Thanks for all the reactions. I bought and installed the DiyFidelity 25 k stepped att. and it works great. No irritating clicks anymore and even much better sound... 😛
Ciao,
Fedde
Ciao,
Fedde
I to also ordered the diyfidelity from aussie. received it in 5 days to LA, Ca.
i have the chipamp LM3886 kit. did i order the wrong switch or will the 50k stepped attenuator be acceptable? would the 10k or 25K put the amp into oscillation?
i have the chipamp LM3886 kit. did i order the wrong switch or will the 50k stepped attenuator be acceptable? would the 10k or 25K put the amp into oscillation?
25k works great. Likely no oscillation, though I still have to measure that. At least the sound is great so I suspect no oscillation ;-)
The amp might even be more stable with 25k (lower resistance usually means less input noise). I am still surprised how much the sound changed here with this attenuator. I have to investigate this for sure!
(actually it was the change in sound I was looking for for two years 😛)
Fedde
The amp might even be more stable with 25k (lower resistance usually means less input noise). I am still surprised how much the sound changed here with this attenuator. I have to investigate this for sure!
(actually it was the change in sound I was looking for for two years 😛)
Fedde
Peter Daniel said:
Thought that there were no audio pot better than the obsolete ALPS RK40 series (the 40mm black body ones).
How these compares to PEC pots?
PEC dual-gang KKA series pots now at DigiKey
Hey guys,
DigiKey now carries the dual-ganged PEC carbon KK( ) series pots.
They're selling for ~$30 for the KKA, which seems to be a good price.
They have a good selection of values in the KKA log tapers, but no 1Meg value of the KKU dual linear taper (for law faking).
Anyhow, they're located on page 1283 of the downloadable PDF catalog.
Best,
KT
Hey guys,
DigiKey now carries the dual-ganged PEC carbon KK( ) series pots.
They're selling for ~$30 for the KKA, which seems to be a good price.
They have a good selection of values in the KKA log tapers, but no 1Meg value of the KKU dual linear taper (for law faking).
Anyhow, they're located on page 1283 of the downloadable PDF catalog.
Best,
KT
Re: PEC dual-gang KKA series pots now at DigiKey
Great news! I love the monos, these with be great for balanced circuit applications.
Do you know if the element is a real log, or is it two linear sections used to approximate a log taper? I read where most log pots are really two linear sections in series.
I would like to find a way to use linear pots and not have the impedance change as it rotates. The Law faking and Neve method both suffer from impedance variations.
Found a bunch of 2w 10K dual linear Ohmite pots. They are made by PEC. They are AB series, thought it meant one section was A taper, the other B -reverse log taper. Measured and found them to be U tapers. Guess I should have known.
George
KT said:
Great news! I love the monos, these with be great for balanced circuit applications.
Do you know if the element is a real log, or is it two linear sections used to approximate a log taper? I read where most log pots are really two linear sections in series.
I would like to find a way to use linear pots and not have the impedance change as it rotates. The Law faking and Neve method both suffer from impedance variations.
Found a bunch of 2w 10K dual linear Ohmite pots. They are made by PEC. They are AB series, thought it meant one section was A taper, the other B -reverse log taper. Measured and found them to be U tapers. Guess I should have known.
George
Those PEC pots are not always accurate, even when 10% is claimed. I had at least two pcs where cjannel difference was approx 6dB, mainly at lower settings.
And what about leading the signal directly to the input, and use the feedback, to control the volume ?
On lower volumes we could increase the feedback, and maybe this would also improve other things too.
I know the usual first reactions about this, but why not ? Of course high quality pots are required here also.
Maybe a shunt pot is enough on the "bottom" feedback resistor.
On lower volumes we could increase the feedback, and maybe this would also improve other things too.
I know the usual first reactions about this, but why not ? Of course high quality pots are required here also.
Maybe a shunt pot is enough on the "bottom" feedback resistor.
Plovati,
That's a good question. I haved compared the two and ultimately opted for the alps black beauty. They are more organic sounding to me. Tone and texture better and the music flows better. I do see how others might prefer the pec. It is clean and detailed, fast from top to bottom. An excellent pot. My tastes tend toward the global understanding of what the music is saying rather then the finer points of sound. So it really depends on personal tastes like everything else.
That's a good question. I haved compared the two and ultimately opted for the alps black beauty. They are more organic sounding to me. Tone and texture better and the music flows better. I do see how others might prefer the pec. It is clean and detailed, fast from top to bottom. An excellent pot. My tastes tend toward the global understanding of what the music is saying rather then the finer points of sound. So it really depends on personal tastes like everything else.
Guys, I have an ALPS RK163121019AJ variable carbon pot. It has a click right in the middle of turns (12o'clock). I was wondering if this is a volume control pot or a balance control? Sorry, very new in this.
If it's a volume control pot, would anyone share their opinions or experience, b4 I try it on.
Thanks.
Link to Spec
If it's a volume control pot, would anyone share their opinions or experience, b4 I try it on.
Thanks.
