Assuming you are placing the pot at the input to the B1k, then what the B1K is driving doesn’t matter. It’s the source that matters. If your source is capable of driving a 10k pot then this will give the lowest noise. But the safer option is the 50k pot. Most sources shouldn’t have trouble with this and the Johnson noise contribution will be lower than the 100k pot.
Claude, would you allow me a link to the Tocos POT you're using in your build, please?
Quality control on Tocos Cosmos Stereo pots has been a bit varied, I put one in my valve amp - it was OK to start but I do have channel imbalance at low listening levels. I bought from Hi fi Collective this from their website:
"Please note that because TOCOS are unable to guarantee 1.2bB channel matching we are no longer stocking the stereo version. A big disappointment."
Hi all
If you read my posts again you will find that all Tocos are made in China and that the channel imbalance was in my case well well below 1.2dB... and also advertised as such as "garanteed" by the seller. I checked it and all fine on my unit.
It turned out my unit was indeed very very fine, and could even be made closer to perfection by a small tweak (although not needed and no listening difference, but then...).
My unit was probably a genuine one - or if not that's the one to have IMHO as it works indeed great vs a fix voltage divider of high quality. In fact I don't really care if it is genuine, I can only guess, point is if I had to purchase it again I would just seek for exactly the same, hence me posting the closely taken pix.
I am sorry, I haven't kept a link of my seller and these may vary a lot anyway, but I would strongly suggest that you inspect the pix I posted as these allow to spot indeed differences between my unit and some sold by some sellers on the usual websites (don't want to advertise here, not sure permitted anyway). By the look of it, indeed a lot of Tocos look quite different from mine, which looks identical to what Tocos has on its website or on its spec sheet, so I can only assume that there are indeed fake Tocos around, but then not me to judge or tell. Note these genuine pots are quite widely used for other purposes and their durability doesn't seem to be questionned... I am quite convinced genuine ones should last quite a bit, they seem well built inside, but then who knows...
So now about durability that's indeed a bit of an unproven topic as far as I am concerned. I have my genuine Black Beauty since 1994 as a daily pot and it is still doing a marvelous job. At under -70dB it may have tracking imbalance, if not it is somewhere else on other amps connections... who knows?
It is impossible for me to predict how the Tocos will be in 20y time, but then it is only a few bucks (although I avoided the lowest prices etc.) and it still fine albeit not used much indeed. I would say if you experience probs at very very low level make sure first it is the pot and if only at very low levels then there might be a cure with a fix resistor network to shift YOUR listening position from very low levels to more level on your pot while having the same listening volume. Of course, no one knows if your Tocos is the same as mine nor probably if it is "really" a genuine one (I can only guess YES based on where you purchased it) but that might for anyone indeed be a problem as I can see there are many fakes that don't even look the job...
I hope this helps clarifying a bit
Claude
If you read my posts again you will find that all Tocos are made in China and that the channel imbalance was in my case well well below 1.2dB... and also advertised as such as "garanteed" by the seller. I checked it and all fine on my unit.
It turned out my unit was indeed very very fine, and could even be made closer to perfection by a small tweak (although not needed and no listening difference, but then...).
My unit was probably a genuine one - or if not that's the one to have IMHO as it works indeed great vs a fix voltage divider of high quality. In fact I don't really care if it is genuine, I can only guess, point is if I had to purchase it again I would just seek for exactly the same, hence me posting the closely taken pix.
I am sorry, I haven't kept a link of my seller and these may vary a lot anyway, but I would strongly suggest that you inspect the pix I posted as these allow to spot indeed differences between my unit and some sold by some sellers on the usual websites (don't want to advertise here, not sure permitted anyway). By the look of it, indeed a lot of Tocos look quite different from mine, which looks identical to what Tocos has on its website or on its spec sheet, so I can only assume that there are indeed fake Tocos around, but then not me to judge or tell. Note these genuine pots are quite widely used for other purposes and their durability doesn't seem to be questionned... I am quite convinced genuine ones should last quite a bit, they seem well built inside, but then who knows...
So now about durability that's indeed a bit of an unproven topic as far as I am concerned. I have my genuine Black Beauty since 1994 as a daily pot and it is still doing a marvelous job. At under -70dB it may have tracking imbalance, if not it is somewhere else on other amps connections... who knows?
It is impossible for me to predict how the Tocos will be in 20y time, but then it is only a few bucks (although I avoided the lowest prices etc.) and it still fine albeit not used much indeed. I would say if you experience probs at very very low level make sure first it is the pot and if only at very low levels then there might be a cure with a fix resistor network to shift YOUR listening position from very low levels to more level on your pot while having the same listening volume. Of course, no one knows if your Tocos is the same as mine nor probably if it is "really" a genuine one (I can only guess YES based on where you purchased it) but that might for anyone indeed be a problem as I can see there are many fakes that don't even look the job...
