Yamaha B-2 restoration journey

@Oilmaster
Are the FKS2 somehow inferior to the MKS2?
A number of long term members here seem to use the MKS2 with success (to replace smaller electrolytics, not existing film caps), and having used them (as well as Panasonic film caps) in a few builds myself I've found them fine. However they are not in the signal path (probably the case for any good amp).

I am not sure what the application is in this amp / this case. Perhaps they are replacing something other than electrolytics and those caps are in the signal path, hence your preference for polypropylene?

Where do you recommend using polypropylene (and for what capacitances)? If you don't mind sharing.

Thanks
 
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@Oilmaster
Are the FKS2 somehow inferior to the MKS2?
A number of long term members here seem to use the MKS2 with success (to replace smaller electrolytics, not existing film caps), and having used them (as well as Panasonic film caps) in a few builds myself I've found them fine. However they are not in the signal path (probably the case for any good amp).

I am not sure what the application is in this amp / this case. Perhaps they are replacing something other than electrolytics and those caps are in the signal path, hence your preference for polypropylene?

Where do you recommend using polypropylene (and for what capacitances)? If you don't mind sharing.

Thanks
And it also seems that the Xicon MPP does not exist in the value I need (0.0022 uF). How about Orange Drops?

Edit, found them: https://www.banzaimusic.com/Xicon-Polypropylene/
 
I was not referring to their performance, only to their looks.
When dealing with high-end heritage gear like this, those square Wima caps are (IMO) an esthetic insult (unless you belong to the "fast-'n-loud" followers that rape any genuine survivor for cutting it up and stuffing it with whatever). Staying with the original form factor "lacquer dipped" is key to me for concours-quality renovation/rebuilds.

RE Xicon MPP inavailability: oh gosh, indeed, another through-hole product line which has been stopped :mad:; soon we are out any quality through-hole component product line.
The Xicon MPP are (were) nicely fitting when 100V rated, sometimes the 250V range fits as well but starts getting too large in some cases.
The 400/630V ranges are too large (2x/3x) to deal with; forget about it.

Some (not all!) Panasonic ECQ series may come to the rescue, but again the lower voltage range is hardly sold nowadays, so same "sizing problem".

Vishay Sprague Orange Drops are often too large as well due to the very high voltage rating; certainly for the cramped B-2 PCB's.

Well, the days of the perfect MKP recap caps are over (Panasonic's ECQ-P in perfect-fitting 50V/100V ratings).
A quality rebuild can take many months for that reason, to source a number of required parts from all over the planet.
 
I was not referring to their performance, only to their looks.

Oh right.
In that case it's a bit silly to throw people in prison over it (and use words like "rape") surely?

Personally while I can certainly appreciate period-correct vintage restorations, there are also many less-expensive pieces that are workhorses (many of mine are anyway) and as such, all that matters is the sonic performance.

I think you might be mistaken that people installing those caps are going for "fast n loud", rather they probably just care most about the sonic qualities rather than the internal visual ones. I used a mix of MKS2 and ECQ and both worked well for me as replacements for small 'lytics.

Anyway, I respect your choices. Different people are in the game for different things though. :)
 
I was not referring to their performance, only to their looks.
When dealing with high-end heritage gear like this, those square Wima caps are (IMO) an esthetic insult (unless you belong to the "fast-'n-loud" followers that rape any genuine survivor for cutting it up and stuffing it with whatever). Staying with the original form factor "lacquer dipped" is key to me for concours-quality renovation/rebuilds.

RE Xicon MPP inavailability: oh gosh, indeed, another through-hole product line which has been stopped :mad:; soon we are out any quality through-hole component product line.
The Xicon MPP are (were) nicely fitting when 100V rated, sometimes the 250V range fits as well but starts getting too large in some cases.
The 400/630V ranges are too large (2x/3x) to deal with; forget about it.

Some (not all!) Panasonic ECQ series may come to the rescue, but again the lower voltage range is hardly sold nowadays, so same "sizing problem".

Vishay Sprague Orange Drops are often too large as well due to the very high voltage rating; certainly for the cramped B-2 PCB's.

Well, the days of the perfect MKP recap caps are over (Panasonic's ECQ-P in perfect-fitting 50V/100V ratings).
A quality rebuild can take many months for that reason, to source a number of required parts from all over the planet.

Then you also won't like the large CDE 22.000 uF cans I'm going to use for the PS :rolleyes:

These orange drops are not that big I guess. I think they'll fit for C120, 121 and C122.
Capture.PNG

http://www.hificollective.co.uk/capacitors/orange-drops-ppn.html
 
@ Zaibatsu : I didn't want to make that impact; perhaps my words were a bit harsh.
The point was about heritage equipment, not just vintage equipment.
The number of slaughtered pieces of mistreated heritage vintage gear that I have seen/got/repaired, frying VFETs in due coarse.... that is sort of criminal.....
My point is just that original heritage pieces should be respectfully preserved, not be changed into an uneducated fun project pumping them full with 'performance parts'.
As you say, each one his/her take on it; that is just mine.

