B1 with Korg Triode

[Zen Mod]

dunno what is ratio of functional vs. problematic ones ( Dodo, excessive microphonic), but - by number of specific posts here - it seems it becomes that Korg Tube is not much of a Tube

 

[ClaudeG]

It is always difficult to assess, isn't it, as people who encounter problems will of course post and be more visible than people who don't...

I have a B1 Korg, so far no problem. If people not having any serious problem caused by this tube would post aswell, perhaps that would help drawing a clear picture?

Saying that because with another strong hobby of mine, cars and Lotus in particular, I am tired to read horror stories about the K engine HGF, posted by always the same individuals (a few not even having such a car, many being careless people that went wrong initialy), while the majority of happy trackers is quite.

Absolutely not saying it is the case here, at least people seem to care and can't do that many things wrong, but it would be nice to read how many folks are happy with the Korg tube before it gets a bad reputation (that should at least be deserved and founded if so).

All IMHO

Claude

 

[Zen Mod]

I said - dunno what's real world ratio ........

though, worth to say - nothing against Papa's and Pete Milett's work on Korg Tube - it's in human nature to have faith in proper engineering

I'm just taken away with comparison between this one and any old tube, even those manufactured in smallest quantity

I mean - they call it tube, they can expect comparison with any preceding one

- ok - even in Gold Era of tubes, there were microphonic ones ........ but even those rarely having problems with dead filament after one year of mild use
-first pocket calculators had same type of screen - I had Casio ........ (damn, I wish I have it still today) - I can't even imagine how much of stress it endured during several years tumbling in all school adventures

I'm really wishing those are great minority cases, if nothing else - because of myriad of work hours involved - first from Pa, then from any Greedy Boy around, assembling own preamp

incidentally - on the lighter note - any proper tube lover is Hoarder ...... why should be different with Korg tube - when you think of buying - buy 5 or 10

 

[turion64]

I’ve built two B1Ks now and have had no issues but I have only been using them for a few months so I’ll keep my fingers crossed.

Two things:

It’s curious that both Arnejo & chanthing had issues with the left channel, no?

I know it’s a pain but might it just be more productive to rebuild the left channel, i.e., pull one leg of all resistors & check their values, etc…, but I guess they’d have to replace all jfets (L & R channels) since they’re all matched sets?

I feel your pain gentlemen…

It is always difficult to assess, isn't it, as people who encounter problems will of course post and be more visible than people who don't...

I have a B1 Korg, so far no problem. If people not having any serious problem caused by this tube would post aswell, perhaps that would help drawing a clear picture?

 

[Soundhappy]

diyAudio Passworks Korg NuTube Preamp Kit Build Tips & Hints - YouTube

 

[R-K Rønningstad]

It is always difficult to assess, isn't it, as people who encounter problems will of course post and be more visible than people who don't...

I have a B1 Korg, so far no problem. If people not having any serious problem caused by this tube would post aswell, perhaps that would help drawing a clear picture?


Claude

I am one with a well working and sounding “K”. I have implemented the on/off button and I am using it.

 

[Sidsmith]

Great video from Blueglow Electronics. His experience with a lot of tube gears, DIY or vintage one, added to the weight of his opinion.

I builded a prototype of the B1K in a 1/8 wood enclosure (do not do that, too thin to use nails, In the end I needed to bolt everything with corner brace, use 1/4 at least!). The tube was very microphonic at first (it add a sound much like a high frequency tinnitus). I put a plastic eraser on the Korg and the cover on the preamp and the sound dissapear. No problem whatsoever since. Listen to it, sound very good, better than the Marantz 2275 preamp it replace.

When I will finish my Pearl II phonostage I will put both in place of my HK Citation IV in my primary system to listen to the difference.

 

[nashbap]

FWIW, this (left channel of nuTube getting blown) has happened to me twice.

Hoping to get some insight into why with the help of a local forum expert this week. Will share what we learn here.

-- Thing

I suggest you take a very close look, with a magnifier if necessary at the underside of the PCB for any solder residue, microscopic bridging or flux. Clean thoroughly. Let us know if you find anything.


nash

 

[JohnnoG]

In my local group there are Five KB1 Builds of which I have use of one as a loaned model.
There are no concerns raised at present about quality issues with the Nutube and these are in use for approx' Two Years.

