Yamaha B-1 and BX-1, instruments of torture

This kit does also exist :

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used with high quality capacitors it is perfect
Old tread with very relevant information regarding B1 filter cap boards. Firstly, thank you to all who have contributed so much of their experinace in these Vfet forms, your information has been so helpful in guiding those who continue to be fasinated by these amps.

I'm a long time B1 owner that resently had my B1 successfully brought out of curcuit protection mode leading to a full rebuild of the amp. The final leg of the journey is tuning the B1's signal path and addressing the filter caps, requiring the boards in your post. Is there a link to purchase the board pictured in your post? There was also mension that members within this B1 community tread may have created there own boards.

If the boards no longer exist, as this is a older thread, would anyone have access to the Gerber files to get a batch made?

As of late the individuals responsable for reviving and tuning the B1 to the Radford preamp have been godsmacked by what their hearing.

Attched is the B1 with the upgraded Radford preamp (Radford is seen in bottom right shelf with thumbnail pictures of ongoing cap upgrades). The upside to this pair is vey impressive indeed!

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oh boy, you had to remind me about the time I got bitten by the B-1 virus :D
I like your preamp and will be lookin it up on the "Art of Sound". I am not surprised the crew that revived your B-1 was shocked by what they were hearing :)

You should look at the line stage of a C-1, with the B-1. Some think they were made for each other.

 
An absolutely amazing video on so many levels. C1 to B1 is the boldest vision of passion realized for the original designers and listeners of the day. Talking about stepping out of the sandbox, the C1/B1 was a moon shot, one of a kind pairing. Congrat's on sticking with the process of unvailing what is possable. What I see that others may not fully appreciate is the work and faith it takes to optimize one piece let alone two. Inspirational to see the two together in pristine condition. My B1 sat for seven years in protection shut down mode, I get the instrument of torture. I tip my hat, you have a high pain threshold and a ton of faith:)

Here's pictures of the repopulated B1 boards as they stand. If there's any info on building or buying new filter cap boards, that would be very helpful in completing the board restoration project and continuing with the tuning process. The updated Radford can no doubt deliver the soundstage that puts the B1 in the remarkable catagory but the C1, well ..... thats what keeps us moving forward one step at a time. Thanks for posting the video.

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An absolutely amazing video on so many levels. C1 to B1 is the boldest vision of passion realized for the original designers and listeners of the day. Talking about stepping out of the sandbox, the C1/B1 was a moon shot, one of a kind pairing. Congrat's on sticking with the process of unvailing what is possable. What I see that others may not fully appreciate is the work and faith it takes to optimize one piece let alone two. Inspirational to see the two together in pristine condition. My B1 sat for seven years in protection shut down mode, I get the instrument of torture. I tip my hat, you have a high pain threshold and a ton of faith:)

Here's pictures of the repopulated B1 boards as they stand. If there's any info on building or buying new filter cap boards, that would be very helpful in completing the board restoration project and continuing with the tuning process. The updated Radford can no doubt deliver the soundstage that puts the B1 in the remarkable catagory but the C1, well ..... thats what keeps us moving forward one step at a time. Thanks for posting the video.

View attachment 2784541
you spent some good coin on those silver mica caps, but we are talking about a B-1 after all :)
two observations:
  • please show the photos of the power supply and protection boards
  • I strongly suggest you replace all of those orange film caps. They have a high failure rate that can cause a stinky and smoky situation....

If there's any info on building or buying new filter cap boards, that would be very helpful in completing the board restoration project and continuing with the tuning process
This is a tough one. There is a way to fit good caps in the B-1 but it is not straight forward. It is challenging even for an experienced shop.
Here is a successful attempt but it is difficult and not sustainable:
index.php


you can read more in the B-1 Quickie thread here:
https://audiokarma.org/forums/index.php?threads/yamaha-b-1-quickie.800509/

Below is the right way of doing it but there is also a problem: Covid-19...and all the F*****G chaos it caused to the supply chain.
if you watched the video I shared the link for, right around minute 10 there is a hint to what I am inferring to. The B-1 you saw in that video is a very special mule B-1. Same unit here:
upload_2023-1-31_23-3-18.png
 
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you spent some good coin on those silver mica caps, but we are talking about a B-1 after all :)
two observations:
  • please show the photos of the power supply and protection boards
  • I strongly suggest you replace all of those orange film caps. They have a high failure rate that can cause a stinky and smoky situation....


