[1] But if the volume pot is not that important why some audio designers select and use very expensive parts like precision stepped attenuators or rotary pot like Penny & Giles, TKD units ? is it just marketing ?
[1a] Hi i agree completely with what you say but the bigger damage to sound is done at the beginning of the chain
[2] Just to ramble a little i have a dac that imho is quite insensitive to incoming jitter an apogee rosetta 200 It converts quite well even the sound coming from the tv optical out that i guess is not the best at all
[3] Moreover the preamp can have a huge impact on sound more than the power amp for instance
Or the preamp stage in an integrated
[3a] I was looking at Burson units the best ones have stepped attenuators i guess for a reason
[4] i would be interested to read stories of people who had a volume pot replaced with a better one in their preamps/amps and what the results have been
1. Whether or not it's "
just marketing" depends on which "
audio designers" you're talking about, what product the part is in and who that product is aimed at. For example, Penny & Giles rotary or linear pots are extremely common in high end Pro-Audio equipment for two reasons: Firstly, they are very robustly engineered. This is vital because the pots maybe adjusted dozens or many hundreds of times a day, pretty much every day for years and by people (engineers) who typically don't personally own the equipment and therefore may not be especially careful/gentle with it. And Secondly, they are very precisely engineered. They're very accurate with low noise/distortion, which is important because there can be several of them "
in the chain" in series, starting with the the mic pre-amp pot virtually at the beginning of the chain, which could be amplified by as much as 1,000 times, by the end of the mastering process. In your case though (a consumer), it IS effectively "
just marketing" because the pots are NOT going to be subject to anywhere near the sort of physical abuse they have to endure in a studio/pro-audio environment AND because:
1a. True but anything you, the consumer does is NOT at the beginning of the chain, it's at the very end of the chain! The beginning of the chain is the musician/sound source, then comes the microphone and then the mic pre-amp (with a rotary pot), after that we'll have the trim pot on the desk and probably a further dozen or more subsequent pots in the chain, although for the last 1-2 decades more of these pots are now digital/virtual (though not necessarily all).
2. Any decent DAC, even a cheap one, should be insensitive to incoming jitter beyond the limits of audibility, regardless of optical or any other transport protocol.
3. Sure, if it's broken or faulty, otherwise it has no audible impact on sound let alone a "huge impact". Even the pots in mic pre-amps don't have a "
huge impact on sound" and their "impact" is probably up to about 1,000 times more "huge" than the impact of the pot on your speaker pre-amp!
3a. Professional mic pre-amp units always (as far as I recall) have stepped pots, mainly for the precise calibration they allow relative to the other input channels/mics. But again, this is at the beginning of the chain, pretty much every subsequent pot in the production chain is not stepped.
4. That would be a thread you should probably start in one of the other forums on head-fi, because this is the Sound Science subforum, not the Sound Stories subforum. Although, if "
what the results have been" are objective, then those results would be appropriate here.
[1] I did some experiments comparing a 10k log Alps Blue Velvet with a 10k log stepped attenuator with the resistors in series (not the very best) used as passive preamp ... in the same chain the sound was quite different.
[1a] And i preferred the stepped attenuator ... the system was more transparent, more detail ... better soundstage ... more dynamics.
1. I would very much like to see the results of those experiments, if as you claim, they show "
the sound was quite different".
1a. Hang on, are these the results of your "experiments"? If so, then you seem to have actually done some informal, subjective comparisons, NOT "some experiments"! And if so, you do NOT know if you actually compared "
a 10k Alps Blue Velvet with a 10k log stepped attenuator" or if in fact you just compared your perception/s!
Moreover the listening at low level to me is very telling. I listen for a sort of "completeness" in the sound. With all frequencies rendered at the same level ... i am also forced to do this for neighbours.
How is listening at low level "very telling" to you? The frequency response of human hearing/perception is NOT the same at different listening levels, see "equal loudness contours". So, "
a sort of completeness in the sound with all the frequencies rendered at the same level" at a typical listening level will NOT sound like "
all the frequencies are rendered at the same level" at a low listening level, it would sound significantly bass light.
[1] But in the consumer audio (more than on professional audio) strange things happen. For instance they do not use connectors already available, cheap and superior by design (BNC) in favour of RCA hugely expensive.
[1a] Even for digital signals RCA are everywhere.
[1b] Not so for scopes where the signal integrity and quality of transmission is a must. A strange world.
[2] If the goal is to reproduce the recordings what is the reason of eq it again ? i do not understand
1. Sure, there are some silly audiophile RCA cables that are "hugely expensive" but standard RCA connectors are no more expensive that BNC connectors. And, BNC connectors are almost never used for analogue audio signals, even in professional audio. In pro-audio, unbalanced analogue audio signals virtually always use 1/4" Jack connectors and balanced uses XLR.
1a. Again in pro-audio, BNC is virtually never used for digital audio signals, with the exception of some MADI variants. Typically it's XLR again or d-sub connectors for multi-channel.
1b. Scopes are one of the few applications where I've seen BNC connectors for (unbalanced) audio connections. BUT, using a BNC connector is not necessarily the "
superior by design" choice. A connector that simply pulls out (does not lock) is the superior design in some situations. For example, in a consumer situation, where the cables might be exposed and caught/tripped on, it's obviously "superior" to just have the cable pull free rather than pulling the connected unit to the ground. And, if electric guitars used BNC connectors instead of jacks, quite a few guitarists would have inadvertently snapped their own necks, which in music circles would be decidedly "un-cool" compared to drug or alcohol overdose, suicide or being shot to death!
2. Two potential reasons: Firstly, personal preference, for example "bass-heads" EQ significantly more bass and Secondly, when reproducing recordings, the speakers/HPs, listening room acoustics or an individual's hearing may not have the frequency response expected by those who created the recording, in these cases EQ can often be used to somewhat compensate.
G
