Volume pot choice
Hello, I hope to pick up the BA-3 build by the end of Sept, most of the hard to supply parts are in stock, 2 x Sigma22 PSU boards, 1 x BA-3 board with caps and most of the passive components, I-Select switch board; still missing the transformers, RCAs, case, cabling and volume pot, my guy advises to go for a 100KOhm to have a smoother control, would like to know what is your suggestion, I guess an ALPS would make it, which model should I look at and what would be the differences between models if there is any?
Grazie
Hello, I hope to pick up the BA-3 build by the end of Sept, most of the hard to supply parts are in stock, 2 x Sigma22 PSU boards, 1 x BA-3 board with caps and most of the passive components, I-Select switch board; still missing the transformers, RCAs, case, cabling and volume pot, my guy advises to go for a 100KOhm to have a smoother control, would like to know what is your suggestion, I guess an ALPS would make it, which model should I look at and what would be the differences between models if there is any?
Grazie
Uhm, this is out of my (very) limited knowledge, the BA-3 would feed a FW F4 and as main source a DAC (cheapo Beresford to begin with whose output impedance should be as per attached screenshot:
ALPS is a great pot for the price. I tend to keep a couple of these floating around for testing, 2nd system preamps etc:
https://www.parts-express.com/ALPS-RK27-50KA-Audio-Taper-Potentiometer-Solid-Shaft-023-208
They sound good for the price and It fits right onto the I-select. I just installed an I-select in my preamp. My objective in going was to take an advantage of the somewhat sealed relays etc. I skipped using the connectors on the inputs and outputs as I didn't want a mechanical connection in the signal path that could get dirty. I used double pole switches before and they didn't take long to start giving me trouble. I need to look into the crimping tool for those little connectors on the I-select though for the channel selector control. Right now I just have input 1 jumped.
If you feel like springing for something nice, Khozmo makes good stepped attenuators. They are beautiful and feel terrific. You can always do that later though if you choose. Most of the Pass preamps do well with 50k.
https://www.parts-express.com/ALPS-RK27-50KA-Audio-Taper-Potentiometer-Solid-Shaft-023-208
They sound good for the price and It fits right onto the I-select. I just installed an I-select in my preamp. My objective in going was to take an advantage of the somewhat sealed relays etc. I skipped using the connectors on the inputs and outputs as I didn't want a mechanical connection in the signal path that could get dirty. I used double pole switches before and they didn't take long to start giving me trouble. I need to look into the crimping tool for those little connectors on the I-select though for the channel selector control. Right now I just have input 1 jumped.
If you feel like springing for something nice, Khozmo makes good stepped attenuators. They are beautiful and feel terrific. You can always do that later though if you choose. Most of the Pass preamps do well with 50k.
@Mikerodrig27 The Khozmos, uh, had seen them before by probably reading the 100+ pages of this thread, dunno which of those might fit my bill but, hey, 200+ dollars, is it worth vs the Alps?
Which one would make it?
So, a 50K rather than a 100?
@nicoch58 what are the carbon ones like?
Grazie
Which one would make it?
So, a 50K rather than a 100?
@nicoch58 what are the carbon ones like?
Grazie
I used an alps 50k on the BA-3 when I had it set up. The taper felt fine to me. The BA-3 to me isn't really the king in terms of fidelity. It is more about playing with distortion characteristics. I installed a Khozmo shunt type stepped 50k attenuator on my BA2018 and did notice a difference over not only an ALPS but a cheapie Chinese stepped attenuator as well.
I like to set up a nice preamp chassis as my main chassis. Good switching, volume control, etc. The preamps that aren't my top favorites get hand-me-down items. I don't know anything about the Sigma22 PSU boards but if the voltage is adjustable, that would be a good solution to try different linestages if you get the itch.
I have the BA-3 driver and amplifier boards waiting for a chassis which will happen someday.
I like to set up a nice preamp chassis as my main chassis. Good switching, volume control, etc. The preamps that aren't my top favorites get hand-me-down items. I don't know anything about the Sigma22 PSU boards but if the voltage is adjustable, that would be a good solution to try different linestages if you get the itch.
I have the BA-3 driver and amplifier boards waiting for a chassis which will happen someday.
I have a friend coming off the US in October so if something esoteric (within 200$) which you think would add to the overall quality please advise which one and, still please, would you be so kind to explain why a 50K vs a 100K and how to choose the right tool for the job (type, value...).
Another question, maybe silly, would some day I want to go biamp what does the BA-3 need being added to provide two outputs and is it difficult to add a way to adapt the output in case of different power amplifiers?
Grazie e buon fine settimana
Another question, maybe silly, would some day I want to go biamp what does the BA-3 need being added to provide two outputs and is it difficult to add a way to adapt the output in case of different power amplifiers?
Grazie e buon fine settimana
Ahum...
The little I can say comes from Salas' threads, and others may correct me (please?)...
You want a lower (10K, 20K) attenuator for a more transparent sound (or to tell it from the other end, highish input impedance make for a more "veiled" sound).
If you will use older gear (vintage tape recorder / phono / etc) this could become problematic and you would need a 50K / 100K attenuator.
The muses chip is highly praised (also used by passlabs...).
TKD 2CP 2511 ( or here) seems to be very good
PEC have been used and liked, too...
another cool solution are relay-ladders like the ELMA relay attenuator
and ZM keeps raving about some AVC, being better than anything else...
I use a PEC in my DCB1 and the elma in my WLS, like both very much. Still wait to build the Muses, and have some autoformers to connect. But I am a scared amp-builder and need a lot of time.
I have a 3U aluminum faceplate to offer for $10.00 to cover shipping.
There are 3 holes left to right: 9.6MM, 10MM and 19MM.
The back side is not pretty but both the selector and Khozmo volume pot were securely fit to my crude aluminum shaping work.
Having learned my lesson, I had a local machine shop do the final panel.
Send me a PM if interested.
There are 3 holes left to right: 9.6MM, 10MM and 19MM.
The back side is not pretty but both the selector and Khozmo volume pot were securely fit to my crude aluminum shaping work.
Having learned my lesson, I had a local machine shop do the final panel.
Send me a PM if interested.
Attachments
Just a little follow-up on the topic: Pfarrell and Salas talking about the input-impedance…
I found this very interesting as both are very openminded/-hearted
https://sound-au.com/project01.htm
under condition that Rin of following stage is higher enough than resulting Rout of pot itself, then value of pot is having nothing with following stage and having everything with Rout of sources (preceding stages)
in ideal world ratio of Rout to following Rin is 100*
in less ideal world 50* is good and 20* is still OK, if Rout is bellow 100R
under condition that Rin of following stage is higher enough than resulting Rout of pot itself, then value of pot is having nothing with following stage and having everything with Rout of sources (preceding stages)
in ideal world ratio of Rout to following Rin is 100*
in less ideal world 50* is good and 20* is still OK, if Rout is bellow 100R