+1 on 6L6
Whatever you do to force them to fit, it will be time consuming and won't really be nice at the end. Last but not least, if following Papa's rec'd PS, there IMHO is very little to be gained in that area.
If I were you, I would keep these and just find some 2200uF caps (one size up) that fit, job done.
Yeah, I know these things can be annoying, but you are nearly there with such a nice built 🙂
Claude
PS: OR, just leave the existing caps (they are doing a good job) and concentrate on another area or another project... while enjoying this little jem that will help you forgetting about that unlucky order?
Whatever you do to force them to fit, it will be time consuming and won't really be nice at the end. Last but not least, if following Papa's rec'd PS, there IMHO is very little to be gained in that area.
If I were you, I would keep these and just find some 2200uF caps (one size up) that fit, job done.
Yeah, I know these things can be annoying, but you are nearly there with such a nice built 🙂
Claude
PS: OR, just leave the existing caps (they are doing a good job) and concentrate on another area or another project... while enjoying this little jem that will help you forgetting about that unlucky order?
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Bravo! Conducted my first extended listening test last night with my wife. Jaw-droppingly good. The finest hi-fi gear change-out experience in my 40 years as a humble audiophile. Of course the "cake" is comprised of various ingredients which all play a part, however this B1K is simply stellar.
Thank you Members that helped recently during my build.
Thank YOU, Nelson and 6L6. The privilege to build these kits and be so aurally satisfied makes me feel like I owe you something more than just the price of entry. Grateful.
Thank you Members that helped recently during my build.
Thank YOU, Nelson and 6L6. The privilege to build these kits and be so aurally satisfied makes me feel like I owe you something more than just the price of entry. Grateful.
Silmic II sound and break-in advice
After replacing the Nichicon caps in the B1 signal path with Elna Silmic II’s, there were some minor differences in the sound. I realize it will take a while for the caps to settle in. However, as good as the B1 sounded with the kit parts, I kept noticing an emphasis in the 4-5KHz region that called attention to itself. That’s why I wanted to replace the coupling caps. It appears the Silmics resolved this issue. Also, the caps seem to allow slightly more body and overtones through. Not a major change, but certainly noticeable. I have a question. Can I leave the preamp on feeding a signal to a non-powered power amp to break in the caps? I only have solid state single ended class A amps and tube amps and don’t want to leave them powered for days at a time. Is there an alternative for breaking in the preamp?
After replacing the Nichicon caps in the B1 signal path with Elna Silmic II’s, there were some minor differences in the sound. I realize it will take a while for the caps to settle in. However, as good as the B1 sounded with the kit parts, I kept noticing an emphasis in the 4-5KHz region that called attention to itself. That’s why I wanted to replace the coupling caps. It appears the Silmics resolved this issue. Also, the caps seem to allow slightly more body and overtones through. Not a major change, but certainly noticeable. I have a question. Can I leave the preamp on feeding a signal to a non-powered power amp to break in the caps? I only have solid state single ended class A amps and tube amps and don’t want to leave them powered for days at a time. Is there an alternative for breaking in the preamp?
Perhaps your thoughts might drift toward something like this
FryBaby3 - Compact Burn-In Generator – Hagerman Audio Labs
Not a recommendation, just thinking aloud
FryBaby3 - Compact Burn-In Generator – Hagerman Audio Labs
Not a recommendation, just thinking aloud
Soundhappy,
Indeed there was a very small piece of wire. It wasn't there on the initial build photos so I can only presume that I managed to migrate it into the case either when I fixed the capacitor or when I put the eraser on the Nutube. Live And learn, I must check every time the lid is off!
Indeed there was a very small piece of wire. It wasn't there on the initial build photos so I can only presume that I managed to migrate it into the case either when I fixed the capacitor or when I put the eraser on the Nutube. Live And learn, I must check every time the lid is off!
Hi all,
I know this is a question that has been asked before in various ways, but since everyone is so helpful, I thought I'd ask anyway and just get some clarification.
I have some LSK170s, which I know the B grade is fine, and the A grade should be ok if they are in the higher Idss end. I was so sure I had bought A grade fets, and from a quick check last night it seems I have at least 4 quad matched sets... but they're grade C.... I'm at work right now, so I can't give you the Idss, but seeing as the datasheet specs are 10-20ma, I guess I can assume it's somewhere around there.
Knowing that the ideal range seems to be between 6mA-10mA, even if I was incredibly lucky, they are unlikely to be exactly 10mA. I have currently got things working fine with the J113 FETs that come with the kits and the matched resistors, so there is no real problem, except me wanting to try and use some parts that I currently don't have earmarked for a project,
So, knowing that the CCS pairs are 'meant' to have a higher Idss than the follower pair (Q2 + resistor I believe being the CCS), what are my options?
- Just use the matched quads on the Q2 transistors only and modify R1 to adjust the Idss to approximately what I currently have with the J113 + resistor combo
- Choose a quad of LSK170s with the lower Idss and use them for Q1 and a higher quad with Q2, changing the values of R1 and adding another resistor for Q1?
- Don't bother with changing them, use the LSK FETs for something else in the future and enjoy the J113s
- Buy matched quads of B Grade LSK FETs and just be happy 🙂
IIRC I bought the LSK's for the B1 Mezmerise, but I have no idea why I would have chosen grade C.