This is a tough one. There is a way to fit good caps in the B-1 but it is not straight forward. It is challenging even for an experienced shop.
Here is a successful attempt but it is difficult and not sustainable:
index.php


you can read more in the B-1 Quickie thread here:
https://audiokarma.org/forums/index.php?threads/yamaha-b-1-quickie.800509/

Below is the right way of doing it but there is also a problem: Covid-19...and all the F*****G chaos it caused to the supply chain.
if you watched the video I shared the link for, right around minute 10 there is a hint to what I am inferring to. The B-1 you saw in that video is a very special mule B-1. Same unit here:
View attachment 2785385

I butchered my original post, after cleaning things up its reads as follows.

Nice parts were used by the two gents that took her on and brought back the B1 from it's curcuit inducted coma. One of them, who has been tuning the B1/Radford pairing, should be along shortly as I introduced your thread and the work you've done specifcally to your B1 PSU baord to him. The time and effort put into sharing your path with the B1 is really quite appreciated.

Unfortunately no pictures were taken of the Curcuit Protection board when being sorted. Every thing back of the PSU/Curcuit protection section was photo documented but no front of house photos.

Based on your Big Cap success I'm looking forward to having a crack as well. I have 4 Kemet's on order with my Tech who's interested in producing a run of 5 PSU boards that might be shared with other B1 owners.

If this has already been done or is in the works, I'd love to be in que for a board. If not, tracking down the PSU Board (Gerber files) is what's needed to get the process started.

As your the OP of both the B1 Quickie and the Torture thread's, I should ask before going off guns blazing: 1) Is having boards prints an appropriate appoach?
2) If so, which tread should be used for discution. 3) Should a new thread be opened
 
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A
Nice parts were used by the two gents that took on bring back the B1 from it's curcuit protection inducted coma. One of them, who has been tuning the B1/Radford pairing, should be along shortly as I introduced your thread and the work you have done specifcally to your B1 PSU baord. Your time and effort put into sharing your path with the B1 is a true gift to the vfet community and those interested in restoring, preseving and enjoying the B1.

Unfortunately no pictures of the Curcuit Protection board were taken when it was being sorted. Inspired by your success in replacing the big filter caps PSU/Curcuit protection section to document work done on the Curcuit board and address the filter caps.
I am thinking they probably used similarity good quality replacement components on the reset of the boards. Just wanted to make sure that a certain cap gets moved to the back of the board and that certain resistors get lifted off the board.

few moons and a few more B-1 have passed through since that B-1 quickie
 
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The parts selection and what to address is where experinace pays off without doubt. Speaking of parts, I picked up the B1/Radford last night to evaluate changes made to date. From there will be addressing the frontend Caps, PSU board and double checking the Curcuit Protection board for any remaining old parts. Ah..and get a few photo's of it all

I made quite a job of my last post and was forced to edit to make some of the questions more legable. I'd like to make sure I'm staying within the intent of your thread with the idea of producing 5 PSU boards that might be shared by those wanting to upgrade there filter caps.

Picking up the gear, I was blown away by the effort taken to clean up the exterior of the B1. Completely unexpected. I've posted two A/B pictures: 1) Before going to the tech to be tuned. 2) After being at the tuners. Remarkable what time can do to these units and what an effective clean can do. Similarly, your picture of the burnt-off cap leg, in the Quickies thread, shows the ravages of heat on the interior boards. Folks with original B1's, it's well healed advise to get thoses old parts out!

I will be getting big Kemet's Caps used in your Quickie thread, were you happy with the Quad or have other caps in that position performed better?

Should also mention the much improved depth and presence of emotion within the B1's sound stage, both connected to upgrades within the Radford, has been very rewarding. The B1 and Radford could easily be lifetime partners.... till a sultry C1 saunters by. I'm sure that unit has broken up a few good audio relationship!

Also attached two thumbnails of the Radford nearly completed. Waiting for attenuators to arrive replacing two balance pots, with that, it should be a wrap for the Radford rebuild.

These are good days in the vfet world.

PXL_20220307_030544635.jpg B1 Clean copy.jpg
 

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The parts selection and what to address is where experinace pays off without doubt. Speaking of parts, I picked up the B1/Radford last night to evaluate changes made to date. From there will be addressing the frontend Caps, PSU board and double checking the Curcuit Protection board for any remaining old parts. Ah..and get a few photo's of it all

I made quite a job of my last post and was forced to edit to make some of the questions more legible. I'd like to make sure I'm staying within the intent of your thread with the idea of producing 5 PSU boards that might be shared by those wanting to upgrade there filter caps.

