Then came the Tocos Cosmos. That one was recommended by some UK sources as heir to the Black Beauty and even perhaps bettering that one. They were measuring outstandingly well and putting shadows on the need for step actuators sonicaly. But then it appears sellers complained about channel tracking and stopped importing it.
I looked closer and found out that this nice and still small sized potentiometer was in fact standard ware, nothing fancy audiophile. That could explain some tolerance variations (and no special line), or the fact sellers didn’t like it – well, they must have made a HUGE margin, but perhaps that was also killing some myths. Nowadays you can buy it online at the usual providers with a 5% tolerance waranty for 8$ only (and nearly as much shipping in my case LOL). A real bargain if it delivers.
You can have it cheaper without tolerance waranty but that wasn’t for me as I expect the bad ones to be sold that way… But that’s just me thinking loud.
Again I couldn’t help carrying out numerous measurements to find out how it behaved. It came with a 5 point channel accuracy record and that one proved to be dead accurate , giving -0 +5% channel tracking (but not voltage divider values). Well done though and as advertised. But these were just… 5 listening positions. This is what I found out, taking of course into account the slightly different full channel resistance for the ratios :
- channel mismatch of around 3% up to 11h00
- Oddity at 10h00 with very punctual 8% mismatch, same around 2h00 (construction ?)
- Other than these picks around 3 to 4% mismatch most of the time, always one channel showing more than the other (did over 70 measurments)
- Front channel total 49.4k, rear one 48.8k
It is like this double mono potentiometer is slightly shifted between channels, but its construction doesn’t allow you to ‘bend it’ right again. One has though to put this values into perspective. These are real life measurements of the full contact line.
Enthousiasts like 1% variation, but once resistors are soldered in place etc. real mismatch is often bigger… but does it matter ? Not really, as if I did my math correctly ( ???), 1% is 0.09dB variation and 5% still very acceptable 0.42dB and 10% would still be acceptable 0.83dB (but as things can add up in a device…). So one has to look beyond the pure values : this pot measures well and has a real several megaohm channel isolation.
However, I figured then something out. Guys, don’t shout at me if this is a COMPLETELY SILLY IDEA - which it is probably again as I couldn’t read anything on what my poor brain decided to do.
As the (slight and non critical again !) mismatch was only in one way, I calculated that adding a 2.1k resistor at the entry of the rear channel would bring outstanding values. And it did ! 1% 50ppm resistor in and we get a compensated pot with :
- +-1% channel variation mostly all the way
- bare the to afore mentionated oddities that are though brought back now to roughly 4% channel mismatch (this is just on 2 points, like something on the track right there)
I don’t know if what I did makes sense, please let me know, I can still undo it when it goes back to the to B1 KORG. And going back it does, as it completely killed any potentiometer I had so that I had only to compare it directly with my reference divider. Whereas the small pot’s weaknesses were spotted in a few seconds, that high level comparison took me hours as the Tocos is nearly as good as a pure directly soldered and wired resistor set up. There was though a little someting, I noted :
- very balanced over all the range,
- very good details and clarity of sounds regardless micro or macro levels, or frequency
- very low noise floor
- very good 3D
- slight loss of deep bass dynamic perhaps
- very close to perfection for a conventional potentiometer
Was it perfect ? For the purpose, yes. Now, litening very very carefully again and again to the reference set up, trying to spot differences rather than listening normaly, I found the reference set-up had:
- a slightly lower noise floor (headphone listening !) which A) gave the feeling to play a tad louder and B) enabled to listen incredibly accurately to very very low level details and revebs, making things more intelligible
- slightly better attack / impulse on bass, very enjoyable, differentiated and balanced drive (slightly better)
- Tocos may sound ‘rounder’ though, more forgiving perhaps on some bad records
TBH, apart from the bottom bass attack and low level noise floor information, all very enjoyable though, there were nearly no noticable difference in direct comparison. That is outstanding, the Tocos belongs into the B1 Korg and should be revealed again IMHO, provided all units are as mine
Am I entirely happy. Yes, very very much… and a little bit less. Very, because the Tocos has exceeded my expectations and I won’t go for another conventional potentiometer. At that price it is a steal, but regardless price it is a real performer (I have no connection to them BTW). A bit sad as that precision I got from direct resistors and wires makes me wonder what LDR can do (but they are likely to colour sound and what about fail safe?) or the MUSE part if it could be had cheap with a conventional manual potentiometer as command… Or if I should rethink all my Hifi, admittely done 2 decades ago around « all non digital but CD » whereas today would be « all digital bare LP »… which means that volume could be controlled digitaly at least in my experience down to -25dB without any audible effect, then having a simple -30dB Mute switch to cover all needs and (Ah, what a shame !) an ADC after my RIAA, to go all digital and room correction… But that’s another story and for the moment and probably a long time the TOCOS remains teh one to beat and it stays of course with the B1 Korg… which will be heart of the system regardless the future, around a conventional 2 stage RIAA that will be required anyway aswell.
