The amp that didn't explode! Yet!

[nige2000]

The same PS consideration applies to the source & one of the possible reasons why vinyl is often preferred to digital source - I'm convinced that most digital sources suffer from this 'dynamic noise' (it's been my focus with all my devices) but vinyl only suffers from a higher 'static noise' floor, not a fluctuating "dynamic noise". This may be the reason Ivor prefers his vinyl sources - when an amplifier doesn't suffer from this noise fluctuation it no longer masks this issue in the source.

i think digital sources pc/dacs/streamers are more prone to noise than amplifiers
this is plainly seen with various ps mods
and you cant undo noise damage once its occured at source

[jkeny]

i think digital sources pc/dacs/streamers are more prone to noise than amplifiers
this is plainly seen with various ps mods
and you cant undo noise damage once its occured at source

Yes, agreed - the perceptual effect of eliminating/reducing this fluctuating noise is along the same lines in source or amplifier which leads one to the premise that the same fundamental mechanism underlies this i.e. fluctuating noise in audio reproduction devices is the most plausible explanation, at the moment.

AFAIK, no suitable method has yet been found/used to measure & show this effect as it requires a dynamic test signal, like music & a method for measuring the difference between signal & noise on the output - remember the measurement equipment needs to be free from such noise fluctuation to properly measure this effect

[nige2000]

is it not some type of modulation where one frequency affects another for example when two dissimilar instruments are playing negatively affecting one another
where improvements are heard as better instrumental clarity and a more individual, distinctive and accurate reproduction

these things are clearly audible with the sd card player vs usb solutions

another thing that seems to be affected is dynamics or speed thereof
the ability to have the power on demand to maintain the speed of the dynamic load

such things are likely warrant a thread of their own

it easily proves that there is much to be improved in current commercial designs

[jkeny]

is it not some type of modulation where one frequency affects another for example when two dissimilar instruments are playing negatively affecting one another

I don't think so as this would be easily seen in measurements & so far this hasn't happened

where improvements are heard as better instrumental clarity and a more individual, distinctive and accurate reproduction

these things are clearly audible with the sd card player vs usb solutions

My take on why we are perceiving these improvements is that noise which fluctuates depending on the ever-changing signal processing causes the start time of a sound to be not as well defined as when that noise is missing. Perceptually, the start time of sounds & the differences between timing of sounds reaching each ear (ITD) gives us our illusion of soundstage & distinctiveness of each instrument in that soundstage. A fluctuating noise & fluctuating timing of the start of sounds muddies this perception. This is particularly noticeable in the bass as this is where the ITD effect is strongest - above a certain frequency ( ithink 500Hz?) perception begins to rely on loudness differences (ILD) between sounds reaching the ears to define soundstage illusion.

another thing that seems to be affected is dynamics or speed thereof
the ability to have the power on demand to maintain the speed of the dynamic load

Yea, again this is a perceptual effect as there is no speed difference, it just appears that way. Again when the timing is accurately reproduced & doesn't fluctuate, the rhythm is nailed down & we are very sensitive to rhythmic sounds & their timing.
The other aspect that perception is very sensitive to & relies on, is the risetime of the signal - we use this attack portion of sounds to quickly define/categorise them. When this attack portion is without noise its inner detail is more clearly perceived & identified - quicker identification of exactly what is being heard.

such things are likely warrant a thread of their own

it easily proves that there is much to be improved in current commercial designs

Yep!!

[nige2000]

i was thinking of the likes of a-b amplifiers were say you feed it a 100hz signal it will surely cause a ripple on the ps at the same frequency now if you have put a 1khz on top of that
will the created noise from the 100hz signal not cause distortion to the 1k frequency because of the 100hz created ps noise
i would have thought the same happens to dacs i suppose all depending on loading

maybe im way off the mark

[jkeny]

i was thinking of the likes of a-b amplifiers were say you feed it a 100hz signal it will surely cause a ripple on the ps at the same frequency now if you have put a 1khz on top of that
will the created noise from the 100hz signal not cause distortion to the 1k frequency because of the 100hz created ps noise
i would have thought the same happens to dacs i suppose all depending on loading

maybe im way off the mark

Right, I get you - we are pretty much saying the same thing except, I'm talking about intermodulation products that also occur between the two frequencies 100Hz & 1KHz which you will see on an FFT. If you do a multitone test where lots of concurrent frequencies are being processed you can see the intermodulation distortions between these frequencies as the 'grass' on an FFT i.e. all the intermodulation products from all the frequencies are falling in between the frequency tones & giving rise to what would be considered noise. Now if you think about music where there are lots of different frequencies being processed concurrently & serially, this noise is modulating like a sea depending on the pattern of frequencies being processed. I believe this modulation of the noise is what is being perceived as disturbing.

With a much more stable PS the modulation products that result from fluctuating noise within the PS are removed so no more sea-sickness with the modulation & I believe this is what we are perceiving

So, rather than one frequency being directly effected by the other, I think it's what is happening to the noise floor that is disturbing our perception

Yes, it seems to be a general principle that can occur in amps & in DACs (the analogue circuitry in DACs is much more sensitive to such disturbances on its ground reference)

But the disturbance is more benign on analogue gear - maybe because there's a higher noise floor & this swamps any modulations?

[jkeny]

I see you are spreading the word, Nige - your post about this amp on DIYAudio is bound to get lots of attention

http://www.diyaudio.com/forums/pc-based ... 60551.html

[nige2000]

I see you are spreading the word, Nige - your post about this amp on DIYAudio is bound to get lots of attention

http://www.diyaudio.com/forums/pc-based ... 60551.html

I think it Got pretty much ignored as a power solution there
Diyaudio can be funny at times
Not one question
I thought it was relevant because running caps in series is a similar situation

I get the feeling it will get dubious attention if it's posted in the amp section
Don't have the energy to defend against the naysayers

[jkeny]

I see you are spreading the word, Nige - your post about this amp on DIYAudio is bound to get lots of attention

http://www.diyaudio.com/forums/pc-based ... 60551.html

I think it Got pretty much ignored as a power solution there
Diyaudio can be funny at times
Not one question
I thought it was relevant because running caps in series is a similar situation

I get the feeling it will get dubious attention if it's posted in the amp section
Don't have the energy to defend against the naysayers

Yea, I've seen lots of people on there still claiming batteries are noisy under load (of course they've never tried them)
They also want to do the complex PS - like the Uptone LPS1 - 2 banks of ultracaps - at any one time, one is powering circuit & other is being charged - then they switch over. Way too complex for little sonic reward - they have to use a voltage regulator on output as ultracaps start dropping voltage as soon as power is drawn!!

Anyone who owns an LPS1 & has tried my ISO-PS battery power have said the ISO-PS sounds noticeably better :)

[nige2000]

yea i think there overcomplicating it
switching between charge and discharge seems like a real pain
if the caps cant function 'as good' in a normal simultaneous charge/discharge situation
im really not seeing the point

if that uptone ps has regulation post caps, surely going to seriously inhibit potential?