My newly acquired Yamaha B-50 (M-50 US)

avionic said:
4-pin snap-in ?

https://www.mouser.com/c/passive-components/capacitors/aluminum-electrolytic-capacitors/aluminum-electrolytic-capacitors-snap-in/?capacitance=10000 uF&number of pins=4 Pin&voltage rating dc=63 VDC&instock=y
Click to expand...

Hmmm … looking at them I can’t tell how many pins, looking at the soldering side of the electrolytic cap board, I see only two soldered pins about 23mm apart. Could it be a 4-pin with two pins snipped off? These have Nichicon Blank printed on them …
 
images
Those Kemets have a 22.5mm LS

Double check width and height of the Kemet's versus the OEM caps. If they will physically fit. Then just snip off the un-needed pins.
 
Last edited:
avionic said:
images
Those Kemets have a 22.5mm LS

Double check width and height of the Kemet's versus the OEM caps. If they will physically fit. Then just snip off the un-needed pins.
Click to expand...

Thanks for providing the info. Yes, the 4-pin ones do … maybe these Nichicons are 4-pin caps with 2 leads snipped off. I guess I’ll know when I remove one. I’ll post an image for everyone’s benefit.
 
avionic said:
images
Those Kemets have a 22.5mm LS

Double check width and height of the Kemet's versus the OEM caps. If they will physically fit. Then just snip off the un-needed pins.
Click to expand...

Thanks … I did, size-wise they fit fine, almost the same. At this point I’m more worried about the eventual sound quality using different parts. I guess I’m trying to find some comparable caps from Nichicon and replace all the big electrolytics from the same series. The original ones are Nichicon OEMs.

Also, after changing the relays a few days ago, I noticed an ever so slight loss of high frequencies which are so dear to my heart. Tried to ignore it but couldn’t. So I opened the old DECs and cleaned them out as best as I could as put them back in using (sorry) the relay sockets. Had no other choice, I didn’t want to repeatedly solder in and out Omrons and DECs for comparison. The result, DECs have a better high frequency rendition (no veiled sound), so they stay in. Changing part after part has a cumulative effect on sound quality, I’m trying to not to veer too much from the original … well, the original after 40 years. Got a bit longer than intended …
 
avionic said:
Bull ****..
Click to expand...

Fine, I can only go by what I hear. The same thing happened with my Sansui au-a607dr three weeks ago. After years I changed the relays and noticed the same thing … maybe it’s a new relay thing which needs aging, I don’t know, but it is what it is. I had read about this in a couple of Japanese blogs also but didn’t think much of it.
 
Sparkplug said:
At this point I’m more worried about the eventual sound quality using different parts.
Click to expand...
Sparkplug said:
I’m trying to find some comparable caps from Nichicon and replace all the big electrolytics from the same series. The original ones are Nichicon OEMs.
Click to expand...
Good luck.... creative modifications may be required. Large Nichicons "snap-ins" are 10mm LS .. Solder lugs @ 63v are 25mm LS
These are 25mm LS solder lugs... You will need to do a little fabricating

https://www.partsconnexion.com/NICHICON-73634.html
 
Thanks. Once I take out one of the giant caps, I’ll take it with to the electric town in Tokyo and try to find a nice match.

On a separate note, since yesterday I’ve noticed a small imbalance between L-ch and R-ch with R-ch being slightly quieter. I went through all the transistors one by one and they all checked out. I think I’ll take the relay sockets out and leave them out. Also, when turning the Amp over carefully, at the last moment, the right side slipped out of my hand and fell about a few inches hitting the table but not very hard. I wonder if that did something. Any ideas? Thanks again.
 
Sparkplug said:
On a separate note, since yesterday I’ve noticed a small imbalance between L-ch and R-ch with R-ch being slightly quieter
Click to expand...
Pre-amp issue most likely -- Clean the input level attenuators and /or speaker select switches.
Or..... :rolleyes: Your DEC relay.
 
avionic said:
Pre-amp issue most likely -- Clean the input level attenuators and /or speaker select switches.
Or..... :rolleyes: Your DEC relay.
Click to expand...

Cleaned the attenuators and the select switches with contact cleaner. The attenuators are good but my switches have issues I guess that particularly affect the R-ch, I hear scratches out of the R-ch only when I change selection from Speaker A to B … are their any equivalent or similar replacements for these? Thanks …
 
Off hand I can't think of any. Probably find something at Mouser . But will take a while to search. I usually disassemble the switches and clean the contacts.
 
avionic said:
Should be able to find something in Tokyo..
Click to expand...
Thanks … already looking, you can find anything here in the back alleys of the Electric town (Akihabara). Might take it apart myself if worse come worse. Asked just in case there was something already …
 
Hey Sparky, on a side note while you're in Japans electronic back alleys ;) see if you can hunt down a Yamaha A-3 integrated amps manual or service manual or schematic . Been looking for one for few years. it was a Japan only model.

Ok carry on, enjoying this thread.
 
No problem, I’ll keep an out out. It’ll be all in Japanese though, I’m assuming that’s okay with you? Also I’ve never seen service manuals or schematics on sale here, just instruction manuals from time to time.

Thanks for reading.
 
avionic said:
Pre-amp issue most likely …
Or..... :rolleyes: Your DEC relay.
Click to expand...

The darn speaker terminals were the culprits, re-soldered them to the board and that was that … L/R imbalance gone, funny thing they looked solid to begin with.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom