It would be interesting to see the "distortion profile" of the Lyngdorf. Especially at low power levels (0 - 5 Watt).
You may have mis-interpreted the response of Mr. Pass. Think the message is that you normally either have the pre or the power amp (not both) to add a bit of 2nd harmonic. But sometimes you can have both. I found the combination with Korg and MoFo quite good. Much better than expected (I expected too much of a good thing).
You may have mis-interpreted the response of Mr. Pass. Think the message is that you normally either have the pre or the power amp (not both) to add a bit of 2nd harmonic. But sometimes you can have both. I found the combination with Korg and MoFo quite good. Much better than expected (I expected too much of a good thing).
Thx Meper for sharing it's interesting match some pre & amp constelation to try
Greetings
Yes, I built BA3-pre for MoFo to have large voltage swing and I adjusted BA3-pre so far to have smallest amount of distortion because I knew MoFo would have some 2nd harmonic. Therefor it was surprising that combination with Korg worked quite well. But I am back to BA3-pre now and Korg is waiting for M2X to be finished. I expect this will be a good combination.
Good to know!
I tested PSUs today for the M2X mono blocks and pulled 120W (44.2 VDC loaded with 16 ohm) from both and that was no problem. The CRCLC filters seems to do the job as DMM set to AC showed .000 VAC. Simulation said about 1 mV ripple. Will see when I get a scope on later. Hope I get silent M2X's.....so Korg can show what it can do.
I tested PSUs today for the M2X mono blocks and pulled 120W (44.2 VDC loaded with 16 ohm) from both and that was no problem. The CRCLC filters seems to do the job as DMM set to AC showed .000 VAC. Simulation said about 1 mV ripple. Will see when I get a scope on later. Hope I get silent M2X's.....so Korg can show what it can do.
So this is the final mod / test, that is unless someone comes up with a bright idea but given the B1 KORG is very simple and we already tackled all usual potential aeras, the future is likely to be variations on the theme.
Initialy I wanted no cap in the signal path, but that is impossible for this pre as there are voltage differences between the stages, so DC blocking caps are absolutely mandatory. There are 3 of them in the signal path per channel, each 10uF, turning out to be a convenient standard value in fact.
TBH, the B1 KORG sounds gorgeous as it is, so why bother ? Well, some claim that electrolytic caps can be advantageously replaced by better ones like polyprop ones (PPP). I experienced this at the input of my own power amp decades ago (only cap in the signal path I have in my system, but that will change with the Korg J ) so if that works for 1 cap, for sure it is worth giving it a trial with 3, hence this test.
However, some warnings: this is a deviation from the original so sound « may » be altered, and, that is a given, appearence of the nice board will be anyway as the replacement caps aren’t 1 to 1 compatible relacements. A bit of fiddling is required to fit them. Another warning is that this upgraded parts cost over 10 times more than the recommended caps by Papa, which DO a very nice job, so if you were an industrial you wouldn’t even think of it ! As DIYer though you will notice we speak of a total of 40$ for all 6 caps, which is possibly still reasonable and at least still in relation with that project. Well, this hobby is not about rational anyway ,and if you are very unreasonable there are people who will happily release you of much more cash for a single « audiophile » cap
Before going for the test, a few technical words. Thanks to Zen Mod, I realised that these 3 caps act as part of a high pass filter, meaning in practice that altering their value would affect the band pass in the bass. The smaller the cap, the higher the high pass cut frequency.
Although usualy people take the cut frequency for reference, you have to bare in mind that kind of filter actually isn’t of course on /off and it indeed robs 3dB at the cut frequency… but still robs 0.95dB at twice the cut frequency and 0.26dB at 4 times the cut frequency and 0.16dB at 5 times. And it adds up for each of our 3 caps…
Going for ZM’s wise and safe values, say cut frequency 5Hz, you can use 0.22uF for the first cap in the signal path, 1uF for the second and ,in my case, I went for 3.3uF for the last one to enable « in case of » an easy sub 10k entry impedance power amp to follow, which is really worst reasonable case, but as space wasn’t a concern anymore because that one wouldn’t fit on the board anyway, why bother ! Well, you may want to bother though depending on your power amp as that last cap is the most expensive one and you could probably go for a smaller one (plus of course you don’t have to replace all 3 caps if you don’t want to !). Anyway, that means roughly a total of theoretical -1dB loss at 20Hz in the line, something you should be able to live with as in practice that doesn’t mean a lot and nothing is perfect in your system already...
For the caps I went for Cornell Dubilier 940 series. I am used to Vishay, Wima, Solen, Siemens, Wondercap and had never tried these, but I read good comparative reviews, they were available at Mouser for a reasonable price plus their form factor meant the 0.22uF and 1uF could hopefully still be fitted on the board with some fiddling. And of course I wanted to test them and be part of that project as quality items.
For this listening test, I only replaced the 2 first caps (out of 3). Despite some preparation work around the (too) big legs in cas of the second cap, you will need fiddling for the installation and that means already more time between listening sessions. Plus I compared the options with a headphone directly connected to the B1 KORG and that meant that the 3rd cap was out of the loop anyway, being replaced by a (lower « quality » electrolytic 100uF cap due to possible impedance issues in HP configuration - a cap probably acting as a muffler but then I can at least quickly assess how replacing 2 caps in the signal path alter the sound. I had the new PPP caps ran in for a few hours before installation… no clue if it helped, but let’s be fair.
As you can see, the first cap fits easily on the board and even its legs are OK for the holes. I used my beloved blutack again to stabilise it though, just in case. The second cap does fit the board provided it is raiseda bit so you don’t interfer with smaller parts. You need to fiddle as the legs are just a tad too large for the holes, and you still want access to the trim pots of course.
Initialy I wanted no cap in the signal path, but that is impossible for this pre as there are voltage differences between the stages, so DC blocking caps are absolutely mandatory. There are 3 of them in the signal path per channel, each 10uF, turning out to be a convenient standard value in fact.
TBH, the B1 KORG sounds gorgeous as it is, so why bother ? Well, some claim that electrolytic caps can be advantageously replaced by better ones like polyprop ones (PPP). I experienced this at the input of my own power amp decades ago (only cap in the signal path I have in my system, but that will change with the Korg J ) so if that works for 1 cap, for sure it is worth giving it a trial with 3, hence this test.
However, some warnings: this is a deviation from the original so sound « may » be altered, and, that is a given, appearence of the nice board will be anyway as the replacement caps aren’t 1 to 1 compatible relacements. A bit of fiddling is required to fit them. Another warning is that this upgraded parts cost over 10 times more than the recommended caps by Papa, which DO a very nice job, so if you were an industrial you wouldn’t even think of it ! As DIYer though you will notice we speak of a total of 40$ for all 6 caps, which is possibly still reasonable and at least still in relation with that project. Well, this hobby is not about rational anyway ,and if you are very unreasonable there are people who will happily release you of much more cash for a single « audiophile » cap
Before going for the test, a few technical words. Thanks to Zen Mod, I realised that these 3 caps act as part of a high pass filter, meaning in practice that altering their value would affect the band pass in the bass. The smaller the cap, the higher the high pass cut frequency.
Although usualy people take the cut frequency for reference, you have to bare in mind that kind of filter actually isn’t of course on /off and it indeed robs 3dB at the cut frequency… but still robs 0.95dB at twice the cut frequency and 0.26dB at 4 times the cut frequency and 0.16dB at 5 times. And it adds up for each of our 3 caps…
Going for ZM’s wise and safe values, say cut frequency 5Hz, you can use 0.22uF for the first cap in the signal path, 1uF for the second and ,in my case, I went for 3.3uF for the last one to enable « in case of » an easy sub 10k entry impedance power amp to follow, which is really worst reasonable case, but as space wasn’t a concern anymore because that one wouldn’t fit on the board anyway, why bother ! Well, you may want to bother though depending on your power amp as that last cap is the most expensive one and you could probably go for a smaller one (plus of course you don’t have to replace all 3 caps if you don’t want to !). Anyway, that means roughly a total of theoretical -1dB loss at 20Hz in the line, something you should be able to live with as in practice that doesn’t mean a lot and nothing is perfect in your system already...
