Does someone believe they do not? That's like believing the earth if flat. I can swap rectifiers alone and you'd swear it was a whole amp change, on my amp. That's not the slightest exaggeration.
I am highly incredulous of the "magic" of a rectifier. Thanks. I'm sure a bit of misbehavior leaks into the output of an amp/preamp, but whole amp change? Were the rectifiers themselves broken?
well build a circuit with low PSRR and then change things such that you get ringing on the transformer and I can believe it could cause an audible effect. However its easily measureable and fixable. No golden ears required.
I saw that and the ringing is pretty nasty. But, how much of that shows up on the output of the amp after everything?
Take a look at the flux coupling data. Your can have an infinite PSSR but the flux coupling is probably going to limit you to less than 60dB and then look at Fletcher Munson curves and I suspect you will get why the power supply noise shows up as a loss of midrange detail.
So what are your plans after next week?
Ed: Who is your dealer. I need some of whatever you are on 🙂
More seriously, what you just said makes no sense to me. If PSU noise is only 60dB down that is easily measurable. Most amplifiers sail through this test so I am clearly missing something.
More seriously, what you just said makes no sense to me. If PSU noise is only 60dB down that is easily measurable. Most amplifiers sail through this test so I am clearly missing something.
Still going, had some fun with my committee so it's being pushed.
Onward and upwards. 🙂
Flux coupling can be as high as 60 dB down. Most certainly not more than 90. But the flux is not the same as the full power supply. It certainly is measurable using even not very specialized gear. Just hook up an FFT analyzer across your chassis. Probably around .001 volts along the length. Drops by about 3 dB per octave.
Nothing was broken. Honestly I was very surprised too. The amp has ok PSRR. The difference on my amp vs. others was much more pronounced btw. I'm sure the differences between amplifiers will show it more and less to a degree. The point is really just that they can be very different.
The amp isn't CCS, btw. I think non-CCS amps probably respond a little more.
BTW I've found adding a filter for peaks in noise in rectifiers can change the sound of an amp an awful lot. For example I had 5 and 20mhz peaks, and adding a filter for that made the sound considerably smoother.
CCS I would normally translate as Constant Current Source. Which made me suppose you were referring to the input stage differential pair(s).
What does constant current supply mean in the context of a power amplifier?
I suspect the difference in diodes is heard more without one, is what I was trying to say. It seems numerous class A amps and such that use them tend to be lax on any sort of rectification choice, but for a dynamic power supply the differences seem to be much more apparent.
I have absolutely no personal interest in these, I just stumbled across it
on s.e.d. and passed it on since I know that at least someone here plays
with microphones.
Me, I'm taming a small flock of IF3602s instead 🙂
In s.e.d. they assumed that ON were killing devices on 6" wafers.
cheers, Gerhard
I still don't know where the constant current is. Class A amps do not per se consume constant current. They consume current constantly, but it varies with the signal level.
Maybe my misunderstanding.
How about high bias transistor vs almost zero bias, gain clone for example.
How about high bias transistor vs almost zero bias, gain clone for example.
OK, high quiescent current, somewhere in an amplifier, versus Doug Self-ish pure class B.
EDIT the latter has to be balanced and/or complementary, the former not. "God's Class A" requires just a resistive load and a transconductance to drive it.
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