WAD Psu3 replacement Board Build

[Richard]

Thanks Colin.

[bob orbell]

For your information Richard and Colin, my WDPSU v3 CD shows C1-2 rated at 450 volts and 375 volts at C1, I wonder if this is to do with the transformers at Peters ownership being made with 230 volt pri. as opposed to the WAD transformer that had a 240 volt pri. even at R4 my CD shows 325 volts loaded, this is a problem for many who have high mains voltages, mine is never lower than 248 volts and for this reason I set about making HV regulators, I now have two very successful PSU's, one supplying 250 volts the other 200 volts, both are rock steady and sound quality has improved dramatically . Bob

[John Caswell]

Hi all,
This 230V primary is becoming a bit of a problem, particularly with some of the valve amps I repair as the heater voltages often reach over well over 7V which can shorten the life of valves drastically. I have often had to add series Rs to bring them back to sensible levels. With S/S items it can often take the "HT" over the capacitor's/transistor's ratings. For instance there is one t/t that relies an a wall wart for power and as most of the are rated for 230Vac it was causing the driver transistors to cook. No power switch obviously, changing it from a 15V to a 12v cured the problem - took me some time to work that one out!

John

[bob orbell]

I don't know about "becoming" a problem John, it has been ever since the powers that be introduced 230 volt + 10% - 15% as I have said on here many times, off peek our voltage can reach just over 252 volts, it never falls below 248 volts .Bob

[colin.hepburn]

Col
Yep, my mains voltage is a constant 243 volts and as I usually do all my building of audio things late into the night so all testing, etc. Is done on that 243 volts mains voltages with 230-volt TXs so usually a few volts higher than the schematic states
But went I noted the PSU 3/ V.3 schematic HT voltage was that high at C1 and R4 was wrong it goes all through the manual testing page my HT. voltages according to this manual for both the phono and pre outputs are 380v to 420v and heaters at 5.9 to 6.7 DC and the schematic shows 250 volts at the outputs of both. and this manual is built version date 03/2011 I wonder how many of these incorrect manuals are out there
But thankfully Richard emailed me the correct Manual so all fixed there thanks you Richard
Colin

[bob orbell]

Colin, the HT voltages will fall when loaded, but you know that. Bob

[colin.hepburn]

Originally Posted by bob orbell

Colin, the HT voltages will fall when loaded, but you know that. Bob

Thanks
Yes, bob but the point I am trying to make is that the manuals have the wrong voltage printed in them in the first place so still too high when loaded

[colin.hepburn]

Hi all
I am about to order new caps for the PSU3 from RS.looking for suggestion on what to go for values should I stay with the 100uf or come up say to 150uf and I forget about ripple current is it the higher the better or the lower I normal use rubycon caps
So any pointer would be helpfully
thanks
Colin

[bob orbell]

Stay with 100uF but move up to 450 volt is my suggestion Colin and look for the lowest ESR in the data. Bob

[colin.hepburn]

Hi All

I am going to order a couple of spare LM1084 Reg. from RS can anyone confirm I have the right part Number Please RS Stock No. 533-9347
Thanks
Colin