GE, who 1st developed mag. carts., devised a circuit around the 6SC7. I've attached a schematic of a Fisher unit that followed GE's lead.
A number of changes are necessary to use modern mag. carts. The I/P resistor has to be 47 KOhms and the HF roll off is achieved by placing a cap. across the O/P.
I'm working with a fellow who has a pair of the Fisher mono units. Perhaps he will be willing to provide a scan of the regulated PSU that was devised, with help from the "crowd" here.
BTW, that cicuitry will work with a 'SL7 or a 5751. Don't forget a DC heater supply.
A number of changes are necessary to use modern mag. carts. The I/P resistor has to be 47 KOhms and the HF roll off is achieved by placing a cap. across the O/P.
I'm working with a fellow who has a pair of the Fisher mono units. Perhaps he will be willing to provide a scan of the regulated PSU that was devised, with help from the "crowd" here.
BTW, that cicuitry will work with a 'SL7 or a 5751. Don't forget a DC heater supply.
Attachments
alexg said:
(I have a 130-0-130 ptx )
Thanks.
With this PT you can also get 300V B+
arnoldc said:Hi Eli, that looks nice and simple. Does your friend like the sound?
Arnold,
The project is not complete. So, no comments are available. FWIW, Avery Fisher's ears were quite decent.
A couple of threads regarding the matter can be found on AA. Search against the Tube and Tube DIY forums.
Edit: fixed typo
Re: Re: phonostage with 150VDC B+
How do I do that? Voltage doubler?
Thanks.
revintage said:
With this PT you can also get 300V B+
How do I do that? Voltage doubler?
Thanks.
Thanks for the input.
I think I can adopt my ptx for Thorsten designed circuit (12ax7/6dj8) phonostage.
BTW, how do you compute for the voltages using the hybrid rectifier (two diodes and a tube rectifier). do multiply the voltages from the diodes with 1.41 and use that to simulate using PSUD2?
Thanks.
I think I can adopt my ptx for Thorsten designed circuit (12ax7/6dj8) phonostage.
BTW, how do you compute for the voltages using the hybrid rectifier (two diodes and a tube rectifier). do multiply the voltages from the diodes with 1.41 and use that to simulate using PSUD2?
Thanks.
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