Playmaster 300W amp humming and thumping - 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 4th August 2004, 10:37 AM   #11
diyAudio Member
Join Date: Jul 2003
Location: Newcastle, Australia
The May issue only has the PCB overlays and construction - no circuits. I could deduce the muting transistor on the preamp overlay, with reference to it in the text, but don't have any circuit details of how it is controlled. Still think speaker switching is a better arrangement.

If you are going to move the transformer closer to the front of the box, you might also consider moving the bridge to a position directly between the transformer and filter caps to reduce cable lengths.

  Reply With Quote
Old 4th August 2004, 10:44 AM   #12
ccoutts is offline ccoutts  New Zealand
diyAudio Member
Join Date: Aug 2004
Location: Auckland
Thanks. I've found both editions at a library, so will get those tomorrow. Librarys are still useful! ;-)

Yeah, will shorten the cables when I reassemble it.

Tried shorting the ends of an RCA lead connected to the input while it was turned off and thumping (to try to simulate the effect of the input muting circuit). It changed the rate of the thumping, and its volume, but didn't remove it completely. Weird.

What is "speaker switching"? Do you mean having a relay disconnecting the speaker after power off?
  Reply With Quote
Old 4th August 2004, 12:58 PM   #13
diyAudio Member
Join Date: Jul 2003
Location: Newcastle, Australia
Originally posted by ccoutts
What is "speaker switching"? Do you mean having a relay disconnecting the speaker after power off?
Yes. There have been a number of designs in EA, ETI and Silicon Chip incorporating DC protection as well, and these used to be available as kits from most suppliers but they don't seem to carry them now. Altronics has a couple of kits but not sure of the details of them.

Another thought on the thumping might be to temporarily remove the input RCA from the case and let it dangle in another position and try it to see if close proximty to speaker terminals has anything to do with the problem.

  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
PLAYMASTER 40/40 - schematic needed brett-ballarat Solid State 9 20th May 2012 09:39 AM
Playmaster series 1 schematic harveyaudio Solid State 0 8th March 2009 04:01 PM
My woofer is thumping (not when I want it to) RSBosma Subwoofers 8 13th April 2007 06:15 PM
Playmaster Pro Series 3 reviews BlairHatcher Solid State 0 23rd December 2004 04:29 AM
Considering playmaster pro series 3... Opinons? wintermute Solid State 40 26th August 2004 08:17 AM

New To Site? Need Help?

All times are GMT. The time now is 10:04 PM.

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