Great video! Not only have you figured out what's wrong with the Nutube and what you don't like, you have (most critically) determined a course of corrective action. I've acquired the Pete Millett balanced version PCBs, and because I'm not an expert on these matters a lot of time is being spent researching all the options for the build. Good work. Keep it coming.
@@NocturneVid66 First of all, Greetings to the internet's number 1 audio tinkerer.😄 Hope all is well. I'm sure you're familiar with the term BACKBURNER. In this case, necessitated by a failed music server and the need to quickly build a new one. Though, in truth, the first build convinced me to do a second (Better) build. Then came the unregulated linear power supply project that the second server build demanded. Easily distracted? Me? Of course not! Unless you mean the burning urge to experiment with Home Audio Fidelity's room correction and crosstalk cancellation filters on the new server. Meanwhile...the Nutube bins continue filling with new parts, like the Salas SSLV 1.3 power supply boards, and, the Sjöström Super Regulator power supply boards. Decisions, decisions. The thing about the Sjöström boards is that they are fire engine RED, with gold pads...and oh so gorgeous. Self control? At this point, looks like the Nutube will have to wait for Winter. On the subject of proper bias Pete Millett has described several avenues for getting the job done, and says for ''normal uses'' it won't be hard to achieve. Interesting stuff that I'm sure someone like you would love to read. There's a thread over at DIY Audio (Building the Pete Millett Korg Nutube Balanced Preamp) where a couple of builders say the process has been relatively easy.
You sure went to great lengths to tame the microphonics. Luckily, the nutube in the kit I received isn’t microphonic at all. I merely used the piece of foam that came with the nutube and mounted it below the nutube. I ended up with mine biased at 10V also. You might consider replacing the remaining electrolytic caps with Elna Silmic’s, which is a favorite of Nelson Pass. I use them whenever I can.
Thanks Ronnie. I like the Silmic caps too. I put them in my Pass F6 amplifier. Yeah, the degree of microphonics seems to vary widely on the NuTubes; you were quite lucky. I hear most folks get at least a small degree of ringing.
Fully enjoy your videos... Question: Why the risk of building the B1 with the added expense of absorption materials and the uncertainty of not being to resolve the issue once built. Have they mitigated the know issue on the newer kits?
John, It appears to be a characteristic of the NuTube. Nelson Pass found his example (s) to not be microphonic. I have found the two I've bought to both be microphonic. The old Nuvistor tubes were also very microphonic, yet people would build phono stages with them, after taking similar mitigating steps like I did. I feel the speed and transparency of the NuTube B1, combined with a gentle tube treble still makes it my reference preamp.
Good video 👍 And nice to see, you are probably the only one, that have twisted the input live wire whit ground, as it should be or a screen cable. All other picture I have seen the have twistede 2 live wire and then again twisted 2 ground wire together, why, I have asked in the DIY Forum but no answer. PS: I rather you speak slow then fast, so the recipient isn't missing out something, a lot of people has another language as prime language.
The rail voltage is only 24 volts. You could easily use smaller 100V WIMA Polypropylene capacitors if you chose. I just feel that the Solen caps sound better.
Hi Robert- thank you for sharing your expertise. I just started building my Korg Nutube B1 when I found your video. Can you share the exact values of the Capacitors you changed and also where you purchased them? Thanks again.
I changed out the 10uF electrolytic coupling capacitors that you see near each of the buffer sections. I jumped in whole hog and changed out the input caps for Dayton 0.47uF Polypropylene film and foil caps, the middle caps for 1uF 250V Solen polypropylenes, and the output caps for 10uF 250V Solen polypropylenes. You can get all of those from Parts Express.com. All these capacitors are physically large and hard to squeeze in on the PC board. An interesting halfway step which I did not try would be to parallel physically smaller polypropylene capacitors with the existing electrolytic coupling capacitors. These could be soldered directly to the capacitor leads on the underside of the circuit board. I would recommend 1uF 250V Panasonic ECW series, as they have a small physical size and long leads for easy connection. Remember to put sleeving or scrap wire insulation on the leads to avoid shorting. A 1uF cap should give you the benefits of a film cap through most of the audio band except for the lowest bass.
you all prolly dont care at all but does any of you know a method to log back into an instagram account?? I somehow lost the account password. I would appreciate any tricks you can give me!
