Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

AKSA's Lender Preamp with 40Vpp Output
AKSA's Lender Preamp with 40Vpp Output
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th January 2019, 11:13 AM   #1001
Skylar88 is offline Skylar88  South Africa
diyAudio Member
 
Join Date: Jun 2017
Location: Pretoria
I think once the main board and DB's are tested and working fine, it may be an option to solder the DB's to the main board. I've never felt very happy with the wobbly DB's. The cheapy header connectors were not designed to hold a board very tight and rigid without any other support. I've also considered adding support to the top edges of the DB's.
  Reply With Quote
Old 16th January 2019, 11:46 AM   #1002
maf_au is offline maf_au  Australia
diyAudio Member
 
Join Date: Jun 2005
Location: Adelaide
Quote:
Originally Posted by twocents View Post
Maf_au I agree with X beautiful work!

I would also advise to use socket connectors on the motherboard for R121 (the pot) for easier connecting to your panel mounted DACT volume switch.
Thanks!

Is there a best socket and plug connector for that R121?
  Reply With Quote
Old 16th January 2019, 02:36 PM   #1003
Skylar88 is offline Skylar88  South Africa
diyAudio Member
 
Join Date: Jun 2017
Location: Pretoria
Any single or double row 0.1" (2.5mm) pitch connector will work. I used two rows of round pin PCB header.
Attached Images
File Type: jpg lXhyd[1].jpg (10.7 KB, 335 views)
  Reply With Quote
Old 23rd January 2019, 10:37 PM   #1004
maf_au is offline maf_au  Australia
diyAudio Member
 
Join Date: Jun 2005
Location: Adelaide
Added some heatsinks to the transistors.

Main board: R141 to 10k
THT: R10 33k, and R11 6k8.
Couldn't get the Vishay Metal film resistors, so found some other Metal film resistors, not as accurate as the Vishay's.

Still waiting for the DACT SMD attenuator.

The cable from the X121 to X111, how do I know what side is to be correct between them?
Attached Images
File Type: jpg AKSALender07.jpg (269.6 KB, 241 views)
  Reply With Quote
Old 23rd January 2019, 10:44 PM   #1005
maf_au is offline maf_au  Australia
diyAudio Member
 
Join Date: Jun 2005
Location: Adelaide
Temp today outside will be at 46C degrees!!!
  Reply With Quote
Old 24th January 2019, 06:25 AM   #1006
Skylar88 is offline Skylar88  South Africa
diyAudio Member
 
Join Date: Jun 2017
Location: Pretoria
Quote:
Originally Posted by maf_au View Post
The cable from the X121 to X111, how do I know what side is to be correct between them?

I checked on the circuit diagram when I built mine.
  Reply With Quote
Old 24th January 2019, 06:25 AM   #1007
maf_au is offline maf_au  Australia
diyAudio Member
 
Join Date: Jun 2005
Location: Adelaide
Done a bit more today.

Attached the AKSA to a timber board, attached the power board, found a previous LED cable, just need to know what resistor is needed for it. Put some PCB headers for the DACT attenuator (it's not here yet)

Just need to sort the power cable to the HP laptop power system, attach some RCA sockets and attach the DACT when it arrives and will see if it works!
Attached Images
File Type: jpg AKSALender08.jpg (258.9 KB, 237 views)
  Reply With Quote
Old 25th January 2019, 12:23 AM   #1008
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
AKSA's Lender Preamp with 40Vpp Output
For LED, 15k works well. Basically 45v and 15k gives 3mA which is not too blinding bright. 20k could work if you like a little but dimmer intensity.
__________________
XRKaudio https://www.etsy.com/shop/XRKAudio
  Reply With Quote
Old 25th January 2019, 06:24 AM   #1009
Skylar88 is offline Skylar88  South Africa
diyAudio Member
 
Join Date: Jun 2017
Location: Pretoria
Quote:
Originally Posted by xrk971 View Post
For LED, 15k works well. Basically 45v and 15k gives 3mA which is not too blinding bright. 20k could work if you like a little but dimmer intensity.
It depends on the wavelength or color of the LED.

I've used 15k on the board plus an extra 56k in series (on the LED lead) to get a blue LED dim enough for night-time use. PSU is set to 48V.
  Reply With Quote
Old 27th January 2019, 03:30 AM   #1010
maf_au is offline maf_au  Australia
diyAudio Member
 
Join Date: Jun 2005
Location: Adelaide
Ok. have been waiting for the SMD DACT, and still hasn't arrived.

Have and set a Mouser potentiometer 10KOhms 688-RK09L12D0A1W, connected it today.

The pre-amp only works on the right side. Can feel the right side of the THT is warm on the heatsinks, and the the left side is cold.

How do I test where the left side is not connecting or some other mistake.

The sound on the right side sounds good, but if I turn the potentiometer up to the normal volume on my old Musical Fidelity Preamp 3A it crackles in the speaker.
  Reply With Quote

Reply


AKSA's Lender Preamp with 40Vpp OutputHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS: AKSA GK-1 (EL) Preamp kit kv2 Swap Meet 1 14th April 2017 12:04 PM
Alternative output transistors for the Baby AKSA 55 cs Solid State 10 13th September 2013 11:06 AM
preamp for aksa 55 Professor smith AKSA 98 12th February 2012 01:11 AM
Borbely-Lender True Symmetry steph_tsf Solid State 33 23rd August 2011 01:52 PM
Aksa preamp? rick57 Solid State 11 19th May 2006 10:26 PM


New To Site? Need Help?

All times are GMT. The time now is 07:39 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki