B1K ON, power amp on, phono preamp on>> but nothing playing! Still rings>>> all by itself with no help from other components. B1k sitting atop an unused (and NO AC) CD player, which is heavy and highly damped top cover. I may try moving it, but under the Described Circumstances, why would I?
Does it ring regardless of the volume level of the pot on the B1K?
So turntable to phono preamp to B1K to amp?
Pete
@ Ixnay
Preamp cover lid is closed or open if music play ?
Closed = minimum microphonic phenomena or none
Preamp cover lid is closed or open if music play ?
Closed = minimum microphonic phenomena or none
You could buy another NuTube and give it a try. Good chance it will be better. Mine doesn't ring at all. I only used double sided tape below. No other measures taken. I put it inside my power amp with slotted holes on top. So I think I got very lucky. Must be a lot in between.
My B1K build…a little late to this party
I built the B1 buffer first and it sounds solid but I became intrigued by everyone gushing over this Korg version. I didn’t intend to get really fancy with the build due to the numerous complaints of ringing and all the sound isolation/insulation that (might) be required. More probably because I could a real tube sounding preamp w/o spending big bucks.
I stole the idea of using a plastic Serpac case from bk856er in Pete Millett’s Korg Nutube forum (post #154) to see if I could build it just as compactly as he did. I intended to use the recommended wallwart so I decided to use Mark Johnson’s PO892ZB inline DC filter. I also made the initial decision to use dual mono pots (ALPS; 100K) so I could balance the L-to-R imaging better (and they were smaller too). I’m not a great believer (ok, snobby) in using electrolytics in signal path but I tried using Silmic II 10uF but didn’t like the sound so I switched to 4.7uF WIMAs. They may not be the optimum film cap to use but I had them and I was being cheap, remember? I decided to use Panasonic FCs in the PS section (low ESR & I’ve used them in similar situations in other builds). Nichicon KAs for the other four 1000uF caps. I mounted little posts into T7&8 so I could use clip on leads when adjusting voltages. I also externalized an LED since everyone was using those white erasers to contain ringing (who was I to argue) and then you couldn’t see if the unit was powered on. Finally, as a final build concept, I wanted to use the Japanese fellow’s magnet implementation to see if it both reduced the time of ringings and if it did (positively) change the sound as he claimed. The Alps pots were grounded to the signal input ground plane. Overall, I really didn’t think this was going to work so I didn’t protect the (easily scratched) plastic as well as I should have as well as having extra holes from moving things around. The initial signal 1K resistors are Takman right now and that’s the only resistor position I’ll potentially change to try and adjust the sound. All others are Dales. High tech bubble wrap under the unit for vibration isolation. Oh yeah, and the PCB is attached at the top of the case, not the bottom with screw terminals attaching everything on the underside of the board.
Holy Cow! The sound out of this unit is hypnotic. Is it accurate & present the music accurately? I can’t answer that but it really gives depth and silkiness to the music. I listen to mostly classical & jazz with Motown & R&R thrown in. It even makes all those terribly sound-engineered early cross-over R&R CDs tolerable. Metallic sounding "TINGS” are still heard if you tap on the case but are very short lived; other than those no ringing is heard.
Thanks to Papa and all the other (early) builders for ideas and observations!
Cheers, Pete
I built the B1 buffer first and it sounds solid but I became intrigued by everyone gushing over this Korg version. I didn’t intend to get really fancy with the build due to the numerous complaints of ringing and all the sound isolation/insulation that (might) be required. More probably because I could a real tube sounding preamp w/o spending big bucks.
I stole the idea of using a plastic Serpac case from bk856er in Pete Millett’s Korg Nutube forum (post #154) to see if I could build it just as compactly as he did. I intended to use the recommended wallwart so I decided to use Mark Johnson’s PO892ZB inline DC filter. I also made the initial decision to use dual mono pots (ALPS; 100K) so I could balance the L-to-R imaging better (and they were smaller too). I’m not a great believer (ok, snobby) in using electrolytics in signal path but I tried using Silmic II 10uF but didn’t like the sound so I switched to 4.7uF WIMAs. They may not be the optimum film cap to use but I had them and I was being cheap, remember? I decided to use Panasonic FCs in the PS section (low ESR & I’ve used them in similar situations in other builds). Nichicon KAs for the other four 1000uF caps. I mounted little posts into T7&8 so I could use clip on leads when adjusting voltages. I also externalized an LED since everyone was using those white erasers to contain ringing (who was I to argue) and then you couldn’t see if the unit was powered on. Finally, as a final build concept, I wanted to use the Japanese fellow’s magnet implementation to see if it both reduced the time of ringings and if it did (positively) change the sound as he claimed. The Alps pots were grounded to the signal input ground plane. Overall, I really didn’t think this was going to work so I didn’t protect the (easily scratched) plastic as well as I should have as well as having extra holes from moving things around. The initial signal 1K resistors are Takman right now and that’s the only resistor position I’ll potentially change to try and adjust the sound. All others are Dales. High tech bubble wrap under the unit for vibration isolation. Oh yeah, and the PCB is attached at the top of the case, not the bottom with screw terminals attaching everything on the underside of the board.
