Hello all. I'm new here so please excuse any dumb questions I may ask.. I have an old "Playmaster unit 2" stereo tube amp, made in Australia around 1959. Several capacitors were melted, so I've decided to replace all caps and resistors. On checking I found the two channels were wired differently to each other.. Maybe it was originally a (poorly assembled) kit amp? The opt's measure both the same as each other, but have two extra wires on the primary side that don't appear on any of the schematics I've found. The wires going to the opt's are white-orange-brown-blue-grey. The orange wires are connected to b+(300v dc) The tubes are 1- 12au7 & 4- 6bm8. Has anybody got a schematic to suit? Any help is appreciated!
woops, I was poking around, I actually meant to post this one Retrovox Data page But glad you liked it 🙂 It wasn't the site I was originally thinking of but seems to fit the bill.
Tony.
Tony.
Thanks wintermute, lots of good reading at that retrovox link. I kept digging around today and found the original schematic (I think). The image quality isn't great, but I think I can read enough of it to fix this old amp. On the schem. you can see the extra wires at the opt's, I think they are 20 or 40 % taps? I'm fairly new to valve amps so I'll get an electrician to check it over before firing it up. I'll post a photo the amp. on here when I work out how to post photos...best regards, Pete.
http://www.ozvalveamps.org/playmaster/playmasterunit2.gif
http://www.ozvalveamps.org/playmaster/playmasterunit2.gif
Pete, is that the unit that went on eBay end of Sept? The A&R 4005's have 20% UL taps. I have a similar amp, and can email you the original article.
Ciao, Tim (at dalmura dot com dot au)
Ciao, Tim (at dalmura dot com dot au)
Thankyou
Hi Tim, thanks for your message. This is the amp that was on the 'bay as you said. It was missing 2 valves, I bought some 6bm8 valves cheap and plugged them in but the plates glowed red and no sound. It was a real rats nest in there! I've only removed caps and resistors that were mostly no good, I'd like to keep it as original as possible. I won't butcher it. I'd really appreciate any info you have on this amp. It's a little piece of Aussie history that should survive into the future. I thank you in advance for anything you can share with me to help get it singing again! Best regards from Pete.
Hi Tim, thanks for your message. This is the amp that was on the 'bay as you said. It was missing 2 valves, I bought some 6bm8 valves cheap and plugged them in but the plates glowed red and no sound. It was a real rats nest in there! I've only removed caps and resistors that were mostly no good, I'd like to keep it as original as possible. I won't butcher it. I'd really appreciate any info you have on this amp. It's a little piece of Aussie history that should survive into the future. I thank you in advance for anything you can share with me to help get it singing again! Best regards from Pete.
A big Thankyou
Hi everyone. I need to say a very big thankyou to trobbins for sending me the original magazine article from 1960 describing the build of this amp. It has a schematic, parts list and assembly instructions.. more information than I could have hoped for. Thanks Tim! Now I need to get soldering 🙂
Hi everyone. I need to say a very big thankyou to trobbins for sending me the original magazine article from 1960 describing the build of this amp. It has a schematic, parts list and assembly instructions.. more information than I could have hoped for. Thanks Tim! Now I need to get soldering 🙂
This playmaster amp started life wit 4 @ ecl86 and 1 @ ecc82
search 100AVA will get you most of the circuit.
good luck it was a good amp
Kiwi88usa
search 100AVA will get you most of the circuit.
good luck it was a good amp
Kiwi88usa
Roly also has some photos of an example of that unit at Playmaster
Pete might want to send Roly some extra photos once his unit is in concourse condition ;-)
Pete might want to send Roly some extra photos once his unit is in concourse condition ;-)
Hi guys, thanks for the interest in this amp. Progress has been slow due to our 5 month old son to look after, also I built a dynaco st-70 clone from Bob Latino over Christmas (which sounds great!)
Just this morning I ordered lots of resistors from "hifi collective" and caps from "justradios.com", including power supply electrolytics. I've also picked up a n.o.s. sleeve of 5 "Miniwatt made in Australia" 6bm8 valves identical to the 2 in the amp when I got it. I have the original 12au7 "miniwatt made in Australia" safely stashed away too. I'm in no great hurry to get it running but I'll be sure to post some photos here when it's done.
Kiwi88USA I think the amp you're referring to is a guitar amp? The model numbers are a little confusing. The amp I have is a stereo amp, the link Trobbins posted above has a photo of "playmaster unit 2". Mine looks just like that.
Take care,
best regards Pete.
Just this morning I ordered lots of resistors from "hifi collective" and caps from "justradios.com", including power supply electrolytics. I've also picked up a n.o.s. sleeve of 5 "Miniwatt made in Australia" 6bm8 valves identical to the 2 in the amp when I got it. I have the original 12au7 "miniwatt made in Australia" safely stashed away too. I'm in no great hurry to get it running but I'll be sure to post some photos here when it's done.
Kiwi88USA I think the amp you're referring to is a guitar amp? The model numbers are a little confusing. The amp I have is a stereo amp, the link Trobbins posted above has a photo of "playmaster unit 2". Mine looks just like that.
Take care,
best regards Pete.
😀 Hi Tim, just a quick note to let you know that I have the playmaster unit 2 working again. I had a few issues along the way 
but I've learned a lot too. I'm fairly surprised by the sound.. It sounds way better than I was expecting. There's still some small issues to sort out, need to order more caps for the tone controls, but until more parts arrive I'm just happy to listen. Thanks again for your help, I couldn't have got it running without the info you sent me. I'll try to post some photos in here tonight.
Best regards, Pete.
but I've learned a lot too. I'm fairly surprised by the sound.. It sounds way better than I was expecting. There's still some small issues to sort out, need to order more caps for the tone controls, but until more parts arrive I'm just happy to listen. Thanks again for your help, I couldn't have got it running without the info you sent me. I'll try to post some photos in here tonight. Best regards, Pete.
It is indeed a pleasure when an old amp is renewed to former glory - and a satisfaction to know that it has many good years ahead of it.
Some forumites enjoy reading about the summarised trials and tribulations of others - it embues a sense of deep satisfaction that they haven't had to endure those issues.
Ciao, Tim
Some forumites enjoy reading about the summarised trials and tribulations of others - it embues a sense of deep satisfaction that they haven't had to endure those issues.
Ciao, Tim
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