bluebird
Well-known member
I fixed a Tube Tech LCA 2B for a friend and noticed it used a 12AT7 for a varimu tube. Its a standard PRR varimu topology plus an added tube output stage. I know a 12AT7 can supply a lot more current than the rest of the 12A*7 family but it dies pretty quickly with diminishing grid voltage.
A 6386 at 100v will do about 5mA at -6V grid. The 12AT7 is in the uV range at that voltage. I can't even read it on the graph.
Its not a bad sounding compressor even though it poops out kina soon but it does a lot better that I thought a 12AT7 would do. The grid voltage balance is a neat idea too.
The whole schematic can be found here:
http://schematic.danrudin.com/index.php?dir=Tube-Tech/
A 6386 at 100v will do about 5mA at -6V grid. The 12AT7 is in the uV range at that voltage. I can't even read it on the graph.
Its not a bad sounding compressor even though it poops out kina soon but it does a lot better that I thought a 12AT7 would do. The grid voltage balance is a neat idea too.
The whole schematic can be found here:
http://schematic.danrudin.com/index.php?dir=Tube-Tech/
