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AKSA's Lender Preamp with 40Vpp Ouput GB

Founder of XSA-Labs
Joined 2012
Paid Member
Edit Jan 27, 2020: I am getting good questions from some members who are just building this preamp now. Here are some links to the BOM for the MB and the tricky to get right rotary switch and Micromatch connectors and 8-pin cable:

The MB BOM is here:
http://www.diyaudio.com/forums/atta...vpp-ouput-gb-aksa-lender-mb_pl_04_01_2018-zip

The cable is the 8 pin Male-Male:2205062-2 TE Connectivity / AMP | Mouser

The jack on the PCBs for the cable are female 8 position (one on each end):2178710-8 TE Connectivity | Mouser

The rotary switch is not stocked at Mouser. I ended up getting it on eBay - seearch for Lorlin CK1051

To order Preamp Boards please order from my Etsy Shop here:
Aksa Lender SE Class A Preamp

From old thread..
It does seem that there is interest in a GB. The nice thing with this design is choice of SMD or through hole on amp core daughterboard. I have not priced those yet but they are small so probably $5 for 10. Is anyone interested in the metal core version? That would allow increased bias to use as headphone amp.

--------------- NEW GB THREAD STARTS HERE ------------------

Link to basics of this preamp starts in post 25:

AKSA's Lender Preamp with 40Vpp Ouput GB - Page 3 - diyAudio

I was asked to move the GB aspects of this preamp here. Thanks to Hugh Dean (AKSA), Keantoken, and JPS64 for making this possible.

The original thread describing this preamp is here:

AKSA's Lender Preamp with 40Vpp Output

Basic schematic of through hole prototype version:
644601d1510165924-aksas-lender-preamp-40vpp-output-lender-preamp-aksa-schematic-v5-png


Implementation in SMT/TH prototype:
646265d1510907783-aksas-lender-preamp-40vpp-output-smt-carbon-fb-jpg


Demonstration of 40vpp output into 25kohm:
644607d1510165924-aksas-lender-preamp-40vpp-output-40vpp-oscope-screenshot-jpg


Measured performance 20vpp into 7kohm (with 21.6dB gain):
646386d1510957760-aksas-lender-preamp-40vpp-output-smt-preamp-20vpp-7kohm-10r-degen-yes-matched-12kcarbon-fb-png


4vpp into 7kohm gives 0.0011% THD:
646388d1510958510-aksas-lender-preamp-40vpp-output-smt-preamp-4vpp-7kohm-10r-degen-yes-matched-12kcarbon-fb-png


Layout design by JPS64 for Main PCB with CLC filter, & cap Mx PSU portion, Input selector, daughterboard sockets for amp cores, and peripheral output caps etc.

647184d1511340359-aksas-lender-preamp-40vpp-output-diy-aksa-lender-main_pba-top-jpg


TH Daughterboard:
647196d1511344542-aksas-lender-preamp-40vpp-output-diy-aksa-lender-pre-tht_pba-top-png


647066d1511284591-aksas-lender-preamp-40vpp-output-aksa-lender-pre-tht_pba-top-png


SMT Daughterboard:
647201d1511346114-aksas-lender-preamp-40vpp-output-diy-aksa-lender-pre-smd_pba-top-jpg


Metal-core (IMS) Daughterboard PCB:
647189d1511342696-aksas-lender-preamp-40vpp-output-diy-aksa-lender-pre-ims_pba-png


Alert - error on main PCB. R141 Should be 10k not 220R.

Alert - error on main PCB diode V141 should be standard 1N400X not breakdown or zener.

Alrert - error on MELF SMT BOM, R102 and R103 are swapped. R102 should be 33k and R102 should be 10k on the MELF SMT v001 PCB.

