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 11th July 2018, 07:52 PM   #691
JPS64 is offline JPS64  Germany
diyAudio Member
 
Join Date: May 2011
AKSA's Lender Preamp with 40Vpp Output
Thanks, Iīll do my best.


JP
  Reply With Quote
Old 11th July 2018, 10:08 PM   #692
vlv81 is offline vlv81  New Zealand
diyAudio Member
 
Join Date: Aug 2017
That looks awesome JPS, very professional fit and finish. Do you plan on GB for the Heat sinks at all? I have standard type eBay ones coming but those are next level
  Reply With Quote
Old 11th July 2018, 10:37 PM   #693
Kokanee is offline Kokanee  Mexico
diyAudio Member
 
Kokanee's Avatar
 
Join Date: Sep 2010
Location: Puerto Vallarta/Kooteneys
AKSA's Lender Preamp with 40Vpp Output
JP,

I looked at your drawings for your aluminum heat sinks. I have some 6.2mm x 50.8mm copper bars (178mm long) that I can use for heat sinks. Is it recommended to use copper rather than aluminum.

Also, been a long time since I looked at this thread, was wondering which transistor's the heat sink's are designed for.

Thanks for the help,

McD
  Reply With Quote
Old 11th July 2018, 10:39 PM   #694
Vunce is offline Vunce  United States
diyAudio Member
 
Join Date: Jan 2014
AKSA's Lender Preamp with 40Vpp Output
Looks great JP! Nice and compact chassis.
I would definitely be in for a GB of those heatsinks for mine.
  Reply With Quote
Old 12th July 2018, 12:37 AM   #695
GASCo is offline GASCo  United States
diyAudio Member
 
GASCo's Avatar
 
Join Date: Jan 2018
Location: Denver, CO
AKSA's Lender Preamp with 40Vpp Output
Quote:
Originally Posted by Kokanee View Post
JP,

I looked at your drawings for your aluminum heat sinks. I have some 6.2mm x 50.8mm copper bars (178mm long) that I can use for heat sinks. Is it recommended to use copper rather than aluminum.

Also, been a long time since I looked at this thread, was wondering which transistor's the heat sink's are designed for.

Thanks for the help,

McD


Jumping in here. Aluminum is a bit better than copper but negligible difference.

I think JP is going still to have this design proven. I hope it works but personally Iím not to confident on a finless design.
  Reply With Quote
Old 12th July 2018, 02:27 AM   #696
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
Copper is a better heat conductor and is used on some CPU coolers as the active contact patch. However it is very difficult to drill and tap by hand. Aluminum is not as high but infinitely easier to drill and tap and a lot less expensive.

Finless can work if the bulk volume and surface area permit sufficient heat transfer. These transistors in HPA mode are dropping 12v ea x 100ma or 1.2w ea or about 2.5w per channel. You don’t need a huge heatsink for that. In preamp mode they are 24v ea x 35mA or 0.84w ea and 1.6w per channel.
__________________
XRKaudio https://www.etsy.com/shop/XRKAudio
  Reply With Quote
Old 12th July 2018, 02:31 AM   #697
GASCo is offline GASCo  United States
diyAudio Member
 
GASCo's Avatar
 
Join Date: Jan 2018
Location: Denver, CO
AKSA's Lender Preamp with 40Vpp Output
Quote:
Originally Posted by xrk971 View Post
Copper is a better heat conductor and is used on some CPU coolers as the active contact patch. However it is very difficult to drill and tap by hand. Aluminum is not as high but infinitely easier to drill and tap and a lot less expensive.

Finless can work if the bulk volume and surface area permit sufficient heat transfer. These transistors in HPA mode are dropping 12v ea x 100ma or 1.2w ea or about 2.5w per channel. You donít need a huge heatsink for that. In preamp mode they are 24v ea x 35mA or 0.84w ea and 1.6w per channel.


Yes sorry. I had it switched... copper is better.

I didnít know the dissipation was only 2.5W. Much more confident that way
  Reply With Quote
Old 12th July 2018, 02:46 AM   #698
zman01 is offline zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
AKSA's Lender Preamp with 40Vpp Output
JP,

I see that the on-board RCA connectors for the selector PCB have been populated. I might be wrong, but IIRC there was some difficulty sourcing this earlier? May we know the model number and source?

And your build is looking compact and functional.
  Reply With Quote
Old 12th July 2018, 03:58 PM   #699
GASCo is offline GASCo  United States
diyAudio Member
 
GASCo's Avatar
 
Join Date: Jan 2018
Location: Denver, CO
AKSA's Lender Preamp with 40Vpp Output
I found them when I was buying my stuff, but they were costly... I ended up buying panel mount RCAs and will wire directly to the board (I'm bypassing the selector, but if had a selector would then wire to the selector board).

Yesterday I found this article on heatsinks that seems interesting:
How Much Heat can be Extracted from a Heat Sink? | Electronics Cooling
  Reply With Quote
Old 12th July 2018, 04:45 PM   #700
zman01 is offline zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
AKSA's Lender Preamp with 40Vpp Output
Hi GASco,

Like you I plan to do my build at first without the selector board. And afterwards I might have to go for panel mount RCA sockets too; but curious if someone has found a good option for the PCB mount RCAs.
  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 11:04 AM
Alternative output transistors for the Baby AKSA 55 cs Solid State 10 13th September 2013 10:06 AM
preamp for aksa 55 Professor smith AKSA 98 12th February 2012 12:11 AM
Borbely-Lender True Symmetry steph_tsf Solid State 33 23rd August 2011 12:52 PM
Aksa preamp? rick57 Solid State 11 19th May 2006 09:26 PM


New To Site? Need Help?

All times are GMT. The time now is 11:57 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki