I needed all of the above to keep the tube from ringing and have no issues - there's very little heat produced to begin with.
Damping material on the face plate and floor of a sealed section of the 2mm+ aluminum plate chassis. Damping material blue-tac'd to the face of the tube. The M3 rubber mounts were quite helpful, too. Now the only time it rings is when snapping the power or source toggle switch, which channels an impulsive sound across the face plate.
Damping material on the face plate and floor of a sealed section of the 2mm+ aluminum plate chassis. Damping material blue-tac'd to the face of the tube. The M3 rubber mounts were quite helpful, too. Now the only time it rings is when snapping the power or source toggle switch, which channels an impulsive sound across the face plate.
It is a 2x50K pot. Log or linear, I don´t know. The brand is ALPS Alpine. RS code 236-9604 ( RS Spain ).
Please check to be sure. I´ll check it at kit reception.
I wonder how they manage to use it in guitar pedals where you slam the pedal boards with your foot all the time....
I've had my B1 hooked to a pair of Amp Camp Amps driving Carfrae little big horns for months. The horns are full range with bass augmented by subwoofers driven by Hypex plate Amps. Huge sound stage and generally very happy but...... I used the same speakers to test a cheap chinese 1969 JLH Class A Integrated the other day that was faster warmer and more dynamic. I think the cheap hardware store bought interconnects between my B1 and Amp Camps (bought as a temporary measure) will have to go!!!
There are other good DIY interconnect options out there, but let me put in a word for Gotham Audio cables. I've used them in my system for years now.
I can afford to spend money on cables but don't see a need. I had Audioquest Lapis (then top of the line) and FMS Nexus 2 (boutique cable). It's better than either of them. I've compared it to $1000/m wire from Nordost, Cardas, etc, and it's every bit as good. What's most impressive is how quiet it is, and how extended the top end is, without ever feeling harsh or overly detailed.
I just sent a pair to a friend who has the best system I've ever heard (outside a show or store) and some very expensive interconnects from a well-known manufacturer. His reply was, "I need more of this wire".
I also know of at least one high-end manufacturer who has used Gotham Cable in their equipment, and used very long runs of it in displays at CES and similar shows.
Seriously, it's ridiculously good wire, especially for the money.
The GAC-4/1 is what I used for about a decade. It's about $1/ft. The GAC-4/1 Ultra Pro is a newer model. It's a bit of pain to work with (every one of the four conductors is individually shielded). But it is better, though more expensive at about $5/ft. But that's basically free, by high-end standards, right?
The Ultra Pro is thick, 9mm, so you have to choose connectors carefully. The standard Neutriks won't work for XLR, but there is a special version that does. RCA choices are also restricted, though the WBT-style Connex plugs from Parts Connexion work ($12 a pair), as do some of the KLE connectors they sell ($40 for 4).
Happy to answer any questions. (No, I'm not a distributor, just a fan!)
I can afford to spend money on cables but don't see a need. I had Audioquest Lapis (then top of the line) and FMS Nexus 2 (boutique cable). It's better than either of them. I've compared it to $1000/m wire from Nordost, Cardas, etc, and it's every bit as good. What's most impressive is how quiet it is, and how extended the top end is, without ever feeling harsh or overly detailed.
I just sent a pair to a friend who has the best system I've ever heard (outside a show or store) and some very expensive interconnects from a well-known manufacturer. His reply was, "I need more of this wire".
I also know of at least one high-end manufacturer who has used Gotham Cable in their equipment, and used very long runs of it in displays at CES and similar shows.
Seriously, it's ridiculously good wire, especially for the money.
The GAC-4/1 is what I used for about a decade. It's about $1/ft. The GAC-4/1 Ultra Pro is a newer model. It's a bit of pain to work with (every one of the four conductors is individually shielded). But it is better, though more expensive at about $5/ft. But that's basically free, by high-end standards, right?
The Ultra Pro is thick, 9mm, so you have to choose connectors carefully. The standard Neutriks won't work for XLR, but there is a special version that does. RCA choices are also restricted, though the WBT-style Connex plugs from Parts Connexion work ($12 a pair), as do some of the KLE connectors they sell ($40 for 4).
