7591 or 7591A for Eiclone?
Posted:
Sat Oct 30, 2004 7:24 pmby Norris
Hi Everyone,
I have a silly question, could a 7591 or 7591A be used succeessfully with the Eiclone circuit?
It is obvious that I do not have a great deal of experience here, but would like to ask for help before I dive into research so this tube can be applied.
Thanks
Norris Wilson
Posted:
Sat Oct 30, 2004 8:40 pmby TerrySmith
The main reason is the pinout is different. :shockingzap: And I forgot to mention they are EXPENSIVE! :eeeeek:
Posted:
Sat Oct 30, 2004 9:16 pmby erichayes
Hi All,
Norris, the easiest way to get around the base wiring differences on the 7591 is to use chassis-mount sockets with flying leads to the circuit board. As far as electrical compatability goes, the bias voltage or cathode resistors, depending on which bias system you choose, will have to be altered to accomodate the tube's spec's. And, even though the 7591 is rated at 550 volts max on the plate, I wouldn't run them with more than 400 volts in fixed bias mode (but that's me).
Now that New Sensor and someone else (JJ?) have come out with new stock 7591s at a reasonable price, we're no longer held hostage by the Mac 225 tube hoarders who pulled a Hunt Brothers on the NOS 7591 market.
This is what DIY is all about.