Hope I haven’t been too long to read and that helps chosing caps and pots. Last test will be replacing the caps in the signal path by PPP ones, but for that I need time J
Enjoy music
Claude
I looked closer and found out that this nice and still small sized potentiometer was in fact standard ware, nothing fancy audiophile. That could explain some tolerance variations (and no special line), or the fact sellers didn’t like it – well, they must have made a HUGE margin, but perhaps that was also killing some myths. Nowadays you can buy it online at the usual providers with a 5% tolerance waranty for 8$ only (and nearly as much shipping in my case LOL). A real bargain if it delivers.
You can have it cheaper without tolerance waranty but that wasn’t for me as I expect the bad ones to be sold that way… But that’s just me thinking loud.
Again I couldn’t help carrying out numerous measurements to find out how it behaved. It came with a 5 point channel accuracy record and that one proved to be dead accurate , giving -0 +5% channel tracking (but not voltage divider values). Well done though and as advertised. But these were just… 5 listening positions. This is what I found out, taking of course into account the slightly different full channel resistance for the ratios :
- channel mismatch of around 3% up to 11h00
- Oddity at 10h00 with very punctual 8% mismatch, same around 2h00 (construction ?)
- Other than these picks around 3 to 4% mismatch most of the time, always one channel showing more than the other (did over 70 measurments)
- Front channel total 49.4k, rear one 48.8k
It is like this double mono potentiometer is slightly shifted between channels, but its construction doesn’t allow you to ‘bend it’ right again. One has though to put this values into perspective. These are real life measurements of the full contact line.
Enthousiasts like 1% variation, but once resistors are soldered in place etc. real mismatch is often bigger… but does it matter ? Not really, as if I did my math correctly ( ???), 1% is 0.09dB variation and 5% still very acceptable 0.42dB and 10% would still be acceptable 0.83dB (but as things can add up in a device…). So one has to look beyond the pure values : this pot measures well and has a real several megaohm channel isolation.
However, I figured then something out. Guys, don’t shout at me if this is a COMPLETELY SILLY IDEA - which it is probably again as I couldn’t read anything on what my poor brain decided to do.
As the (slight and non critical again !) mismatch was only in one way, I calculated that adding a 2.1k resistor at the entry of the rear channel would bring outstanding values. And it did ! 1% 50ppm resistor in and we get a compensated pot with :
- +-1% channel variation mostly all the way
- bare the to afore mentionated oddities that are though brought back now to roughly 4% channel mismatch (this is just on 2 points, like something on the track right there)
I don’t know if what I did makes sense, please let me know, I can still undo it when it goes back to the to B1 KORG. And going back it does, as it completely killed any potentiometer I had so that I had only to compare it directly with my reference divider. Whereas the small pot’s weaknesses were spotted in a few seconds, that high level comparison took me hours as the Tocos is nearly as good as a pure directly soldered and wired resistor set up. There was though a little someting, I noted :
- very balanced over all the range,
- very good details and clarity of sounds regardless micro or macro levels, or frequency
- very low noise floor
- very good 3D
- slight loss of deep bass dynamic perhaps
- very close to perfection for a conventional potentiometer
Was it perfect ? For the purpose, yes. Now, litening very very carefully again and again to the reference set up, trying to spot differences rather than listening normaly, I found the reference set-up had:
- a slightly lower noise floor (headphone listening !) which A) gave the feeling to play a tad louder and B) enabled to listen incredibly accurately to very very low level details and revebs, making things more intelligible
- slightly better attack / impulse on bass, very enjoyable, differentiated and balanced drive (slightly better)
- Tocos may sound ‘rounder’ though, more forgiving perhaps on some bad records
TBH, apart from the bottom bass attack and low level noise floor information, all very enjoyable though, there were nearly no noticable difference in direct comparison. That is outstanding, the Tocos belongs into the B1 Korg and should be revealed again IMHO, provided all units are as mine