Picking up the gear, I was blown away by the effort taken to clean up the exterior of the B1. Completely unexpected. I've posted two A/B pictures: 1) Before going to the tech to be tuned. 2) After being at the tuners. Remarkable what time can do to these units and what an effective clean can do. Similarly, your picture of the burnt-off cap leg, in the Quickies thread, shows the ravages of heat on the interior boards. Folks with original B1's, it's well healed advise to get those old parts out!

I will be getting big Kemet's Caps used in your Quickie thread, were you happy with the Quad or have other caps in that position performed better?

Should also mention the much improved depth and presence of emotion within the B1's sound stage, both connected to upgrades within the Radford, has been very rewarding. The B1 and Radford could easily be lifetime partners.... till a sultry C1 saunters by. I'm sure that unit has broken up a few good audio relationship!

Also attached two thumbnails of the Radford nearly completed. Waiting for attenuators to arrive replacing two balance pots, with that, it should be a wrap for the Radford rebuild.

These are good days in the vfet world.

View attachment 2787157 View attachment 2787211

That B-1 looks superb!

True, the C-1 line stage with the B-1 is difficult to beat and it is the only vfet amp and preamp pair ever made, BUT, there are other very good preamps out there that are excellent match for B-1.
The very nice thing about the B-1s is that with 100Kohm input impedance, they are a light load for most preamps and this is what makes them also a good match for passive preamps. Look into something like "The Truth" or other passive preamps.

I am intrigued with the Radford preamp as well. I would be very curious to learn more about it. Since this is a related thread, feel free to add any information you find relevant to share about your B1/Radford setup.

As far as the boards for the B-1 filter caps, this would not be the right time for me to build the boards... not until the parts I am using come back in stock. As I mentioned earlier, most suppliers are out of stock for good audio caps. Maybe other AKers will be interested to build other kit types.

If you want to use the 50mm Kemet caps, which are very good caps for this application, it will be a difficult preposition to get them in there, but they would work. Not easy though. If you end up doing it, Use just the lyrics and skip the polypropylene bypass caps you see in those photos.
Keep us updated on what you decide.

Also, I that record player is massive! What is it?
 
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That B-1 looks superb!

True, the C-1 line stage with the B-1 is difficult to beat and it is the only vfet amp and preamp pair ever made, BUT, there are other very good preamps out there that are excellent match for B-1.
The very nice thing about the B-1s is that with 100Kohm input impedance, they are a light load for most preamps and this is what makes them also a good match for passive preamps. Look into something like "The Truth" or other passive preamps.

I am intrigued with the Radford preamp as well. I would be very curious to learn more about it. Since this is a related thread, feel free to add any information you find relevant to share about your B1/Radford setup.

As far as the boards for the B-1 filter caps, this would not be the right time for me to build the boards... not until the parts I am using come back in stock. As I mentioned earlier, most suppliers are out of stock for good audio caps. Maybe other AKers will be interested to build other kit types.

If you want to use the 50mm Kemet caps, which are very good caps for this application, it will be a difficult preposition to get them in there, but they would work. Not easy though. If you end up doing it, Use just the lyrics and skip the polypropylene bypass caps you see in those photos.
Keep us updated on what you decide.

Also, I that record player is massive! What is it?

Good to know the B1/Radford pairing are on topic with the work being done to them and the Kemets are good caps. The Kemets have arrived for the B1 but without a path to a new PSU kit were going the route of modding the original PSU board and doing 'whatevers needed' to get the caps safely to fit, short of using a chain saw. Jason, who has been tuning the B1 and Radford, is up for giving it a go. If there's an AKer out there ready to put a kit together, I hope to hear from you, saving Jason a seat in the next anger management class.

Thanks for the Truth suggestion, shows there's some great mates for the B1. Personally most of the preamps I've used, before stumbling upon the Radford, kept the B1's sound repressed. The best of the bunch was the JVC JP-S7, origanally sold as the preamp mate to JVC's VFET offering. There's potential for the JP-S7 to be a very good preamp but requires a complete rebuild and thats not going to happen anytime soon with the performace I'm getting from the Radford.

The turntable is a Jean Nantais Lenco 75 in his custom 100lb plinth. The lenco really likes it when displayed next to large receicers and amps, get's it out of 'do these smaller receivers make me look heavy' complex! In truth it does require a large piece of equipemnt next to it or it looks very disproportionate on the display cabinet. It is however a very nice turntable.

Work on the PSU board and cap mounting should begin in the next week or so, all suggestions on how to make this project go as smooth as possable are welcomed.