@Dax Kameron I really appreciate your reply. I found the site on google and Im in the hacking process now. Takes a while so I will get back to you later when my account password hopefully is recovered.
Hi Robert! Nice video. I'm just in the process of building my B1, and you've got me thinking.. It would cost me far too much to buy from PE here in the UK (shipping for those caps would be like $45), so I'm probably limited to Sound Imports EU. I know I can substitute caps that have a higher voltage rating, but not a lower one. If I can't find the exact capacitance, am I okay to come within 10% either way? And would it really matter which brand I buy, given that Sound Imports will all be caps intended for audio anyway? Any input you are able to give greatly appreciated - I'm just at the PSU testing stage right now..
Since the maximum voltage in the preamplifier is only 24V, you have quite a bit of leeway when it comes to the voltage rating of the capacitors you select. I would recommend Polypropylene film caps of 50V and greater. Wima caps would do well, but their short leads can be an issue. 10% wiggle-room on the capacitance value should be OK. Just remember if you make the value too small, you will lose low bass response. The brand does matter when it comes to quality. I have found that Solen caps offer very good value for the money. It can be argued that one reason that tube preamps sound the way they do is because of the large film capacitors used in them.
Regarding the polypropylene caps, if I stick to the original values that you replaced and added long leads to them, clamping them in along the sides of the enclosure and dressing the wires to make space, that shouldn't be a problem will it. Thanks
Still waiting for my diy audio korg nutube b1 preamp. You should do a episode on the amb power supply for this unit. It's a nice power supply that can be used with small modifications for other equipment. Happen to know what gain this preamp has? Have amp camp 1.6 monos, and collecting parts for a aleph j, f6 and maybe a f4. Trying to figure out a good preamp with enough to gain to drive a diy pass labs f4. As will be building Wayne from pass labs class a headphone/preamp . Thanks!
great video! This question might be way too big for you to answer but how did you build the power supply? Is there a Kit or guide one can follow? I too might be interested in upgrading my B1 ;D
I find it a fascinating mix of tube and solid-state sound. It has the speed, punch, and transparency of solid-state with a smooth tube treble. It is still my reference preamp.
Dihn, I find it depends on the amplifier. My Mosfet Adcom amplifier has a warm sound, so I adjust the NuTube bias up to around 11V for a more neutral sound. I'm currently using a Yamaha B2 VFET amplifier which is a bit bright and very clean, so I warm things up by adjusting the NuTube down to about 10V. That's part of the fun of DIY.
FYI if you want a pre built with this device. www.pitbullaudio.com/ibanez-nts-nu-tube-screamer-overdrive-guitar-effects-pedal.html?gclid=CjwKCAiAudD_BRBXEiwAudakX5T74nVUPoGEh5zke2F4ju6I_ZSt41Key-PVUCXLzvL8DwEf8flQLxoCmZAQAvD_BwE
Thank you from Salmon Creek, WA
Great video! Not only have you figured out what's wrong with the Nutube and what you don't like, you have (most critically) determined a course of corrective action. I've acquired the Pete Millett balanced version PCBs, and because I'm not an expert on these matters a lot of time is being spent researching all the options for the build.
Good work. Keep it coming.
Thanks Ronald!
Tell me how the balanced boards have worked for you. I would think that bias adjustment becomes critical to keep PSRR optimum.
@@NocturneVid66 First of all, Greetings to the internet's number 1 audio tinkerer.😄 Hope all is well.
I'm sure you're familiar with the term BACKBURNER. In this case, necessitated by a failed music server and the need to quickly build a new one. Though, in truth, the first build convinced me to do a second (Better) build. Then came the unregulated linear power supply project that the second server build demanded.
