vmac011 said:
Interesting. Just wondering: do you hear (loud) clicks when you change the volume? I currently use Elna 23 step, but it sucks. It is probably break before make, so it gives very loud clicks at lower volume. Also, one position doesn't work right and gives very a high volume at one channel (at medium position of switch). If the attenuator of DIY fidelity is better I might consider to try that! Do you use 50k or 100k? Could you maybe tell me the resistor values of the lowest position? This way I determine if the volume can be made low enough...
Thanks in advance,
Fedde
The Dact CT2-10k-2 doesn't give clicking sounds when upping the volume. It is a 24 way Elna attenuator.
Have 2 of them and build them in 2 passives. They are very "silent" in operation, remarkable.
When the "diyfidelity" attenuators arive I'll test them to the Dacts.
Have 2 of them and build them in 2 passives. They are very "silent" in operation, remarkable.
When the "diyfidelity" attenuators arive I'll test them to the Dacts.
Ok,ok.............got your point, but for now let me enjoy the cleanness of the music/sound. They do sound very honest and don't click at all.
In my experience working with jewelry the problem with pure silver is that it oxidizes in air quickly while gold doesn't. Anyone have pure silver silverware sitting around? Thats the reason it's been popular over time to gold plate when it comes to contacts. Though silver is a better conductive metal then gold. This is meant in response to the claim of rotting gold contacts vs. pure silver contacts. Though silver will still conduct well when it oxidizes a clean gold contact conducts a little better and has a higher resistance to oxidation which will promote a long life for your switch. Maybe someone wants to build a switch with a vacuumed section for the pure silver contacts?
gold wikipedia
silver wikipedia
one last
elma switches
Naz
gold wikipedia
silver wikipedia
one last
elma switches
Naz
I've tried it, it doesn't click. It appears to be "make-before-brake" type of switch. Since you've mention it, I know some people who have [DAC active I/V] => [Attenuator] => [Tripath AMP] setting.
Output of DAC needs to be coupled with at least 10uf as well as input of an amp. Many people omit AMP input cap because they already have output cap of a DAC. That is fine if you use standard pot, but with switch attenuator it may induce some clicking noise due to AMP being DC biased to 2.5V or 5V. So, with attenuators CAP before and CAP after.
DC
Any pot or switch should not have DC on it. The point is the 5µm of Gold. 1 µm = 0.001 mm. When weared out you are on the nickel layer.😎
vmac011 said:
Any pot or switch should not have DC on it. The point is the 5µm of Gold. 1 µm = 0.001 mm. When weared out you are on the nickel layer.😎
But the DACTs sound super, who cares if they live a bit shorter than the Alp pots. Just buy new ones. But the pleasure you get out of them is more important...for me anyway! I have everything DC coupled...no clicks, from DAC-passive pre-UCD's.
Maybe someone can point out if I'm wrong but DACT's wipers are actually bronze with a silver plate and then a gold plate to prevent oxidation and the contacts are brass with a silver plate and then a gold plate on top of that. So if you go through the hard gold plate your actually on silver. Might I ask what contacts should be? They also seem to rated 25,000 switching cycles which is the industry standard for rotational life. Anyways...
Naz
Naz
An <i>in theory</i>, noise is produced each time the signal passes through the junction of different metals!
But what options do you have, you need to compromise between longivity/physical material limits and mfg limits and factor in the physics of materials. Though I'm really no expert but I think every option for controlling resistance (stepped attenuator or pot) or switching (inputs? etc.) has it up and downs and not everything works for everyone? I guess go with what you like and not really worry about it eh?.. hehe 😀
Naz
Naz
Not a bad philosophy in this game Naz! 😉
I am lucky enough to have a few different stepped attnuators here, the most simple of which are the 12 step types made up from a switch mech and wafers.
Yes, they are open to the elements but also open for easy (and quick) cleaning from time to time using a cotton bud dipped in Isopropyl Alcohol. And they sound as good as the others that I have using more expensive switches!
Nuuk said:Yes, they are open to the elements but also open for easy (and quick) cleaning from time to time using a cotton bud dipped in Isopropyl Alcohol. And they sound as good as the others that I have using more expensive switches!
What has always worked wonders for me is Philips 390CCS contact cleaner. The red one.
Made in Holland. 🙂
Nuuk said:
😀
Seriously, this solves problems that others don't.
Dirty pots, contacts... even to remove labels. 😀
My father always used this Philips contact cleaner, I saw this at home in his bench since I was a kid.
I tried others, but he was absolutely right: this one is the best.
I always have a couple of these at home.
Attachments
Hmmm, really? This seems to have become accepted wisdom in some quarters with absolutely no science to back it up. In much the same vein as micro-diodes. If the junction has resistance it has noise, but if you measure the end to end resistance of the entire conduction path you can trivially calculate the noise. Any noise will be totally and utterly swamped by other sources to be absurd in the contemplation.
The problem seems to be a misreading of real science. There are micro-diode effects and metal crystal boundary effects that yield excess noise, but they only occur at mesoscale sizes. That is in conductors that have size similar to the wavelength of the conducting electrons. The failure of understanding is that these effects disappear at normal scales. The point is disappear - not reduced - not something at some very low level to worry those that want the ultimate - they quite simply don't happen at all.
Once the conductor scale is large compared to the electron wavelength the electron propagates without such hindrance, and models of noise obey the existing well known physics. To get the effects you must fabricate a very tiny (or thin) conductor, and then the effect springs into effect quite dramatically. Think of an ocean wave passing a tiny atoll.
One suspects that these urban legends of audio come about through garbled misinterpretation of the physics, and then once published somewhere, take on some sort life of their own, repeated and embellished to the point that they are no longer questioned.
Sorry, for those of you that don't know HTML, the <i> was meant to emphasise the 'in theory' part of my statement! 😉
But I agree Francis. There must be any number of people out there searching for such theories with which to launch another 'must have' hi-fi gizmo/cureall on a gullible public!
So it's good to be aware of the theory but also to be knowledgeable enough to know if that theory holds true in practise!
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