Hello.
I just built a pair of very revealing speakers (MarkAudio Alpair 12p in SuperPensil design) and noticed some noise. After connecting the DAC straight to the amp, bypassing B1K, it was dead quiet. So it seems my B1K is a little bit noisy. Not much, but putting my ear to the speaker it sounds like a far away ocean. Is this as you would expect from this wonderful preamp, or have I done a sloppy job building it?
I just built a pair of very revealing speakers (MarkAudio Alpair 12p in SuperPensil design) and noticed some noise. After connecting the DAC straight to the amp, bypassing B1K, it was dead quiet. So it seems my B1K is a little bit noisy. Not much, but putting my ear to the speaker it sounds like a far away ocean. Is this as you would expect from this wonderful preamp, or have I done a sloppy job building it?
Thank you Claude for your welcoming.
The Nutube worked perfectly yesterday with cd player & tuner for seven hours. This morning i changed my set up; out the se 6v6, in my old Rotel rb960bx power amp. It started fine then a few minutes later a loud strident hiss came through the speakers though still playing music. I went back to the tube amp setting that worked well yesterday but the hiss still was there. The only other thing i changed since the previous setting was that the Nutube b1 had gone on top of the linear psu instead of beside. That was it : the powerfull regulators interfered with the j-fets (i have to say that the B1 is not covered yet). So psu has to be away from the B1, my conclusion! Now this issue being cured i can enjoy both amps with the B1 and no hiss can be heared. Ouf!!!
I put some images of my little beast; hope they will go through.
Good day or night to all DiYers.
The Nutube worked perfectly yesterday with cd player & tuner for seven hours. This morning i changed my set up; out the se 6v6, in my old Rotel rb960bx power amp. It started fine then a few minutes later a loud strident hiss came through the speakers though still playing music. I went back to the tube amp setting that worked well yesterday but the hiss still was there. The only other thing i changed since the previous setting was that the Nutube b1 had gone on top of the linear psu instead of beside. That was it : the powerfull regulators interfered with the j-fets (i have to say that the B1 is not covered yet). So psu has to be away from the B1, my conclusion! Now this issue being cured i can enjoy both amps with the B1 and no hiss can be heared. Ouf!!!
I put some images of my little beast; hope they will go through.
Good day or night to all DiYers.
Attachments
Thanks for the pix 🙂
It is seldom a bad thing to have a PSU away from your unit. Having said that, once properly earthed and with a lid, it might not have been an issue anymore. Anyway, you found a solution, so enjoy this little unit!
It is seldom a bad thing to have a PSU away from your unit. Having said that, once properly earthed and with a lid, it might not have been an issue anymore. Anyway, you found a solution, so enjoy this little unit!
You are welcome. Soon after i did post my mail it starded again as the B1 was now seated on the amp. So has you said i closed the box and till now
music is playing with no more assle. Just the j-fets that needed intimacy. Good Earthing should be a rule to everyone for safety my dad always said to me
Many thanks for taking time & advices. I surely enjoy this sweet little device that saved me a lot of money. Finding a truly transparent preamp that gives you just what is there with good gain & remaining cool for cheap is quite difficult these days. Master Nelson Pass did it. Next trial in a few days with PSI Audio a-17...
music is playing with no more assle. Just the j-fets that needed intimacy. Good Earthing should be a rule to everyone for safety my dad always said to me
Many thanks for taking time & advices. I surely enjoy this sweet little device that saved me a lot of money. Finding a truly transparent preamp that gives you just what is there with good gain & remaining cool for cheap is quite difficult these days. Master Nelson Pass did it. Next trial in a few days with PSI Audio a-17...
The hiss is there and at the same level, even if the volume knob is at zero. I also noticed a much louder buzz when I touch the B1K and that sound gets louder as I turn the volume up. It goes back to the hiss when I take my hand off.
I opened it upp and made sure there was no resistans between any of the ground points. But I noticed that the case wasn't connected to ground. Shouldn't it be? I thought it would, because the stand-off nuts was grounded, but it seems there is no connection to the case despite the screws. (I have the full kit from diyAudio Store.)
Do you think I should try to get the case grounded?
Anodisation or paint on the case panels needs to be ground off in places to make good electrical connection between the various case parts. Otherwise, the anodisation or paint make good insulators.
Hahaha. Thank you for the tip, master Mod. I don't really know this stuff and if the case doesn't get grounded when I follow the build guide, I assume that it's ment to be that way.
I love this forum though. I can ask questions, stupid to most off you, and get answers from true legends.
I love this forum though. I can ask questions, stupid to most off you, and get answers from true legends.
just imagine how stupid I'm in cooking, for example
luckily, I married good, so allowed to stay a Fool, for entire life
luckily, I married good, so allowed to stay a Fool, for entire life
Hi All,
So i built my B1 Korg maybe 18mths ago and love it. I've just swapped over from a meanwell "cage" (internal) SMSP to an external laptop brick and the amazing DC filter.
I have to say, I am one very happy panda!
So, i now want to pimp my ride, re-do the inputs and sort out the power wiring.
