Assembled expensive control: DACT audio attenuators
Assembled cheap control: DACT Type SMD Stepped Attenuator 21 step volume control pot D Shape Shaft | eBay
For Sheffield's direct to disc LPs, Doug Sax replaced each of the console pots with a pair of fixed resistors after setting levels for the session.
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Elma has an unpopulated one on this data sheet but I thought I saw a less expensive version with the switch mounted on a square green board. Can't remember what it was now . . . .
Yeah, it's a struggle. Trying to steer a course past the obsessive boutique fetish mystics on the one side, and the terrified cat on a car roof hanging on for all its worth technical smartasses on the other.
Yeah, it's a struggle. Trying to steer a course past the obsessive boutique fetish mystics on the one side, and the terrified cat on a car roof hanging on for all its worth technical smartasses on the other.
Or way too many, IMO. If (with a capital I) one's gain structure is actually designed correctly such that it's barely uncomfortably loud at full volume, then the number of gradations one needs to bring it down to "normal" listening levels is few.
I hardly ever change the volume on my setup, am I the exception?
I hardly ever change the volume on my setup, am I the exception?
Yes, that's a fair point: I've ripped all my cd's to my computer and don't presently have a vinyl playback setup.
In any case, your recommendation to figure out where you're sitting on your potentiometer already and find a close equivalent in fixed resistors and play with different styles is pretty sensible. I personally think "pick a decent, inexpensive thin film resistor in 1/4 watt (e.g. the rn55's or the yageo mf0207 series) and be done with it" but if one is waffling on rolling resistors, this is a good way to move forward.
In any case, your recommendation to figure out where you're sitting on your potentiometer already and find a close equivalent in fixed resistors and play with different styles is pretty sensible. I personally think "pick a decent, inexpensive thin film resistor in 1/4 watt (e.g. the rn55's or the yageo mf0207 series) and be done with it" but if one is waffling on rolling resistors, this is a good way to move forward.
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I have a 63 step khozmo smt remote relay jobby. I need 10 steps to cover difference between dac and phonostage levels. Nightime listening is about 20 steps from zero daytime 40. So maybe 24 would do, but the finer control is nice. None of my digital stuff is level matched/ limited so rickie Lee Jones needs 10db more than the pixies for example.
I've recorded the Metal Film and the Bulk Foil samples individually from Youtube and am providing them here for people to compare. It's 34 seconds of each resistor playing back the same unmixed material, which should provide enough data for comparison to see what is actually going on. It's not a precise trim and unfortunately I have to run out for a few hours, so you'll have to line them up yourself.
My vote is still in minor attenuation difference if anything. However the critical issue of "Is the replacement resistor the same value as the original?" has not been determined as it's not touched on in the video. Anyone want to take a stab at comparing waveforms? If it is so obvious, which is which and why?
Resistor A: Resistor A.mp3 - Google Drive
Resistor B: Resistor B.mp3 - Google Drive
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You're kidding aren't you? In any case A has a lead in break that totally makes an objective comparison impossible.
I’m aware it’s ridiculous and absurd. I’m not suggesting this is a sensible way to compare. However Chris Daly suggested the sound quality difference in the YouTube article to be obvious. He’s been lurking around advocating his LDR preamp and cross posting content from this thread. Our conversation has lost context over too many threads.
I don’t hear a difference in sound, maybe slight difference in attenuation. But others say they can, so I wanted to offer an opportunity to them to identify the bulk foil with ears only. Not suggesting it’s a valid AB test. If someone wants to sync up the tracks and do it right and repost for comparison in foobar I’m “all ears.” I only had a moment today to crudely throw them up. Either way I don’t think I’ll be able to hear a difference.
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No you aren’t.
I’m using a YouTube video which some feel shows an obvious audible difference via the replacement of one resistor as a vehicle to express its absurdity, to show the cognitive biases at play and suggest that they likely cannot identify the bulk foil when audio is separated from the video unless they use a slight of hand, benefitting from my clumsy chop job.
If there is a difference it’s attenuation level and you can sort that by looking at the files in audacity. Since the poster of the video gave us almost no useful information as to his methods, values of resistors, etc. I saw no reason to attempt a more stringent comparison. I’ll leave a more vetted test methodology to the more industrious and capable among us if they feel inclined.
It doesn’t help that VPG (Vishay spinoff) has identified the audio market as a fruitful area to cultivate: Vishay Precision Group - Applications - Audio and Low Frequency
“ The audio discrimination level is sometimes beyond the instrument measuring capability but nonetheless aurally detectable.”
And their brochure on audio noise reduction using Bulk Foils: https://www.element14.com/community...94/AudioNoiseReductionBulkMetalFilmVishay.pdf
The writings from Yuval Hernick on the Vishay Bulk Foils seems to be quite criticized as leaving a lot of details out:
Page 1: https://www.eetimes.com/document.asp?doc_id=1278251
Page2: https://www.eetimes.com/document.asp?doc_id=1278251&page_number=2
Scott- he cites one of your application notes: http://www.analog.com/media/en/tech...018494695982855668424783486554001060AN348.pdf
Some additional sketchy “case studies” which read like reviews and contain no actionable information. This one is on attenuators with ZFoils:
Vishay Precision Group - Foil Resistors - Case Study: Switched (Stepped) Attenuator Passive Volume Control
I personally expected better from Vishay. I think they have done just as much harm promoting this kind of thinking because they have the unique reputation as a high quality manufacturer backed by a legion of engineers and thus a more reputable source of information than let’s say Mundorf or Bybee or Audio Note. It’s far more understandable for a layperson to assume they are making a choice which will result in improved performance.
Engineers and scientists are our Jedi, the guardians of technology. Without them to trust it will be an unfortunate world. There are only two possible options:
The engineers here with tons of industry experience and no financial incentive are misguided and wrong.
Vishay with tons of industry experience, the capability and funding to fully evaluate its claims and a huge financial incentive is misleading its customers.
Vishay Precision Group - Foil Resistors - Case Study: Switched (Stepped) Attenuator Passive Volume Control
I personally expected better from Vishay. I think they have done just as much harm promoting this kind of thinking because they have the unique reputation as a high quality manufacturer backed by a legion of engineers and thus a more reputable source of information than let’s say Mundorf or Bybee or Audio Note. It’s far more understandable for a layperson to assume they are making a choice which will result in improved performance.
Engineers and scientists are our Jedi, the guardians of technology. Without them to trust it will be an unfortunate world. There are only two possible options:
The engineers here with tons of industry experience and no financial incentive are misguided and wrong.
Vishay with tons of industry experience, the capability and funding to fully evaluate its claims and a huge financial incentive is misleading its customers.
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