Maybe you could cobble together a mezzanine board that used several Zero Insertion Force test sockets to grab the NuTube pins?
Flip up all the clamp levers, insert the NuTube, and flip down the levers one by one.
Flip up all the clamp levers, insert the NuTube, and flip down the levers one by one.
I'm having this installed into my B1.
Not quite a plug in, but it would make the re-installation simpler.
Nutube vibration mount
But I think you get the idea. Since those traces are flexible, a zero insertion socket with just a few connectors should be sufficient, with the caveat that you'd still need to solder the Nutube to the mounting "plate". But at least you would not be doing any damage to the PC board below it.
Not quite a plug in, but it would make the re-installation simpler.
Nutube vibration mount
But I think you get the idea. Since those traces are flexible, a zero insertion socket with just a few connectors should be sufficient, with the caveat that you'd still need to solder the Nutube to the mounting "plate". But at least you would not be doing any damage to the PC board below it.
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I've tracked down the faulty solder join, which was one of the ones you pointed out in your photo. Once I had an idea where to start, it was actually pretty easy to see and fix. Thank you for pointing me in the right direction. It really made a difference.
I've had it up and running and it really sounds pretty good. The microphonics is an issue when you flick a switch and there is a bit of a thump when turning on, but I can live with that.
EXCELLENT!
You did invert your speaker leads , yes?
I always make sure I turn on my amp last, and turn it off first (after turning down the BIK volume pot) when shutting everything down..gets rid of the thump…
You did invert your speaker leads , yes?
I always make sure I turn on my amp last, and turn it off first (after turning down the BIK volume pot) when shutting everything down..gets rid of the thump…
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The Korg Nutube (and the H2/ H2V2 board) inverts the phase of the audio signal so one has to switch speaker leads out of the amp (+ of speaker will match up to "-" out of amp and "-" of speaker connects to the + out of the amp) to correctly hear the phase of the music again. It’s not wrong to leave the speaker leads as you normally would have them but the soundstage really broadens when you invert the speaker leads.
If you want to go through the hassle, remounting the Nutube using Pete Millett’s mounting harness (search EBay for Anti-vibration mount for Korg nutube 6P1). I’ve found that any way of isolating the Nutube mounting pins from the PCB eliminates the vibration microphonics (see post # 6928 for my solutions).
Other folk say they have no issue and it might be a Nutube-to-Nutube variation.
Pete
Other folk say they have no issue and it might be a Nutube-to-Nutube variation.
Pete
FWIW, I tried it both ways and I prefer the non-inverted (speaker wires connected "normally") configuration. I did hear a difference, but preferred it this way. YMMV.
Also, for those who have been following along at home. I'm the guy who has had two nuTubes fail (left channel triode blown in both cases).
I'm now periodically measuring at test points to see if something in the left channel drifts over time. So far, everything is within spec: both T5 and T6 at 0.6 VDC. T7 and T8 at 9.5 VDC.
-- Thing
The thing is that inverting or not the LS sadly moves 2 important sound parameters at the same time:
- so called "negative or positive H2 phase"
- absolute phase
Just playing with the LS connections moves the two at the same time, so whereas of course it is still a plus and at the end you chose the one you prefer, you may still be away from your optimal setting (that the B1K can give).
In short, if for example you like negative H2 (I like a small dosis of it), and that's all what this unit is about, but for whatever reason should prefer inverted polarity (not my case...), or not be too sensitive to it, you could still run the LS wires the normal way... while setting the bias higher than 12V to find your prefered negative H2 level. That's what I did (for various reasons).
Or, as another example out of 4 possibilities, you could indeed prefer positive H2, and absolute phase. Or whatever combo... the thing is you may not prefer to link both at the same time...
I hope this helps
Claude
- so called "negative or positive H2 phase"
- absolute phase
Just playing with the LS connections moves the two at the same time, so whereas of course it is still a plus and at the end you chose the one you prefer, you may still be away from your optimal setting (that the B1K can give).
In short, if for example you like negative H2 (I like a small dosis of it), and that's all what this unit is about, but for whatever reason should prefer inverted polarity (not my case...), or not be too sensitive to it, you could still run the LS wires the normal way... while setting the bias higher than 12V to find your prefered negative H2 level. That's what I did (for various reasons).
