I posed this question elsewhwre, but perhaps this is the right place for it. Some audiophiles seem to feel that stepped-attenuators (DACT etc) thin-out the lower-mids. A poster here relates that; in past he's tried stepped attenuators, ladder type, with metal film resistor. Compared to common cheap carbon pot (like ALPS and some TKD) the sound of stepped was somewhat clearer, better soundstage, but overall the carbon pot sounds better, more musical, more natural.
Others, elsewhere go further to claim that the atts' clarity border on 'edginess', made more obvious by the atts thinner mids, compared to carbon pots, and other forms of volume-control.
Has anyone else here experienced this? And is there any stepped attenuator which actually sounds 'full', in the lower-mids?
Others, elsewhere go further to claim that the atts' clarity border on 'edginess', made more obvious by the atts thinner mids, compared to carbon pots, and other forms of volume-control.
Has anyone else here experienced this? And is there any stepped attenuator which actually sounds 'full', in the lower-mids?
the most 'correct' or 'clean' can easily lead to thin annoying sound
and with 'passive' att especially I would say its important to think 'synergy'
and with 'passive' att especially I would say its important to think 'synergy'
Actually, the criticisms I encountered were in the context of the stepped-atts' application in active pre-amps, in the quest for an upgrade in sound-quality. The detractors do acknowledge an increase in transparency, but they also claim this is at the cost of thinner lower-mids, which no other means of volume-control displays. Thanx for responding!
Part of the issue may relate to the specific switch(es) used in the stepped attenuator, AND the type, mfr, and WATTAGE of the resistors employed.
Some switches used for stepped attenuators work out to be essentially "point contact" switches, and imo that creates a problem sonically.
In general, speaking to this same issue, I do not like to use single contact relays, and greatly prefer multiple contacts in parallel whenever possible, and certainly in signal carrying application.
The resistor wattage, type and mfr issue has been spoken to in other threads, including some extensive testing... I prefer 1/2 watt MF for attenuators. Alternately paralleled 1/8, or 1/4 equalling 1/2 watt rating or better tests exceptionally well... fwiw.
Carbon pots have a distinctive sound, as do carbon comp resistors, and that is not neutral - so by comparison there may be some sort of audible difference that appears to some to be less "good".
I'd agree that for reasons that are entirely unclear, an awful lot of things *appear* to make the lower mids sound "thinner". What the heck is going on with this isn't entirely clear to me at all and in general. The odd thing about it is that back in the early 70's audio friends and I referred to the lower mids as the "mud frequencies". Getting *rid* of the mud was a big goal and not easy to do. By contrast it seems like today you can't *get* good lower mids like one once had. So wazzup wit dat?
😀
_-_-bear
Some switches used for stepped attenuators work out to be essentially "point contact" switches, and imo that creates a problem sonically.
In general, speaking to this same issue, I do not like to use single contact relays, and greatly prefer multiple contacts in parallel whenever possible, and certainly in signal carrying application.
The resistor wattage, type and mfr issue has been spoken to in other threads, including some extensive testing... I prefer 1/2 watt MF for attenuators. Alternately paralleled 1/8, or 1/4 equalling 1/2 watt rating or better tests exceptionally well... fwiw.
Carbon pots have a distinctive sound, as do carbon comp resistors, and that is not neutral - so by comparison there may be some sort of audible difference that appears to some to be less "good".
I'd agree that for reasons that are entirely unclear, an awful lot of things *appear* to make the lower mids sound "thinner". What the heck is going on with this isn't entirely clear to me at all and in general. The odd thing about it is that back in the early 70's audio friends and I referred to the lower mids as the "mud frequencies". Getting *rid* of the mud was a big goal and not easy to do. By contrast it seems like today you can't *get* good lower mids like one once had. So wazzup wit dat?
😀
_-_-bear
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Hi Bear, thanks for the input. I'm not technically-oriented, but I have (barely) been able to follow you so far, I think. Bottom-line; Is there a brand of stepped-atts (whether DACT, TKD, Goldpoint, etc) resistor-wattage/type notwithstanding, which actually sounds 'full' in the lower-mids? Thanks again!
I can't tell you that, I make my own! (not for resale though... and not cheap either)
But what I said gives some base line criteria by which to make a preliminary judgement?
_-_-bear
PS. by way of an experiment you might make up some simple attenuators (2 resistors) using
different resistors (same values / attenuation) different type/mfrs. and a rig to plug them in and see what you hear?
PPS. I prefer the discrete stepped "L" over the usual "potentiomenter" tapped resistor string...
But what I said gives some base line criteria by which to make a preliminary judgement?
_-_-bear
PS. by way of an experiment you might make up some simple attenuators (2 resistors) using
different resistors (same values / attenuation) different type/mfrs. and a rig to plug them in and see what you hear?