Holy Cow! The sound out of this unit is hypnotic. Is it accurate & present the music accurately? I can’t answer that but it really gives depth and silkiness to the music. I listen to mostly classical & jazz with Motown & R&R thrown in. It even makes all those terribly sound-engineered early cross-over R&R CDs tolerable. Metallic sounding "TINGS” are still heard if you tap on the case but are very short lived; other than those no ringing is heard.
Thanks to Papa and all the other (early) builders for ideas and observations!
Cheers, Pete
Attachments
-
CA68B15D-3EB4-4EDD-B995-3994DAFE0C37.jpeg -
0370EFAC-B9BB-4704-A1EE-BF54883A04E5.jpeg -
D899DE46-6252-4F98-853C-9CF9D3809B84.jpeg -
7CCE5A82-7B54-4826-A57E-AA4AB3E13909.jpeg -
6154EA92-6FEA-45F4-9A3F-AC597A7DF10F.jpeg -
760940BB-E81A-4F6D-851F-AAA0E07BDB45.jpeg -
E1EEB304-0D4D-41E2-B966-2B807BAFA48F.jpeg -
25EC6154-CEA2-49B6-94CF-19746B9D4341.jpeg -
F9CB2C3A-4BBE-4CA8-9602-C41EBE14DEAD.jpeg -
AFD72890-FC40-4059-9F7D-802414FFDDF0.jpeg
Last edited:
Well done Pete!
You will love it... plus you can adjust the bias to your linking!
Have fun with it
Claude
You will love it... plus you can adjust the bias to your linking!
Have fun with it
Claude
With all the TLC this seems to demand it makes me really wonder how Korg could ever use these in the Pro Audio market where most Korg stuff resides. They bang stuff around a lot and sound levels and associated vibration is off the chart compared to us.
Bob, my brother is an electric guitar enthusiast. He tells me guitar players love anything that will give them a different sound when they play. Distortion and bizarre harmonics are embraced in these circles, and you can put this little, flat tube in foot petal activated assemblies driven by mere DC voltages.
Pete
Very good point. I tend to forget our goals are different. When I have folks that want to hear highly distorted music to evaluate a system I think, how can you tell if the distortion is distorted? But I guess that's pretty-much true of any music. We all just perceive what it should sound like. We can never know what it actually sounded like originally.
Hi Nash, go post #1591 for the original observation and observation. The link provided there (Japanese web site) will have to be translated by your browser in English. Hope this is what you seek!
Cheers,
Pete
Preamp cover off. No Music Playing
You are correct about cover being off, but the room is Silent When This Happens, and it comes and goes.
Do a process of elimination…take the TT & phono preamp out of the equation. Drive a signal using another controllable input source. Still rings? Try my bubble wrap thing under your B1K unit. Do you have the eraser on top of the tube?
Pete
I have had luck with the position of the preamplifier. in my main system, it doesn't ring. In another room, it rings quite a bit. However, I don't have any treatment on the tube. I actually tried positioning it on different shelves on my rack to minimize ringing.
I noticed the room that it rang in is more reflective with sounds. Also, horn speakers...
I noticed the room that it rang in is more reflective with sounds. Also, horn speakers...
Here is a link to an English translation of that Japanese web page. It takes a while (20-30 seconds) to load in your browser.
(Google Translate link)
(Google Translate link)
The elimination process so far has come to the point that this tube/circuit is the culprit. As mentioned before, it rings all by itself with no signal applied to it.
Regardless of what seems obvious, I will try your advice connect a CD Player to it. Before I even turn on the CD Player, I will wait to see if it continues to ring. If not, then I will turn on the CD player and play music at a low level. The lid will also be in place when I do this. I am betting that it will ring as before. If so, then the tube will be replaced. Question, can a tube self oscillate?
Regardless of what seems obvious, I will try your advice connect a CD Player to it. Before I even turn on the CD Player, I will wait to see if it continues to ring. If not, then I will turn on the CD player and play music at a low level. The lid will also be in place when I do this. I am betting that it will ring as before. If so, then the tube will be replaced. Question, can a tube self oscillate?
It really is amazing how finicky this tube/assembly is. Is your Nutube attached to the PCB with anything? As a test, try removing the Nutube from that foam/gel support, slightly bending the Nutube upwards so only it’s attachment pins support it (kinda free-floating). You just might have to buy another tube to eliminate a bad tube as the first factor.
Pete
Yes, in fact the tube is attached to the board. I will do as you suggest and see what happens. Thanks for reading my post and understanding about the conditions that apply or do not apply.
Here’s a link to the magnets I bought for this project from Amazon.
https://www.amazon.com/dp/B07BLJBP5P/ref=cm_sw_em_r_mt_dp_AR5JMEAJHVJEMYRSVVA8?_encoding=UTF8&psc=1
Pete
https://www.amazon.com/dp/B07BLJBP5P/ref=cm_sw_em_r_mt_dp_AR5JMEAJHVJEMYRSVVA8?_encoding=UTF8&psc=1
Pete