I would like to change my hi-gain VTA board in my ST-70 to a lo-gain. I have aready replaced the center tube with a 12AU7. I would like to know which resistors I change, and to what value.
thanks,
Bill
thanks,
Bill
2 posters
Changing VTA board to lower-gain
myaddiction- Posts : 15
Join date : 2009-03-27
Bob Latino- Admin
- Posts : 3277
Join date : 2008-11-26
Location : Massachusetts
Hi Bill,
Below are the resistor sets for the standard gain and the lower gain driver boards. The numbers on the right side are Mouser Electronics part numbers. Some of the numbers could be out of date and changed.
An asterisk notes which resistors are different between the two board configurations
Unless noted all resistors are 1/2 watt
R40 - R43 are not on the board but are the 4 bias resistors
R44 is a 2.2K resistor that is not on the board but goes between sections 3 and 4 of your quad cap
Bob
Below are the resistor sets for the standard gain and the lower gain driver boards. The numbers on the right side are Mouser Electronics part numbers. Some of the numbers could be out of date and changed.
An asterisk notes which resistors are different between the two board configurations
Unless noted all resistors are 1/2 watt
R40 - R43 are not on the board but are the 4 bias resistors
R44 is a 2.2K resistor that is not on the board but goes between sections 3 and 4 of your quad cap
Bob
myaddiction- Posts : 15
Join date : 2009-03-27
Bob thanks. You mention the (4) bias resistors, and the resistor on the quad cap, but there is not an asterisk by them. So I replace them also?
Bob Latino- Admin
- Posts : 3277
Join date : 2008-11-26
Location : Massachusetts
myaddiction wrote:Bob thanks. You mention the (4) bias resistors, and the resistor on the quad cap, but there is not an asterisk by them. So I replace them also?
No - You already have them there since you have the VTA driver board already installed.
Bob
myaddiction- Posts : 15
Join date : 2009-03-27
That's what I thought. Thanks!