Revised BOM for MB (8-pin connector was incorrect), file here:
http://www.diyaudio.com/forums/atta...vpp-ouput-gb-aksa-lender-mb_pl_04_01_2018-zip

Mainboard schematic looks like this (note R141 is 10k not 220R):
649511d1512424995-aksas-lender-preamp-40vpp-ouput-gb-jps64-aksa-lender-preamp-main-schematic-png


Schematic for Mainboard here:
http://www.diyaudio.com/forums/atta...-preamp-40vpp-output-diy-aksa-lender-main-zip

Schematic for Through-Hole Daughterboard:
649512d1512425408-aksas-lender-preamp-40vpp-ouput-gb-jps64-aksa-lender-preamp-th-daughterboard-schematic-png


Stuffing Guide for TH amp daughterboard:
657357d1516206987-aksas-lender-preamp-40vpp-ouput-gb-th-placement-stuffing-guide-jpg


Schematic for SMT Daughterboard (updated V2 correct for silkscreen error from V1 - R102/103 were swapped, corrected now):
650412d1512862009-aksas-lender-preamp-40vpp-ouput-gb-aksa-lender-pre-smt-schematic-v2-png


SMT & IMS Daughterboard Parts List/BOM:
http://www.diyaudio.com/forums/atta...-output-diy-aksa-lender-pre-ims_or_smd_pl-zip

TH Daughterboard Parts List/BOM:
http://www.diyaudio.com/forums/atta...r-preamp-40vpp-output-aksa-lender-pre-tht-zip

****
Please place orders in Etsy shop.

Edit Dec 8, 2017 - GB1 MB and TH board test:
650200d1512777832-aksas-lender-preamp-40vpp-ouput-gb-gb-th-demo-test-jpg


650198d1512777779-aksas-lender-preamp-40vpp-ouput-gb-aksa-lender-pre-gb-mb-th-8vpp-7kohm-fft-png


Both SMT and TH daughterboards verified to work:
650482d1512912624-aksas-lender-preamp-40vpp-ouput-gb-gb-smt-build-completed-jpg


Playing in stereo with TH and SMT:
650489d1512914952-aksas-lender-preamp-40vpp-ouput-gb-aksa-lender-pre-gb-smt-th-stereo-jpg


FFT of SMT for 20Vpp into 7kohms is THD of 0.001%:
650483d1512912624-aksas-lender-preamp-40vpp-ouput-gb-aksa-lender-pre-gb-mb-smt-20vpp-7kohm-fft-zoom-no2-png


Edit (Dec 2, 2018) - Latest measurements with MELF board...

4Vpp into 7kohms (45v Vcc):
654181d1514879318-aksas-lender-preamp-40vpp-ouput-gb-aksa-lender-pre-melf-4vpp-7kohm-fft-png


20Vpp into 7kohms (45v Vcc):
654180d1514879318-aksas-lender-preamp-40vpp-ouput-gb-aksa-lender-pre-melf-20vpp-7kohm-fft-rt-png


40Vpp into 7kohms (50v Vcc):
654182d1514880003-aksas-lender-preamp-40vpp-ouput-gb-aksa-lender-pre-melf-40vpp-7kohm-fft-50vcc-png


51.4Vpp into 7kohms (59v Vcc):
654183d1514880354-aksas-lender-preamp-40vpp-ouput-gb-aksa-lender-pre-melf-51-4vpp-7kohm-fft-59vcc-png


Maybe thread title should be renamed to 51v? :)

Edit Jan 16, 2018: Aksa Lender as very nice HPA:

657047d1516059914-aksas-lender-preamp-40vpp-ouput-gb-aksa-lender-hpa-amp-cores-2-jpg


2.0Vpp into 50ohms with HPA (title is a typo):
657054d1516060213-aksas-lender-preamp-40vpp-ouput-gb-aksa-lender-hpa-130ma-1-0vpp-50hms-png


657048d1516059914-aksas-lender-preamp-40vpp-ouput-gb-aksa-lender-hpa-amp-main-jpg


Edit April 16: Recent review by DrPro. http://www.diyaudio.com/forums/anal...ender-preamp-40vpp-output-58.html#post5407342
 
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So far we have the following interested members, please quote message and edit with your name and qnty and type if interested.