Thanks all
I know this is a question that has been asked before in various ways, but since everyone is so helpful, I thought I'd ask anyway and just get some clarification.
I have some LSK170s, which I know the B grade is fine, and the A grade should be ok if they are in the higher Idss end. I was so sure I had bought A grade fets, and from a quick check last night it seems I have at least 4 quad matched sets... but they're grade C.... I'm at work right now, so I can't give you the Idss, but seeing as the datasheet specs are 10-20ma, I guess I can assume it's somewhere around there.
Knowing that the ideal range seems to be between 6mA-10mA, even if I was incredibly lucky, they are unlikely to be exactly 10mA. I have currently got things working fine with the J113 FETs that come with the kits and the matched resistors, so there is no real problem, except me wanting to try and use some parts that I currently don't have earmarked for a project,
So, knowing that the CCS pairs are 'meant' to have a higher Idss than the follower pair (Q2 + resistor I believe being the CCS), what are my options?
- Just use the matched quads on the Q2 transistors only and modify R1 to adjust the Idss to approximately what I currently have with the J113 + resistor combo
- Choose a quad of LSK170s with the lower Idss and use them for Q1 and a higher quad with Q2, changing the values of R1 and adding another resistor for Q1?
- Don't bother with changing them, use the LSK FETs for something else in the future and enjoy the J113s
- Buy matched quads of B Grade LSK FETs and just be happy 🙂
IIRC I bought the LSK's for the B1 Mezmerise, but I have no idea why I would have chosen grade C.
Thanks all
This. 😀
The NuTube has such an incredible and beautiful signature that the only thing you need to do is to get it working. The J113 do a phenomenal job.
I've got a B1K with J113 and another one with K170 (Toshibas even...) and I can't tell the difference at all.
Sometimes is happening in the process of cutting all resistors and caps legs ,
some short piece of wire can jump inside of the chassis and make electrical short after power on.
Now I verify twice and clean PCB and all inside of the box at the finish of ensembling process..
😀 Kind regards
The parts are chosen so that you can accurately measure the plate
voltage of the Nutube. If the follower after the Nutube Plate is run at
Idss, then the Source voltage on it is close the DC of the Plate and you
can use the chart to adjust it.
Measuring the plate voltage directly with a multimeter is usually not
accurate because the impedance of the multimeter will load the Plate
down.
If you have a distortion analyzer, then you don't need that, and you
can choose the R1 values to set the CCS current arbitrarily to 7 to 8 mA
or so and not worry about it.
Alternatively, a handheld multimeter can be used to measure the voltage
difference between the Gate and Source of the follower, and you can use
this added to the Source voltage to get the Plate voltage.
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Makes sense, thanks very much for the explanation.
You mention a chart, do you mean from the data sheet or is there somewhere else I should look?
I might do as 6L6 suggests for the moment and just sit back and relax with the J113's before tinkering. For some reason the magic blue smoke often likes to escape when tinkering happens 😉
You mention a chart, do you mean from the data sheet or is there somewhere else I should look?
I might do as 6L6 suggests for the moment and just sit back and relax with the J113's before tinkering. For some reason the magic blue smoke often likes to escape when tinkering happens 😉
Hi guys,
I'm in the process of assembling my B1 Korg Nutube kit (woohooo!)
Based on the installation/assembly guide, you need to put an air gap in between the Nutube chip and the PCB (so it's floating), upon soldering it.
But I read somewhere here in this thread that some people do put something underneath the Nutube such as double-sided foam tape or something similar, so the tape is sandwhiched in between the 2 components (PCB ---> foam/tape/etc ---> Nutube).
What do you think is the best approach (also to minimize microphonics in this case, if it helps) based on your experience?
I'm in the process of assembling my B1 Korg Nutube kit (woohooo!)
Based on the installation/assembly guide, you need to put an air gap in between the Nutube chip and the PCB (so it's floating), upon soldering it.
But I read somewhere here in this thread that some people do put something underneath the Nutube such as double-sided foam tape or something similar, so the tape is sandwhiched in between the 2 components (PCB ---> foam/tape/etc ---> Nutube).
What do you think is the best approach (also to minimize microphonics in this case, if it helps) based on your experience?
Post #1396 - B1 with Korg Triode
A quick question on the wiring that you done if I may ask. I am building similar kind of Korg for a friend and I am getting horrible hum using a aluminium chassis with a meanwell 24v psu. I see that you have connected all the input/output grounds of left and right channels separately. Then used a resistor (what value is it) in series with the signal and grounds of each RCA jack. I also see the volume pot ground wires pair of them going to the Korg input side. Now did you isolate 3 of the Korg board legs and mounted only 1 leg to the bottom panel as chassis ground? As I do not see any other wire going specifically for the Korg board ground to the chassis.
Thanks
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Please follow 6L6’s B1 Korg Nutube build guide to create an air gap between the Nutube and the PCB.
B1 with Korg Nutube - diyAudio Guides
In my original build, I used the foamed double-sided tape that came with the Korg Nutube. Not sure if this contributed to the microphony, but it sure did ring whenever I turned on the preamp or switched sources.
When I replaced the Nutube with a new one (original was damaged by a lightning strike near my home), I followed 6L6’s build guide and I haven’t had any problems with microphony.
Do you have a copy of the First Watt article:
http://www.firstwatt.com/pdf/art_diy_nutube_preamp.pdf