Sure hope to avoid the torture part of this thread.
 
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Good to know the B1/Radford pairing are on topic with the work being done to them and the Kemets are good caps. The Kemets have arrived for the B1 but without a path to a new PSU kit were going the route of modding the original PSU board and doing 'whatevers needed' to get the caps safely to fit, short of using a chain saw. Jason, who has been tuning the B1 and Radford, is up for giving it a go. If there's an AKer out there ready to put a kit together, I hope to hear from you, saving Jason a seat in the next anger management class.

Thanks for the Truth suggestion, shows there's some great mates for the B1. Personally most of the preamps I've used, before stumbling upon the Radford, kept the B1's sound repressed. The best of the bunch was the JVC JP-S7, origanally sold as the preamp mate to JVC's VFET offering. There's potential for the JP-S7 to be a very good preamp but requires a complete rebuild and thats not going to happen anytime soon with the performace I'm getting from the Radford.

The turntable is a Jean Nantais Lenco 75 in his custom 100lb plinth. The lenco really likes it when displayed next to large receicers and amps, get's it out of 'do these smaller receivers make me look heavy' complex! In truth it does require a large piece of equipemnt next to it or it looks very disproportionate on the display cabinet. It is however a very nice turntable.

Work on the PSU board and cap mounting should begin in the next week or so, all suggestions on how to make this project go as smooth as possable are welcomed.

Sure hope to avoid the torture part of this thread.
Jeez, 100lbs, and I thought my record players were heavy

EE778084-7736-4CBF-8613-8126AFD9FBD7.jpeg

About the Kemet caps for the B-1:
All I can tell you is that there is not half of mm of room to spare. This is critical. Whatever you do, it is critical that you understand that the only thing between the life and death of your precious vfets is the skinny capacitors vinyl shielding of the caps, which isolates the lytic aluminum casing from the amp chassis. If those two get in contact and the vfets are inside the unit, KAPUT!
This is why I abandoned this solution. It is not sustainable for me. To optimal make use of the original space without other mods, the caps would need to be either skinnier or shorter. Unfortunately, no caps worth their salt are available with those dimensions.
 
Jeez, 100lbs, and I thought my record players were heavy

View attachment 2792869

About the Kemet caps for the B-1:
All I can tell you is that there is not half of mm of room to spare. This is critical. Whatever you do, it is critical that you understand that the only thing between the life and death of your precious vfets is the skinny capacitors vinyl shielding of the caps, which isolates the lytic aluminum casing from the amp chassis. If those two get in contact and the vfets are inside the unit, KAPUT!
This is why I abandoned this solution. It is not sustainable for me. To optimal make use of the original space without other mods, the caps would need to be either skinnier or shorter. Unfortunately, no caps worth their salt are available with those dimensions.

Your Yamaha Px-3 is absolutely lovely, I'm use to seeing lineer trackers in much smaller plinths. The larger mass plinth, formed dust cover and machined componates of the tracker makes the PX-3 a very ellegent partner for your B1.

I've got the Kemet caps for the B1 and two Attenuators for the Radford so the work begins, starting with the Radford first. The Attenuators are larger then expected so the pictures attached tell this story: 1) Oh joy, the Attenuators are finally here. 2) Oh no.. there not going to fit 3) whoo.. enlarging the hole works and they fit perfectly. 4) Looks good. Now just wiring and the Radford is completly rebuilt and tuned for the B1 (thanks to all who helped with the parts selection and install) .

Jason has started work on an acrylic spacer for the Kemet caps and hoping he has a few other tricks up his sleeve to insulate the caps from one another. Before starting, I let him know the risks you pasted about installing the larger Kemets. From my end, rightly or wrongly, it was my goal right from the beginning to rebuilt and modernize the B1 curcuit top to bottom to fully free its soundstage, so any negative outcomes are on me.

Should have pictures of the modified PSU board with installed caps in a week or so.

Its pins and needle time.

Rad Altenuator 1.jpeg Rad Altenuator 2.jpeg Rad Altenuator 3.jpeg Rad Altenuator 4.jpeg
 
Your Yamaha Px-3 is absolutely lovely, I'm use to seeing lineer trackers in much smaller plinths. The larger mass plinth, formed dust cover and machined componates of the tracker makes the PX-3 a very ellegent partner for your B1.

