On other fronts, I played around a bit more with Pico's loading resistors for SixPack. I found a spot (4K7) where they deliver a nice even ramp of harmonics. (Without the loading the ramp is still monotonic, but not as even.)
Nice one.
Now you have another toy to play with.
You can never have too many toys. Hahahahaha
Some people actually like the sound of tubes.
What ever pleases your ear.
I find it works well when it is applied in one area only.
A DAC should be zero distortion.
Agreed, that is the best way if a little distortion is wanted.
Only good for masking other problems in reproduction system though, IMHO. It may take a lot of work and puzzling through symptoms to get the point where clean, ultra-low distortion sounds really good. People can be fooled by 'false brightness' that can be mistaken for clarity. Happens very commonly. Some 2nd order HD can sort of thicken up the sound to make it seem more balanced. Bad dac is a good place to start looking. Very hard to make a good one.
Just sayin'
On other fronts, I played around a bit more with Pico's loading resistors for SixPack. I found a spot (4K7) where they deliver a nice even ramp of harmonics. (Without the loading the ramp is still monotonic, but not as even.)
I’m guessing you have already corrected the actual circuit. It looks like Q3 in your schematic is the wrong polarity.
Ooops. One of the downsides of using different simulation and schematic capture programs....
Thanks for catching that!
Rewind a bit to my last foray with BuzzBomb and you might remember that I couldn't get the second differential to drive enough output pairs to survive shorting the output.
In a completely unrelated conversation someone asked what I thought of the Hitachi topology with pucks. Ah ha!
(They may not say it but Pico and Itsmee are thinking "told you so".)
Ignore the gain, FR, slew rate and margins. I haven't recalculated them yet....
In a completely unrelated conversation someone asked what I thought of the Hitachi topology with pucks. Ah ha!
(They may not say it but Pico and Itsmee are thinking "told you so".)
Ignore the gain, FR, slew rate and margins. I haven't recalculated them yet....
Just be aware, many of the pucks don’t like to be run at high voltages into class A linear operation, at least that’s what the ixys engineer told me. Many of the devices develop hot spots on the die which can lead to failure, apparently, there are a few that don’t have this problem. At 30V Vds it might not be as much of a problem compared with 50v Vds.
Gentlemen,
The buzzbomb needs a pair of drivers in my humble opinion, I don't think cascodes are the solution for the output stage.
See Goldmund schematic.......
Jam
He went to cascode to reduce Vds and dissipation on pucks not for performance reasons.
Many of the pucks suffer from hotspots when operated in linear class A mode, espescially at high Vds (eg 52V) and bias currents.
I tried to suggest to the IXYS engineer that his testosterone levels weren’t quite as high as mine and I am member of the FAB gang and not to be messed with but he assured me, even with testosterone levels as high as mine I would be pushing the parts into failure.
He mentioned to me a few parts that would work but I can’t specifically remember what the parts were and I don’t have access to my work email.