suggestions for improvement - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

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
Thread Tools Search this Thread
Old 9th September 2003, 01:32 PM   #11
diyAudio Moderator
wintermute's Avatar
Join Date: Aug 2003
Location: Sydney
Blog Entries: 22
Thanks jcx.

Most of what you said is beyond my comprehension level, but I'll take your word on it

The amp definitely has some problems in the preamp design (It's actually an integrated amp, I only showed the power amp), so It doesn't surprise me that there may be other problems.

I guess what I really need to do is get off my behind and make my new speakers (which I'm sure are a weaker link at the moment than the amp), then do some A B comparisons with a known good amp, so I can see whether I can hear the difference, and then decide what to do with it.


  Reply With Quote
Old 9th September 2003, 08:03 PM   #12
DrG is offline DrG  South Africa
diyAudio Member
Join Date: Aug 2003
Location: Pretoria
This post is not necessarily a suggestion for you, Wintermute but more of a question for jcx, aksa and the other very knowledgable SS engineers here.

The 12k/15nF combo in the 2nd LTP doesn't appeal to me. What do you think about replacing it with another BF469, base connected to ground?

Other mods I might try: (1) increase tail current or tail resistors slightly in 1st LTP, in order to increase Iq in 2nd LTP, (2) increase the 100nF shunt cap across the bias pot (substantially).

I'm keen to hear the forum opinions on these proposals.

Besides these "ideas", I would personally replace all caps: larger psu caps with poly by-passes, much larger NFB cap (NP type); replace CCS with resistor. Most of these suggestions have already been made...
  Reply With Quote
Old 10th September 2003, 03:52 AM   #13
diyAudio Moderator
wintermute's Avatar
Join Date: Aug 2003
Location: Sydney
Blog Entries: 22
Originally posted by DrG
replace CCS with resistor.
This one may not be such a good idea (I'm only going on what the original amp designer said here not on my own wisdom )

According to the writeup about the design, that came with the kit, the ccs is there to substantially improve the PSRR of the amp, so getting rid of it might improve sonics at the expense of hum????

I've bought a soundcard preamp (which I haven't built yet) and downloaded some CRO software, I'd like to do some measurments around the place (once I work out how ) and do some comparisons before and after changing caps etc as suggested.


  Reply With Quote


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
KEF Chorale Improvement? audioboy Multi-Way 10 20th September 2012 03:10 AM
PPI A600 improvement manina Car Audio 7 3rd April 2009 04:16 AM
Room for improvement shatt3r Car Audio 0 17th November 2005 07:26 AM

New To Site? Need Help?

All times are GMT. The time now is 05:19 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2