rafafredd
Well-known member
Hi. I am trying to come up with a simple DC amplifier for buffering variable mu Sidechain before it reaches the compression tube grids.
This is very useful for a series of reasons: faster attack times, simple ratio control, lower load on output tubes, etc...
But the circuit should stand up to -50v output for driving remote cutoff tubes to its maximum compression. Also, it should be able to provide DC gain (for ratio control), and have low output impedance.
This could be made into a small board and used to upgrade existing vari mu comps.
I was thinking about a pair of transistors with a feedbak loop, but I wasn't able to come up with a functional circuit, as I have no experience with DC amplifiers.
So, in the end, I am using high power opamps, like the LM3886 (overture series / gainclones) for this purpose with a single negative supply, connected like in the picture attached. It shows a simple DC amp with a gain of 10. I used an audio amplifier because that is what I know.
I though about posting and asking for opinions. Maybe someone knows there is a much better chip for this job, or maybe someone could help me come up with a simple discrete solution, like a transistor pair, that could be simpler and cheaper. A FET hiZ input and powerfull Darlington output sounds to me like a good idea. But I wasn't able to come up with a working discrete solution...
This is very useful for a series of reasons: faster attack times, simple ratio control, lower load on output tubes, etc...
But the circuit should stand up to -50v output for driving remote cutoff tubes to its maximum compression. Also, it should be able to provide DC gain (for ratio control), and have low output impedance.
This could be made into a small board and used to upgrade existing vari mu comps.
I was thinking about a pair of transistors with a feedbak loop, but I wasn't able to come up with a functional circuit, as I have no experience with DC amplifiers.
So, in the end, I am using high power opamps, like the LM3886 (overture series / gainclones) for this purpose with a single negative supply, connected like in the picture attached. It shows a simple DC amp with a gain of 10. I used an audio amplifier because that is what I know.
I though about posting and asking for opinions. Maybe someone knows there is a much better chip for this job, or maybe someone could help me come up with a simple discrete solution, like a transistor pair, that could be simpler and cheaper. A FET hiZ input and powerfull Darlington output sounds to me like a good idea. But I wasn't able to come up with a working discrete solution...