Since it's only 24v and 1amp(ish), I know I can basically use any awg but what would be the optinum gauge for the internal power wiring? 18awg, 20awg?? I realise it is not going to dramatically change the sound but if i have to buy some more, it's a good chance to do it right.
thanks to Papa, MJ, 6L6, ZM and cast of thousands for this project and all the notes/assistance/etc!
next project? In the coming months, the M2X (have been stockpiling parts for 3yrs??).
So i built my B1 Korg maybe 18mths ago and love it. I've just swapped over from a meanwell "cage" (internal) SMSP to an external laptop brick and the amazing DC filter.
I have to say, I am one very happy panda!
So, i now want to pimp my ride, re-do the inputs and sort out the power wiring.
Since it's only 24v and 1amp(ish), I know I can basically use any awg but what would be the optinum gauge for the internal power wiring? 18awg, 20awg?? I realise it is not going to dramatically change the sound but if i have to buy some more, it's a good chance to do it right.
thanks to Papa, MJ, 6L6, ZM and cast of thousands for this project and all the notes/assistance/etc!
next project? In the coming months, the M2X (have been stockpiling parts for 3yrs??).
For signals go as low as you can (awg28-awg32 solid core). For power, you are good with anything awg22 and below, but do note that the thicker solid core, the more chance of cold joint (your choice of solid vs strand, won't really matter as much).
Hello again.
I've now made sure the case is grounded and the buzz when touching it has gone completely. But the constant hiss is still there. The level of noise is the same regardless where the volume knob is set. So it doesn't seem to be in the signal, but rather the device itself that has this noise. I can live with it because it's not very loud, and the sound of the B1K is truly beautiful. But I'm trying to figure out if I screwed something up when building it, so I still wonder if anyone else has noticed the same? Without the B1K my system is dead quiet.
Can the hiss be generated by the SMPS somehow? I'll throw in Mr Johnsons DC-filter and see what happens.
I've now made sure the case is grounded and the buzz when touching it has gone completely. But the constant hiss is still there. The level of noise is the same regardless where the volume knob is set. So it doesn't seem to be in the signal, but rather the device itself that has this noise. I can live with it because it's not very loud, and the sound of the B1K is truly beautiful. But I'm trying to figure out if I screwed something up when building it, so I still wonder if anyone else has noticed the same? Without the B1K my system is dead quiet.
Can the hiss be generated by the SMPS somehow? I'll throw in Mr Johnsons DC-filter and see what happens.
As i said, it could be the overly high gain inducing noise. You should try it in a system where there is already an amplification required trough the preamp. B1k nutube has quite substantial gain.
B1K here... dead quiet as original, still dead quiet once slightly modded, lucky me 🙂
Noise has never been an issue TBH.
Grounding can be the main issue, then of course checking all your soldering points are Ok / reflow if in doubt.
Last but not least of course some SMPS can be noisy. I don't know if Mark's excellent filter can change that in your case (nor if that's your issue), but given it is an improvement it is hence anyhow good to have whatever the SMPS you keep.
Can't you just use another PS, be it SMPS or not, even a low quality adjustable one, to check if the noise is still there or changes?
Good luck, at the end I see no reason why a working B1K shouldn't be dead quiet and that is even when connecting HP directly to it...
Claude
Noise has never been an issue TBH.
Grounding can be the main issue, then of course checking all your soldering points are Ok / reflow if in doubt.
Last but not least of course some SMPS can be noisy. I don't know if Mark's excellent filter can change that in your case (nor if that's your issue), but given it is an improvement it is hence anyhow good to have whatever the SMPS you keep.
Can't you just use another PS, be it SMPS or not, even a low quality adjustable one, to check if the noise is still there or changes?
Good luck, at the end I see no reason why a working B1K shouldn't be dead quiet and that is even when connecting HP directly to it...
Claude
Hello, please could someone give me the full specs for the green Led that goes behind the faceplate of the Korg Nutube B1 preamp build. Thanks.
3mm size if it needs to fit into the B1 Korg chassis face plate. Any colour will work. The resistor can be 24K or higher. Higher and it will be less bright. Value is not critical.
Hi, thanks you say the resistor can be 24K or higher, but the one that came with the kit and is listed in the parts list is 10K 1\4W, the old LED on it's own measured 1.850V, I am confused as to what to order regarding forward voltage and current.
cheapest LED in color you wish - that's good enough for choice when no other function than illumination
resistor - rule of thumb is 1K per PSU volt, and it'll shine while not drilling your eye
so for 24V, you can start with 18K and end with much more, depending how bright you want it
regular 0207 resistors size/power is OK - you can call it 250mW or 500mW or 600mW, depending of manufacturer ........ but you can't miss if you choose resistor 2mm Dia, 7mm long
resistor - rule of thumb is 1K per PSU volt, and it'll shine while not drilling your eye
so for 24V, you can start with 18K and end with much more, depending how bright you want it
regular 0207 resistors size/power is OK - you can call it 250mW or 500mW or 600mW, depending of manufacturer ........ but you can't miss if you choose resistor 2mm Dia, 7mm long