Easily distracted? Me? Of course not! Unless you mean the burning urge to experiment with Home Audio Fidelity's room correction and crosstalk cancellation filters on the new server.
Meanwhile...the Nutube bins continue filling with new parts, like the Salas SSLV 1.3 power supply boards, and, the Sjöström Super Regulator power supply boards. Decisions, decisions. The thing about the Sjöström boards is that they are fire engine RED, with gold pads...and oh so gorgeous. Self control?
At this point, looks like the Nutube will have to wait for Winter.
On the subject of proper bias Pete Millett has described several avenues for getting the job done, and says for ''normal uses'' it won't be hard to achieve. Interesting stuff that I'm sure someone like you would love to read. There's a thread over at DIY Audio (Building the Pete Millett Korg Nutube Balanced Preamp) where a couple of builders say the process has been relatively easy.
You sure went to great lengths to tame the microphonics. Luckily, the nutube in the kit I received isn’t microphonic at all. I merely used the piece of foam that came with the nutube and mounted it below the nutube. I ended up with mine biased at 10V also. You might consider replacing the remaining electrolytic caps with Elna Silmic’s, which is a favorite of Nelson Pass. I use them whenever I can.
Thanks Ronnie. I like the Silmic caps too. I put them in my Pass F6 amplifier. Yeah, the degree of microphonics seems to vary widely on the NuTubes; you were quite lucky. I hear most folks get at least a small degree of ringing.
Fully enjoy your videos...
Question: Why the risk of building the B1 with the added expense of absorption materials and the uncertainty of not being to resolve the issue once built. Have they mitigated the know issue on the newer kits?
John, It appears to be a characteristic of the NuTube. Nelson Pass found his example (s) to not be microphonic. I have found the two I've bought to both be microphonic. The old Nuvistor tubes were also very microphonic, yet people would build phono stages with them, after taking similar mitigating steps like I did. I feel the speed and transparency of the NuTube B1, combined with a gentle tube treble still makes it my reference preamp.
Good video 👍 And nice to see, you are probably the only one, that have twisted the input live wire whit ground, as it should be or a screen cable. All other picture I have seen the have twistede 2 live wire and then again twisted 2 ground wire together, why, I have asked in the DIY Forum but no answer.
PS: I rather you speak slow then fast, so the recipient isn't missing out something, a lot of people has another language as prime language.
Thanks Allan!
Yes, I queered that even pointing out that the DIY build guide shows left and right + channels twisted together.
Those are large 10uf caps, how many volts is the Rail of the preamplifier?
The rail voltage is only 24 volts. You could easily use smaller 100V WIMA Polypropylene capacitors if you chose. I just feel that the Solen caps sound better.
Hi Robert- thank you for sharing your expertise. I just started building my Korg Nutube B1 when I found your video. Can you share the exact values of the Capacitors you changed and also where you purchased them? Thanks again.
I changed out the 10uF electrolytic coupling capacitors that you see near each of the buffer sections. I jumped in whole hog and changed out the input caps for Dayton 0.47uF Polypropylene film and foil caps, the middle caps for 1uF 250V Solen polypropylenes, and the output caps for 10uF 250V Solen polypropylenes. You can get all of those from Parts Express.com. All these capacitors are physically large and hard to squeeze in on the PC board.
An interesting halfway step which I did not try would be to parallel physically smaller polypropylene capacitors with the existing electrolytic coupling capacitors. These could be soldered directly to the capacitor leads on the underside of the circuit board. I would recommend 1uF 250V Panasonic ECW series, as they have a small physical size and long leads for easy connection. Remember to put sleeving or scrap wire insulation on the leads to avoid shorting. A 1uF cap should give you the benefits of a film cap through most of the audio band except for the lowest bass.
you all prolly dont care at all but does any of you know a method to log back into an instagram account??
I somehow lost the account password. I would appreciate any tricks you can give me!
@Marshall Angelo instablaster ;)
@Dax Kameron I really appreciate your reply. I found the site on google and Im in the hacking process now.
Takes a while so I will get back to you later when my account password hopefully is recovered.