Am I entirely happy. Yes, very very much… and a little bit less. Very, because the Tocos has exceeded my expectations and I won’t go for another conventional potentiometer. At that price it is a steal, but regardless price it is a real performer (I have no connection to them BTW). A bit sad as that precision I got from direct resistors and wires makes me wonder what LDR can do (but they are likely to colour sound and what about fail safe?) or the MUSE part if it could be had cheap with a conventional manual potentiometer as command… Or if I should rethink all my Hifi, admittely done 2 decades ago around « all non digital but CD » whereas today would be « all digital bare LP »… which means that volume could be controlled digitaly at least in my experience down to -25dB without any audible effect, then having a simple -30dB Mute switch to cover all needs and (Ah, what a shame !) an ADC after my RIAA, to go all digital and room correction… But that’s another story and for the moment and probably a long time the TOCOS remains teh one to beat and it stays of course with the B1 Korg… which will be heart of the system regardless the future, around a conventional 2 stage RIAA that will be required anyway aswell.
Hope I haven’t been too long to read and that helps chosing caps and pots. Last test will be replacing the caps in the signal path by PPP ones, but for that I need time J
Enjoy music
Claude
Thanks for reading me guys... and sorry for typos.
This community is so great it really encourages me to carry on as soon as I can with the cap swap (PPP Cornell Dubilier)... and to report back of course.
Enjoy music and give that B1 Korg a go if not done already - it is trully an amazing little pre!
Claude
This community is so great it really encourages me to carry on as soon as I can with the cap swap (PPP Cornell Dubilier)... and to report back of course.
Enjoy music and give that B1 Korg a go if not done already - it is trully an amazing little pre!
Claude
About the Tocos it seems HiFi Collective had them for a while but they don't stock them more because Tocos could not guarantee 1.2 dB channel matching. More info here:
Tocos Cosmos Stereo Potentiometers | Hifi Collective
There are some review also. As they are quite cheap you could just buy a lot and then select the best of them. Apart for the not so good channel match they seems to be good value.
Tocos Cosmos Stereo Potentiometers | Hifi Collective
There are some review also. As they are quite cheap you could just buy a lot and then select the best of them. Apart for the not so good channel match they seems to be good value.
Yep, that's were I discovered them and there is (<as years ago at least) also a proper review of them against other pots on the net... But this old and I wanted real life experience.
Hmm, they could perhaps not guarantee 1.2dB channel matching... but you can get units advertised with +-5% tolerances (lower most of the time but could have bad spots as I found out)... that is still better than 1.2dB matching as 10% are less tha 1dB if I am not mistaken. So no batch needed, but I must confess I initialy indeed thought about ordering 2 in case of, LOL
Where I am lucky, unless it is always like that, it is that one channel reads nearly always proportionaly higher than the other, and, if my little trick with the the additional resistor is not wrong, you can then correct good channel tracking... to outstanding channel tracking.
Well, not that I heard a difference though ,I must confess, but somewhere it is "satisfiying" and for one more $ (makes 9 in total) what a pot you get... these old reviews were probably right, but they are so old that prod may have changed etc., hence testing myself.
Hope it triggers some interest again on non expensive traditional pots
Claude
Hmm, they could perhaps not guarantee 1.2dB channel matching... but you can get units advertised with +-5% tolerances (lower most of the time but could have bad spots as I found out)... that is still better than 1.2dB matching as 10% are less tha 1dB if I am not mistaken. So no batch needed, but I must confess I initialy indeed thought about ordering 2 in case of, LOL
Where I am lucky, unless it is always like that, it is that one channel reads nearly always proportionaly higher than the other, and, if my little trick with the the additional resistor is not wrong, you can then correct good channel tracking... to outstanding channel tracking.
Well, not that I heard a difference though ,I must confess, but somewhere it is "satisfiying" and for one more $ (makes 9 in total) what a pot you get... these old reviews were probably right, but they are so old that prod may have changed etc., hence testing myself.
