Hi, does anyone have an original schematic or manual for a Stern's Valve Amp please?
Despite being an electronics engineer and having done a bit of hobbyist work on valve radios years ago, I am a bit of newbie on valve amp's and the only one I have is a Stern's amp that someone gave me years ago. I think that they built it as a kit back in the 1960's. Unfortunately, the schematic and any other documentation that went with it had been lost.
As well as the amp chassis, I have a control unit similar to the one pictured on this thread and various leads that go with it but no idea how to connect it all up.
The amp in question has a control unit (seperate from the the main chassis) with input selection switch, volume and tone controls (maybe balance?). The amp itself has a built in power supply with 5Z4 rectifier. The pre-amps are Mullard EF86's and the outputs are Mullard ECL86's (I assume in dual AB push-pull setup). The mains transformer and x2 output transformers have "Partrdige" labels on them. On the whole the unit seems in very good condition and I was hoping to get it working. Rather than have to sit down and "suss" out the schematic and risk damaging something by powering, I was keen to arm myslef with some documentation/info.
Some other forums make reference to this kind of amp being a "Mullard" desing - Iam not sure but seem to recall the freind who gave me the amp years ago maybe mentioned this?
If I get sometime, will see if I can post some pictures later.
Any help please?
Stern's Valve Amp (1960's?) Schematic & Info Please?
#2
I just joined this forum and saw your post for info. I have a Sterns 10+10 amp, and the original construction manual and circuit. Did you obtain the info you asked and get your amp working? Mine has a little residual hum but otherwise sounds nice.
Rich
Rich
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Mike H
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#3
I found this, traced schematic in post #5. 
http://www.diyaudio.com/forums/tubes-va ... 6-amp.html
HTH
http://www.diyaudio.com/forums/tubes-va ... 6-amp.html
HTH
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
#4
Mike,
That looks pretty much like the original circuit I have in the actual construction "book". Drawn a bit different of course. I am RichG4PCE in the other forum!
An amendment page dated 4 Nov 1965 I have recommended doing away with the EF86 s and using a ECC83. It gives the changes to the resistors and caps and claims the ECC83 improves signal/noise ratio.
That looks pretty much like the original circuit I have in the actual construction "book". Drawn a bit different of course. I am RichG4PCE in the other forum!
An amendment page dated 4 Nov 1965 I have recommended doing away with the EF86 s and using a ECC83. It gives the changes to the resistors and caps and claims the ECC83 improves signal/noise ratio.