| ampage Tube Amps / Music Electronics |
For current discussions, please visit Music Electronics Forum. |
ampage archive
Vintage threads from the first ten years
| previous: Ben Hi, |
 |
|---|
Re: Ideas on biasing
 8/17/2000 5:21 PM |
|
| kg | Re: Ideas on biasing ben, it can certainly be done. something to keep in mind is that the CCS has a minimum voltage which must be maintained across it in order to function. thus you might need to impliment a negative supply rail. is this for a SE or PP application? i have seen schematics for using a mosfet in the (shared) cathode circuit of a PP amp, but the outputs were run in class A. the advantage of the mosfet is that they draw no grid current, so that you can bias them VERY quietly with a simple 9V battery. it will last years in that kind of service. the other advantage in a PP amp is that it raises the CMRR, so that you will get even LESS noise injected by the phase splitter and output stage. there was some talk on here a while back about using 3 terminal voltage regulators as CCS's with the intent of biasing output stages. the dropout voltage is higher with that kind of approach, but it has simplicity going for it. iirc, someone actually TRIED it out. kg |
|---|---|
| Replies: |
| Ben Thanks for the reply Ken. |