JPS64 - 2 sets w/ SMT daughterboards
Algar Emi - 1 set, SMT or TH?
Redarc12 - 1 set, SMT or TH?
CFT - 1 set, SMT or TH?
Jacques Antoine - 1 set TH
Silasmellor - 1 set THT
 
JPS64 - 2 sets w/ SMT daughterboards
Algar Emi - 1 set, SMT or TH?
Redarc12 - 1 set, SMT or TH?
CFT - 1 set, SMT or TH?
Jacques Antoine - 1 set TH
Silasmellor - 1 set THT
Bvtrinh- 1 set TH
ggetzoff - 1 set TH
tubesguy - 1 set TH
Aatto - 1 set SMT
Mordikai - 1 set TH
Johnny2Bad 1 set TH; 1 set SMT
 
Member
Joined 2011
Paid Member
JPS64 - 2 sets w/ SMT daughterboards
Algar Emi - 1 set, SMT or TH?
Redarc12 - 1 set, SMT or TH?
CFT - 1 set, SMT or TH?
Jacques Antoine - 1 set TH
Silasmellor - 1 set THT
Bvtrinh- 1 set TH
ggetzoff - 1 set TH
tubesguy - 1 set TH
Aatto - 1 set SMT
Mordikai - 1 set TH
Johnny2Bad 1 set TH; 1 set SMT
vvs07 - 2 sets TH

Thank you!
 
JPS64 - 2 sets w/ SMT daughterboards
Algar Emi - 1 set, SMT or TH?
Redarc12 - 1 set, SMT or TH?
CFT - 1 set, SMT or TH?
Jacques Antoine - 1 set TH
Silasmellor - 1 set THT
Bvtrinh- 1 set TH
ggetzoff - 1 set TH
tubesguy - 1 set TH
Aatto - 1 set SMT
Mordikai - 1 set TH
Johnny2Bad 1 set TH; 1 set SMT
vvs07 - 2 sets TH
Fabian85 - 1 set SMT
 
Founder of XSA-Labs
Joined 2012
Paid Member
GB status update...

JPS64 -2 sets w/ SMT daughterboards, Paid
*Algar Emi - 1 set, TH, Invoice sent
Redarc12 - 1 set, TH, Paid
CFT - 1 set, TH, Paid
Jacques Antoine - 1 set TH, Paid
Silasmellor - 1 set THT, Paid
Bvtrinh- 1 set TH, Paid
*bvtrinh - 1 set TH (second set), Invoice sent
*ggetzoff - 1 set TH, Invoice sent
tubesguy - 1 set TH, Paid
Aatto - 1 set SMT, Paid
*Mordikai - 1 set TH, Need PayPal address
*Johnny2Bad 1 set TH; 1 set SMT, Invoice sent
vvs07 - 2 sets TH, Paid
*Fabian85 - 1 set SMT, Need PayPal address
PCGAB - 1 Set(MB) with SMT boards, Paid
Harry3 - 1 set MB plus TH, Paid
Wayne1 - 1 set TH, Paid
obh - 1 Set(MB) plus TH, Paid
PJN - 1 set TH, Paid
manniraj - 1 set TH, Paid
Erik777 - 1 set TH, Paid
Zman01 - 1 set SMT, Paid
AKSA - 1 set SMT, Paid
xrk971 - 1 set SMT, Paid
spind - 1 set TH, Paid
 