Hope it triggers some interest again on non expensive traditional pots
Claude
There are many for sale from China but maybe better to get them from a "trusted source".
Do you know which pots Yamamoto use in their phono pre-amp (picture)? From distance they could look like normal cheap pots.....but I guess they are not. Maybe some that could be used in DIY constructions also. My guess is they are very good.
Do you know which pots Yamamoto use in their phono pre-amp (picture)? From distance they could look like normal cheap pots.....but I guess they are not. Maybe some that could be used in DIY constructions also. My guess is they are very good.
Attachments
They all come from China and are now even manufactured there. Some sellers are more trustfull than others, as said some offer measurements (some don't) and, well, try pressurizing them a bit saying you want low tolerance 
Re Yamamoto I can't see on the pix, but browsing on internet through other pix (bottom view) it could indeed well be the Tocos by the look of it.
This was just a sidepost to try to open wider the field for B1 KORG DIYer regarding (IMHO) good non pricey components: for sure they are many possible options - take your pick and let us know!
Re Yamamoto I can't see on the pix, but browsing on internet through other pix (bottom view) it could indeed well be the Tocos by the look of it.
This was just a sidepost to try to open wider the field for B1 KORG DIYer regarding (IMHO) good non pricey components: for sure they are many possible options - take your pick and let us know!
The TKD are fantastic, I have had incredible success with them!
ClaudeG - Thank you for the details reports of the pots, I'm not surprised the small one tracks badly at low rotations - that seems to be fairly universal with small potentiometers. And in my experience bigger IS actually better with audio pots.
Great insight using the resistor on the Tocos!
I am genuinely looking forward to your next report, this is wonderful to read.
ClaudeG - Thank you for the details reports of the pots, I'm not surprised the small one tracks badly at low rotations - that seems to be fairly universal with small potentiometers. And in my experience bigger IS actually better with audio pots.
Great insight using the resistor on the Tocos!
I am genuinely looking forward to your next report, this is wonderful to read.
Hi! I have two mono 10K Tocos that I bought in Hifi collective about 3 years ago. It is much better than a Blue Alps, indeed, but I think I'll put a resistor pot instead. Or may be I'll try both. Now I'm curius to see the difference.
Anyway, in the long term I may install a LDR preamp, because this gives very good sound to the system. I wouldn't say it's colorful, it's just that I think that cadium gives the most beautiful sound and a lot of fluidity. It's hard to explain. When you have a good ldr pre amp, just try to remove it. The magic is gone. It feels like something falls down. But this is very subjective, I agree.
Anyway, in the long term I may install a LDR preamp, because this gives very good sound to the system. I wouldn't say it's colorful, it's just that I think that cadium gives the most beautiful sound and a lot of fluidity. It's hard to explain. When you have a good ldr pre amp, just try to remove it. The magic is gone. It feels like something falls down. But this is very subjective, I agree.
I don't want to digress too much in this thread where the B1 KORG should get all the light it trully deserves. So a last one from me on pots...
I did my home work and apparently all Tocos are manufactured in China (no wonder, many JPN companies do). I don't know if mine is genuine, but it sounds good and that's how it looks on the back (different logo). Note for our stereo use my understanding is you want RV24YG - at least that's what I understood from the JPN spec sheet, please see their website.
Regarding the TDK CP2511, I long time hesitated and that would have been my other choice, out of only 2! It seems indeed to be an excellent pot with rave reviews - but I haven't tried it myself. It is not non expensive and at that price I was wondering if another technical solution (MUSES etc.) wouldn't be just a better alternative. I didn't want to bite the bullet to find out so I went Tocos as 10% of the price (= little risk... and someone here had to try it one day and report, isn't it?) while possibly displaying 95% of what a traditional pot can achieve. I can't say if it is better or worst than the big TDK, but if old reviews are to be believed it is supposed to be in the same league (also with a Noble), depending on sources. If size is to be believed, then the CP2511 and the Cosmos are exactly the same... and a bit smaller than the Black Beauty, which is though probably similar size inside
To stay with Papa's choices, something I would have loved to test against my reference resistor set up would have been a simple kit around the MUSES 72320 (using only the passive resistor network) but with a conventional single track (mono) pot just to give the volume order and so keeping a traditional manual command (and no need for displays etc.) . That would also enable a much shorter signal path (remote pot) and possibly also a remote control solution if the very basic command pot is motorised. Sadly I haven't found such a kit, although it shouldn't be that expensive to make, perhaps an idea for the gifted and skilled developers here in that forum, as it could possibly complement well the B1 KORG. I still would love to find out how a good modern chip can perform vs traditional resistors, a test I couldn't carry out so far sadly...
