Yes, the Duke Ellington songbook is fantastic quality, I haven't got the Irving Berlin one, perhaps I should.....
I don't know any Chinese type to kome even close to it. Could you suggest one?
For the price, OK, but they use super small SMD resistors that have non-linearities - See Bruce Hofer's paper.
I have no idea what resistors that switch is using, but they look like they could be 1206 or maybe 0805. I think it's possible to find resistors in that size that do not contribute measurable distortion in an attenuator if carefully selected.
I have had absolutely no trouble with the contacts or with noise. The only time I had some noise was with DC offset and only a click when turning to a different level. As for harmonic distortion I think it must be very low, probably under 0.001% as I have done some measurements with it in use, although not exhaustive.
Are those stepped volume controls designed for constant impedance output ?
i wonder why, for everything nowadays, sellers and manufacturers provide so incomplete and poor datas.
According to what I've seen, the Elma A47 is not.
The schematic should look like this:
i wonder why, for everything nowadays, sellers and manufacturers provide so incomplete and poor datas.
According to what I've seen, the Elma A47 is not.
The schematic should look like this:
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It's constant input impedance, although the make-before-break contacts cause input impedance to drop momentarily between positions.
The "special dB Cuvre" cheap DACT versions give the attenuation curve and also tell what series of resistor was used:
DACT Type 21 Stepped Attenuator / Volume 10K * Special dB Cuvre * Hi Fi Grade * | eBay
Vishay CRCW 0805 1% 1/8W 100PPM
https://www.vishay.com/docs/20035/dcrcwe3.pdf
They are about 2db per step above the 7th step. I would have preferred a more precise step size for measurement purposes.
I suspect the "special curve" versions are exactly the same as the original version and are just given a higher price.
DACT Type 21 Stepped Attenuator / Volume 10K * Special dB Cuvre * Hi Fi Grade * | eBay
Vishay CRCW 0805 1% 1/8W 100PPM
https://www.vishay.com/docs/20035/dcrcwe3.pdf
They are about 2db per step above the 7th step. I would have preferred a more precise step size for measurement purposes.
I suspect the "special curve" versions are exactly the same as the original version and are just given a higher price.
I have 4 from a HK seller, can live with them no problem (about 2 years so far). On the other hand, XRK971 got unexpected high H3 on the use of similar 0805 metal oxide resistor on as feedback resistor on a power amp. Perhaps the crap appears with exposure to higher signal level.
I have the unloaded R switch and used R's of my choice (Dale) and hand soldered each of them ....rather I got someone else to do that.
-RNM
-RNM
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