Yup, IMD typically sounds like muddy LF crap present beneath strong HF content caused by poor HF linearity. Back in the day a simple listening test for IMD was to jingle some keys in front if a mic.. Keys have all kinds of >20kHz energy that stresses slow circuitry.mediatechnology wrote:Yes. And it was absent in the gritty one.By switching artifacts are you talking about crossover distortion (spikey looking in THD product)?
Grunge is also what I mean by grit.
Just dirty - like HF leakage through a pot.
Grunge is probably the better word for it.
(Though I tend to think of "Grunge" more as a genre.
Maybe "Grungre" would be the grunge genre. Did I invent a word?)
The base resistance is divided down by the power transistor's Hfe, but still significant in the context of 0.22 emitter degeneration. Beta is actually rising with higher current and higher temperature.I think that it is. While in the linear region maybe approximated by Re/2 plus some change?Your output stage not only goes ohmic, but probably is ohmic all the time.
What's also invisible are the series base resistors, 50 Ohms, hiding inside the DRV134.
The apparent curved "soft" clipping could come from one output device hard clipping so the summed output signal drops 6 dB, until the other output clips. I think I saw something like that before but can't remember where just now.
I used TO-220 output devices in my Peavey HP amp, but they were silly cheap so I didn't mind the overkill. Even though I drove speakers with it, I discouraged customers from doing so.Thanks for the compliment.Of course it should sound fine as is, and the extra complexity will detract from it's elegance that such customers will embrace.
It seems ultra simple to make from something I already had.
People seem to like the transparency of the headphone amp.
radiance was one of the first to build one that I'm aware of besides me.
I dunno how many people that have bought the boards have actually used one for a line amp but I do sometimes hear from those that have used it for 'phones.
Roger uses it in the FCS Class-A to drive transformers.
The bigger output devices kick up the power up a few notches.
Glad we can get TO-3P devices with good gain and BW.
BTW it slews around 10V/uS with the DRV134 which is a little more than I get with the THAT1646 at around 8V/uS.
JR