Happy to answer any questions. (No, I'm not a distributor, just a fan!)
Thanks for a detailed and lengthy response - I'll have a good look for something available from NZ audio shops first. Covid has totally stuffed up a lot of deliveries to NZ with things taking months to arrive if at all. Depends on what shippers are used. I've got a parcel en route from Anticable a pair of 5ft speaker cables. They where sent via USP and made it from US to Japan in a couple of days but has been AWOL for two weeks since then. Love Anti cables for speaker wire but this forum practically tore me a new one for using their interconnects as no shielding.
I've done some work to help with the microphonics issue. I lined the chassis with Noico 80 mat, and used rubber standoffs to mount the PCB. The mat seems very effective.
https://www.amazon.com/Noico-Deaden...&refinements=p_36:-1500&rnid=386419011&sr=8-1
https://www.amazon.com/iFlight-Anti...mm+anti+vibration+mount&qid=1603204558&sr=8-2
https://www.amazon.com/Noico-Deaden...&refinements=p_36:-1500&rnid=386419011&sr=8-1
https://www.amazon.com/iFlight-Anti...mm+anti+vibration+mount&qid=1603204558&sr=8-2
Attachments
I thought I was done with the excellent sounding B1 Korg. However, Mark Johnson recently « released » an interesting low cost / easy to assemble general purpose SMPS filter. He outlined this could be suited for the B1 Korg PS. More here
PO89ZB , an inline DC filter for SMPS wall warts . Preamps, HPA, Korg NuTube, etc
Given Mark’s reputation and excellent projects, I gave it (of course) a try. In fact several tries as I built 2 of them.
Just to discard one variable, in all my various tests both filters I built sounded identical and this consistency is a credit to its design as that applied with different SMPS for different units.
My B1 Korg is a bit special as it has a low ripple quality SMPS, already an excellent filtering courtesy of M. Pass and on top the PS caps have been doubled in capacity to enhence further the original filtering with some further minor positive effect.
I didn’t expect this filter to make any improvement here, given the unit sounds already excellent to me and different PS (such as linear regulated etc.) brought a slightly different caracter (tad more bass etc.) but it was always a trade off and a matter of taste - at the end I prefered to stick to the original PS.
It is not easy to carry out comparisons with the B1 Korg. That is because a) you need it to stabilise, you can’t just switch in on and off / listen on the fly, so you need a lot of listening time and effort, but mainly because b) it is so addictive that it is very difficult to concentrate on listening impressions without being carrying away ! J
However, for me the filter worked, although… I really didn’t expect it to work at all ! Basicaly the same as when applied to a cheap chinese unit, but with a much lower amplitude, say 60% of the benefits (say +2 in my scale). It gets harder to find it out, requires careful listening, but the main outstanding figures are IMHO :
- improved drive / punch in the lower bass (and that can’t be in that case just the filter’s cap increase, something is happening here), very nice flesh and speed
- better resolution overall, more easy to pick in the higher frequencies (those finding this unit somewhat agressive in the treble, something I can’t back up at all for myself, should try this filter as it makes the treble more precise and yet more natural)
- a tad wider soundstage and overall better register integration, although the B1 Korg didn’t really need any improvement on that and it is was marginal, but still not a negative of course
At the end the most noticeable things are the bass drive and refined treble. But that’s with careful listenings and all IMHO. In terms of gain, I would say the magnitude is similar/slightly more to the PS capacity doubling I did, so overall a small step, on the verge of what is noticeable, let’s be realistic. We aren’t transforming the unit here, say the cherry on the cake, but who doesn’t like an extra J
The small gain in this application is probably due to the power supply being well designed already (of course, Papa did it !), not a big step… but on the other hand it doesn’t cost a leg and it manages to enhence a device I thought already close to perfection and consistency, so every increase from there is already incredible. And the gains are somewhere the gains various PS could bring without their trade-offs, so the better.