Link to Spec
Attachments
Re: Center detent
George, any suggestions on how to confirm it short of putting it into an amp?
Panelhead said:
George, any suggestions on how to confirm it short of putting it into an amp?
4 lug ganged stereo log 250K potentiometer needs
Are you fellows still around? I ask this question since I read your 2002 pot evals and I have a Marantz 2270 receiver with a worn out volume pot.
I can only find 3 lug pots such as Alp. The 2270 uses a 4 lug setup and this 4th pin goes out to the Loudness PB.
Is this type of pot still available from anyone you know?
What if I do the unthinkable, only use a 3 lug and leave the Loudness PB connections unconnected?
Any direction or thoughts would be appreciated.
Are you fellows still around? I ask this question since I read your 2002 pot evals and I have a Marantz 2270 receiver with a worn out volume pot.
I can only find 3 lug pots such as Alp. The 2270 uses a 4 lug setup and this 4th pin goes out to the Loudness PB.
Is this type of pot still available from anyone you know?
What if I do the unthinkable, only use a 3 lug and leave the Loudness PB connections unconnected?
Any direction or thoughts would be appreciated.
My experience with the PEC pot
I bought 3 PEC 100k dual log carbon pots from Digi-Key recently.
I put one in my Cary SLP-94 preamp, replacing a Noble pot.
My first impression was "Peter was right about the tubiness." The sound was warm, more recessed, resonant in the lower midrange, but actually quite dry and slightly pinched and nasal sounding.
I could hear the promise in the pot, but somehow it wasn't sounding right in my system.
I figured I would let the pot burn in and maybe things would improve. It did, sounding more fluid and integrated, but the dryness never went away. There was a papery-sounding syllibance that reminded me of sheets of paper rubbing together. Also, there was something that reminded me of ringing in the higher frequencies. The sound was warm, but still dry. Interesting, considering the Noble is thought to be the more analytical sounding pot.
I let the pot run for three weeks and then I got tired of it. Before I changed back to the Noble, though, I replaced it with one of the remaining PEC's just to see if it was that specific pot.
Wow, big difference. I don't know what was going on, but the new pot sounded much, much better. There was still some syllibance, but not nearly as bad. Also, the sense of fluidity and integration was much better, making the music really flow. For the first time listening to the Cary with a PEC, I could really relax into the sound rather than feeling irritated by it.
Anyone experience such a drastic sample-to-sample variation?
I put the third PEC pot into my Sun Audio SV-300BE, and that worked brilliantly right from the start. I didn't notice any syllibance and there was just a tiny bit of dryness at the beginning which disappeared rather quickly. I didn't notice the tubby signature that was quite noticeable in the Cary. After a few days, I was hearing the best sound I'd ever heard from my Sun amp. The PEC pot was a resounding success, here - a real winner. Totally awesome with the AVVT 300BSL's doing the honors.
I'd like the sound of this pot, but my experience has led me to believe that the results may be very system and sample dependent.
I'm very interested in hearing feedback from anyone who's used these extensively.
Best,
KT
I bought 3 PEC 100k dual log carbon pots from Digi-Key recently.
I put one in my Cary SLP-94 preamp, replacing a Noble pot.
My first impression was "Peter was right about the tubiness." The sound was warm, more recessed, resonant in the lower midrange, but actually quite dry and slightly pinched and nasal sounding.
I could hear the promise in the pot, but somehow it wasn't sounding right in my system.
I figured I would let the pot burn in and maybe things would improve. It did, sounding more fluid and integrated, but the dryness never went away. There was a papery-sounding syllibance that reminded me of sheets of paper rubbing together. Also, there was something that reminded me of ringing in the higher frequencies. The sound was warm, but still dry. Interesting, considering the Noble is thought to be the more analytical sounding pot.
I let the pot run for three weeks and then I got tired of it. Before I changed back to the Noble, though, I replaced it with one of the remaining PEC's just to see if it was that specific pot.
Wow, big difference. I don't know what was going on, but the new pot sounded much, much better. There was still some syllibance, but not nearly as bad. Also, the sense of fluidity and integration was much better, making the music really flow. For the first time listening to the Cary with a PEC, I could really relax into the sound rather than feeling irritated by it.
Anyone experience such a drastic sample-to-sample variation?
I put the third PEC pot into my Sun Audio SV-300BE, and that worked brilliantly right from the start. I didn't notice any syllibance and there was just a tiny bit of dryness at the beginning which disappeared rather quickly. I didn't notice the tubby signature that was quite noticeable in the Cary. After a few days, I was hearing the best sound I'd ever heard from my Sun amp. The PEC pot was a resounding success, here - a real winner. Totally awesome with the AVVT 300BSL's doing the honors.
I'd like the sound of this pot, but my experience has led me to believe that the results may be very system and sample dependent.
I'm very interested in hearing feedback from anyone who's used these extensively.
Best,
KT
PEC Pots
I have only used the mono versions of the log taper pots. After using them in a couple projects, there does not seem to be any variations on sound quality.
