OTL
Hi,
LOL.
The powerxformer is the most important component in any OTL design.
No wonder Futterman didn't use one.😀
Joel,
I hope you don't use your OPT as a powerxformer and vice versa?
Ciao,😉
Hi,
LOL.
The powerxformer is the most important component in any OTL design.
No wonder Futterman didn't use one.😀
Joel,
I hope you don't use your OPT as a powerxformer and vice versa?
Ciao,😉
re: non push-pull 1952
I have another copy of the scheme in my files and it uses 4 tubes (8 sections). Had built this in the early eightys, with a smaller inductor ~ 300mh as the 600mh wasn't available surplus. The orignal artical had the amp set up for two 16 ohm in parallel or series. As I remember it was 9 -10 watts into 8 ohms. Drove old Quads well as well as Altec 604s. The output topology is almost indentical to Pathos 'inpol' output stage, just lower voltage and add fets. The inductor makes this a useable design, but a 600mh 2A choke ain't cheap, or small. I do have around 50 pcs of 6336, so thats not a problem.
I have another copy of the scheme in my files and it uses 4 tubes (8 sections). Had built this in the early eightys, with a smaller inductor ~ 300mh as the 600mh wasn't available surplus. The orignal artical had the amp set up for two 16 ohm in parallel or series. As I remember it was 9 -10 watts into 8 ohms. Drove old Quads well as well as Altec 604s. The output topology is almost indentical to Pathos 'inpol' output stage, just lower voltage and add fets. The inductor makes this a useable design, but a 600mh 2A choke ain't cheap, or small. I do have around 50 pcs of 6336, so thats not a problem.
OTL
Hi,
Scottnixon,
Can you tell us why you would go for SE OTL as opposed to PP OTL?
If you have such a stash of 6336As you can build a PP OTL with only four of these tubes.
That would yield about 100W into 8 Ohm.
Just a thought...😎
Kristijan,
Thanks for the circuit diagrams.
Keep us informed on how you intend to build it.
Cheers,😉
Hi,
Scottnixon,
Can you tell us why you would go for SE OTL as opposed to PP OTL?
If you have such a stash of 6336As you can build a PP OTL with only four of these tubes.
That would yield about 100W into 8 Ohm.
Just a thought...😎
Kristijan,
Thanks for the circuit diagrams.
Keep us informed on how you intend to build it.
Cheers,😉
re: OTL
I offered the info on the SE amp because Joel was thinking about SE OTL output. I don't need or want high power otl amp personally. The last OTL I've done is a 6 watt 8 ohm SEPP with one input tube and one 6336. Was going to be a Sound Practices article, but magazine disappeared. In the '80's I built every 1950's OTL design I could find, just to see which one did what. Kinda drove my friends crazy, but it was interesting.
I offered the info on the SE amp because Joel was thinking about SE OTL output. I don't need or want high power otl amp personally. The last OTL I've done is a 6 watt 8 ohm SEPP with one input tube and one 6336. Was going to be a Sound Practices article, but magazine disappeared. In the '80's I built every 1950's OTL design I could find, just to see which one did what. Kinda drove my friends crazy, but it was interesting.
I actually drew the formula wrong before - it's
required gm=1000000/Zo
Sorry.
And of course, final Ro' will vary depending on Rk, which seems to be close to max gain (1) at 2Rp. So, for the 6080, we would use a load resistor of 560 ohms.
required gm=1000000/Zo
Sorry.
And of course, final Ro' will vary depending on Rk, which seems to be close to max gain (1) at 2Rp. So, for the 6080, we would use a load resistor of 560 ohms.
OTL
Hi,
I can well imagine.😎
Scott,
If you have any preferences re OTL SE you're welcome to share them of course.
Cheers,😉
Hi,
I can well imagine.😎
Scott,
If you have any preferences re OTL SE you're welcome to share them of course.
Cheers,😉
Re: Link for old cathode follower OTL
So, when they say "6080 (x4)" do they mean (2x4) eight triodes?
scottnixon said:
So, when they say "6080 (x4)" do they mean (2x4) eight triodes?
Re: Better view
Is it even a good idea to use a choke as the RL for a CF config? I would think we wouldn't want its high impedence characteristics.... That would increase its output impedence, wouldn't it? The smaller you make RL, the lower Ro' will be, is my understanding.
scottnixon said:
Is it even a good idea to use a choke as the RL for a CF config? I would think we wouldn't want its high impedence characteristics.... That would increase its output impedence, wouldn't it? The smaller you make RL, the lower Ro' will be, is my understanding.
OTL.
Hi,
Joel,
You are aware your 6080 circuit is very reminnecent of your headphone /preamp based on the 6SN7?
Reconsider the function of the choke in the cathodes too.
I'm sure your circuit would work although I'd hoped to see something more innovative.😀
Cheers,😉
Hi,
Joel,
You are aware your 6080 circuit is very reminnecent of your headphone /preamp based on the 6SN7?
Reconsider the function of the choke in the cathodes too.
I'm sure your circuit would work although I'd hoped to see something more innovative.😀
Cheers,😉
Come on Frank,
He's taken the half way consession on the grid leak resistors.
470K to 220K. ( I suggested 100k😉 ).
He's taken the half way consession on the grid leak resistors.
470K to 220K. ( I suggested 100k😉 ).
MY GOODNESS.
Hi John,
LOL LOL LOL...
Man...you're something else.😉
Errr..should be OTL OTL OTL.
Cheers,😉
Hi John,
LOL LOL LOL...
Man...you're something else.😉
Errr..should be OTL OTL OTL.
Cheers,😉
It'll be OK (probably)
Because the valves aren't matched.
If they were matched, it'd need 100K.
Do you understand why I say that?
Because the valves aren't matched.
If they were matched, it'd need 100K.
Do you understand why I say that?
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