Yamaha B2 - the "why" and the "how" of a comprehensive rebuild

[Vint Age]

I'll post on it in my B-1 thread once I cross that bridge.

And looking forward to it.

 

[rottalpha]

Pete has inspired me to up my game with my rebuilt B2s.

I look forward to restoring the function on these units that has been disabled.

I ordered two full sets of everything he's offering and the fun begins. I may even put my third parts unit back into service, since it's not missing much in the way of parts.

I'll share a few pictures when things get completed, but it'll be awhile...

no B-2 that has all good vfets should ever become a parts unit.
Godspeed!

 

[rottalpha]

My first thought is that by using the analyzer to do a slight bias tweak on the mule B-2, it might bring it a tad closer to the other one ...

I should clarify that I could bring up the harmonics in the rebuilt unit easier than to lower those of the original unit without starting to replace other major components.

 

[ivandezande]

One more annoying question - the new power supply board rocks, but I would say it would be a lot better to use an Omron G4W-2212P-US-TV5-HP-DC12 or a G2R-2A4-DC12 for cost, size, and reliability. Maybe even that footprint may be supported longer.

 

[rottalpha]

One more annoying question - the new power supply board rocks, but I would say it would be a lot better to use an Omron G4W-2212P-US-TV5-HP-DC12 or a G2R-2A4-DC12 for cost, size, and reliability. Maybe even that footprint may be supported longer.

Or use a SS relay and get rid of the contact problem forever, BUT, I tried to stay true to the original design and part numbers.

Any more changes to the original design and I will have to call it a B-2 MKII

 

[vintagejapan]

One of the lucky ones that just finished a B-2 for a fellow here down under with all 3 boards upgrade from @rottalpha. Amazing work everything laid up beautifully and the boards are top quality.
I have been lucky enough to have a few Yamaha Vfets go through my hands and own all the B's(although the B-2 I own is waiting patiently for this upgrade)
This particular unit has the Gold Tune on the filter board. The difference from the start was very noticeable. The B-2 highs had more air and with so much nuance and movement than prior the upgrade.
I listen to a lot of ECM records and the B-2 was able to extract more information and I could almost feel the air around the instruments, shimmering cymbals and long lasting piano decays.
I can confidenlty say that the upgraded B-2 is now a notch above my Sony TA-N7(which has been rebuild completely) Congratulation on your work Pete and thank you for this mod.
The listening that I did was with the Direct In option. Looking forward to do mine now

 

[vintagejapan]

Forgot to mentioned that also replaced the dual input jfets on the drivers board.
The completed B-2 has the Toshiba dual fet from Pete. And loving that selector board

 

[Sparkplug]

View attachment 2777026 View attachment 2777028 View attachment 2777029 One of the lucky ones that just finished a B-2 for a fellow here down under with all 3 boards upgrade from @rottalpha. Amazing work everything laid up beautifully and the boards are top quality.
I have been lucky enough to have a few Yamaha Vfets go through my hands and own all the B's(although the B-2 I own is waiting patiently for this upgrade)
This particular unit has the Gold Tune on the filter board. The difference from the start was very noticeable. The B-2 highs had more air and with so much nuance and movement than prior the upgrade.
I listen to a lot of ECM records and the B-2 was able to extract more information and I could almost feel the air around the instruments, shimmering cymbals and long lasting piano decays.
I can confidenlty say that the upgraded B-2 is now a notch above my Sony TA-N7(which has been rebuild completely) Congratulation on your work Pete and thank you for this mod.
The listening that I did was with the Direct In option. Looking forward to do mine now

Well done on a great job. I just have one question, which gold tune did you use, type l or type ll? Type lll is the Super Through. Have any part numbers? I’m planning to potentially use one of them and would like to know which type your glowing review corresponds to. Thanks and god speed.

 

[vintagejapan]

Well done on a great job. I just have one question, which gold tune did you use, type l or type ll? Type lll is the Super Through. Have any part numbers? I’m planning to potentially use one of them and would like to know which type your glowing review corresponds to. Thanks and god speed.

@rottalpha provided the caps and I think they were the type II
You will need 50mm max diameter on the caps. The ones that will fit are either type I or type II
Type III is 63mm and will not fit

 

[Sparkplug]

@rottalpha provided the caps and I think they were the type II
You will need 50mm max diameter on the caps. The ones that will fit are either type I or type II
Type III is 63mm and will not fit

, thanks for the info.

 

[rottalpha]

Well done on a great job. I just have one question, which gold tune did you use, type l or type ll? Type lll is the Super Through. Have any part numbers? I’m planning to potentially use one of them and would like to know which type your glowing review corresponds to. Thanks and god speed.

After lengthy scrutiny for this application, there is no tonal difference between I and II. And you can only fit I and II.

Edit: missed that Alex already called out that III would not fit

 

[rottalpha]

Forgot to mentioned that also replaced the dual input jfets on the drivers board.
The completed B-2 has the Toshiba dual fet from Pete. And loving that selector board

Glad to hear everything worked out and I am not surprised with the sound impressions you are describing.

Also glad that you saved one more B-2

 

[zaibatsu]

One of the lucky ones that just finished a B-2 for a fellow here down under with all 3 boards upgrade from @rottalpha. Amazing work everything laid up beautifully and the boards are top quality.

Nice work, super neat and very fast too!
Agree on the quality of the boards, the attention to layout detail is also exceptional.

