50 Ohm 5w 10 turn wirewound resistors at a great price

[Paul Birkeland]

Hiss or noise can drive you insane with Highly efficient 105 dB 1W / 1M speakers. A 270 degree pot makes it very difficult to get the noise to a minimum.

With Paramounts and wiring for 4 Ohm impedance, you should be able to get the noise floor down into the hundreds of microvolts (less than 0.0008V) with the stock pot. 

-PB

[Paul Joppa]

Historical clarification: I think Grainger had the older 50-ohm pots before he replaced them with 10-turn pots; all our present designs (including the Paramount mentioned by PB) use a 10-ohm pot with a series 22-ohm resistor on each side, giving 5 times the resolution. Grainger's experience with the single pot was the same as ours, which is why we made the change.

[wylymon]

The paramounts are currently set for 8 ohm. I will change to 4 Ohm and see if that solves the issue. Thanks everyone for your help. Best Regards, James

[2wo]

My 300B amps have a bit of low level hum and I suspected it was from the AC heating. I had one on the bench a while back with the thought of changing to DC or other form of supply. But when I hooked up the scope I am able to easily zero out whatever component is contributed by the 300B filament. the bad news is there is still some hum. these were one of my first DHT projects, I may well have some copulating issues or noise from the driver stage. I am using some old stock WW pots that are about 1.5" in diameter, so maybe that buys me something...John         

[Doc B.]

I may well have some copulating issues