I've got the Kemet caps for the B1 and two Attenuators for the Radford so the work begins, starting with the Radford first. The Attenuators are larger then expected so the pictures attached tell this story: 1) Oh joy, the Attenuators are finally here. 2) Oh no.. there not going to fit 3) whoo.. enlarging the hole works and they fit perfectly. 4) Looks good. Now just wiring and the Radford is completly rebuilt and tuned for the B1 (thanks to all who helped with the parts selection and install) .

Jason has started work on an acrylic spacer for the Kemet caps and hoping he has a few other tricks up his sleeve to insulate the caps from one another. Before starting, I let him know the risks you pasted about installing the larger Kemets. From my end, rightly or wrongly, it was my goal right from the beginning to rebuilt and modernize the B1 curcuit top to bottom to fully free its soundstage, so any negative outcomes are on me.

Should have pictures of the modified PSU board with installed caps in a week or so.
Its pins and needle time.

View attachment 2803316 View attachment 2803317 View attachment 2803318 View attachment 2803319


No PX-3 here, just a PX-1 and the L-07D, both about 70lbs each, from factory.
The only thing the PX-3 has in common with the PX-1 is that they are black Yamaha badged TTs with linear tracking. The appearance is deceiving otherwise.
The PX-1 is a beast with a plinth carved out of aluminum and a linear tracking system that is in a league of its own, external power supply and likely the only serious Linear TT to come out of Japan. The PX-1 is likely of Micro Seiki DNA, where the rest of the PX TTs are Yamaha homebrew.

About the Kemet caps: there is little room at the top and to the sides. The problem is not to isolate the caps from one another, but the caps from the sharp ages of the cage. The entire capacitor assembly must be fitted so that the top cover fits over as well. Top cover on the inside is smaller than the bottom of the cage, so CAUTION there!!.

The Radfrord looks sweet and those pots look to be step attenuators rather than regular potentiometers. Top shelve product for sure.
 
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The 63mm Nichicon KG replacement assembly is the sustainable way to accomplish the B-1 filter caps replacement, with a sound mechanical fitment and excellent sonic performance. Unfortunately, the freaking lockdowns and related supply chain problems are still blocking any progress with scaling this setup.
I am almost tempted to redo another setup to allow for a few different mountings of 50mm caps , but I am a bit beyond with other projects… so the 50mm version would have to wait.


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No PX-3 here, just a PX-1 and the L-07D, both about 70lbs each, from factory.
The only thing the PX-3 has in common with the PX-1 is that they are black Yamaha badged TTs with linear tracking. The appearance is deceiving otherwise.
The PX-1 is a beast with a plinth carved out of aluminum and a linear tracking system that is in a league of its own, external power supply and likely the only serious Linear TT to come out of Japan. The PX-1 is likely of Micro Seiki DNA, where the rest of the PX TTs are Yamaha homebrew.

About the Kemet caps: there is little room at the top and to the sides. The problem is not to isolate the caps from one another, but the caps from the sharp ages of the cage. The entire capacitor assembly must be fitted so that the top cover fits over as well. Top cover on the inside is smaller than the bottom of the cage, so CAUTION there!!.

The Radfrord looks sweet and those pots look to be step attenuators rather than regular potentiometers. Top shelve product for sure.


Thank you, very happy with the way the Radford turned out and its performance. You now have me looking at the Truth Pre amp for my Sony 5650, the truths signal path is so liberated.

The mistaken identity of your PX-1 is now understandable with the addition of your silver-faced B1 UC-1 and the C1 pictures. The PX-1 and silver-faced C-1 are so rare they don't immediately come to mind. My brain fired Yamaha CA-1010 when first looking at the silver C-1 picture, I would have stayed locked in 'mistaken identity mode' if I hadn't seen the C-1 identifier on your unit. This thread is not about the common!

The 63mm Nichicon KG is a helpful spatial reference to the 50mm board were pursuing. Thank you for getting my eyes in the right place to understand where the danger lies. We were focused on the bottom adapter plate, not the top cage fitting. I will pass this information to Jason while he's mulling over the Kemet installation and final fitting. Also good to have confirmation there is a sonic reward for the effort taken to correctly replace the filter caps.

With the B-1s that have passed through your listening room and a Sony TA-N7B or two in the house, does a Vfet currently hold a spot in your main system?
 
Completed the assessment, the Kemets are in and fine tuning the B-1. Very good things are a foot with the B-1/Radford pair.

Researched the Kemets as a filter Cap and came back with some very interesting information that changed the way we finalized the install.

A day or two of testing to confirm stability then will provide follow up impressions and pictures. It ended up being something of an upside down cake approach:)
 
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