I have found a schematic in a 1982 ussr ham magazine that I want to make, but I am a newbie on this topic.
-Note that "B" is Volts in Russian in the attached circuit-
1.How come this schematic does not need a HV supply?
http://www.tubes.ru/techinfo/HiFiAudio/6n23p.html
stated that the anode voltage=100V for the tube 6n23p
2.Can I just use regular 2n2222's for the KT602B transistors?
3.Is there a way to leave off the last part with the transistors?
4.Is there a way to only construct one channel to see how it works before making the other?
-Note that "B" is Volts in Russian in the attached circuit-
1.How come this schematic does not need a HV supply?
http://www.tubes.ru/techinfo/HiFiAudio/6n23p.html
stated that the anode voltage=100V for the tube 6n23p
2.Can I just use regular 2n2222's for the KT602B transistors?
3.Is there a way to leave off the last part with the transistors?
4.Is there a way to only construct one channel to see how it works before making the other?
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Rouslan,
Since this is from a ham magazine it is obviously not intended to be “hi-fi”. It may work adequately (barely) for ham voice purposes only. The anode voltage is probably run way low to accommodate voltages already present in the chassis. The plates are loaded with resistors values that are way too low for good distortion performance, and the emitter followers add a further non-linear load. You could raise B+, increase the plate loading resistors, replace the emitter followers with cathode followers - but then you’ve got a totally different amp. In other words, may I suggest abandoning this particular circuit and searching for a better headphone amp circuit in this forum?
Since this is from a ham magazine it is obviously not intended to be “hi-fi”. It may work adequately (barely) for ham voice purposes only. The anode voltage is probably run way low to accommodate voltages already present in the chassis. The plates are loaded with resistors values that are way too low for good distortion performance, and the emitter followers add a further non-linear load. You could raise B+, increase the plate loading resistors, replace the emitter followers with cathode followers - but then you’ve got a totally different amp. In other words, may I suggest abandoning this particular circuit and searching for a better headphone amp circuit in this forum?
He's right, why start at a disadvantage? There are all sorts of good quality designs, both with OPT and OTL, at this site.
I don't agree with the two replies. I think this circuit is OK. For your questions,
1. no need for HV, because you don't need the voltage range. You have a head phone, and its impedance is maybe 32 Ohms. 6v p-p output voltage will give you 150mW.
2. I think most NPN with enough dissipation will work.
3. No, you can't omit the transistor part. If so, the output impedance is too high and you will not have enough current.
4. Yes, you can construct only one channel.
1. no need for HV, because you don't need the voltage range. You have a head phone, and its impedance is maybe 32 Ohms. 6v p-p output voltage will give you 150mW.
2. I think most NPN with enough dissipation will work.
3. No, you can't omit the transistor part. If so, the output impedance is too high and you will not have enough current.
4. Yes, you can construct only one channel.
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