What about me now ? Well, I will integrate this filter to the B1 Korg permanently and given its low cost and ease of built I can only think that it would be benefical to most B1 Korg owners aswell, especialy those that are not using an extra low ripple with extra caps PS : I can only think that the improvements then are going to be greater while this filter can easily be added as an external device and requires no changes / desoldering on the B1 Korg ! Easy job, easy to try, why shouldn’t you ? Of course, and as you can read on its dedicated thread, it does perform even better on normal designs using an SMPS. Thanks Mark, thanks Papa, thanks Konst !
Enjoy music
Claude
PS : I like my B1 Korg with negative H2 and less harmonics / spice than suggested as starting point in Papa’s paper. Just as a side note, the filter didn’t noticeably affect the bias voltage of the B1 Korg, so the effects are not due to bias changes (as this affects the sound)… and are anyway very different from what a small bias change would bring around my chosen bias.
PO89ZB , an inline DC filter for SMPS wall warts . Preamps, HPA, Korg NuTube, etc
Given Mark’s reputation and excellent projects, I gave it (of course) a try. In fact several tries as I built 2 of them.
Just to discard one variable, in all my various tests both filters I built sounded identical and this consistency is a credit to its design as that applied with different SMPS for different units.
My B1 Korg is a bit special as it has a low ripple quality SMPS, already an excellent filtering courtesy of M. Pass and on top the PS caps have been doubled in capacity to enhence further the original filtering with some further minor positive effect.
I didn’t expect this filter to make any improvement here, given the unit sounds already excellent to me and different PS (such as linear regulated etc.) brought a slightly different caracter (tad more bass etc.) but it was always a trade off and a matter of taste - at the end I prefered to stick to the original PS.
It is not easy to carry out comparisons with the B1 Korg. That is because a) you need it to stabilise, you can’t just switch in on and off / listen on the fly, so you need a lot of listening time and effort, but mainly because b) it is so addictive that it is very difficult to concentrate on listening impressions without being carrying away ! J
However, for me the filter worked, although… I really didn’t expect it to work at all ! Basicaly the same as when applied to a cheap chinese unit, but with a much lower amplitude, say 60% of the benefits (say +2 in my scale). It gets harder to find it out, requires careful listening, but the main outstanding figures are IMHO :
- improved drive / punch in the lower bass (and that can’t be in that case just the filter’s cap increase, something is happening here), very nice flesh and speed
- better resolution overall, more easy to pick in the higher frequencies (those finding this unit somewhat agressive in the treble, something I can’t back up at all for myself, should try this filter as it makes the treble more precise and yet more natural)
- a tad wider soundstage and overall better register integration, although the B1 Korg didn’t really need any improvement on that and it is was marginal, but still not a negative of course
At the end the most noticeable things are the bass drive and refined treble. But that’s with careful listenings and all IMHO. In terms of gain, I would say the magnitude is similar/slightly more to the PS capacity doubling I did, so overall a small step, on the verge of what is noticeable, let’s be realistic. We aren’t transforming the unit here, say the cherry on the cake, but who doesn’t like an extra J
The small gain in this application is probably due to the power supply being well designed already (of course, Papa did it !), not a big step… but on the other hand it doesn’t cost a leg and it manages to enhence a device I thought already close to perfection and consistency, so every increase from there is already incredible. And the gains are somewhere the gains various PS could bring without their trade-offs, so the better.
What about me now ? Well, I will integrate this filter to the B1 Korg permanently and given its low cost and ease of built I can only think that it would be benefical to most B1 Korg owners aswell, especialy those that are not using an extra low ripple with extra caps PS : I can only think that the improvements then are going to be greater while this filter can easily be added as an external device and requires no changes / desoldering on the B1 Korg ! Easy job, easy to try, why shouldn’t you ? Of course, and as you can read on its dedicated thread, it does perform even better on normal designs using an SMPS. Thanks Mark, thanks Papa, thanks Konst !
Enjoy music
Claude
PS : I like my B1 Korg with negative H2 and less harmonics / spice than suggested as starting point in Papa’s paper. Just as a side note, the filter didn’t noticeably affect the bias voltage of the B1 Korg, so the effects are not due to bias changes (as this affects the sound)… and are anyway very different from what a small bias change would bring around my chosen bias.
