The only advice that I would give is to inspect or even replace RCA jacks if they aren't perfect. I have been made a fool of so many times because of less than great RCA connectors, not to mention cables. In fact, just last night was one of those hunts leading to a cable connector (factory) that was cutting in and out. And make sure that this is not happening due to some other component either. We get 'once bit, twice shy'. At least I do.
Still a low number. Seems by the thread posts, it affects smps powered more. QC is a big possibility too. Another thing is decoupling, this thing needs to be decoupled, it seems to be also related to that as well as perhaps a strain on filament (probably several factors altogether).
This calls for a poll. Which channel, what power supply and maybe if you are using filtration or soft start. It would help have numbers at hand since so many of these have been made.
@Ixnay Thanks for the tip - I honestly have been frustrated with the korgb1 and just stuck it on the shelf since finishing the iron pre. Regarding RCAs - they're nice quality gold plated Neutrik ones.
The only idea I had was something going to that left channel like a cap was being funky. Went over all solder joints, the nutube is mounted on that foam gizmo with a ribbon cable so its nice and isolated. I half debated not using the isolation mount the 2nd go around just to see what would happen but was afraid of microphonics.
RE: power supply - I'm using the standard kit wall wort. Maybe making an external power supply would be a better idea- don't think anything else would fit in the chassis
A poll would be interesting. From searching on here I think every single "my nutube died" post stated the Left side was the problem.
The only idea I had was something going to that left channel like a cap was being funky. Went over all solder joints, the nutube is mounted on that foam gizmo with a ribbon cable so its nice and isolated. I half debated not using the isolation mount the 2nd go around just to see what would happen but was afraid of microphonics.
RE: power supply - I'm using the standard kit wall wort. Maybe making an external power supply would be a better idea- don't think anything else would fit in the chassis
A poll would be interesting. From searching on here I think every single "my nutube died" post stated the Left side was the problem.
Hi blue30cda
It is a long time since I followed this thread.
I am also one of the poor guys who invested in a Nutube and whose Nutube blew up. Yes, the heater on the left side. I scanned the Thread art that time.
As far as I remember there were >10 Nutubes were always the left side of the heater blew. There was only one were the side was not specified.
To me it seems the nutubes are flawed. They either work or the heater on the left (!) side blows.
I am a bit frustrated as there is no help not even a warning or comment from Nelson Pass nor from the diyAudio shop.
At 50 USD plus shipping plus toll a nutube is not cheap. I remember one other guy who bought a second one which also blew up.
And YES they sound good as long as they work.
It is a long time since I followed this thread.
I am also one of the poor guys who invested in a Nutube and whose Nutube blew up. Yes, the heater on the left side. I scanned the Thread art that time.
As far as I remember there were >10 Nutubes were always the left side of the heater blew. There was only one were the side was not specified.
To me it seems the nutubes are flawed. They either work or the heater on the left (!) side blows.
I am a bit frustrated as there is no help not even a warning or comment from Nelson Pass nor from the diyAudio shop.
At 50 USD plus shipping plus toll a nutube is not cheap. I remember one other guy who bought a second one which also blew up.
And YES they sound good as long as they work.
Hardly that we can blame either of them - Nutube was all the rage in that moment, not just on DiyAudio, and Pa gave us project with funny part which is supposedly proper one, made by reputable Brand.
Korg is one to blame, while no one else really had any extensive time for evaluation of longevity, nor even basis for any suspicion
Dunno what's ratio of good/dud........ but I'm sure one having such luck of getting 2 Duds isn't interested to find about numbers
For a 30000h rated tube, QC seems to be quite bad. It seems batch by batch related. Pops one is still working hard since the project inception, so theres that. One thing that comes to mind is that we could collectively contact Korg with issues at hand, so they may push a task to QC. What is weird too is, seems the more microphonic it is, the more it suffers failure (pops mentioning no microphonics and he did not decouple), at least reading trough the thread, so tension of the filament may be the issue.
The Nutubes I have used came directly from Korg, and they have all worked well, but I don't know the provenance of the others out there...