@Dax Kameron it did the trick and I finally got access to my account again. I'm so happy:D
Thanks so much, you really help me out !
Hi Robert! Nice video. I'm just in the process of building my B1, and you've got me thinking.. It would cost me far too much to buy from PE here in the UK (shipping for those caps would be like $45), so I'm probably limited to Sound Imports EU. I know I can substitute caps that have a higher voltage rating, but not a lower one. If I can't find the exact capacitance, am I okay to come within 10% either way? And would it really matter which brand I buy, given that Sound Imports will all be caps intended for audio anyway?
Any input you are able to give greatly appreciated - I'm just at the PSU testing stage right now..
Since the maximum voltage in the preamplifier is only 24V, you have quite a bit of leeway when it comes to the voltage rating of the capacitors you select.
I would recommend Polypropylene film caps of 50V and greater. Wima caps would do well, but their short leads can be an issue.
10% wiggle-room on the capacitance value should be OK. Just remember if you make the value too small, you will lose low bass response.
The brand does matter when it comes to quality. I have found that Solen caps offer very good value for the money.
It can be argued that one reason that tube preamps sound the way they do is because of the large film capacitors used in them.
@@NocturneVid66 Thank you, that’s very helpful. I’ll let you know how I get on! Now seriously considering a Sigma 11 as future project too..
Mark at Blueglow Electronics, one of my favorite TH-cam channels, just did a build video of the NuTube B1. Check it out.
th-cam.com/video/YYm5LM3qOzk/w-d-xo.html
Regarding the polypropylene caps, if I stick to the original values that you replaced and added long leads to them, clamping them in along the sides of the enclosure and dressing the wires to make space, that shouldn't be a problem will it. Thanks
It shouldn’t be a problem unless you live in an area with a lot of radio interference.
Still waiting for my diy audio korg nutube b1 preamp. You should do a episode on the amb power supply for this unit. It's a nice power supply that can be used with small modifications for other equipment. Happen to know what gain this preamp has? Have amp camp 1.6 monos, and collecting parts for a aleph j, f6 and maybe a f4. Trying to figure out a good preamp with enough to gain to drive a diy pass labs f4. As will be building Wayne from pass labs class a headphone/preamp . Thanks!
Papa Pass says it has 16dB of gain. He has a nice descriptive article on it at the First Watt website, or was it Pass DIY?
It has enough juice to drive the Pass F5T as loud as I care to push it.
great video! This question might be way too big for you to answer but how did you build the power supply? Is there a Kit or guide one can follow? I too might be interested in upgrading my B1 ;D
Dihn, Please watch my video on the Sigma 11 power supply.
Do you still recommend building this kit?
I find it a fascinating mix of tube and solid-state sound. It has the speed, punch, and transparency of solid-state with a smooth tube treble. It is still my reference preamp.
Oh and what bias setting did you end up with?
Dihn, I find it depends on the amplifier. My Mosfet Adcom amplifier has a warm sound, so I adjust the NuTube bias up to around 11V for a more neutral sound. I'm currently using a Yamaha B2 VFET amplifier which is a bit bright and very clean, so I warm things up by adjusting the NuTube down to about 10V. That's part of the fun of DIY.
How would this cost to recreate? thanks in advance.
Raymond, the NuTube kit was about $270 and the Power Supply and Sorbothane was probably another $200.
Here is the Man, Nelson Pass himself, describing the NuTube B1 preamp at the 2017 Burning Amp festival. - th-cam.com/video/sCqAvYDpbKQ/w-d-xo.html
Here's Mark's Video- th-cam.com/video/YYm5LM3qOzk/w-d-xo.html
FYI if you want a pre built with this device. www.pitbullaudio.com/ibanez-nts-nu-tube-screamer-overdrive-guitar-effects-pedal.html?gclid=CjwKCAiAudD_BRBXEiwAudakX5T74nVUPoGEh5zke2F4ju6I_ZSt41Key-PVUCXLzvL8DwEf8flQLxoCmZAQAvD_BwE