ampage
Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

 
Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  
  View Thread

What does these resistors do (DR/SR)?

12/5/1999 7:29 PM
Bjorn
email
What does these resistors do (DR/SR)?
In the BF DR it’s (AB763) very few differences when compared other AB763 amps such as the BF SR.  
 
1. The resistor by the bias pot in the DR is 10K compared to 27K in the SR. Is this due to the differences in the power transformer?  
 
2. There is also a difference in the ground resistor by the driver (I think it’s called so). In the DR it’s 47R and in the SR 100R. Why is this so? I tried 47R in the SR – it sounded brighter, almost as if reducing the negative feedback. With the strat there was a hint of oscillation, which disappeared when switching back to the 100R again. The DR sounded a bit duller when using the 100R as compared to the 47R. What does this resistor do?  
 
Bjorn  
 
 
 

 
Replies:
Jim S. 1. The main reason for the differe... -- 12/6/1999 4:02 AM