Yamaha B2-S5151 Diode replacement with FRED's

[Yamaha B-2]

OK.....Everything is on order, so am making progress. Here is what I should have by the end of the week.

2 pairs for the speakers: http://www.diycable.com/main/product_info.php?cPath=26_44_49&products_id=397
2 for the back of the B-2: http://www.diycable.com/main/product_info.php?cPath=26_44_49&products_id=399
8 for the speaker cable ends: http://www.diycable.com/main/product_info.php?cPath=26_44_48&products_id=218
2 of these for the B-2 inputs: http://www.diycable.com/main/product_info.php?products_id=406

If you wish to stay with two speaker outputs on your B-2, then you would need two pair of the second item, above. But I only want to drive one pair at any one time.

Only thing left to source is some silver signal wire for the new runs inside the amp. Want the input and output side to be silver. Anyone got a recommended source for same?

 

[nbourbaki]

YB2 have you ordered the plastic blocks yet? Have you figured out the cost of those machined blocks for the CPBP-CRS binding posts?

 

[Yamaha B-2]

Not yet. Have to toss the B-2 up on the bench (not an easy task) to make the measurements. OK, OK.....I'll do it shortly. Probably take a few days to get a response.

 

[nbourbaki]

No worries, take your time. BTW the last time I ordered from DIYCable this is what the recycled box looked like when it arrived :thumbsdn:

 

[Yamaha B-2]

That's pretty sad. Hopefully, you complained and they do better now. Guess I'll see in a few days.

Anyway. After pulling open the back panel and checking everything out, I think I will simply use the blank panel to the right of the existing speaker terminals. Cardas was kind enough to fax me the drawing of the binding posts I ordered. I will simply send the drawing of binding posts and blank panel to the fabricator and ask that he quote for me. I will order three for my use and will also order three blank panels to cover the holes where the old terminals were mounted. More later.

 

[endeeinn]

blank panel

If you are going to use the blank panel to the right of the stock speaker terminals there is no need to order anything special. I used a standard non-metalic double duplex electrical box blank cover that you can get anywhere for less than a dollar. Use the Yamaha cover as a template and trim to the same size and drill mounting holes. It should now be a non-metalic duplicate of the Yamaha plate which you can drill for your custom speaker terminals. I used that spot to mount a fan, however, your idea of using it to mount the terminals is a good one.

I've looked at those cardas terminals in the past and they look pretty good. Could you post or send me the cardas drawing with dimensions?

 

[Yamaha B-2]

Well......I'm looking for something 'professionally' finished. By the time I run to the store to get the part, scribe the needed marks to insure that it square and holes are on the correrct bolt-circle, drill and then break the edges, etc., I'll have at least three hours in it. At my professional rate, I could buy another B-2. So am happy to have someone else do it. Unless, of course, he thinks it is worth more than I am willing to pay. Then I'll resort to doing it myself. Will be using 1/4" black plastic if all goes well.

Drawing for the two parts is in the fabricator's hands, so should know something before too much longer.

Also ordered four different colors of 20ga silver coated OFHC copper wire to do the rewire of the B-2 with. Think that is the last item other than the mounting blocks.

 

[Yamaha B-2]

OK....here's the scoop. Black plastic is not available for what I have designed. Simply too expensive in the 1/4" thickness. So will be clear acrylic. The two pieces are $20. That would be $20/amp. If anyone else wants them, make it $25 for the two pieces and USPS Priority shipping in the lower 48. Please let me know by the end of the week as I want to get them ordered.

My parts from DIY Cable arrived today in good shape. Good box and good packing no complaints and their prices for Cardas are the best I've found.

Getting close to a 'go' on this.

 

[nbourbaki]

I'm in for two sets for two B-2s. Glenn send me payment details and I'll send you the money.

 

[Yamaha B-2]

Am ordering one set of these as a prototype and then will order the balance. Delivery on the prototypes is about two weeks, so that puts the final parts out about 4-5 weeks.

 

[Yamaha B-2]

Prototypes are on order.

Ordered the 12ga power cables from Zebra Cables in a 5' length. Scott of Zebra seems to be a nice person to deal with. So parts are a-gathering. Figure about another 4-6 weeks to get all the items in-hand so can do the work.

 

[nbourbaki]

Cool, I picked up my second Yamaha B-2 today in Dayton. I just spent the last hour listening to my new amp. It's very close to the mint one I got from dnewma04. Same fantastic sound!

 

[Yamaha B-2]

Congrats. Can't have too much of a great thing.

Next step in the chain arrived today. New 12ga power cord from Zebra.

Prototypes of the speaker terminal mounts should be finished the end of this week or next. Will see how they fit and make any mod's needed and then order our production run.

 

[buddha_beats]

"I'm all for sensible modifications, but the B-2 is a rather special piece"

Greetings & salutations fellow YB-2 brothers....wow, I must say you guys are hardcore YB-2 enthusiasts, I have read the entire thread and I must say that I am duly impressed, and I am also pleasantly surprised, I had no idea that something I already owned (a YB-2 of my very own), for close to 10 years was something so esteemed and “rather special” it gives me a new sense of reverence for my YB-2, thanks for that.

The idea of breathing some new life into my YB-2 and making it even better than it is… is very tempting indeed. Although attempting an upgrade or a mod myself is a just a tad out of my league (me thinks), I am very curious and will be watching to see how all these projects turn out in the end - and in the final analysis if there is in your expert opinion(s), any marked improvement in sound quality of your newly revamped amps, which is to a large degree the whole point of the exercise.

 

[Yamaha B-2]

Hi Mark - Welcome to AK! I'll bet yours is the only used record shop in the entire world that has a VFET amp supplying the music. We have quite a few folks from the Toronto area on AK. You should list your shop address with your rig and see if anyone drops by. To admire your B-2, if nothing else.

 

[buddha_beats]

Thanks Glenn - you may be right, I’m guessing that these amps [circa ’75 to ‘80] were manufactured somewhere in Japan so there may be more than a couple of sushi shops using a VFET B-2 in ol’ Edo tho…

 

[buddha_beats]

heh heh…..cool….this is like a secret society for B-2 brethren….

Admittedly I am a B-2 neophyte of sorts [the hidden inner workings of..], and I wonder if anyone would be so kind to enlighten me and briefly summarize and (or), recap the merits of this rather special piece of gear. Instead of me having to search through a 1001 older threads to glean the info in fragments…? And what the frick is a VFET anyways...?

 

[Yamaha B-2]

Do a search in this forum on VFET and read. Is a different type of FET that was to expensive to make to last long. Audio market is simply too small to support a particular technology on its own, unless is mass-market end of things (such as the CD). Audio, unfortunately, is a scavenger. We are almost always forced to use technology adapted from other uses.

 

[Yamaha B-2]

Received the prototypes this morning and am glad I did. They are excellent workmanship, but I need to move some of the holes on the 'real thing', so will be a day or two for me accomplish that and then a couple of additiona weeks more turn-around. Remember.........patience is a virtue. :yes:

 

[buddha_beats]

nudies of my YB2...

....finally got around to pulling her out and doing a little spring clean up / dust off, here you go Glenn ....as promised...