Back to the potential replacement caps.... the ETR PPN being sold at HifiCollective (where I do buy regurarily myself), are a bit akward.
First of all.... a polyprop cap of 2.2nF/630V should be larger in size than 9x9x4 mm.
Such size belongs to low voltage and/or to polyester film caps

Checking out ETR's own web page; that suspicion is confirmed:
http://etr.com.tw/eng/dc_use_film_capacitors/polypropylene/dc04_01.htm

According ETR themselves, a 630V/2.2nF PPN cap should measure 15x13.5x7.5, which is around 4.5x the volume of the advertised cap at HFC (and conform all identical Xicon, Panasonic and others caps I have laying around). This might mean that HFC has potentially bought a fraud supply; which is not unheard of for parts like this.
Since polyester and polypropylene caps in this segment are identical looking, but MKT being much cheaper to make than MKP; many counterfeit products are infiltrating even official retailers (unnoticed).
I am going to send an email to HFC about this; perhaps ETR has some magic unpublished polyprop development ongoing.... but I guess not so....
very awkward :idea:
 
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message to HFC sent

@ Mr. Yamaha : you selected a 2.2nF cap, not a 22nF cap as required for the B-2
It doesn't change the awkward case I spotted on HFC though
 
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@Oilmaster
Fair enough, I think certainly people will appreciate the pieces you've restored in future. My stuff certainly isn't heritage and I can appreciate the difference. Actually the reason I asked is because I saw an old post from you suggesting polypropylene replacements for film caps used across flameproof resistors (in a Sony amp), and you seemed to hint at some kind of sonic improvement. Not too fussed about how things look personally but am always interested in modern parts improving the sound. Does this apply to Yamaha amps as well, and would there be any value in replacing those bright green lacquer-dipped things? Or is the configuration different?

I hope Mr. Yamaha isn't offended by my mild hijack. :)
 
@Oilmaster
Does this apply to Yamaha amps as well, and would there be any value in replacing those bright green lacquer-dipped things? Or is the configuration different?

The green lacquer-dipped capacitors are mylar (i.e. polyester or MKT) caps; when used for bypassing those fusible resistors in signal path of the TA-N7B, it certainly does yield a sonic improvement . The B-2 has similar bypass caps across signal carrying resistors (from VAS to bias/driver stage); and therefore worth replacing by quality caps (luckily I have my stock of ECQ-P caps for these). It removes quite a lot of the lame sound, making it more open, more detailed and more sparkling (as part of an overall renovation, so don't pin me done on some specific part replacement). I simply tried it out in a rebuilt TA-N7B and B-2; keeping those old green mylar caps versus some ECQ-P..... the results were clear.

The purpose here NOT to start another capacitor debate. Modern quality MKT (polyester) caps can yield very good sonic results, but those 70's green beans in Japanese gear are (or become) very lame and dull sounding. Hence, having MKP (polypropylene) caps all over the place does not have to be the holy grail objective for a rebuilder.
 
First of all, let me clear up something. I'm not trying to "fast 'n loud" this B-2 nor trying to mutilate it. This B-2 will stick to me forever and I want to replace the parts which are needed to keep it playing for the next 30 years without destroying the VFET's and I want it to be as reliable as possible, because it will me my every day main amp. I care more about quality and availability than about looks when the top cover is removed. Because the only one who will be seeing that is me.

That does not say that I'm not open to suggestions or critics from guys who obviously have very more B-2 expertise than me. To be honest, this will be my first rebuild, so I'm still considering whether I'll do all the work myself.
So that's that and now let's continue :beerchug:

@ Zaibatsu : I didn't want to make that impact; perhaps my words were a bit harsh.
The point was about heritage equipment, not just vintage equipment.
The number of slaughtered pieces of mistreated heritage vintage gear that I have seen/got/repaired, frying VFETs in due coarse.... that is sort of criminal.....
My point is just that original heritage pieces should be respectfully preserved, not be changed into an uneducated fun project pumping them full with 'performance parts'.
As you say, each one his/her take on it; that is just mine.

Back to the potential replacement caps.... the ETR PPN being sold at HifiCollective (where I do buy regurarily myself), are a bit akward.
First of all.... a polyprop cap of 2.2nF/630V should be larger in size than 9x9x4 mm.
Such size belongs to low voltage and/or to polyester film caps

Checking out ETR's own web page; that suspicion is confirmed:
http://etr.com.tw/eng/dc_use_film_capacitors/polypropylene/dc04_01.htm

According ETR themselves, a 630V/2.2nF PPN cap should measure 15x13.5x7.5, which is around 4.5x the volume of the advertised cap at HFC (and conform all identical Xicon, Panasonic and others caps I have laying around). This might mean that HFC has potentially bought a fraud supply; which is not unheard of for parts like this.
Since polyester and polypropylene caps in this segment are identical looking, but MKT being much cheaper to make than MKP; many counterfeit products are infiltrating even official retailers (unnoticed).
I am going to send an email to HFC about this; perhaps ETR has some magic unpublished polyprop development ongoing.... but I guess not so....
very awkward :idea:

That's a strange case indeed. I also regularly order stuff at HFC.

message to HFC sent

@ Mr. Yamaha : you selected a 2.2nF cap, not a 22nF cap as required for the B-2
It doesn't change the awkward case I spotted on HFC though

You're right, I was 1 zero off.

