Volume controls - what are you using?

pmcuk

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Because digital volume control was becoming complicated on my system, I switched to a quality analog control using a Denafrips Hestia. It has a 60 step relay controlled stepped attenuator with a really nice heavy aluminium IR remote.
There are a few of these relay controlled attenuators about, and there are a few DIY versions if you can dig them up. Here's the Tentlabs one

http://www.tentlabs.com/Products/page31/page31.html Not cheap at €239 but a good reputation.
 
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karlsushi

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I used a Tisbury Audio passive for a while (which uses an SMD stepped attenuator) and couldn't believe what it brought to my system when swapping out a very moderately-priced preamp I was using at the time.

I have since discovered LDR passives and now have a Stereo Coffee LDR in both of my systems, which is an improvement in every area, but especially in terms of 'smoothness'.

My only warning about the Stereo Coffee LDR is that I have had to play around a bit to get the volume levels right (when I say 'I', I mean 'someone else'). The first version I had wouldn't go to zero volume and after some tweaking, it does now go to full mute, but now it is up to 100% volume at about 11 O'clock on the dial.

That aside though, they are incredible sounding things (or should I say, incredible non-sounding things).

Some very well written thoughts on LDR passives (and the passive vs active debate in general) on the Tortuga Audio website if you're interested: https://tortugaaudio.com/active-vs-...u have a source,results than a passive preamp.

(and just for the record, I use mine with a buffer, so I'm on the 'passive plus active' side of the debate).
 
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Rothwell Audio

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Some very well written thoughts on LDR passives (and the passive vs active debate in general) on the Tortuga Audio website if you're interested: https://tortugaaudio.com/active-vs-passive-preamp/#:~:text=If you have a source,results than a passive preamp.

(and just for the record, I use mine with a buffer, so I'm on the 'passive plus active' side of the debate).
I don't like the "passive plus active" view. It's just as active as any other active preamp. It's a sensible approach if you don't need any gain (and often you don't), but it's an active preamp all the same. Here's a quote from the link in your post:
"Whether we call this a passive preamp with a buffer or an active preamp without a gain stage, is mostly a matter of semantics and marketer’s perogative."
I'd say it's an active preamp without gain.
 
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Rothwell Audio

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When I started in hi-fi I used to make my own stepped attenuators. Off-the-shelf stepped attenuators were as rare as hen's teeth then, and multiway switches with enough switch positions were hard to come by too. I worked out a way to get a 64 way attenuator without a huge cost by having fine and coarse controls.
Of course, these days stepped attenuators are much easier to find. You kids today, you don't know you're born. :ROFLMAO::ROFLMAO:
 

mac72

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There are a few of these relay controlled attenuators about, and there are a few DIY versions if you can dig them up. Here's the Tentlabs one

http://www.tentlabs.com/Products/page31/page31.html Not cheap at €239 but a good reputation.
They do some interesting stuff, I used bias supply designed by Menno , clocks and electronic chokes always delivered promptly but some guys on DIY Audio complained about delivery time .
As to the “pots” K&KAudio shunt attenuator worked nicely with a differential tube gain stage I built while ago .
 

Jazid

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Hi Andy,
Like you I mostly listen to music from a computer source. I keep my volume control entirely in the digital domain except when listening to records, and find it is completely transparent unlike volume pots which I find are not and don't track very linearly either. I have a resistive bridge attenuator using sealed relays which is effective, seems transparent, but feels like a weirdly complicated solution to losing gain, and have a TVC on order to play with on analogue as an equally weird alternative, and will report.
 

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According to the Stereophile review, in my Ayre AX-7e integrated the "Gain control is accomplished with discrete metal-film resistors and a bank of FET switches, and the AX-7's logic section is designed to drop all switching devices out of the signal path after a given command has been executed".
That seems cool, whatever it means.
It certainly sounds very good!
It has 66 1db steps.
 
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Gray

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Channel balance better than anyone's ears, adequate visual guide from the LEDs and never any need for a Servisol blast.
 

steve 57

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When I started in hi-fi I used to make my own stepped attenuators. Off-the-shelf stepped attenuators were as rare as hen's teeth then, and multiway switches with enough switch positions were hard to come by too. I worked out a way to get a 64 way attenuator without a huge cost by having fine and coarse controls.
Of course, these days stepped attenuators are much easier to find. You kids today, you don't know you're born. :ROFLMAO::ROFLMAO:
Ii remember building a few in the late 90s after the hifi world designs article in the 90s
I managed to acquire a job lot of gold plated Elmer switches, the best one I built used vishay resistors, but I found if I used 2 watt metal film they weren't much different in sound, I also have some Panasonic and alps blue pots too.