PPS. I prefer the discrete stepped "L" over the usual "potentiomenter" tapped resistor string...
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As I said, I'm a non-techie, I'm really seeking the best volume-control, sonically (carbon-pot, stepped-att, LDR, etc) that I can purchase, complete, over the counter. However, out of curiousity, I wiil try your suggestion, it seems simple enough. Thanks!
Ever consider the possibility that the carbon pot is adding pleasing sounding colorations to the sound? That the stepped attenuator particularly the LPAD configuration might be telling the truth and the pot might actually be masking something? 😀
Also true that some resistors may more closely approach ideal resistors than others which is sometimes measurable in controlled experiments. (Linearity, voltage coefficients, shunt capacitance, thermal tails, excess noise, etc..)
Also true that some resistors may more closely approach ideal resistors than others which is sometimes measurable in controlled experiments. (Linearity, voltage coefficients, shunt capacitance, thermal tails, excess noise, etc..)
The fuller lower-mids - of a Tannoy-system vs the thinner mids of a mini-monitor, for instance - always sound more natural and musical to me. The same applies to an active pre-amp vs a passive, respectively.
In comparing my components and systems to live acoustic music (in real-time) over the years, I've always found that full-toned components more accurately depict the sound of these live instruments, despite opinions to the contrary, from several souces - magazines, etc. If this is a coloration, then that's the sound I'm content with.
The Blue-ALPS pot, in my ARC pre, already displays the traits I desire. In seeking to improve on its transparencey, I'm determined not to upset the overall balance. Nevertheless, I appreciate your input.
Thanks for responding.
In comparing my components and systems to live acoustic music (in real-time) over the years, I've always found that full-toned components more accurately depict the sound of these live instruments, despite opinions to the contrary, from several souces - magazines, etc. If this is a coloration, then that's the sound I'm content with.
The Blue-ALPS pot, in my ARC pre, already displays the traits I desire. In seeking to improve on its transparencey, I'm determined not to upset the overall balance. Nevertheless, I appreciate your input.
Thanks for responding.
If these attenuators are being used as passive volume controls, it is very important to have the right impedance figures on the source and power amp. If not you will get thinning of the bass or lower mids (dynamic compression in these areas)
This is for me a rule of thumb.
Sources output impedance should be at least 10 x or more lower than the input impedance of the stepped attenuator
IE: source output impedance is 100ohm, the attenuators input should be 1000ohm (1K) or more input impedance.
Then the poweramp input impedance should be 10 x higher or more than the output impedance of the stepped attenuator
IE: If the attenuator has approx 5000ohms (5k) output impedance the power amp should be 50000ohms (50k) or higher. And keep interconnects at 1.5mt or lower and low capacitance (100pf per foot or lower).
If these parameters are met which is usually the norm for poweramps and sources then the signal transfer between source and amps will flow unhindered to the power amp, adding nothing and taking away nothing.
Then there the pin point contact on most attenuators, this is another separate problem I believe.
Cheers George
Speaking to replacement in active preamps:
This is because the "audiophile" is conditioned to the sound of cheap carbon comp. or plastic pots at $2 a piece.
These pots are notoriously colored, noisy, and almost never track right between channels.
He or she accepts this as their "reference" especially when subjected to peer pressure, group think and "conventional wisdom".
I would suggest people get out of their comfort zones and listen for prolonged periods to quality discrete stepped attenuators, either series or ladder. Open your mind. After that I suspect they won't want to go back to the muddy, unbalanced, cheap, sonic degradation they were used to before.
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George, I have to tell you that, in so far as pre-amps are concerned, I'm a devout 'activist'. (I'm averse to certain characteristics of passives, after several years of endurance, and I'm resolute). The audiophile paraphrased in my original post was refering to the atts' use in active pre-amps, as I'd stipulated in a subsequent post, in this thread. However your arguments are well recieved. Btw, I have been investigating the possible upgrade of my pre-amp with a LDR V-C kit, from a source which accommodates the kit-form. Those who've done similar upgrades (over at Transendence-Sound forum, for instance) have no complaints regarding the lower-mids of an LDR, in the context of its use in an active pre. I really think you LDR guys are on to a good thing. Thanks for sharing.
You must consider the entire "system", before you can say that anything has a characteristic sound. Otherwise, it's meaningless to even talk or think about comparing the characteristic sounds of different components or subsystems. (Actually, that's meaningless, anyway, unless you use buffers on both sides of whatever you're trying to hear the characteristic sound of.)
By "system", for an attenuator or pot, I mean everything between the source and the load. That includes source output impedance--> cable impedance --> attenuator input impedance --> attenuator output impedance --> cable impedance --> load impedance.
And mainly, by "impedance" I do NOT mean only "resistance". There are also ALWAYS capacitive and inductive components to EVERY impedance, just to varying degrees, sometimes significant and sometimes not.