For the caps I went for Cornell Dubilier 940 series. I am used to Vishay, Wima, Solen, Siemens, Wondercap and had never tried these, but I read good comparative reviews, they were available at Mouser for a reasonable price plus their form factor meant the 0.22uF and 1uF could hopefully still be fitted on the board with some fiddling. And of course I wanted to test them and be part of that project as quality items.
For this listening test, I only replaced the 2 first caps (out of 3). Despite some preparation work around the (too) big legs in cas of the second cap, you will need fiddling for the installation and that means already more time between listening sessions. Plus I compared the options with a headphone directly connected to the B1 KORG and that meant that the 3rd cap was out of the loop anyway, being replaced by a (lower « quality » electrolytic 100uF cap due to possible impedance issues in HP configuration - a cap probably acting as a muffler but then I can at least quickly assess how replacing 2 caps in the signal path alter the sound. I had the new PPP caps ran in for a few hours before installation… no clue if it helped, but let’s be fair.
As you can see, the first cap fits easily on the board and even its legs are OK for the holes. I used my beloved blutack again to stabilise it though, just in case. The second cap does fit the board provided it is raiseda bit so you don’t interfer with smaller parts. You need to fiddle as the legs are just a tad too large for the holes, and you still want access to the trim pots of course.
Attachments
Now to the sound. The B1 KORG with its original caps, while transparent, has a very enjoyable sound, something you don’t want to overdo though and that can be adjusted with the trim pot. While the 3D and localisation of the soundstage is amazing, I have to confess it is of course not the absolute most revealing / neutral / cold monitor machine - BUT instead it is revealing, balanced over a wide frequency range and its large dynamic field… and it is very musical… always. It is not a just an euphonic sound machine, but a proper preamp. TBH, it has also a very very enjoyable drive : it really kicks your bottom or makes your foot tap. To my taste, to make it perfect, I would want the same (not losing any of the fun factor) but with even more transparency, less grain, extended bottom and high frequency ranges, and perhaps getting a very little bit rid of a little enthousiam in the mid bass region… while not losing that kick... nor the quite forgiving character on not so good records. It could probably be even faster, but is already quite good and I am really nickpicking. That is what I would call then perfect TO MY TASTE, regardless price, and it might be possible to get close with that little unit at a ridiculously low price !
Re caps, would this be perfection ? No clue and for that cap test, as in opposition with my reference voltage divider for the volume pots, I can’t say where the truth / reference / perfection is : I can’t say how it sounds without any cap. So all I can do is report on a differential base, original electrolytic vs CD 940 PPP caps and give hints on tendencies and my preference.
And here are the result :
- The PPP caps didn’t alter the sound in terms of sonic balance, caracter, frequencies… it is all nearly the same, but even better !
- The PPP caps definitely added even more kick and extended bottom frequencies, the extra kick not being a problem as all remained balanced and in fact more differentiated between bass notes
- the PPP caps outlined another dimension in terms of precision, « grain » / resolution, both opening a curtain in transparency while also taking a slight veil out
- All frequencies seem better balanced, no more of the slight mid-bass exageration
- It all sounds very pure but also flows much better, intergration of music is better, making a very enjoyable whole – so addictiv I must say that carrying listening tests is difficult, you get carried away !
- Frequency range seems a bit extended, deepest bass being now clearly as well representated than the other frequencies, both energic and subtle, I also believe that the highest treble is a bit better
- Noise floor seems lower, lowest sounds more natural, easier to follow and better integrated
All in all a great upgrade IMHO. There is nothing wrong with the original recommendation as the original caps sound quite balanced, are doing a fine job for little money and space and are probably adding a bit of extra nice sound for dynamic material which probably goes in line with the B1 Korg original intention.
Now, as if me you don’t consider this kit to be a sound machine doing also a very fine preamp job, but rather a trully proper pre-amp having the ability to add (as you want) a (little very bit of) nice flavour to your neutral and purely transparent sound while being always an outstandingly muscial pre for a budget price, then you may want to raise it to its max neutral level in terms of caps distorsion, PS cleaness, proper volume control… just leaving the added extra falvour you can control,adjusting the KORG to your preference.