Is it possible something could impact on the Nutube during the build and the life is shortened as the outcome ?

 

[Paddy Garcia]

Maybe the Nutube is actually very tube-like and either fails early or not for a long time.

There seem to be more early failures than with hot tubes but that production system was very mature and robust by the time it was pumping out the classic tubes people use now.

 

[Sidsmith]

And with standart tubes, you have grading scale, some based on noise and microphonics, especially for tubes destined to low level amplification. Since it is unlikely that audiophile will buy low grade tube, there is a bias in the audiophile population concerning the performance of standart tube.

A friend of mine said that in the early 80's, company like Conrad-Johnson dismissed nearly 90% of the tubes they test that were destined put in their preamplifier.

In any case, is there something to do to improved reliability of the Korg tube?

 

[Soundhappy]

Noritake who produce for Korg are one old company in Japan with high quality control products experiences
not a young start-up.
Korg show us in official documents all informations future Diyers need to knows
about correct technique to avoid microphonic problem.
I believe this miniature Nutube production are made with automatised process by machines ,
not the old days craft technology with hands and tools so the triode parameters are in the data sheet specyfications
with tight good tolerance.

 

[Soundhappy]

Test with guitar but interesting video Classic Vacuum Tube VS New Korg Nutube - Tone Comparison - YouTube

 

[ryder177]

Hi. Newbie here. I broke the LED for my Korg Nutube B1 kit. Would anyone know what the part number is so I can purchase a replacement?

 

[Mark Johnson]

Test with guitar but interesting video ...

Thanks for that! Honestly I preferred amp "A" in each comparison.

 

[chanthing]

I suggest you take a very close look, with a magnifier if necessary at the underside of the PCB for any solder residue, microscopic bridging or flux. Clean thoroughly. Let us know if you find anything.


nash

Thanks.

The continuing saga: Met with 6L6 to give it a onceover before installing a replacement nuTube. Inspection of board did not turn up anything suspicious.

We somewhat speculatively replaced Q1 on the output side, where the existing component had a lower Vgs than a reference part.

Installed new nuTube. All test points measure as expected.

I guess I'm just lucky wrt microphonics, as this one is showing no tendency (or maybe it's just the non-rigid standoffs I use).

It's interesting that during these maintenance periods when I'm running my old Advent Model 300 receiver, I think it's close to as nice sounding as the B1K, but after I resume using the B1K, I realize it's not.

Hoping to *not* be back here posting in 3-4 months.

-- Thing

Thanks again to 6L6 for the assistance.

 

[ranshdow]

Just wanted to say, the B1K does wonders for the sound of a class D amp like the ICEpower ICE125ASX2, they really complement each other well.

 

[Soundhappy]

Thanks for that! Honestly I preferred amp "A" in each comparison.

My pleasure, thanks for the kind words 🙂

At my home, I compared Decware classic triode preamp with B1K and the conclusion
was favorable to Pass Nutube sound, more clarity and precision in tone with just slight touch of warm
who can be an extraordinary good match with the semiconductors power amplifiers.

In Japan Akihiko Kaneta / Kaneda legendary DIY designer make dozen projects for hobby amateurs:
DAC's , preamps and hybrid Korg power amplifiers with SIC mosfets.

Kaneda DC amp No.262 NuTube Hybrid Batterydrive Power IVC2 - YouTube

 

[Soundhappy]

All Kaneta audio gear is always build point-to-point on the perfboards
Athletic training with soldering iron 😀 Papa style DIY is super easy !
You can find pdf. documentations on this blog: レポート | 趣味の自作半導体アンプ

Nutube Current Power IVC MK2 http://myaudio.sakura.ne.jp/report/6P1_Current_Power_IVC_MK2_電圧伝送対応.pdf

Nutube Current Power IVC http://myaudio.sakura.ne.jp/report/6P1_Current_Power_IVC_電圧伝送対応.pdf

Power Supply Box2 http://myaudio.sakura.ne.jp/report/ACPowerSupplyBOX2.pdf

Korg Triode USB DAC http://myaudio.sakura.ne.jp/report/I2S接続USB DAC作成レポート.pdf

 

[Soundhappy]

Kaneta San gear is always in the same one or two black chassis: amp etc. + separated psu ( or batterys )
First 3 photos..the silver color is a build by the hobby blog writer Holy soldering smoke! Builds only for peacefuĺ minds..