+1 on ZM
I couldn't blame Pa for giving us a nice design for US to build (actually several)... and because a (NON PASS) component of the BOM seems to fail admittely a bit more often than it should.
Com'on... nor would I shoot on the poor and great DIY Audio shop.
I though understand the frustration and the constructive action to "help Korg enhence its quality".
Nice day to all....peace and love ;-)
I couldn't blame Pa for giving us a nice design for US to build (actually several)... and because a (NON PASS) component of the BOM seems to fail admittely a bit more often than it should.
Com'on... nor would I shoot on the poor and great DIY Audio shop.
I though understand the frustration and the constructive action to "help Korg enhence its quality".
Nice day to all....peace and love ;-)
Me too - - just last week. One channel out, can't remember which. I do remember $50 + $10 shipping. Is this a tube thing?
If we don't have some sort of poll, the info will be one sided. How might this be done? This little DHT deserves to be kept somehow.
The closest that I came to having this sound ever before was with the Bottle Head Quickie, which used a 3S4 tube, and yes, it was very microphonic. put it inside a thick, heavy lead case and your problem was solved.
The closest that I came to having this sound ever before was with the Bottle Head Quickie, which used a 3S4 tube, and yes, it was very microphonic. put it inside a thick, heavy lead case and your problem was solved.
Mine was two left sides blown, SMPS, Kit from the diyAudio store, and the second tube bought from the store July 2, 2024 (didn't even last a year). I didnt deviate from and of the "stock" parts recommendations.I have the tube foam and extension kit from eBay and added the SMPS filter from the DAS in July.
Not sure how long the first one lasted, but I guess about a year. Second one popped last week while I was sitting on the couch. made a very large pop and scared the crap out of my cats! ha!
Now I'm back onto my cheap aliexpress C-3850 kit and happy enough with that....
Not sure how long the first one lasted, but I guess about a year. Second one popped last week while I was sitting on the couch. made a very large pop and scared the crap out of my cats! ha!
Now I'm back onto my cheap aliexpress C-3850 kit and happy enough with that....
2 devices with it, never leaving them always on.
1. B1K preamp, mounted in a big thick case on the front aluminium panel, with plastic (=flexible) standoffs [to somehow attenuate possible vibrations]. No issue after 200h or so.
2. Pete Millet's headphone http://www.pmillett.com/nuhybrid.html. PCB is just protected by self-designed rigid plastic cover (top & bottom), connected through rigid standoffs. On/Off switch on PCB = when switching on, there are some mechanical effects on PCB and the NuTube is ringing for 3sec.
Used for 50/75h or so. No issue but thinking about having a more "damping" case/system for mounting to avoid the initial ringing
1. B1K preamp, mounted in a big thick case on the front aluminium panel, with plastic (=flexible) standoffs [to somehow attenuate possible vibrations]. No issue after 200h or so.
2. Pete Millet's headphone http://www.pmillett.com/nuhybrid.html. PCB is just protected by self-designed rigid plastic cover (top & bottom), connected through rigid standoffs. On/Off switch on PCB = when switching on, there are some mechanical effects on PCB and the NuTube is ringing for 3sec.
Used for 50/75h or so. No issue but thinking about having a more "damping" case/system for mounting to avoid the initial ringing
Yes. I leave my chipamp and MoodeAudio raspberrypi on all the time too. Still, a year is less then 9000hrs and these tubes are rated way more than that.
Oh i'm sure none of the talk about tube QC is aimed at diya shop or pops 🙂
Another thing comes to mind is, how is the soldering done. Since it's such a small device, prolonged heating may damage it internally as it cannot dissipate temperature properly.
@Nelson Pass Both tubes I bought were right off the DIY store website. I'm assuming you guys order directly from Korg?
Is there anything in the design that could favor L side blowing or a specific component to look closely at? On mine the L channel was cutting in/out so I pulled all the electrolytics on that side and double checked the caps. Replaced with new tube, all good, now the new nutube (haha) has started cutting in out a few times on that same L channel. scratched my head, put it on the shelf and plugged in the iron pre . . . happy days
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