Hot Rod Deluxe Biasing "too high" at lowest point

[TerryD]

MY friends Hot Rod deluxe crapped out on him because his JJ 6L6s bit the dust.  I threw in a set of TAD 6l6s that I had on hand from an amp I bought.


I am biasing by the standard method of biasing these Hot Rod Deluxes as found on the internet.  Quite simple.



I am biasing the TAD 6l6s in the Deluxe but the lowest millavolts you can dial in is 76 but reccommended is 68 to 70.


What can I do?  Or will that be fine?


Thanks Terry

[sluckey]

Before doing anything, I'd try a different set of 6L6s. Those TADs may just be hotter than other 6L6s. Another brand of 6L6s may not need any modification. Fender set the bias on the cool side at the factory (60mA).

The Fender schematic calls for 60mV at pin 8 of the 6L6s. That's even lower. Increase the value of R77 to get lower current. R77 is currently 100K. Try 150K. Take that up/down to get what you want.

TIP... Rather than removing the board and actually unsoldering R77 correctly, I would snip the leads of R77 real close to the body of the resistor. Then tack solder a 150K resistor to the stubby leads of what was R77. You may have to try several different values such as 120K, 150K, 180K, 220K, etc. Once you have figured out the value you want then you can do it right.

[John]

Once you have figured out the value you want then you can do it right.

Or, just wrap the leads around the stubs, solder it, and drive Sluckey bonkers. 

[TerryD]

Thanks!