PLAYMASTER 40/40 - schematic needed - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

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
Reply
 
Thread Tools Search this Thread
Old 31st August 2007, 08:17 AM   #1
diyAudio Member
 
brett-ballarat's Avatar
 
Join Date: Jun 2007
Default PLAYMASTER 40/40 - schematic needed

Hi all,
I have been digging in the shed and found my part built Playmaster 40/40 amp. It was an Electronics Australia design from the late 70's.

It has a quasi complimentary output (4*2N3055) and quite a few parts missing on board -- never did finish it.
I am hoping someone out here may have a schematic for this project, it has been sitting waiting in my shed for at least 18yrs and the mice have already had their way with the diagrams and things.
Anyone help?

Brett
__________________
My amplifier worked until all the smoke leaked out !
  Reply With Quote
Old 31st August 2007, 11:39 AM   #2
glennb is offline glennb  Australia
diyAudio Member
 
Join Date: May 2004
Location: Melbourne
Contact me via email and we can arrange something. I have every issue of Electronics Australia ever published.
__________________
Glenn.
  Reply With Quote
Old 31st August 2007, 02:04 PM   #3
quasi is offline quasi  Australia
diyAudio Member
 
quasi's Avatar
 
Join Date: Sep 2004
Location: Adelaide, Australia
Hi Glenn,

Do you mind if I can get a copy of the schematic as well. I've been looking for this one myself. I'll send an email and if you can reply at your convenience I would be most grateful.

Cheers
Quasi
  Reply With Quote
Old 4th September 2007, 10:49 AM   #4
glennb is offline glennb  Australia
diyAudio Member
 
Join Date: May 2004
Location: Melbourne
If anyone is interested, I've scanned the articles for the Playmaster Forty Forty amplifier from the Dec 1976 and Jan 1977 issues of Electronics Australia and they are available as a 12 page PDF file (1.37MB) at http://au.geocities.com/glennbaddele...ster-40-40.pdf

The Forty Forty is a fairly pedestrian and typical differential input pair - VAS - Complementary symmetry BJT power amplifier. It uses garden variety 2N3055 output transistors. It included a phono stage based on the LM741 and a 3 transistor bass / treble controls stage.

The precedessor to the Forty Forty was the Playmaster Twin 25, which was featured in the April, May, June and September 1976 issues. There were several popular solid-state power amps prior to that in the early 1970s, the Playmaster 136, 140 and 143. I built both the Twin 25 and the 136 at the time they came out.

These amplifiers were superceded in the late 70's by the Playmaster 50W MOSFET amp, which was followed by other more powerful MOSFET amps, such as the series 200 and 300 over the following years. I built my own variation of the series 200, as a 3 channel version for stereo plus a sub woofer. This featured pairs of Toshiba MOSFETS (which are now unavailable) and could pump 150W into 8Ohm and 200W into 4 Ohm.

All of these power amplifiers were all available as kits in Australia during the 1970s-1980s and they sold by the tens of thousands.
__________________
Glenn.
  Reply With Quote
Old 4th September 2007, 11:24 AM   #5
glennb is offline glennb  Australia
diyAudio Member
 
Join Date: May 2004
Location: Melbourne
Quote:
Originally posted by glennb
...The Forty Forty is a fairly pedestrian and typical differential input pair - VAS - Complementary symmetry BJT power amplifier...
Oops, I meant quasi complementary. ie. NPN devices in both + and - sections of the output stage.
__________________
Glenn.
  Reply With Quote
Old 3rd August 2009, 01:26 AM   #6
diyAudio Member
 
Join Date: Aug 2009
Default Playmaster 50W MOSFET amp

Hi Glennb,

I have a Playmaster 50W MOSFET amp that I built when I was at school. My son uses it now (!) but it recently died.

Do you have a copy of the circuit diagram so I can troubleshoot it?

Cheers,
Richard.
  Reply With Quote
Old 3rd August 2009, 02:01 AM   #7
diyAudio Member
 
Join Date: Feb 2004
Location: Queensland Australia
And that pair of amps (the 25/25 and 40/40) had a couple of nice features. I remember the power amp' compensation was unusual and I suspect the 25 Watt edition may have been the first published circuit with the Neville Thiele dual purpose sabilization and RFI rejecting network at the output.
BTW that network only gave a 1st order rejection. In his JAES paper there are further developements with values for 2nd and 3rd order networks........but not for those who don't like chokes on their outputs!
__________________
"It was the Springtime of the year when aunt is calling to aunt like mastodons bellowing across primeval swamps." P.G. Wodehouse.
  Reply With Quote
Old 3rd August 2009, 03:53 PM   #8
diyAudio Member
 
Join Date: Jul 2004
Location: Hobart, Tasmania
I also built a Playmaster 40-40 when I was at high school in the 70's, and managed to blow it up at first switch on by turning it on before I'd completely finished building it! The impetuosity of youth. I had to learn quickly about fault finding after that, although the burnt out resistors were a clue, and luckily, the only fault. I still have it gathering dust in a spare room, although I haven't used it for years.

The preamp stages used 741 op amps, and a cheap upgrade was to use TLO71 op amps, which were used on the later Playmaster Twin 50 Mosfet amp. I found that out from a fellow Telstra trainee a few years later - thanks Spider.

-Don
  Reply With Quote
Old 7th August 2009, 12:54 PM   #9
diyAudio Member
 
Join Date: Feb 2004
Location: Queensland Australia
Richard your email is denied. I'm closer than glennb. Drop us an email and I'll get send you a copy.
Jonathan
__________________
"It was the Springtime of the year when aunt is calling to aunt like mastodons bellowing across primeval swamps." P.G. Wodehouse.
  Reply With Quote
Old 20th May 2012, 09:39 AM   #10
diyAudio Member
 
Join Date: May 2012
hi all,

I have just unearthed my Playmaster 40 40. Itwould appear to be still OK, although it has only been out of service for about 2 1/2 years.

I was wondering if anyone out there still has the connector diagram as supplied in the DSE kit? I would like to put this amp back into service but am unable to remember what connects to what (input wise).

Thanks in anticipation.
  Reply With Quote

Reply


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 series 1 schematic harveyaudio Solid State 0 8th March 2009 04:01 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
Playmaster 300W amp humming and thumping ccoutts Solid State 12 4th August 2004 12:58 PM
Help faultfinding Jaycar Playmaster Subwoofer Amp Kit VT Calais Solid State 27 3rd January 2004 03:27 AM


New To Site? Need Help?

All times are GMT. The time now is 06:50 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2