New two JFET SE Class A amp with superb harmonic profile.
http://www.diyaudio.com/forums/solid-state/301164-mosfet-source-follower-headamp-15.html#post4933888
http://www.diyaudio.com/forums/solid-state/301164-mosfet-source-follower-headamp-15.html#post4933888
That's a measurement I have never done.My work in progress, small preview. New(Old) Class A syncro-biased :
preliminary measurement
Looks like the tiny blip after equallising the voltage of the in/out is the phase delay of the out vs the in.
Does anyone agree?
What happens if you use the horizontal expand by 10?
Can you see where the blip coincides, near the beginning of the rise, or near the end?
Hi kct,
What oscilloscope are you using? Looks like some kind of Tektronix, but I can't place the model. It has an above average display from what I can see.
-Chris
What oscilloscope are you using? Looks like some kind of Tektronix, but I can't place the model. It has an above average display from what I can see.
-Chris
Hi Andrew, Chris,
well, I am using an old trusty Tektronix 2246A as a poor mans substitution for a real scope and before firing up the spectrum analyzer I felt this might be a good measurement to do. It would definitely show if I am grossly wrong with the amp somewhere...
I am using the calibrator output from the scope for this measurement as my signal generator is -really- crappy and totally unsuitable, the generator itself already produces terrible overshoots at the rising edge. This thing is ok for power measurements and general stuff but that's about it. Unfortunately the calibrator output is not steep enough for a meaningful test drive but gives a good feel for what to expect from the amp. I will likely repeat this measurement again with a decent signal source.
I don't won't to clutter this fine thread with my amateurish stuff here, so have a peek at my gallery I uploaded another screen shot with a finer time scale showing the same plot but with some music playing highs. I took another screen shot but have not gotten around yet to upload. I will try to upload it soon.
Feel free to PM me if you have questions.
Happy New Year BTW...
well, I am using an old trusty Tektronix 2246A as a poor mans substitution for a real scope and before firing up the spectrum analyzer I felt this might be a good measurement to do. It would definitely show if I am grossly wrong with the amp somewhere...
I am using the calibrator output from the scope for this measurement as my signal generator is -really- crappy and totally unsuitable, the generator itself already produces terrible overshoots at the rising edge. This thing is ok for power measurements and general stuff but that's about it. Unfortunately the calibrator output is not steep enough for a meaningful test drive but gives a good feel for what to expect from the amp. I will likely repeat this measurement again with a decent signal source.
I don't won't to clutter this fine thread with my amateurish stuff here, so have a peek at my gallery I uploaded another screen shot with a finer time scale showing the same plot but with some music playing highs. I took another screen shot but have not gotten around yet to upload. I will try to upload it soon.
Feel free to PM me if you have questions.
Happy New Year BTW...
Hi kct,
Nothing wrong with your scope at all. I wish my 2465B looked as good.
Look on Ebay for "Ultra low distortion (<0.00005%) 10kHz sine generator assembled and tested PCB". It was $50 US and represents great value. One of our members has this store and it's all his design. It can be had in 1 KHz and 10 KHz. You're going to have a difficult time finding a better oscillator. I have one of each version coming, so I've put my $$ where my mouth is.
-Chris
Nothing wrong with your scope at all. I wish my 2465B looked as good.
Look on Ebay for "Ultra low distortion (<0.00005%) 10kHz sine generator assembled and tested PCB". It was $50 US and represents great value. One of our members has this store and it's all his design. It can be had in 1 KHz and 10 KHz. You're going to have a difficult time finding a better oscillator. I have one of each version coming, so I've put my $$ where my mouth is.
-Chris
New two JFET SE Class A amp with superb harmonic profile.
http://www.diyaudio.com/forums/solid-state/301164-mosfet-source-follower-headamp-15.html#post4933888
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Very nice. Would you dare compare it to Mimesis or A33/40? I would like to hear your impressions. Thanks.
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Single Ended Class A Pocket Handwarmer.
BF862 input stage and ZVN4306GTA output running 67mA bias.
http://www.diyaudio.com/forums/solid-state/301164-mosfet-source-follower-headamp-25.html#post4945242
BF862 input stage and ZVN4306GTA output running 67mA bias.
http://www.diyaudio.com/forums/solid-state/301164-mosfet-source-follower-headamp-25.html#post4945242
3055 Retro Stripboard Amp
I build this amp last year to gain some experince for my current project, the honey badger on stipboard. Also I like the old and simple 3055 designs. Of course not the best sound quality but I like it nevertheless. Currently I am using it with my 'Das Viech' speakers which are awesome!
Schematic is from Elektor and a standard 70's design. Was recently published as a retro-amp.
I build this amp last year to gain some experince for my current project, the honey badger on stipboard. Also I like the old and simple 3055 designs. Of course not the best sound quality but I like it nevertheless. Currently I am using it with my 'Das Viech' speakers which are awesome!
Schematic is from Elektor and a standard 70's design. Was recently published as a retro-amp.
kct, please also post an English translation along with any post in another language.
Sorry, it's one of the rules around here.
kct, please also post an English translation along with any post in another language.
Sorry, it's one of the rules around here.
Whoops.
Well then, I said that it doesn't look bad at all.