The green lacquer-dipped capacitors are mylar (i.e. polyester or MKT) caps; when used for bypassing those fusible resistors in signal path of the TA-N7B, it certainly does yield a sonic improvement . The B-2 has similar bypass caps across signal carrying resistors (from VAS to bias/driver stage); and therefore worth replacing by quality caps (luckily I have my stock of ECQ-P caps for these). It removes quite a lot of the lame sound, making it more open, more detailed and more sparkling (as part of an overall renovation, so don't pin me done on some specific part replacement). I simply tried it out in a rebuilt TA-N7B and B-2; keeping those old green mylar caps versus some ECQ-P..... the results were clear.

The purpose here NOT to start another capacitor debate. Modern quality MKT (polyester) caps can yield very good sonic results, but those 70's green beans in Japanese gear are (or become) very lame and dull sounding. Hence, having MKP (polypropylene) caps all over the place does not have to be the holy grail objective for a rebuilder.

Which green beans do you suggest to replace with MKP's?
 
Or what about the Mullard Tropical Fish? http://www.hificollective.co.uk/capacitors/mullard-tropical-fish-capacitors.html

Maybe they look even worse than the Wima's, but they have the vintage look, but are definitely not Japanese :D

Capture.PNG

Edit: these are perfect I guess: http://nl.mouser.com/ProductDetail/Cornell-Dubilier/DME2S22K-F/?qs=KO1/fvdAAolyOJmNkXMcig==

Or: https://www.conrad.nl/nl/panasonic-...-mm-l-x-b-103-mm-x-44-mm-1-stuks-1468492.html

Edit 2: there's more: http://nl.rs-online.com/web/p/polyester-film-capacitors/0115247/

Or these Yellow Nichicons, pretty small: http://nl.rs-online.com/web/p/polyester-film-capacitors/7554361/

Red Nichicons: http://nl.rs-online.com/web/p/polyester-film-capacitors/7554462/

These are only AC rated, does that mean it can't be used in DC circuits? http://nl.rs-online.com/web/p/polyester-film-capacitors/7554208/
 
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Made some progress here. Took me quite some time to source all parts, knowledge and information. Oilmaster helped me a great deal with it, thanks for that. It is almost becoming a complete restoration and it's my first, so it's pretty exciting :biggrin:

Finished the power board today. I replaced all electrolytics, fuses, some films, all zeners, varistors, speaker relays, trim pots, 2SC458 trannies, regulator trannies, rectifier diodes and the large resistors.

All old solder / tin was sucked out and all connections have new solder. Also from the components which were not replaced.

Also removed all old glue, re-glued the heatsinks to the board and did a deep clean. All old and new flux removed.

Pretty happy with the results :thumbsup:

Before:

IMG_0965.JPG

After:

IMG_1836.JPG

IMG_1835.JPG
IMG_1833.JPG IMG_1837.JPG IMG_1838.JPG IMG_1839.JPG IMG_1840.JPG IMG_1841.JPG
 
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Then you also won't like the large CDE 22.000 uF cans I'm going to use for the PS :rolleyes:

These orange drops are not that big I guess. I think they'll fit for C120, 121 and C122.
View attachment 826741

http://www.hificollective.co.uk/capacitors/orange-drops-ppn.html

According to my B-2 schematic, those caps are 0.022 not 0.0022. I haven't looked at the actual caps on my drive board to see if the schematic is correct, but I do have one in tear down and can check tonight.

upload_2017-1-20_9-8-19.png

EDIT: re-reading this thread I see that Mr Yamaha already caught this error. Nevermind...
 
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Made some progress here. Took me quite some time to source all parts, knowledge and information. Oilmaster helped me a great deal with it, thanks for that. It is almost becoming a complete restoration and it's my first, so it's pretty exciting :biggrin:

Finished the power board today. I replaced all electrolytics, fuses, some films, all zeners, varistors, speaker relays, trim pots, 2SC458 trannies, regulator trannies, rectifier diodes and the large resistors.

All old solder / tin was sucked out and all connections have new solder. Also from the components which were not replaced.

Also removed all old glue, re-glued the heatsinks to the board and did a deep clean. All old and new flux removed.

Pretty happy with the results :thumbsup:

Before:

IMG_0965.jpg


After:

IMG_1836.jpg


IMG_1835.jpg


IMG_1833.jpg


IMG_1837.jpg


IMG_1838.jpg


IMG_1839.jpg


IMG_1840.jpg


IMG_1842.jpg

Simply wonderful work!

So I have to ask what your final parts list was, how you got all the nasty bonding glue off and in general cleaned up the board?
 
No intention to hi-jack this thread, but since it is the current B2 thread with all resident experts actively participating, I thought I'd throw this out there:

Does anyone think there is much to be gained by wiring one of the inputs directly to the driver boards therefore bypassing numerous selector switches, volume pots, etc.? I never use those anyway. I just use one set of inputs in DC mode with volume unattenuated.

I'm not a big fan of making modifications to heritage equipment, but this one is easily reversible.
 
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