Secondaries for two heaters going to the middle of the pcb, blue wires - they are twisted together - You can try to run them separate, twisted for each heater rectifier, maybe there is coupling beetwen them when the both secondaries are twisted together... just a guess, i run them separately in my phono pre, had peviously various secondary coupling issues.
That’s all part of it! Gotta try stuff!!!
I think, it actually “sounds” better w the twisted wires, even though I used cheap wire. It’s just the damned noise.
Feels like it’s more open sounding.
I thought I have mentioned before where I have to convert RCA to XLR for SS amp, otherwise, it will be noisy. No problem with RCA to RCA for tube amp.
If your SS amp doesn't have XLR, you may be out of luck. Or you can try the same method as below by using RCA to RCA audio transformer, it may help.
Using 600:600 or 10K:10K to convert RCA to XLR
If your SS amp doesn't have XLR, you may be out of luck. Or you can try the same method as below by using RCA to RCA audio transformer, it may help.
Using 600:600 or 10K:10K to convert RCA to XLR
I recently completed this build in australia and have very loud hum, i also bought the transformer 10k xlr. While the transformer does reduce the hum by 50% the music feels muted and airiness of the music is lost. So im back to square one also.
For the b+ is 330V which is more than the spec of 280v i think its the transformer provided for australia which i was told can be reduced with changing the r23 to 360k. I have tried from 270k to 360k and the b+ remains the same.
For the b+ is 330V which is more than the spec of 280v i think its the transformer provided for australia which i was told can be reduced with changing the r23 to 360k. I have tried from 270k to 360k and the b+ remains the same.
Check the voltage at R24 or after B+ 100 ohm, you should get around 330-350v
Voltage between R24 and R25 should be around 70-75v
Voltage between R24 and R25 should be around 70-75v
Yes my volatge at r24 abd b+ is 315v i assume its because i have 360k resister at r23 instead of the normal 330k.
Voltage betweeb r24 and r25 is 78v
Voltage betweeb r24 and r25 is 78v
Replace 100 ohm to 300 ohm could drop to 290v. I think you can try from here first. Adding up in series like 100 ohm at a time to see how much it drops.
Whatever you change r23, it's only affect the B+ at (265v) , 360k would add up another 30v while 270k would drop around 50v. Assume 330k is 265v, you want to have smaller r23 to drop more voltage.
Whatever you change r23, it's only affect the B+ at (265v) , 360k would add up another 30v while 270k would drop around 50v. Assume 330k is 265v, you want to have smaller r23 to drop more voltage.
I'm in need of some help. I have a SP-14 preamp that I built last year and am looking to mod the rectifier to the 6by5. My questions are do both R-FILLS get jumped? I have one side jumped and one side has a resistor currently. I've noticed that a lot of the Don Sachs preamps that are tied still have a resistor. Just to clarify? I just need to tie 1-8 and 3-4 together to run the 6BY5? And I'm assuming I can still use the 6x5? Plus, I've also seen pin 7-8 tied together. Did anyone figure the pin 7-8 thing out yet? I'd appreciate any help I can get. Thanks Ian.