So, besides just the possible loss of signal level because of the "hidden" additional resistive voltage dividers, there is a real possibility of creating filters (with voltage dividers that are frequency-dependent because they're not only resistive), or changing existing filters' cutoff frequencies.
That is why one should always consider using a buffer (or some other active stage), right after any passive attenuator (of any kind, including pots, stepped, LDR, etc).
Just a trivial example or two:
Your passive attenuator feeds an amplifier input that also includes a proper low-pass RF filter. You have just lowered the filter's cutoff frequency. By how much, you probably don't know. Some designers like to use low-value series resistors when they insert a simple RC filter, with a capacitor to ground. In that case, you have possibly brought the filter down into the audio band. Even worse, the cutoff frequency probably changes when you change the attenuation setting.
Got cable capacitance? Your passive attenuator just created a new low-pass filter. How low? That depends on both the cable capacitance and the attenuator's impedance. And it probably changes when you change the attenuation setting.
I don't see how anyone can stand worrying about all of that. Use a freaking buffer already (or an active amp stage).
Tom
By "system", for an attenuator or pot, I mean everything between the source and the load. That includes source output impedance--> cable impedance --> attenuator input impedance --> attenuator output impedance --> cable impedance --> load impedance.
And mainly, by "impedance" I do NOT mean only "resistance". There are also ALWAYS capacitive and inductive components to EVERY impedance, just to varying degrees, sometimes significant and sometimes not.
So, besides just the possible loss of signal level because of the "hidden" additional resistive voltage dividers, there is a real possibility of creating filters (with voltage dividers that are frequency-dependent because they're not only resistive), or changing existing filters' cutoff frequencies.
That is why one should always consider using a buffer (or some other active stage), right after any passive attenuator (of any kind, including pots, stepped, LDR, etc).
Just a trivial example or two:
Your passive attenuator feeds an amplifier input that also includes a proper low-pass RF filter. You have just lowered the filter's cutoff frequency. By how much, you probably don't know. Some designers like to use low-value series resistors when they insert a simple RC filter, with a capacitor to ground. In that case, you have possibly brought the filter down into the audio band. Even worse, the cutoff frequency probably changes when you change the attenuation setting.
Got cable capacitance? Your passive attenuator just created a new low-pass filter. How low? That depends on both the cable capacitance and the attenuator's impedance. And it probably changes when you change the attenuation setting.
I don't see how anyone can stand worrying about all of that. Use a freaking buffer already (or an active amp stage).
Tom
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Hags,
Here's another quote, on the subject ( http://www.diyaudio.com/forums/chip-amps/40676-so-i-did-try-all-those-different-potentiometers-4.html
"My expreience is with SMD and Dale types, maybe not the best-of-breed. There is no doubt the stepped has greater transparency, but compared to the linear PEC, not that much. The stepped att thin-down the music, to my ears. The PEC linear is much more musical. So in totality, I rate the PEC much higher. I'm sure others may hear it differently.
For me it's a gobsmacker because I reckoned carbon pots to be fluffy, diffuse and noisy sounding".
I've been an audiophile since age 11 (ie; well over thirty years). For many of those years I've lived next-door to a venue where a live acoustic band/orchestra plays, from time to time. This is what I've compared my systems to, in real-time, over the years. My current system is now very close to those live instruments, in dynamism and overall tonality (perhaps lagging somewhat in transparency). Components, such as you advocate, which render a thinner presentation, have always been found to be lacking in realism, compared to the live sound, in my experience.
If this is what you like, then more power to you. But your suggestion that those of us who prefer the realism of a 'fuller' presentation are aficianados of "muddy, unbalanced, cheap, sonic degradation," is entirely unwarranted. My pre-amp, at present, does use a carbon pot (Blue-ALPS) and, yes, it could be more transparent, but it also does render the essence and tonality of those afore-mentioned live instruments, regardless of your opinion of carbon-pots. Btw, I'm not alone in this opinion, the ARC LS3 may not be the most expensive, but it is rated amongst the best by the Audio-Critic, and Class 'A' Stereoplile recommended, for whatever that's worth. It certainly does not exemplify 'sonic degradation'.
Kindly note that, in the context of volume-controls for active pre-amp, neither LDRs, carbon-pots, or TVCs, have been accused of this deficiency - only stepped attenuators. Niether am I the author of this criticism, I've never used them. I'm only seeking opinions on the criticisms raised by others, since atts factored into my consideration for an upgrade to my own pre.
That's it!
I had the PEC pots pushed on me and even installed them in some of my gear. Sorry I ever did. Muddy, awful, terrible tracking. Give me a good stepped attenuator any day.
That's from someone who also thinks the lower mid is too thin on my high end systems, and doesn't sound like real music. Maybe some of these pots make up for systmes that are too bright to begin with.