This last mod brings this pre to a high level, - what still stays is probably just the pure KORG sound and that is mainly linked to the adjustment YOU make. In my case, all tests were conducted at the nominal Papa setting, not inverting phase, with an output level of max 0.5V in my case. I really enjoy it like this, so much I haven’t yet played with the adjustments. Knowing me, it could well be I won’t bother about phase, I will enjoy the drive of positive 2nd harmonics very much, but won’t overdo it, probably at mine 0.5V reducing it a slightly bit (in relation to 3rd harmonic) to get (do I need that?) an even more neutral and still faster drive and overall not too much distorsions (can’t say I don’t like what stays now the caps are gone J. Well, a tad… maybe… maybe not, as for now I enjoy it so much like this and I need anyway to build an extra board for the 3rd caps… and move on to a Salas RIAA pre !
Enjoy music and thanks again to everyone!
Claude
Re caps, would this be perfection ? No clue and for that cap test, as in opposition with my reference voltage divider for the volume pots, I can’t say where the truth / reference / perfection is : I can’t say how it sounds without any cap. So all I can do is report on a differential base, original electrolytic vs CD 940 PPP caps and give hints on tendencies and my preference.
And here are the result :
- The PPP caps didn’t alter the sound in terms of sonic balance, caracter, frequencies… it is all nearly the same, but even better !
- The PPP caps definitely added even more kick and extended bottom frequencies, the extra kick not being a problem as all remained balanced and in fact more differentiated between bass notes
- the PPP caps outlined another dimension in terms of precision, « grain » / resolution, both opening a curtain in transparency while also taking a slight veil out
- All frequencies seem better balanced, no more of the slight mid-bass exageration
- It all sounds very pure but also flows much better, intergration of music is better, making a very enjoyable whole – so addictiv I must say that carrying listening tests is difficult, you get carried away !
- Frequency range seems a bit extended, deepest bass being now clearly as well representated than the other frequencies, both energic and subtle, I also believe that the highest treble is a bit better
- Noise floor seems lower, lowest sounds more natural, easier to follow and better integrated
All in all a great upgrade IMHO. There is nothing wrong with the original recommendation as the original caps sound quite balanced, are doing a fine job for little money and space and are probably adding a bit of extra nice sound for dynamic material which probably goes in line with the B1 Korg original intention.
Now, as if me you don’t consider this kit to be a sound machine doing also a very fine preamp job, but rather a trully proper pre-amp having the ability to add (as you want) a (little very bit of) nice flavour to your neutral and purely transparent sound while being always an outstandingly muscial pre for a budget price, then you may want to raise it to its max neutral level in terms of caps distorsion, PS cleaness, proper volume control… just leaving the added extra falvour you can control,adjusting the KORG to your preference.
This last mod brings this pre to a high level, - what still stays is probably just the pure KORG sound and that is mainly linked to the adjustment YOU make. In my case, all tests were conducted at the nominal Papa setting, not inverting phase, with an output level of max 0.5V in my case. I really enjoy it like this, so much I haven’t yet played with the adjustments. Knowing me, it could well be I won’t bother about phase, I will enjoy the drive of positive 2nd harmonics very much, but won’t overdo it, probably at mine 0.5V reducing it a slightly bit (in relation to 3rd harmonic) to get (do I need that?) an even more neutral and still faster drive and overall not too much distorsions (can’t say I don’t like what stays now the caps are gone J. Well, a tad… maybe… maybe not, as for now I enjoy it so much like this and I need anyway to build an extra board for the 3rd caps… and move on to a Salas RIAA pre !
Enjoy music and thanks again to everyone!
Claude
Attachments
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Hi ZM, you typed your question faster than me my (sorry) long posts, but of course this was just part 1 on installation and explanation, while the second post is just on sound.
Differences aren't day and night or like different units of course, but I must say though quite substential and like usual Special Edition tuning you can encounter ususaly (the same but better and extented). In my case I very much prefer the sound with these PPP caps, as IMHO that takes away some distorsions, noises and losses while just letting the pure Korg sound through. Just my feeling of course.