Most of my listening is done via adjustable out cd player and the best sound I get is with that straight into the amp, using the CD players volume control.

When those ldr pre amps came out, one did the rounds over on the audio talk forum, many reported ( and I heard ) a brighter sound,
When I tried it on my system, it gave an obvious noticeable grain to the sound.
Nick gorham measured the one that did the rounds and concluded that it was causing distortion.
It was clearly audible on my set up, but it did improve many systems.
Luckily my mate was there with me and we both agreed what we heard, and it's negative effect.
 

Rothwell Audio

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When those ldr pre amps came out, one did the rounds over on the audio talk forum, many reported ( and I heard ) a brighter sound,
When I tried it on my system, it gave an obvious noticeable grain to the sound.
Nick gorham measured the one that did the rounds and concluded that it was causing distortion.
The attraction of LDR attenuators is the lack of moving parts and mechanical contacts. Unfortunately, LDRs aren't particularly good resistors. My opinion is that mechanical contacts aren't the evil they're portrayed as.
 
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karlsushi

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I too have seen some discussion about LDR attenuators causing distortion, but I have also heard it suggested that if there is any, it is all second order harmonic, so in theory pleasing to the ear.

I'm not of the mind to go looking at graphs, but using my ears, I have done a fair bit of back-to-back with a Tisbury stepped attenuator and my own perception is that if there is any distortion with the stereo coffee LDR, it certainly isn't getting in the way of detail retrieval.

In my simple and non-technical mind, it would seem odd that a system that effectively uses light to attenuate an audio signal would cause any more distortion than a physical resistor, but the world of audio can be a funny old thing.
 

rabski

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An LDR is still a resistor and still has inherent noise. I haven't looked at specs, but I would imagine that possibly resistor noise is higher in an LDR than a metal film. The rest of the circuit will presumably have some effect, even if just by minimal coupling.

All resistors have noise. The 'trick' is either to use digital volume control or to use resistors/pots that have the lowest noise. The rest of the circuit on both sides will also of course have an effect in terms of impedance. As my primary source is vinyl, a digital control would be pointless and would possibly 'take away', as I would need the do analogue to digital, volume control, digital to analogue.

It's all fascinating trivia, but basically I'll try a serious stepped attenuator sooner or later, but stick with the Noble till then
 

steve 57

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Of course there is a chance that the transparency of the LDR was highlighting some grain elsewhere in the chain. Perhaps. Maybe.
Thats a interesting point, my system will be at the wam show and I have no objection to you bringing one to hopefully show what myself and Scott Lindgren heard.

But I do agree with your earlier point that they do improve many systems just not mine it seems.

I few years ago nick brought the top of the range music first pre amp round he had built, he said it had improved every system he had tried it on, but on my system he concurred you could tell it was there..
 
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Lokes

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When I started in hi-fi I used to make my own stepped attenuators. Off-the-shelf stepped attenuators were as rare as hen's teeth then, and multiway switches with enough switch positions were hard to come by too. I worked out a way to get a 64 way attenuator without a huge cost by having fine and coarse controls.
Of course, these days stepped attenuators are much easier to find. You kids today, you don't know you're born. :ROFLMAO::ROFLMAO:
I had a pair of Meridian M2 active speakers in the mid eighties and a 101B preamp, I remember knocking up a pot in a box and it was a lot better than the 101, I think Mark Levinson then brought out a stepped attenuator for silly money and I made something similar using Holco resistors and a rotary switch that was about to be binned in work,
it stayed around for quite a while.
 

steve 57

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I too have seen some discussion about LDR attenuators causing distortion, but I have also heard it suggested that if there is any, it is all second order harmonic, so in theory pleasing to the ear.

In my simple and non-technical mind, it would seem odd that a system that effectively uses light to attenuate an audio signal would cause any more distortion than a physical resistor, but the world of audio can be a funny old thing.

Some testing was done in 2014 in hifi World, it produced just under 1% 3rd harmonic at mid volume. Nick gorham had similar test results.
They are not really passive as in a resistor. The light source causes the photoelement to make electrons available, sort of a semiconductor.
 

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