 

[rottalpha]

Nice work, super neat and very fast too!
Agree on the quality of the boards, the attention to layout detail is also exceptional.

if we are gonna do this, we are gonna make it sound good and look good

 

[Sparkplug]

After lengthy scrutiny for this application, there is no tonal difference between I and II. And you can only fit I and II.

Edit: missed that Alex already called out that III would not fit

Thanks … wondering what is the benefit of KG ll over l? Nichicon’s English data sheet is incomprehensible (Google English), their Japanese data sheet says
KG l : Newly developed electrolyte, small package, high sound quality
KG ll: Versatile, best sound quality, middle category

It’s a bit of digression but they say LKS is better sound quality than KG l …

 

[zaibatsu]

I suspect these vague/subjective sonic descriptions are intended for coupling applications rather than PSU filtering applications.
This would explain why some (myself included) have found no notable sonic difference between I/II/III when used in PSU applications.

 

[rottalpha]

Thanks … wondering what is the benefit of KG ll over l? Nichicon’s English data sheet is incomprehensible (Google English), their Japanese data sheet says
KG l : Newly developed electrolyte, small package, high sound quality
KG ll: Versatile, best sound quality, middle category

It’s a bit of digression but they say LKS is better sound quality than KG l …

yeah, it looks like they used a bad version of google translate, but we can apply some logic and leverage some data we already know to be valid, so let's leave the translation aside and look at visual interpretations:

For example, if the arrows they show mean what I am thinking and what we can verify, that means that Super Tough is the best of the Gold Tune series:



So the arrow pointing up to the better model

Same between the Fg and KZ, pointing to the left? (albeit, I prefer the FG sound over the KZ sound):




so we can conclude that the arrows are used to indicate premium grade (which I interpret as sound quality) over the other and are uses directionally either pointing up or left towards the better quality parts (in their marketing / opinion)

so then why pointing down from LKG to LKS??



Well, in the case of LKS vs LKG, it does not say higher tone quality. It just says smaller. So to me, they are pointing at size difference not tonal or grade differences.

As a rule of thumb, good quality caps are typically larger. That is the case in all other Nichicon lineups, e.g the KZs are larger than the FGs and the FGs are larger than the FWs, etc.

The way I see this: Nichicon is saying that the LKS is also "high-tone" audio grade capacitor, but smaller package than the LKG. Unless we find a direct response from a Nichicon engineer I will not give this much more of an additional thought or believe that the LKS is superior in any way than the LKG. Besides, LKS series does not have options we could use for this application anyways.

 

[Sparkplug]

is it?
Yes confusing, but we can apply some logic and leverage some data we already know to be valid, so let's leave the translation aside and look at visual interpretations:

if the arrows they show mean what I am thinking and what we can verify, that means that Super Tough is the best of the Gold Tune series:

View attachment 2777848

So the arrow pointing up to the better model

Same between the Fg and KZ, pointing to the left? (albeit, I prefer the FG sound over the KZ sound):
View attachment 2777853

View attachment 2777854

so we can conclude that the arrows are used to indicate premium grade (which I interpret as sound quality) over the other and are uses directionally either pointing up or left towards the better quality parts (in their marketing / opinion)

so then why pointing down from LKG to LKS??

View attachment 2777858

It does not say higher tone quality. It just says smaller. So they are pointing at size difference no tonal or grade differences.

As a rule of thumb, good quality caps are typically larger. That is the case in all other Nichicon lineups, e.g the KZs are larger than the FGs and the FGs are larger than the FWs, etc.

The way I see this: Nichicon is saying that the LKS is also "high-tone" audio grade capacitor, but smaller package than the LKG. Unless we find a direct response from a Nichicon engineer I will not give this much more of an additional thought or believe that the LKS is superior in any way than the LKG. Besides, LKS series does not have options we could use anyways.

Rot, don’t mean to distract or hijack this thread, far from it, but arrow down (written on the arrow itself, LOL) means size goes down, not quality. Although the size gets only reduced by a few meager mm, not more.

As a rule of thumb, good quality caps are typically larger. That is the case in all other Nichicon lineups, e.g the KZs are larger than the FGs and the FGs are larger than the FWs, etc.

True, say that to some other people around here and I’ll leave it at that. BTW, I double checked with Nichicon’s main website here and all it says is that LKS is LKG type l in smaller package. I guess they can’t bother hiring translators these days and write whatever garbage in their foreign language catalogs. Anyway, I’ll get a bunch of LKS one of these days and give them a try. The problem with LKG is that values of 10000uF and higher in voltage ratings of 63V and higher are only available in lug terminal form. Sometimes a PITA.

Now back to regular programming …

 

[rottalpha]

Rot, don’t mean to distract or hijack this thread, far from it, but arrow down (written on the arrow itself, LOL) means size goes down, not quality. Although the size gets only reduced by a few meager mm, not more.

True, say that to some other people around here and I’ll leave it at that. BTW, I double checked with Nichicon’s main website here and all it says is that LKS is LKG type l in smaller package. I guess they can’t bother hiring translators these days and write whatever garbage in their foreign language catalogs. Anyway, I’ll get a bunch of LKS one of these days and give them a try. The problem with LKG is that values of 10000uF and higher in voltage ratings of 63V and higher are only available in lug terminal form. Sometimes a PITA.

Now back to regular programming …

 

[rottalpha]

I was gonna say, as long as we stay on the B-2 topic, and that includes discussing replacement parts, you are not distracting at all. On the contrary....