clinic-audio
all on YAMAHA untill 1990
I will clean them one by one but not by pass them
I think he meant keep the tone controls off.I will clean them one by one but not by pass them
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.This kit does also exist :
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used with high quality capacitors it is perfect
you spent some good coin on those silver mica caps, but we are talking about a B-1 after allAn 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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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.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
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:
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:
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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.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.
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.
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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?
Jeez, 100lbs, and I thought my record players were heavyGood 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
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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.
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sure, that would work too, but I think this is the match for the silver UC-1:
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.