Mine are matched up. I measure the resistance across the pot. With a handfull, it is possible to match them to less than 1%. I suspect resistance variations may be what you are hearing with those stereo pots. If one is 107K and the other channel is 96K, this MAY be audible.
All mine have been 25K units also. Do not know if there is any difference in sound quality compared to a 100K.
George
I have only used the mono versions of the log taper pots. After using them in a couple projects, there does not seem to be any variations on sound quality.
Mine are matched up. I measure the resistance across the pot. With a handfull, it is possible to match them to less than 1%. I suspect resistance variations may be what you are hearing with those stereo pots. If one is 107K and the other channel is 96K, this MAY be audible.
All mine have been 25K units also. Do not know if there is any difference in sound quality compared to a 100K.
George
Hi George,
This is the second day listening to the Cary pre with the new PEC pot, and boy, it's a whole different experience than that first PEC pot I had in there. It's so fluid and cohesive, now, and that slight touch of dryness is starting to smooth out. I listened to the first pot for three weeks and it was clearly compromised somehow.
I don't think it's a channel balance problem. The PEC I'm listening to now has a bit of a channel balance mismatch, which I'm correcting with the preamp's level trim control. The tonality and overall sound, as I've mentioned, is far superior, even before level correction.
I wonder if these carbon pots are especially sensitive to oversoldering? I had to desolder and resolder the first pot after I initially installed it as it required some rearrangement of the wiring. Maybe the extra heating cycle affected the sonics?
Anyway, I'm quite pleased with PEC's performance in both my Sun amp and my Cary preamp, now. I'm just curious as to why the first pot sounded so off.
Best,
KT
This is the second day listening to the Cary pre with the new PEC pot, and boy, it's a whole different experience than that first PEC pot I had in there. It's so fluid and cohesive, now, and that slight touch of dryness is starting to smooth out. I listened to the first pot for three weeks and it was clearly compromised somehow.
I don't think it's a channel balance problem. The PEC I'm listening to now has a bit of a channel balance mismatch, which I'm correcting with the preamp's level trim control. The tonality and overall sound, as I've mentioned, is far superior, even before level correction.
I wonder if these carbon pots are especially sensitive to oversoldering? I had to desolder and resolder the first pot after I initially installed it as it required some rearrangement of the wiring. Maybe the extra heating cycle affected the sonics?
Anyway, I'm quite pleased with PEC's performance in both my Sun amp and my Cary preamp, now. I'm just curious as to why the first pot sounded so off.
Best,
KT
Alternatives....
Just wondering... since there's been so much talk about pots and attenuators for volume control, can anyone please share their experience with relay-based stepped attenuators? In theory, they seem to offer the best of everything:
- Precision resistors in signal path (no more than 2)
- Sealed long life relay contacts
- Better channel separation
Only disadvantages I can think of are:
- Higher cost & complexity
- Need to carefully route control signals away from audio signals
- Need to incorporate some form of digital control system
There is also the IC-based digital stepped attenuator chips to consider, e.g. TI PGA2310, Crystal CS3310. Conrad Johnson and Jeff Rowland for example, use them.
Can the experienced folks please share their OBSERVATIONS? I know this area is highly subjective and all I am asking for are listening impressions (and related areas such as feel, quality, lifespan, usability...). Thank you in advance for sharing. My diyaudio budget is limited - I can try a few of them but not all of them so your input is much appreciated.
PS: If this is deemed as a thread hijack, moderators may delete or move this post. I also used the search function already. Just seeking more comments.
Just wondering... since there's been so much talk about pots and attenuators for volume control, can anyone please share their experience with relay-based stepped attenuators? In theory, they seem to offer the best of everything:
- Precision resistors in signal path (no more than 2)
- Sealed long life relay contacts
- Better channel separation
Only disadvantages I can think of are:
- Higher cost & complexity
- Need to carefully route control signals away from audio signals
- Need to incorporate some form of digital control system
There is also the IC-based digital stepped attenuator chips to consider, e.g. TI PGA2310, Crystal CS3310. Conrad Johnson and Jeff Rowland for example, use them.
Can the experienced folks please share their OBSERVATIONS? I know this area is highly subjective and all I am asking for are listening impressions (and related areas such as feel, quality, lifespan, usability...). Thank you in advance for sharing. My diyaudio budget is limited - I can try a few of them but not all of them so your input is much appreciated.
PS: If this is deemed as a thread hijack, moderators may delete or move this post. I also used the search function already. Just seeking more comments.
You missed out the biggest disadvantage (for me) which is the number of steps vs a good pot. In the end it comes down to what matters most to you.
Apart from that, everything else points to using a SA if cost isn't a primary issue, and SQ is.
Apart from that, everything else points to using a SA if cost isn't a primary issue, and SQ is.
It seems like it's a perfect oppurtunity for part two on that popular subject, this time we will cover switching attenuators 😉
http://www.diyaudio.com/forums/showthread.php?s=&threadid=73538
http://www.diyaudio.com/forums/showthread.php?s=&threadid=73538
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