| Posted by Dave | September 22, 2014 - 12:06 pm |
| Hi Stephen -- For clarity: In each channel, pin #3 of the two output tubes are connected together with a wire; therefore, the two tubes for the left channel are connected together, and the two tubes for the right channel are connected together. Then, from terminal #3 of ONE output tube in each channel is connected one end of a 5 ohm resistor. The other end of these two resistors are connected together, and then connected to the regulator/regulator bypass cap/hum balance control point. Therefore, you will need a tie point near/around the output tubes to tie the two 5 ohm resistors to, as well as a lead from that point running back to the regulator circuit. You could use the spade lug option I mentioned earlier for that connection point. I hope this helps! Dave |
| Posted by Joe Janus | September 22, 2014 - 11:56 am |
| Completed EFB, PC-10 and PC-11 replacement using Pacific Audio Regenesis that George provided a few years back... BIG improvement... but of course I had to go for more tweaks, remove tone controls, etc. but the last one, 3-prong grounded power cord and replacing the speaker output lugs has left only a hi pitched hum(feedback) coming from the speakers.... even with the input wires coming from balance control disconnected from pc-10, this hum is present and uneffected by selector switch, Volumn and/or any other control or switch... The grounds looks good and have not been changed... Any suggestions on where a guy with little theory and a bit of hardware skill might start on this issue? |
| Posted by Dave | September 22, 2014 - 11:55 am |
| Hi Ed -- Your pot is perfect. The control dissipates less than .01 watt, so a .5 watt unit is plenty big! Dave |
| Posted by stephen zaneteas | September 22, 2014 - 11:41 am |
| Hi again DAVE..I connected one pair of output tubes to the 5 ohm resistors via the regulator/regulator bypass cap/hum balance. (using terminal clocks)How would you connect the other 5 ohm resistor to the other pair of output tubes? Should I take a tap from pin #3(first pair connnected) and connect to the second 5 ohm resistor then connect resistor output to pin #3 ON THE second pair of output tubes? Im a little confused. |
| Posted by Ed Benway | September 22, 2014 - 09:11 am |
| Hey Dave, what wattage rating would be sufficient for the 5 k pot? I purchased a .5 watt PC board mountable trimmer pot. Is that going be hefty enough? |
| Posted by stephen zaneteas | September 19, 2014 - 09:20 am |
| OK....everything makes sense now..i should go your route for easier testing, of course. Just got me 4 matched MULLARD re-issues from Mother Russia for ...50$...that's a nice price. I purchased precision 1% MILLS 1 watt for the cathodes......... |