Thanks everybody for your input. I would prefer simple to complex, even at a higher price. Belts are out, I think.
As I said before, Dave Slagle showed exacrtly what you want, in Denver at the RMAF this October.
Remote control, stepper motor with discrete cap/R loading steps, display.
My only gripe was that the display showed the step you're at, not the actual value, but that's just a small firmware change, a no-brainer.
Not very expensive as hi-end goes, but hey, you can always add a zero at the end 😉
Jan
Dave doesn't have the device on his web site. intact audio He does have a pretty questionable resistor (coil of copper?) and relatively reasonable transformers.
What Dave did looks OK, but many here just don't seem to know what is really required, because most here don't have any experience with hi end audio.
Of course there is the engineering side, and many approaches have been used in the past:
In my case: fixed loads, manually switched loads, relay switched loads, fet switched loads, mini pots of the highest quality, larger rotary pots, etc.
The task here is to give the USER a well defined variable load that is remote controlled and remotely read, with a precision of around 1 ohm or so over a reasonable range, let's say 10-300, and maybe a few ohms up to a higher number, possibly 5K, perhaps only 2K.
This load must be distortion free by every measured and subjective evaluation. This is not an easy task. It must be free of hum and RFI pickup as well.
I ONLY expect this feature to be seriously used by hi fi designers and users, where expense is secondary, to convenience and accuracy.
We already know how to do it manually, without direct measurement of the exact value, only the subjectively 'correct value'. The Vendetta Research preamp did it with a tantalum film pot, Constellation has done it with a quality dual potentiometer. These have passed serious evaluation by independent hi fi reviewers.
Now for the ultimate!
Of course there is the engineering side, and many approaches have been used in the past:
In my case: fixed loads, manually switched loads, relay switched loads, fet switched loads, mini pots of the highest quality, larger rotary pots, etc.
The task here is to give the USER a well defined variable load that is remote controlled and remotely read, with a precision of around 1 ohm or so over a reasonable range, let's say 10-300, and maybe a few ohms up to a higher number, possibly 5K, perhaps only 2K.
This load must be distortion free by every measured and subjective evaluation. This is not an easy task. It must be free of hum and RFI pickup as well.
I ONLY expect this feature to be seriously used by hi fi designers and users, where expense is secondary, to convenience and accuracy.
We already know how to do it manually, without direct measurement of the exact value, only the subjectively 'correct value'. The Vendetta Research preamp did it with a tantalum film pot, Constellation has done it with a quality dual potentiometer. These have passed serious evaluation by independent hi fi reviewers.
Now for the ultimate!
Yes that's the one a saw in Denver. It was operational. As I said, the display shows the step number but I would want it to show the load R and/or C, so people would know which step to like 😉
Edit: "...John will have boards available for OEM's to add this functionality to their devices....". There you go John C, another problem solved. Don't you love this forum.
Jan
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Hi all, Hi John,
Ask directly to John Chapman he is a very nice guy, I am in contact these days with him for input selector and level adjust remotes.
you can get more info here:
BentAudio.com :: TAP
Ask directly to John Chapman he is a very nice guy, I am in contact these days with him for input selector and level adjust remotes.
you can get more info here:
BentAudio.com :: TAP
Thanks guys, but this BentAudio system, while interesting, does not meet our requirements. Not enough resolution.
Is it so important these so fine MC loading adjustements? Usually I prefer not loading at all just 47/68k as per MM Cartridges and I think that I am not the only one that prefer this way...
Too bad, Richard. Just because I also use the same as you, does NOT mean that my customers are happy with it.
While some here feel that they have directed me to the solution, they really haven't. My needs may exceed what is practically possible, and that is OK. I still need 1-2 ohm resolution up to 500 ohms minimum.
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