Finally got a couple of winged Svetlana 6H13C, I found on the net several schematics using as first stage ECC88/6DJ8/6922, 6SN7, 5687, wich one have the best sound quality?
otl...🙄
most of sound signature comes from driver..
you can improve this nonsense by implementing ccs instead Rc endstage
most of sound signature comes from driver..
you can improve this nonsense by implementing ccs instead Rc endstage
Thanks guys, really appreciate the help.
I still have some several questions:
I have some Sylvania 7N7 with a very good SQ, I guess I can use in place of 6SN7 without change anything?
It's necessary to parallel the Svetlana 6H13C or with one is OK for a load of 300 ohms?
What's the power rating necessary for the cathode resistor of Svetlana 6H13C?
What are the requirements necessary for the PT for B+ & heaters?
Heaters DC or AC?
TIA for support.
I still have some several questions:
I have some Sylvania 7N7 with a very good SQ, I guess I can use in place of 6SN7 without change anything?
It's necessary to parallel the Svetlana 6H13C or with one is OK for a load of 300 ohms?
What's the power rating necessary for the cathode resistor of Svetlana 6H13C?
What are the requirements necessary for the PT for B+ & heaters?
Heaters DC or AC?
TIA for support.
What impedance headphones do you intend to drive? All of those circuits would do a terrible job of driving modern low impedance headphones.
If you insist on OTL tube circuit then look up "super triode." This is a configuration where a triode controls a MOSFET. Bias it with a CCS.
If you don't know how to do this, then build a simple op amp based headphone amp. It'll work a whole lot better.
And don't rely on circuits on the web. That first circuit is oh so poorly thought out and wouldn't work properly even as a preamp. (f3 = 159 Hz STUPID) Somebody didn't put their thinking cap on, because it could be massively improved just by changing a few component values. What a waste.
If you insist on OTL tube circuit then look up "super triode." This is a configuration where a triode controls a MOSFET. Bias it with a CCS.
If you don't know how to do this, then build a simple op amp based headphone amp. It'll work a whole lot better.
And don't rely on circuits on the web. That first circuit is oh so poorly thought out and wouldn't work properly even as a preamp. (f3 = 159 Hz STUPID) Somebody didn't put their thinking cap on, because it could be massively improved just by changing a few component values. What a waste.
OTL amps using the 6H13 are an insane waste of iron, space and energy, dual is even worse.
Just for the heating you will need close to 6A of supply. When you don't know how to build this either go read up on it
(it is ALL on the internet) or build something else. When you look closely you will find the power rating
you were asking about in the first posting by you, for instance.
A single tube doesn't have a SQ.... that's a myth. Only a tube properly employed in a circuit can be judged.
You have too many questions after so many years. Sorry.
Have a good sunday.
Just for the heating you will need close to 6A of supply. When you don't know how to build this either go read up on it
(it is ALL on the internet) or build something else. When you look closely you will find the power rating
you were asking about in the first posting by you, for instance.
A single tube doesn't have a SQ.... that's a myth. Only a tube properly employed in a circuit can be judged.
You have too many questions after so many years. Sorry.
Have a good sunday.
http://www.diyaudio.com/forums/tube...dphone-project-ec88-6080-a-8.html#post3834514
Have a look. Only suitable for highish impedance headphones.
Have a look. Only suitable for highish impedance headphones.
This is the best circuit so far. It's simple, easy to troubleshoot, well thought out.
C3 = 0.5 uF for f3 = 1 Hz with values shown. Don't forget the output pole, which would be around 1 Hz with 300 ohm cans. Not bad.
C3 = 0.5 uF for f3 = 1 Hz with values shown. Don't forget the output pole, which would be around 1 Hz with 300 ohm cans. Not bad.
Yes. Constant current sources optimize distortion and increase power output, while the signal is handled by the tubes. It's an inverting circuit with global feedback.
From what I can see, the designer covered all his bases. Might need some tweaking; I haven't built it.
Do you know a little about tubes? If you do it should be simple to build.
I need to know how much current draws B+ and the heaters to know if I have on my stash the proper PT?
About 130mA (both channels) for b+. About 3A@6.3Vac for the heaters.
The output could be run hotter than 50ma but watch out the heat dissipation of the transistor, especially if you ommit c3 and r7. See the original thread for more info about that.
The output could be run hotter than 50ma but watch out the heat dissipation of the transistor, especially if you ommit c3 and r7. See the original thread for more info about that.
The Bottlehead Crack which is an OTL amp I have built and still use is such an amp. Many, many users of it swear by its quality with high impedance headphones.
I use Beyer T90's and T1's, 250 and 300 ohm respectively and they play very well with this OTL amp.
Alex
I use Beyer T90's and T1's, 250 and 300 ohm respectively and they play very well with this OTL amp.
Alex
What about to change the plate load resistor of ECC88 for a CCS?
N.B. Without the VR150 and the cap.
N.B. Without the VR150 and the cap.
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