I hope this helps clarifying a bit
Claude
Steve, Claude thanks for sharing this information. It's really sad that finding a good quality, reasonably priced Attenuation device of some sort would be this difficult. Indeed seems like buying something and hope it's not a knock-off or that the manufacturer no longer cares about quality. A little discouraging for me as I'm new in the hobby. I'm looking very hard at this Twisted Pear solution now but really hoped I wouldn't have to do that. But I'm going back through the B1K with wiring/cap and other upgrades. So I guess I'll bite the bullet on this too. Joshua Tree - A Twisted Log Attenuator
I can only speak from my experiences, but to my tastes a good potentiometer sounds better than a good stepped attenuator. I've tried many attenuators, some with ridiculously expensive resistors, series, ladder, series/ladder hybrids. I don't know why the differences exist, and like many others, I'm predisposed to think the attenuators are better, but in practice, I haven't found that to be true. Of course, your experiences may differ.
The RK27 are very good pots.
The RK27 are very good pots.
Hi Bullit
Oh, perhaps I wasn't clear, sorry. Short story: The Tocos is less than 10$ and works absolutely great in my case, I would say little risk to try and just make sure the seller garantees the channel tracking and job done, likely to have a good one.
TDK is an excellent recommandation.OK, of course in another price league. I would tend to be on Jim's side: a good pot can equal some very good stepped attenuators, although the engineer in me doesn't like saying it. That matches my experience and TBH once you have an excellent pot there isn't much more to gain, air gets thin...
Re caps, if happy with the sound, leave it as it is and enjoy ! If you want to give it a try, try replaceing the 2 (per channel) first caps in the signal path as per my post or if to expensive take the same values and take any PPP cap you fancy. Nothing can go wrong doing so and dead easy and you can have a flavour for little money of what it may add (or not) to your ears... and decide later on the 3rd cap or reverse.
Sorry if my long post may have been confusing, or the last one which replied to several posters in one go.
Fab hobby, nothing can really go wrong with the B1 Korg and there are non expensive solutions and paths out of the audiophilia which perhaps tend to magnify things a lot (me being contaminated aswell).
And you are welcome for any question, Jim / 6L6 having been more then patient wth my tons of questions when I gots started again
Claude
Oh, perhaps I wasn't clear, sorry. Short story: The Tocos is less than 10$ and works absolutely great in my case, I would say little risk to try and just make sure the seller garantees the channel tracking and job done, likely to have a good one.
TDK is an excellent recommandation.OK, of course in another price league. I would tend to be on Jim's side: a good pot can equal some very good stepped attenuators, although the engineer in me doesn't like saying it. That matches my experience and TBH once you have an excellent pot there isn't much more to gain, air gets thin...
Re caps, if happy with the sound, leave it as it is and enjoy ! If you want to give it a try, try replaceing the 2 (per channel) first caps in the signal path as per my post or if to expensive take the same values and take any PPP cap you fancy. Nothing can go wrong doing so and dead easy and you can have a flavour for little money of what it may add (or not) to your ears... and decide later on the 3rd cap or reverse.
Sorry if my long post may have been confusing, or the last one which replied to several posters in one go.
Fab hobby, nothing can really go wrong with the B1 Korg and there are non expensive solutions and paths out of the audiophilia which perhaps tend to magnify things a lot (me being contaminated aswell).
And you are welcome for any question, Jim / 6L6 having been more then patient wth my tons of questions when I gots started again
Claude
Junk.
Get a chinese DACT off of eBay.
The Joshua unit looks nice.
Claude thanks for the clarifications. I may actually build another board and play with some Caps on it.
I'm going to order a DACT. When it finally gets here from China I'll do some comparison against the ALPs but I'm also going to buy a TKD. I assume below is is the correct one? If so, is this the best place to acquire one? And after this post I promise not to muck-up the thread for a while. Thanks for the info today group!
TKD Potentiometer 50K 2CP-2511 Series Stereo Conductive Plastic Volume Potentiometer (50dB Audio Taper)
I'm going to order a DACT. When it finally gets here from China I'll do some comparison against the ALPs but I'm also going to buy a TKD. I assume below is is the correct one? If so, is this the best place to acquire one? And after this post I promise not to muck-up the thread for a while. Thanks for the info today group!
TKD Potentiometer 50K 2CP-2511 Series Stereo Conductive Plastic Volume Potentiometer (50dB Audio Taper)
I am a bit more relaxed about which potentiometer to use after I have experienced how good the Starving Student II preamp works together with M2X. SS II has a PCB mounted small pot. But seems to be a quality one……
When both RCA connectors and pot are mounted on PCB this gives a very tight coupling and short signal path. This may have a positive effect on sound.
When both RCA connectors and pot are mounted on PCB this gives a very tight coupling and short signal path. This may have a positive effect on sound.