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

Group Buys Members group buys

PCB for the HAWK A18 amplifier (+ fets if required)
PCB for the HAWK A18 amplifier (+ fets if required)
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 13th June 2019, 08:19 PM   #31
Tarasque is offline Tarasque  Netherlands
diyAudio Member
 
Tarasque's Avatar
 
Join Date: Dec 2002
Location: Netherlands
2 PCB's left
__________________
----------------------------------------------
WWW.DelftAudio.com
  Reply With Quote
Old 24th June 2019, 08:16 AM   #32
Tarasque is offline Tarasque  Netherlands
diyAudio Member
 
Tarasque's Avatar
 
Join Date: Dec 2002
Location: Netherlands
All PCB's are sold!
__________________
----------------------------------------------
WWW.DelftAudio.com
  Reply With Quote
Old 10th October 2019, 10:57 AM   #33
Dave S is offline Dave S  United Kingdom
diyAudio Member
 
Join Date: Mar 2003
Location: Searchin' for Sweet Singletrack
In case anyone else is building this:

I believe pins 2 and 3 on the opamp are swapped around on the pcb layout (not 100% verified yet).
TR3 and 4 need to be fitted in the reverse orientation to the PCB ident.
C18 had to fitted under the PCB in my build because there is not enough room for it next to the fast-on terminal.


I would recommend buiding the boards without the output devices for testing. I ran mine off a bench PS which helped me find the reversed TR3,4 without smoke:

Click the image to open in full size.

I have left the big caps out for now, to make it easier to jig/align the output FETs.
I had to buy some hex headed screws so that the output devices can be tightened with a spanner, because CP7 & 16 block access to posi or allen headed screws.
I also added some extra mounting holes to avoid stress on the legs of the FETs.

Despite the above caveats it's a nice PCB overall, and I'm looking forward to hearing this amp!
  Reply With Quote
Old 10th October 2019, 09:28 PM   #34
gary s is offline gary s  Australia
diyAudio Member
 
Join Date: Nov 2002
Location: Australia
Thanks for the info Dave, I have 2 of these pcb,s - project for next year now. I was aware of the issue with TR3 and TR4 orientation, but was not aware of the op amp inputs swapped, can you update here when you have verified this for sure, thanks. Have printed out your photo showing the mods on the back of the pcb around the op amp for reference.

C18 is no big deal, and I look forward to your listening impressions when up and running.

Also would be interested in the PSU you have implemented for your build.

Regards,

Gary..
  Reply With Quote
Old 15th October 2019, 07:40 PM   #35
Dave S is offline Dave S  United Kingdom
diyAudio Member
 
Join Date: Mar 2003
Location: Searchin' for Sweet Singletrack
Stage 2 of testing complete with FETs fitted, then dc servo fitted powered from bench supply:

Click the image to open in full size.

Mine biased up at 560/600mA for the each channel using R17 = 180R.
I can confirm that pins 2 & 3 of the opamp need swapping (need to cut the tracks on the topside).

It's ready for final assembly now.

PS is a pair of toroids and MUR820s + 10KuF-0.47R-10KuF

Last edited by Dave S; 15th October 2019 at 07:48 PM.
  Reply With Quote
Old 15th October 2019, 11:45 PM   #36
gary s is offline gary s  Australia
diyAudio Member
 
Join Date: Nov 2002
Location: Australia
Thanks for the further update on your testing.
  Reply With Quote
Old Today, 12:51 PM   #37
Dave S is offline Dave S  United Kingdom
diyAudio Member
 
Join Date: Mar 2003
Location: Searchin' for Sweet Singletrack
The A18 has been running for a day or so. I backed the Iq down to 450mA due to limited heatsink.

I was reading about the Simpelstark amp and came across a quote of a quote, Charles Hansen & Hugh Dean:
No-global-loop amplification

I think this may well be true!

The sound is just so clear and lacking artifice.
  Reply With Quote

Reply


PCB for the HAWK A18 amplifier (+ fets if required)Hide 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
Tin of FETs headphone amplifier easphyx Headphone Systems 41 26th May 2018 01:23 AM
hifonics hawk audiooverlord Car Audio 8 22nd January 2016 04:09 PM
Hawk A18 kits Tarasque Swap Meet 2 26th July 2015 01:06 AM
Hawk a-18 amplifier maartentje Solid State 7 18th February 2005 03:45 PM
Hawk Audio mpIII dac any good? wazzup Digital Source 2 28th March 2003 05:46 PM


New To Site? Need Help?

All times are GMT. The time now is 02:09 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki