Paid Member
GB #1 shipped out today.

651483d1513428950-aksas-lender-preamp-40vpp-ouput-gb-gb1-packed-labeled-finished-jpg
 
If anyone can find deals on the special RCA jacks that would be appreciated. They are currently circa $9ea from mainstream dealers. Actually, I am having a hard time finding them.

I couldn't pass up the opportunity for some late night eBay / AliExpress sleuthing...

From what I can tell from comparing the morethanall.com and Hifi Collective CAD, these appear to be the same connectors as the much more readily available right-angle mounted jacks.

The best CAD of the right-angle variant I could find is on AliExpress at Taiwan GIGABAD plate welding BNC turntable DAC decoder digital coaxial input and output PCB instal special copper RCA socket-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group.

Looking at the CAD and the pictures on that page, it appears that it is only a matter of bending the pins straight and repositioning the pins from the bottom holes to the rear holes (I've see pictures with the rear holes both drilled and not drilled). This of course assumes that the pins are just press fit, but I would be surprised if they were not.

The right-angle version are available at around $2.66 each: Taiwan-made gold-plated RCA turntable DAC decoder digital coaxial PCB board sock | eBay. Given the price difference, it might be worth giving it a DIY try.
 
Founder of XSA-Labs
Joined 2012
Paid Member
Using on main system now

I connected the Aksa Lender preamp to my new Pass Aleph J amp that I just finished building. The Aleph J is driving my ScanSpeak 10F/8424 & Dayton RS225-8 FAST speakers (fitted with transient perfect XO). The combination sounds amazingly dynamic and lifelike. Super clarity - so yes, the choice of preamp makes a difference with some power amplifiers. I will listen long term now. Initial impressions from the Eric Clapton "Unplugged" CD is very very good. That recording has a very high dynamic range and is ambient recorded with minimal post-production I think. Anyhow, I am quite certain that you will all be very pleased and blown away by the sound quality of the preamp.

attachment.php
 

Attachments

  • Aksa-Lender-Pre-Aleph-J.jpg
    Aksa-Lender-Pre-Aleph-J.jpg
    447 KB · Views: 1,116
Last edited:
Founder of XSA-Labs
Joined 2012
Paid Member
Despite being from Aliexpress/China/Taiwan and the incorrect 90deg version... they are still $10ea! The one on eBay was more resonable at $3ea. I am not sure if they can be converted to 0deg from the stock 90deg config.

The multiple JST connectors with leads to panel mount RCA' s may still be the way to go, albeit, quite a bit more work. However, drilling all those holes precisely to fit 10 RCA hard mount jacks could be a challenge.
 
Founder of XSA-Labs
Joined 2012
Paid Member
Is there a guide to selecting R148 and R151 based on the V+? What did you end up using X? And remind me what your V+ was, for reference?

Also, looking at substituting this inductor for L161 so I don't have to source from Farnell. Thoughts?
2105-V-RC J.W. Miller | Mouser

Not sure where R151 is? I used 15k for R148 for Vcc of 45v to 48v that’s about 3mA through the LED. Could use 22k even.

The CLC filter is optional and I do not see it is needed in clean mains areas. The DC to DC step up actually has a CLC as part of the circuit and blocks mains RF spurious noise nicely. Coilcraft might have something like toroidal ferrite choke with about 1mH and passing 200mA DC should work.

Any n channel TO220 mosfet capable of 1amp should work fine. IRF510/540 etc. IRF610 is such a common part can’t believe they are out. That FQP should be perfect.