A good Nobel or TKD potentiometer also makes me happy.
That's from someone who also thinks the lower mid is too thin on my high end systems, and doesn't sound like real music. Maybe some of these pots make up for systmes that are too bright to begin with.
A good Nobel or TKD potentiometer also makes me happy.
I'd hope that if all these devices are functioning as reasonably wide bandwidth voltage dividers, there wouldn't be huge differences between them. There's a well known tendency to exaggerate differences in the audio world that really don't amount to a hill of beans.
I'd like to just toss all of this stuff out as unsupported by any quantitative data, but the fact is I believe I've heard similar things. I only use carefully matched stepped attenuators because I believe matched channels are important for imaging and fullness. When the balance is off things can sound thin. I do think they sound thinner than some pots, but I also believe it's more accurate. I believe there's a difference between the big old Allen Bradley carbon pots and modern plastic element pots. The ABs sound fatter to me. The cheap little Alps pots that Radio Shack used to sell were also surprisingly good.
I can't support any of this with measurements, though I haven't tried. Like some other things I've tried to track down, my guess is the differences would fade into the noise if examined too closely.
I'd like to just toss all of this stuff out as unsupported by any quantitative data, but the fact is I believe I've heard similar things. I only use carefully matched stepped attenuators because I believe matched channels are important for imaging and fullness. When the balance is off things can sound thin. I do think they sound thinner than some pots, but I also believe it's more accurate. I believe there's a difference between the big old Allen Bradley carbon pots and modern plastic element pots. The ABs sound fatter to me. The cheap little Alps pots that Radio Shack used to sell were also surprisingly good.
I can't support any of this with measurements, though I haven't tried. Like some other things I've tried to track down, my guess is the differences would fade into the noise if examined too closely.
Hags,
Here's another quote, on the subject ( http://www.diyaudio.com/forums/chip-amps/40676-so-i-did-try-all-those-different-potentiometers-4.html) from another member here:
"My expreience is with SMD and Dale types, maybe not the best-of-breed. There is no doubt the stepped has greater transparency, but compared to the linear PEC, not that much. The stepped att thin-down the music, to my ears. The PEC linear is much more musical. So in totality, I rate the PEC much higher. I'm sure others may hear it differently.
For me it's a gobsmacker because I reckoned carbon pots to be fluffy, diffuse and noisy sounding".
I've been an audiophile since age 11 (ie; well over thirty years). For many of those years I've lived next-door to a venue where a live acoustic band/orchestra plays, from time to time. This is what I've compared my systems to, in real-time, over the years. My current system is now very close to those live instruments, in dynamism and overall tonality (perhaps lagging somewhat in transparency). Components, such as you advocate, which render a thinner presentation, have always been found to be lacking in realism, compared to the live sound, in my experience.
If this is what you like, then more power to you. But your suggestion that those of us who prefer the realism of a 'fuller' presentation are aficianados of "muddy, unbalanced, cheap, sonic degradation," is entirely unwarranted. My pre-amp, at present, does use a carbon pot (Blue-ALPS) and, yes, it could be more transparent, but it also does render the essence and tonality of those afore-mentioned live instruments, regardless of your opinion of carbon-pots. Btw, I'm not alone in this opinion, the ARC LS3 may not be the most expensive, but it is rated amongst the best by the Audio-Critic, and Class 'A' Stereoplile recommended, for whatever that's worth. It certainly does not exemplify 'sonic degradation'.
Kindly note that, in the context of volume-controls for active pre-amp, neither LDRs, carbon-pots, or TVCs, have been accused of this deficiency - only stepped attenuators. Niether am I the author of this criticism, I've never used them. I'm only seeking opinions on the criticisms raised by others, since atts factored into my consideration for an upgrade to my own pre.
That's it!
I gotta laugh when someone compares the sound of a live instrument to a recording being played back on "hi-fi" equipment.
I've been a musician and audio enthusiast for longer than I care to admit. I can tell you from my experience there is no comparison. Set up a piano or drumset in your listening room and compare. No way, not even close.
Components that I recommend do not render a "thinner presentation". They are of the highest quality and the epitome of transparency. If you're relying on a carbon or plastic pot to add "realism" or a "fuller" presentation that's a problem in my book. If you have a "thinner" presentation due to a volume control swap I would suggest the problem lays elsewhere.
Citing an example of a particular component that's popular and highly regarded in the audio press is exactly what I was pointing out about peer pressure, group think and conventional wisdom. It's meaningless, especially with regard to volume controls. In fact I can say it would sound better with a better, ie, discrete series or ladder attenuator. So what?
You asked for opinions, I gave mine. You obviously aren't happy and are considering an upgrade. All of this is subjective as you are well aware. Why not think for yourself, get what you want, if you know, and find out for yourself? That's what DIY is all about.
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