Is it worth trying? YES IMHO, but only if you are serious about this being an absolute pre with... caracter. If I had though to do it again I would go straight to PPP caps (at least the 2 first easy doing caps) as desoldering the original caps is quite a pain with the usual hand pump and wick... unless you have a proper desoldering station (which my neighbour had never used, but lucky me), and that saved my day.
Hope I managed to make my findings clear
Claude
PS: I listened to 2 caps because 3rd cap will take longer than expected, would be different listening conditions anyway and would have added time between listening sessions. But I expect more of the same...
Differences aren't day and night or like different units of course, but I must say though quite substential and like usual Special Edition tuning you can encounter ususaly (the same but better and extented). In my case I very much prefer the sound with these PPP caps, as IMHO that takes away some distorsions, noises and losses while just letting the pure Korg sound through. Just my feeling of course.
Is it worth trying? YES IMHO, but only if you are serious about this being an absolute pre with... caracter. If I had though to do it again I would go straight to PPP caps (at least the 2 first easy doing caps) as desoldering the original caps is quite a pain with the usual hand pump and wick... unless you have a proper desoldering station (which my neighbour had never used, but lucky me), and that saved my day.
Hope I managed to make my findings clear
Claude
PS: I listened to 2 caps because 3rd cap will take longer than expected, would be different listening conditions anyway and would have added time between listening sessions. But I expect more of the same...
Thanks for the additional idea
Perhaps... has someone tried it?
Less is more, of course, however, I could be easily convinced that there isn't much to gain between one of these PPP caps and... nothing at all (that is once you paid for them anyway of course), plus the first stage is likely to be quite pure in comparison to the KORG which seems to be the main sound generator. Just pure speculation though, I would love to be proved wrong
So on that one I will let first another one burn his fingers... coward I know
Perhaps... has someone tried it?
Less is more, of course, however, I could be easily convinced that there isn't much to gain between one of these PPP caps and... nothing at all (that is once you paid for them anyway of course), plus the first stage is likely to be quite pure in comparison to the KORG which seems to be the main sound generator. Just pure speculation though, I would love to be proved wrong
So on that one I will let first another one burn his fingers... coward I know
I find that polypropylene caps give the best performance, but of course the
improvements are weighed against the cost and physical space.
The cheapest 10 uF PP board mounts start around $3 (and go up to $30) and this
is from Digikey, not audio specialty guys. The $3 one is large enough to dominate
the board space in quantities of 6.
I have had good luck with the NOS 10 uF Elnas, but I am informed that perhaps
the newer ones are not quite as good....
improvements are weighed against the cost and physical space.
The cheapest 10 uF PP board mounts start around $3 (and go up to $30) and this
is from Digikey, not audio specialty guys. The $3 one is large enough to dominate
the board space in quantities of 6.
I have had good luck with the NOS 10 uF Elnas, but I am informed that perhaps
the newer ones are not quite as good....
Thanks Papa... indeed space and cost are of course key and in no relation to the initialy proposed parts.
I had never tried the 940s from CD, but must confess I am very happy with the result and can't really fault them in one aera, although only a direct comparison (I haven't done) could outline the (in real life) probably marginal differences / flavours (treble perhaps?) with the very best PPP. I like PPP caps but indeed I am not carried away by the viral audiophila that recommends caps costing an arm or a requiring the entire room
Going back to the B1 Korg, as one can see on the (very poor, sorry!) pix, the beauty of these big 940s is the 2 first stage caps can still fit on the board without ruining the look or risking to alter function - at least it is much better than I initialy thought.
As for the 3rd cap, I came to the conclusion a mini outboard linked to the mounting studs is probably the most simple "stable solution"... unless of course you are dead sure you won't never use a power amp with less than say 30k Ohm input impedance in which case you "may just still" be able to get away with an onboard PPP solution as for the other caps.
Again many many thanks for this B1 KORG, Papa!