Founder of XSA-Labs
Joined 2012
Paid Member
Group Buy Update

JPS64 -2 sets w/ SMT daughterboards, Paid
*Algar Emi - 1 set, TH, Invoice sent
Redarc12 - 1 set, TH, Paid
CFT - 1 set, TH, Paid
Jacques Antoine - 1 set TH, Paid
Silasmellor - 1 set THT, Paid
Bvtrinh- 1 set TH, Paid
bvtrinh - 1 set TH (second set), Paid
ggetzoff - 1 set TH, Paid
tubesguy - 1 set TH, Paid
Aatto - 1 set SMT, Paid
*Mordikai - 1 set TH, Need PayPal address
Johnny2Bad 1 set TH; 1 set SMT, Paid
vvs07 - 2 sets TH, Paid
*Fabian85 - 1 set SMT, Need PayPal address
PCGAB - 1 Set(MB) with SMT boards, Paid
Harry3 - 1 set MB plus TH, Paid
Wayne1 - 1 set TH, Paid
obh - 1 Set(MB) plus TH, Paid
PJN - 1 set TH, Paid
manniraj - 1 set TH, Paid
Erik777 - 1 set TH, Paid
Zman01 - 1 set SMT, Paid
AKSA - 1 set SMT, Paid
xrk971 - 1 set SMT, Paid
spind - 1 set TH, Paid

So I still have not heard from Algar_emi, Fabian85, or Mordikai yet. Thank you to all the other folks who have sent payment.
 
Group Buy Update

JPS64 -2 sets w/ SMT daughterboards, Paid
*Algar Emi - 1 set, TH, Invoice sent
Redarc12 - 1 set, TH, Paid
CFT - 1 set, TH, Paid
Jacques Antoine - 1 set TH, Paid
Silasmellor - 1 set THT, Paid
Bvtrinh- 1 set TH, Paid
bvtrinh - 1 set TH (second set), Paid
ggetzoff - 1 set TH, Paid
tubesguy - 1 set TH, Paid
Aatto - 1 set SMT, Paid
*Mordikai - 1 set TH, Need PayPal address
Johnny2Bad 1 set TH; 1 set SMT, Paid
vvs07 - 2 sets TH, Paid
*Fabian85 - 1 set SMT, Need PayPal address
PCGAB - 1 Set(MB) with SMT boards, Paid
Harry3 - 1 set MB plus TH, Paid
Wayne1 - 1 set TH, Paid
obh - 1 Set(MB) plus TH, Paid
PJN - 1 set TH, Paid
manniraj - 1 set TH, Paid
Erik777 - 1 set TH, Paid
Zman01 - 1 set SMT, Paid
AKSA - 1 set SMT, Paid
xrk971 - 1 set SMT, Paid
spind - 1 set TH, Paid
schlomoff-1set mb,1set th
 
Founder of XSA-Labs
Joined 2012
Paid Member
GB status update.

JPS64 -2 sets w/ SMT daughterboards, Paid
*Algar Emi - 1 set, TH, Invoice sent
Redarc12 - 1 set, TH, Paid
CFT - 1 set, TH, Paid
Jacques Antoine - 1 set TH, Paid
Silasmellor - 1 set THT, Paid
Bvtrinh- 1 set TH, Paid
bvtrinh - 1 set TH (second set), Paid
ggetzoff - 1 set TH, Paid
tubesguy - 1 set TH, Paid
Aatto - 1 set SMT, Paid
*Mordikai - 1 set TH, Invoice sent
Johnny2Bad 1 set TH; 1 set SMT, Paid
vvs07 - 2 sets TH, Paid
*Fabian85 - 1 set SMT, Need PayPal address
PCGAB - 1 Set(MB) with SMT boards, Paid
Harry3 - 1 set MB plus TH, Paid
Wayne1 - 1 set TH, Paid
obh - 1 Set(MB) plus TH, Paid
PJN - 1 set TH, Paid
manniraj - 1 set TH, Paid
Erik777 - 1 set TH, Paid
Zman01 - 1 set SMT, Paid
AKSA - 1 set SMT, Paid
xrk971 - 1 set SMT, Paid
spind - 1 set TH, Paid
schlomoff- 1 set TH, Paid
—— Waiting List - please add name below ——

Fabian85 and Algar_Emi, please respond by 23:00UTC. I have several people interested in boards via PM. Thanks,
X
 
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