Hi,
This is one reason why I like to use tubes in preamps, it may well be masking detail but I find it unobtrusive.
@John Curl, I read how you shun away from using cap followers in MC preamps Why?
I use one in a valved preamp followed by a CCS with fine results.
Noise can't be totally suppressed but I'm with SY (if I read correctly) in that lowish levels of non-peaky noise is to be preferred over low noise but with peaks in the audio band.
Cheers,
@SY, really do appreciate your work. How about the ideal valve heater supply? I'm sure you're aware that all heater supplies couple back into the cathode through inter-electrode capicitance, right?
This is one reason why I like to use tubes in preamps, it may well be masking detail but I find it unobtrusive.
@John Curl, I read how you shun away from using cap followers in MC preamps Why?
I use one in a valved preamp followed by a CCS with fine results.
Noise can't be totally suppressed but I'm with SY (if I read correctly) in that lowish levels of non-peaky noise is to be preferred over low noise but with peaks in the audio band.
Cheers,
@SY, really do appreciate your work. How about the ideal valve heater supply? I'm sure you're aware that all heater supplies couple back into the cathode through inter-electrode capicitance, right?
That's a misnomer - usually when people say 'its just semantics' they're arguing over choice of words. However semantics is about meanings. So in my view the popular use of 'semantics' should be termed 'syntactics'
Broadband but far from flat. Like CFA there are accepted terms that don't work for everybody.
Not a biggie. I guess almost any unwanted signal is considered noise with some qualifying term.
Maybe we're really about this, Lexical semantics - Wikipedia, the free encyclopedia ...That's a misnomer - usually when people say 'its just semantics' they're arguing over choice of words. However semantics is about meanings. So in my view the popular use of 'semantics' should be termed 'syntactics'
As regards what is "not nice" about the PS, it doesn't take much investigation to see that it can get very messy, for numerous reasons. So, the big question is whether that effects the sound in any way that is audible ...
load current/signal dependent ps modulation is highly correlated with signal frequency content: you should see signal fundamental and half wave rectified harmonic series depending on the Class A/B mix
not much reason to call it "noise like" when it is a deterministic and relatively simple function of signal with perhaps some additional mixing with line frequency as rectifier conduction modifies ps impedance
not much reason to call it "noise like" when it is a deterministic and relatively simple function of signal with perhaps some additional mixing with line frequency as rectifier conduction modifies ps impedance
You will see it as IM "skirts" in the vicinity of signal and distortion spectral lines in amplitude spectrum.
Did those words have any sens ?john curl said:
Dither helps with digital. Symmetrical lines ( input transformers gives the best rejection) helps to reject current noise generated by voltages between grounds of different AC connected equipments.
We are talking about PSUs, and we do not consider what they are supposed to feed ?
We don't have the same needs if a PSU have to power digital converters, clocks, or analog class A, or class AB circuits.
We have to consider the effects of AC leakeages of RFI, RMI, random noises, (generated by any regulation circuits), internal impedance of the PSU (Dynamic behavior) and find the best compromise, depending of the need and situation.
I don't thing a little random noise (hisses) is a big problem for quality. Our brain discriminate-it very well from the musical signal. It can improve our comfort, in some situations. Any AC related noise is a problem, and dynamic distortion (Modulation noise) as well for analog.
If you are looking for what some call "high end hifi", i don' know any good solution other than batteries for sources.
Only one equipment connected to AC (power amp). Preamps on batteries, Digital sources connected with optical lines. AC ISOLATION !
Last edited:
I do not think so. We made direct listening comparisons, there seem to be no "secrets" in Parasound amplifiers.
Dejan,
AM transmitted musical content spectrum is limited to 5kHz. FM to 15kHz.
If there are -consistently- higher frequencies than these amplified at the receiving side, they are harmonic and intermodulation distortion products (easily produced at the detector and/or the stereo decoder section).
I still can hear 10-12kHz but with some 26+dB loss (rel mid freq).
...
Yes George, I know AM is limited to 5 kHz, which is why I mentioned it. Where would you have the crossover from mid to tweeter? It is mostly found well below the 5 kHz limit, so if somebody can't tell if it's working or not, I suggest that somebody has a seriously impaired hearing.
A "golden ear" he's not, that's for sure.
You are talking to one of those.
A year ago I was matching a tweeter and a FR driver. The tweeter had a 6dB/oct ~5-6kHz HP and the wide bander was filter less.
After I spent an hour or two listening for to decide on the polarity of the tweeter and fine tuning the drive on the two units (two amps), I was satisfied with the final settings and proceeded to make the temporary crocodile connections of the tweeter into permanent.
It was then I noticed that one crocodile clip was not in contact with the tweeter’s terminal anymore. I couldn't say for how long there was no electrical connection but I was shocked with my handicapped listening conclusion.
I run a test again with tweeter unconnected and reconnected and I wasn’t sure I could say which is which with confidence.
I made a freq sweep and recorded the output with a mic at the listening position. The graph showed that the tweeter smoothed the response above 7-8kHz and added some 2 db at 12kHz
(at a later time I LP the widebander too. Then the difference the tweeter made was clear to my decorative ears)
George
George, there are several possibilities here.
You might have used musical material which had little but the harmonics above the crossover point.
The tweeter might have become disconnected seconds before you noticed it.
You might have had the tweeter polarities mixed up and in opposition L to R.
Your hearing may have significant losses above a point, because after all, it doesn't just plummet down, it gradually rolls off (the hearing).
I honestly feel blessed that I can still hear 16 kHz 10/10 if it's a single sine wave, although I need about twice the power relative to 1 kHz. At least, I'm still better than the stereo FM range.
You might have used musical material which had little but the harmonics above the crossover point.
The tweeter might have become disconnected seconds before you noticed it.
You might have had the tweeter polarities mixed up and in opposition L to R.
Your hearing may have significant losses above a point, because after all, it doesn't just plummet down, it gradually rolls off (the hearing).
I honestly feel blessed that I can still hear 16 kHz 10/10 if it's a single sine wave, although I need about twice the power relative to 1 kHz. At least, I'm still better than the stereo FM range.
- Status
- Not open for further replies.