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That's interesting JM, I didn't realise it was so easy to build one.
I got the DA4084 for about $170. It was (relatively) cheap because it's the version without the low-distortion oscillator built in: you have to supply your own and it locks to whatever frequency you put in. I planned to use my computer audio interface, but I didn't realise that the THD spec for that only applied inside the audio band: it pumps out about 0.1% THD worth of ultrasonic crud. That was fine for testing the Crown, because it can't amplify much above 20kHz, and filters it all out. But solid-state power amps let it all through: in the long run I need to build an oscillator.
There is absolutely no need to own a distortion analyzer if you design tube guitar amps. You're not trying to minimise distortion, but to make lots of raunchy sounding distortion! The analyzer can't tell you how good the distortion is sounding, you really do have to tune it by ear. It's more like cookery than science
I imagine the "clean" channel on an old Fender is probably about 5% THD, but it does absolutely no good to know that, any more than knowing that your homebrewed beer was 4.32% alcohol.
I got the DA4084 for about $170. It was (relatively) cheap because it's the version without the low-distortion oscillator built in: you have to supply your own and it locks to whatever frequency you put in. I planned to use my computer audio interface, but I didn't realise that the THD spec for that only applied inside the audio band: it pumps out about 0.1% THD worth of ultrasonic crud. That was fine for testing the Crown, because it can't amplify much above 20kHz, and filters it all out. But solid-state power amps let it all through: in the long run I need to build an oscillator.
There is absolutely no need to own a distortion analyzer if you design tube guitar amps. You're not trying to minimise distortion, but to make lots of raunchy sounding distortion! The analyzer can't tell you how good the distortion is sounding, you really do have to tune it by ear. It's more like cookery than science
I imagine the "clean" channel on an old Fender is probably about 5% THD, but it does absolutely no good to know that, any more than knowing that your homebrewed beer was 4.32% alcohol.
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