Hello again. This time I would like to get your opinion about the best way to use potentiometers. I have few, good quality conductive plastic pots ( linear ) made by Spectlor, Bourns, Vishay, and Clarostat. It looks like there are three ways to use them as volume controls: as they designed, shunt mode, and third way to converted them into log pots ( idea from ESP website ). Again, any ideas which way would be the best?
Thanks
Thanks
If your source and load impedances allow for that and the control range is good, I would go for shunt mode, as it seems to be more purist approach than the other two. Next would be converting them into log pots.
Don't forget perhaps putting a load resistor 10x the size of the gain resistor in series with two of the pot's pins, for a dynamic gain control.
Heres a question.
Why are dual ganged pots so freakin hard to find. Digikey only sells a couple, and Mouser has a couple dozen precision pots, yet only one dual ganged one I could find. Although Digikey sells several sliding dual pots, but how many poeple could possibly want dual sliders over a dual turner.
I really don't like the idea of having a seperate volume controll for each channel.
Am I missing something here? It takes two decks to make a stereo pot right?!?
Why are dual ganged pots so freakin hard to find. Digikey only sells a couple, and Mouser has a couple dozen precision pots, yet only one dual ganged one I could find. Although Digikey sells several sliding dual pots, but how many poeple could possibly want dual sliders over a dual turner.
I really don't like the idea of having a seperate volume controll for each channel.
Am I missing something here? It takes two decks to make a stereo pot right?!?
Hi, thanks for the inputs. Peter, what does "source and load impedances allow..........." mean to use shunt mode? How to " judge" the system will take an advantage of shunt attaenuator?
There is an information on Goldpoint website about shunt attenuators. Info says, they are better than series attenuators,, but because of various impedance they are not good for every system. No more specifics.
Hybrid fourdoor: yes, this is a problem. Usually conductive plasic pots are not available as dual ganged. Duals which I have are from Clarostat. This problem is not related to manufacturer, though. They can make them with no problem. Everything depends on distributors. So, firms like DigiKey, Mouser, Newark could order them if demand on duals would fulfill minimum order. I like Bourns pots more than Alps. They even make similar pot to Penny&Giles one, which can be ganged ( price tag is also similar- $200.00). On the other hand, I did used to single ones. It is easier to calibrate them to get equal resistance.
There is an information on Goldpoint website about shunt attenuators. Info says, they are better than series attenuators,, but because of various impedance they are not good for every system. No more specifics.
Hybrid fourdoor: yes, this is a problem. Usually conductive plasic pots are not available as dual ganged. Duals which I have are from Clarostat. This problem is not related to manufacturer, though. They can make them with no problem. Everything depends on distributors. So, firms like DigiKey, Mouser, Newark could order them if demand on duals would fulfill minimum order. I like Bourns pots more than Alps. They even make similar pot to Penny&Giles one, which can be ganged ( price tag is also similar- $200.00). On the other hand, I did used to single ones. It is easier to calibrate them to get equal resistance.
Hibrid foudoor: I mentioned Bourns pots, because those which I like to use are available only as singles. I did spoke to Bourns representant and answer was the same: no one orders them as duals, but the mentioned $200.00 ones.
soundNerd: my experience is more related to series stepped attenuators than regular pots. But, because they are more expensive, I recently started to use conductive plastic ones. My question came out after I saw two projects, both passive "preamps", which used regular pots in shunt mode ( one project is from Bottlehead site and one was published on this forum). In addition, there is another recommended idea shown on ESP site. Those who used shunt mode pots prised the sound quality. I just wanted to get your opinions about each mode. I usually use linear, conductive plastic ones by Bourns in its "regular" mode. They already sound very nice, but if I can enhance sound quality even more by using shunt mode.....
Depending on the source output imp (preferably low) and the impedance of the next stage, after the pot, (preferably high), the shunt attenuator performance might vary. Sometimes the incompatibility is so big that the proper control range is hard to achieve, or some frequencies might suffer.
I used successfuly 100k Alps pot as shunt element and 22k fixed series resistor at the input of my preamp. You might also want to check this thread for more specific info: http://www.diyaudio.com/forums/showthread.php?s=&threadid=2608
I used successfuly 100k Alps pot as shunt element and 22k fixed series resistor at the input of my preamp. You might also want to check this thread for more specific info: http://www.diyaudio.com/forums/showthread.php?s=&threadid=2608
Hello Peter, how to calculate proper value of fixed resistor in relationship to available pot? I think this question has been asked with no response. Is, for example, possible to use 200k pot
in system which calls for 10k volume control?
in system which calls for 10k volume control?
Hybrid fourdoor said:
Try searching for ModPots at Allied Electronics -- I've been using Allied since the early, and I mean very early 1960's -- they are one of the largest electronics distributors in the U.S. but have a $25 minimum order.
Newark Electronics is also quite good for this kind of stuff.
Squalish said:
Now I'm sure someone has tried this, anyone here? I may be adding it to something I'm building now, with a bypass switch.
Tomek said:
ouch... for that you could get a stepped attenuator .... just hit my mailbox today, the new price leader:
http://www.transcendentsound.com/step attenuator.htm
dave
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