Attachments
Got there first
Nice ClaudeG, I was about to post the same thing here. These things are great and cost just a few bucks to stuff.
If anyone is interested, I have ordered a batch of these and will have around 15 boards available which I am happy giving people for an optional donation for postage of $2/$3 (you can have them free, hence optional, but if you want to contribute that is cool to).
If there is lots of demand I am happy reordering as many as are required)
Please PM me, I can send these out after the election (on an election project), when I get some time.
Below is a pic of the before and after filter "DC" on my Korg B1
Nice ClaudeG, I was about to post the same thing here. These things are great and cost just a few bucks to stuff.
If anyone is interested, I have ordered a batch of these and will have around 15 boards available which I am happy giving people for an optional donation for postage of $2/$3 (you can have them free, hence optional, but if you want to contribute that is cool to).
If there is lots of demand I am happy reordering as many as are required)
Please PM me, I can send these out after the election (on an election project), when I get some time.
Below is a pic of the before and after filter "DC" on my Korg B1
Last edited:
hello everyone, can someone explain my question to me? I can already see a difference there. And did someone have increased cathode voltage 6.7V despite all remaining exactly right? Thank you.
No Microphonics
I recently completed the build of a B1 Korg using the full kit and it's sounding great with an M2x. I'm a bit puzzled by the lack microphonics of the Nutube though.
After getting it to a working state I connected it in my system and could not produce any ringing whatsoever. The top of the case is not even attached yet. Neither at high volume levels nor by rapping on the case. I did use the iFlight rubber standoffs but that is the only mitigation measure so far. The Nutube is cantilevered in air supported by the pins. I did NOT provide any alternate means of grounding the PC board since the rubber standoffs insulate it. It's just grounded via the power connection.
Is this just a product of my very inefficient speakers (83 dB)? Or just lucky with this Nutube being insensitive to microphonics? I had bought some blu tack putty to dampen vibrations but have not used it yet. Maybe the iFlight standoffs are just very effective.
Should I just close it up and use as it is now or put some blu tack below the Nutube?
I recently completed the build of a B1 Korg using the full kit and it's sounding great with an M2x. I'm a bit puzzled by the lack microphonics of the Nutube though.
After getting it to a working state I connected it in my system and could not produce any ringing whatsoever. The top of the case is not even attached yet. Neither at high volume levels nor by rapping on the case. I did use the iFlight rubber standoffs but that is the only mitigation measure so far. The Nutube is cantilevered in air supported by the pins. I did NOT provide any alternate means of grounding the PC board since the rubber standoffs insulate it. It's just grounded via the power connection.
Is this just a product of my very inefficient speakers (83 dB)? Or just lucky with this Nutube being insensitive to microphonics? I had bought some blu tack putty to dampen vibrations but have not used it yet. Maybe the iFlight standoffs are just very effective.
Should I just close it up and use as it is now or put some blu tack below the Nutube?
Hey everyone. I fired up my B1k on that big blue board with integrated UBiB and room for bog caps. There are two things:
1: I accidentally soldered all Q1 in reverse, fired it noticed it almost right away. Soldered in properly.
2: All values related to the tube measure fine as described in Papa's article, other things:
-- point between first to jfets before the grid cap: ~11V
-- I am running out of 10k pot and lowest T7,8 voltage I get is 14V
-- Voltage across R1 is ~1.7V
Are those number reasonable or look like I burner Q1s? If everything looks fine, why I cant get to 9.5V?
Thank you!
1: I accidentally soldered all Q1 in reverse, fired it noticed it almost right away. Soldered in properly.
2: All values related to the tube measure fine as described in Papa's article, other things:
-- point between first to jfets before the grid cap: ~11V
-- I am running out of 10k pot and lowest T7,8 voltage I get is 14V
-- Voltage across R1 is ~1.7V
Are those number reasonable or look like I burner Q1s? If everything looks fine, why I cant get to 9.5V?
Thank you!