I'm playing some 'what if' games with a set of tubes, and I could use some help.
Imagine a SEP stereo amp built around the oddball 50C6G tubes. Essentially identical to the 6Y6, except with 50 volt @ 150ma heaters.
So two output tubes will either require 100 volts @ 150ma (series) or 50 volts @ 300ma (wired parallel) for the heaters.
Now, I need a voltage amplifier tube or tubes.
Looking around at octal tubes (because I like octal tubes), I find the 12SL7GT and the 12J5GT as possibilities. The 12SL7GT is a twin triode and the 12J5GT is a single triode. All have 150ma heaters at 12.6 volts.
Now, it seems to me that if I use one 12SL7GT and two 50C6G tubes, and wire the heaters in series, I'm looking at a transformer that will provide 112 volts and 150ma. Basically an isolation transformer will do the job with a little work.
Or, I could wired the tube heaters individually. Then I'd need a transformer that puts out 50 volts @ 300ma and 12.6 volts at 150ma.
Moving on to the 12J5GT, since each tube is only a single triode, I'd need to either wire 2 of them in series with 2 50C6G tubes for a total of 125.2 volts @ 150ma, or wire each heater separately, requiring 50 volts @ 300ma and 12.6 volts at 300ma.
There are other permutations of serial and parallel, but the numbers begin to boggle the mind.
So basically, I'm trying to figure out what sort of power transformer I will need to supply the heaters.
In any case, B+ will be something less than 200 volts. These tubes don't require much to sing, apparently.
What are your thoughts on a proper power transformer and configuration for this mess?
Are there any 'gotchas' or am I making any stupid mistakes?
Thanks!
Imagine a SEP stereo amp built around the oddball 50C6G tubes. Essentially identical to the 6Y6, except with 50 volt @ 150ma heaters.
So two output tubes will either require 100 volts @ 150ma (series) or 50 volts @ 300ma (wired parallel) for the heaters.
Now, I need a voltage amplifier tube or tubes.
Looking around at octal tubes (because I like octal tubes), I find the 12SL7GT and the 12J5GT as possibilities. The 12SL7GT is a twin triode and the 12J5GT is a single triode. All have 150ma heaters at 12.6 volts.
Now, it seems to me that if I use one 12SL7GT and two 50C6G tubes, and wire the heaters in series, I'm looking at a transformer that will provide 112 volts and 150ma. Basically an isolation transformer will do the job with a little work.
Or, I could wired the tube heaters individually. Then I'd need a transformer that puts out 50 volts @ 300ma and 12.6 volts at 150ma.
Moving on to the 12J5GT, since each tube is only a single triode, I'd need to either wire 2 of them in series with 2 50C6G tubes for a total of 125.2 volts @ 150ma, or wire each heater separately, requiring 50 volts @ 300ma and 12.6 volts at 300ma.
There are other permutations of serial and parallel, but the numbers begin to boggle the mind.
So basically, I'm trying to figure out what sort of power transformer I will need to supply the heaters.
In any case, B+ will be something less than 200 volts. These tubes don't require much to sing, apparently.
What are your thoughts on a proper power transformer and configuration for this mess?
Are there any 'gotchas' or am I making any stupid mistakes?
Thanks!