Claude
I had never tried the 940s from CD, but must confess I am very happy with the result and can't really fault them in one aera, although only a direct comparison (I haven't done) could outline the (in real life) probably marginal differences / flavours (treble perhaps?) with the very best PPP. I like PPP caps but indeed I am not carried away by the viral audiophila that recommends caps costing an arm or a requiring the entire room
Going back to the B1 Korg, as one can see on the (very poor, sorry!) pix, the beauty of these big 940s is the 2 first stage caps can still fit on the board without ruining the look or risking to alter function - at least it is much better than I initialy thought.
As for the 3rd cap, I came to the conclusion a mini outboard linked to the mounting studs is probably the most simple "stable solution"... unless of course you are dead sure you won't never use a power amp with less than say 30k Ohm input impedance in which case you "may just still" be able to get away with an onboard PPP solution as for the other caps.
Again many many thanks for this B1 KORG, Papa!
Claude
I used Mitsubishi symboled 2.5 microfarad orange drop type poly pros throughout from the get go. I already had several of them laying around in an audio graveyard. They seem to work great and I doubt that I miss a few Hz on the bottom end.
Listening to Korg-Pass B1 now feeding Pass Clone VFET to transformer and Stax headphones. It is the best sounding Stax performance I have heard to date. All the detail but tone-ful in the mids and impact-ful in the bass.
Listening to Korg-Pass B1 now feeding Pass Clone VFET to transformer and Stax headphones. It is the best sounding Stax performance I have heard to date. All the detail but tone-ful in the mids and impact-ful in the bass.
to cjfrbw #2619
Hello cjfrbw,
I tried similar combinations to drive my STAX (which I call my 'acoustic
microscope').
B1 NUTUBE followed by
BA-3 / M2X /F5-T
STAX.
All combies sound very very good. A little bit more or less 'salt and pepper'
here and there in the acoustical spectrum.
Papa Nelson gave us a very beautiful 'toy'. Thanks again!
Greets
Dirk
Hello cjfrbw,
I tried similar combinations to drive my STAX (which I call my 'acoustic
microscope').
B1 NUTUBE followed by
BA-3 / M2X /F5-T
STAX.
All combies sound very very good. A little bit more or less 'salt and pepper'
here and there in the acoustical spectrum.
Papa Nelson gave us a very beautiful 'toy'. Thanks again!
Greets
Dirk
Thanks to all of you for reading me!
It is indeed best to jump straight to PPP if you want to go that route, but no doubt a skilled DIYer like Jim 6L6 will be able to desolder easily the existing caps. As of me, I must admit double sided and probably through hole contact meant FOR ME a lot of time and care for just one cap... until that wonderful desoldering vacuum station came, which made it an increadibly 10 min easy job for all remaining caps.
This little pre really deserves the best parts. When the thread started I was afraid it would be a somewhat "euphonic loundness knob sound machine" with a short ah ha effect but it is not! It is a proper preamp... adjustable to gusto, an incredible gift to the community (and to lucky me).
I had a look at the kit in the store: it is a great piece you put together and with a beautiful casing that does the B1 KORG justice: well done! It is a steal IMHO... it will overshadow existing ready products plus you get the fun of an easy and robust (see all my novice abuses) DIY. Means highly recommended to any HIFI fan, young and old!
Enjoy your Sunday very much
Happy Claude
It is indeed best to jump straight to PPP if you want to go that route, but no doubt a skilled DIYer like Jim 6L6 will be able to desolder easily the existing caps. As of me, I must admit double sided and probably through hole contact meant FOR ME a lot of time and care for just one cap... until that wonderful desoldering vacuum station came, which made it an increadibly 10 min easy job for all remaining caps.
This little pre really deserves the best parts. When the thread started I was afraid it would be a somewhat "euphonic loundness knob sound machine" with a short ah ha effect but it is not! It is a proper preamp... adjustable to gusto, an incredible gift to the community (and to lucky me).
I had a look at the kit in the store: it is a great piece you put together and with a beautiful casing that does the B1 KORG justice: well done! It is a steal IMHO... it will overshadow existing ready products plus you get the fun of an easy and robust (see all my novice abuses) DIY. Means highly recommended to any HIFI fan, young and old!
Enjoy your Sunday very much
Happy Claude
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