Good luck with pots!
Claude
I did my home work and apparently all Tocos are manufactured in China (no wonder, many JPN companies do). I don't know if mine is genuine, but it sounds good and that's how it looks on the back (different logo). Note for our stereo use my understanding is you want RV24YG - at least that's what I understood from the JPN spec sheet, please see their website.
Regarding the TDK CP2511, I long time hesitated and that would have been my other choice, out of only 2! It seems indeed to be an excellent pot with rave reviews - but I haven't tried it myself. It is not non expensive and at that price I was wondering if another technical solution (MUSES etc.) wouldn't be just a better alternative. I didn't want to bite the bullet to find out so I went Tocos as 10% of the price (= little risk... and someone here had to try it one day and report, isn't it?) while possibly displaying 95% of what a traditional pot can achieve. I can't say if it is better or worst than the big TDK, but if old reviews are to be believed it is supposed to be in the same league (also with a Noble), depending on sources. If size is to be believed, then the CP2511 and the Cosmos are exactly the same... and a bit smaller than the Black Beauty, which is though probably similar size inside
To stay with Papa's choices, something I would have loved to test against my reference resistor set up would have been a simple kit around the MUSES 72320 (using only the passive resistor network) but with a conventional single track (mono) pot just to give the volume order and so keeping a traditional manual command (and no need for displays etc.) . That would also enable a much shorter signal path (remote pot) and possibly also a remote control solution if the very basic command pot is motorised. Sadly I haven't found such a kit, although it shouldn't be that expensive to make, perhaps an idea for the gifted and skilled developers here in that forum, as it could possibly complement well the B1 KORG. I still would love to find out how a good modern chip can perform vs traditional resistors, a test I couldn't carry out so far sadly...
Good luck with pots!
Claude
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While waiting for my fets I decided to take a very accurate reading of all my resistors, again. I had not taken all the resistors out. This time I decided to take those that don't correspond 100% to the right values. I saw that the two R1 near the Nutubes have 150 ohm, instead of 100 ohm. I want to report this, even if it is to late, may be it could have given some light to the context, since a few persons were trying to help me to find what was the origin of some weird voltages on the board. I will be sure that this time there will not be any mistake.
All R1 must be 100 ohm, right?
I really believe that any of those fets were not defective, There was a mass going on in the circuit.
Another lesson, I have to do these things more concentrated and pay more attention, be focused!
All R1 must be 100 ohm, right?
I really believe that any of those fets were not defective, There was a mass going on in the circuit.
Another lesson, I have to do these things more concentrated and pay more attention, be focused!
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Claude: Thanks for all of the details and comparisons!
Polaron: Long ago, I received a bunch of resistors from Mouser/Digikey (don't remember which) that were ordered as 220R, labelled as 220R, but the bag actually contained 220K parts. Oops... Since then, I have measured EVERY part I have ever used and never trusted whatever is on the invoice, bag, or part. It takes a little while longer to stuff to boards, but it helps to reduce errors. Now, the only errors are the ones I've made all by myself
Polaron: Long ago, I received a bunch of resistors from Mouser/Digikey (don't remember which) that were ordered as 220R, labelled as 220R, but the bag actually contained 220K parts. Oops... Since then, I have measured EVERY part I have ever used and never trusted whatever is on the invoice, bag, or part. It takes a little while longer to stuff to boards, but it helps to reduce errors. Now, the only errors are the ones I've made all by myself
Claude: Thanks for all of the details and comparisons!
Polaron: Long ago, I received a bunch of resistors from Mouser/Digikey (don't remember which) that were ordered as 220R, labelled as 220R, but the bag actually contained 220K parts. Oops... Since then, I have measured EVERY part I have ever used and never trusted whatever is on the invoice, bag, or part. It takes a little while longer to stuff to boards, but it helps to reduce errors. Now, the only errors are the ones I've made all by myself
Yes Eric, you're right, from now on I will check allways all values. Others do mistakes too.