Or, as another example out of 4 possibilities, you could indeed prefer positive H2, and absolute phase. Or whatever combo... the thing is you may not prefer to link both at the same time...
I hope this helps
Claude
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Ok.
So i went to read most part of this thread, then to measure the test points and make sure about the filament in the nutube.
What i got:
T1 - 24,3v
T3 - 22,7v
T4 - 9,4v
T5 - 9,5v
T6 - 0,7v
T7 - 20,7v
T8 - 8,5v
Also sure the nutube filament is broken on the left channel.
So let's order a new one to replace, before replacing make sure all solders are as should (i am not very skilled solder) and then put the new nutube and also add a pad to hold it in place.
So i went to read most part of this thread, then to measure the test points and make sure about the filament in the nutube.
What i got:
T1 - 24,3v
T3 - 22,7v
T4 - 9,4v
T5 - 9,5v
T6 - 0,7v
T7 - 20,7v
T8 - 8,5v
Also sure the nutube filament is broken on the left channel.
So let's order a new one to replace, before replacing make sure all solders are as should (i am not very skilled solder) and then put the new nutube and also add a pad to hold it in place.
Finished my B1 Nutube
Hello All,
I really enjoyed building this Preamp, parts kit was sold out so had to source my own parts. I was able to find all I needed between Digi-key, Mouser, Parts express, Amazon and the Volume Knob is still in-bound from China. All other parts took about a week to arrive at the house, not terrible during these high shortage times.
I didn't run into any issues during the power up procedure, all voltages were in range required.
I only have powered speakers, so I only have been able to listen to Amp playing out of phase. (I don't want to disassemble my speakers to reverse wiring) but even out of phase, the sound is warm and pleasant. I found some short music sections on Youtube that played out of Phase, but the content was not good enough to really make a proper judgement. I guess that is a good excuse to Build a Power Amp and either Build or Buy a pair of new speakers.
I have (2) small issue to resolve:
- the tube is slightly microphonic but only when I move it while in operation or if the Cover is removed. the rubber feet are the biggest instigators of the wonderful high pitch, my plan of action is to replace the feet, add some damping material between the tube and the board and also investigate the mounting of the PCB board to the Bottom panel that is only being secured on the sides. When I press down on the PCB the Whole assembly is a bit flexible and could be a great (soundboard) amplifier for vibrations that will travel to the NuTube.
- My second problem is that my New Preamp thinks it is also a tuner when I touch it, it is picking up a radio frequency. Any suggestions are appreciated, from the little time I spend on it so far it seam to come from the Input wiring.
Greeting From Miami,
Max
Hello All,
I really enjoyed building this Preamp, parts kit was sold out so had to source my own parts. I was able to find all I needed between Digi-key, Mouser, Parts express, Amazon and the Volume Knob is still in-bound from China. All other parts took about a week to arrive at the house, not terrible during these high shortage times.
I didn't run into any issues during the power up procedure, all voltages were in range required.
I only have powered speakers, so I only have been able to listen to Amp playing out of phase. (I don't want to disassemble my speakers to reverse wiring) but even out of phase, the sound is warm and pleasant. I found some short music sections on Youtube that played out of Phase, but the content was not good enough to really make a proper judgement. I guess that is a good excuse to Build a Power Amp and either Build or Buy a pair of new speakers.
I have (2) small issue to resolve:
- the tube is slightly microphonic but only when I move it while in operation or if the Cover is removed. the rubber feet are the biggest instigators of the wonderful high pitch, my plan of action is to replace the feet, add some damping material between the tube and the board and also investigate the mounting of the PCB board to the Bottom panel that is only being secured on the sides. When I press down on the PCB the Whole assembly is a bit flexible and could be a great (soundboard) amplifier for vibrations that will travel to the NuTube.
- My second problem is that my New Preamp thinks it is also a tuner when I touch it, it is picking up a radio frequency. Any suggestions are appreciated, from the little time I spend on it so far it seam to come from the Input wiring.
Greeting From Miami,
Max
