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Yamaha preamp out of retirement

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Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 4:28 pm
by shufflebeat
I'm just beginning to discover the joys of JST PCB connectors in an attempt to revive an old Yamaha system 49 onboard preamp with gooseneck mic which has been hanging prettily off the side of my mandola without being connected.

I'm considering fitting a K&K twinspot and sending it through the preamp just because it's there and otherwise I'll have a sizeable hole in the instrument.

I can't find any kind of docs for this box so I am seeking wisdom.

Questions:

¹) Connectors look like JST XH but there are a lot of similar looking conns, any ideas?
2) There are two unconnected at the minute (2 pin, 3 pin). Is it safe to assume the 2 pin is p/u in and 3 pin is jack out with battery switching?
3) I don't have the Latin to judge whether the output of the K&K will be suitable for the preamp or v/v. Anyone like to make an educated guess on this?

I'll probably fit the K&K passive for now but it seems such a waste.

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 4:41 pm
by Sam Spoons
Can't help with the tech stuff but I have found the Tone Dexter works best with passive pickups. At least it works best with my Gypsy Jazz guitar (which has a passive BigTone) and my mandolin (fitted with a passive Fishman bridge). It doesn't work as well with the other guitars which have B-Band UST and preamp or active Fishman Rare Earth sound hole pickups.

That may be because I just haven't got the 'training' right yet though.

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 4:50 pm
by Wonks
Not sure about the preamp. The original saddle transducer used with the system 49 was a B-Band, which isn't a piezo system but was described as a capacitive system, 'like a microphone'. So it's probably providing some voltage and probably doesn't have a high input impedance. B-Band no longer exist, though you may be lucky and find some NOS transducers. I found one for a friend about 18 months ago, but there weren't many left even then.

I'd try and find a replacement pre-amp that fits the hole (or is slightly bigger so the hole can be enlarged to fit) .

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 4:53 pm
by shufflebeat
Cheers Sam.

I feel pretty confident I can get something useful out of a passive installation but I'd like to harness the preamp if possible.

I can even imagine getting the p/a working and then bypassing it anyway. Crazy world.

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 4:56 pm
by shufflebeat
Wonks wrote:Not sure about the preamp. The original saddle transducer used with the system 49 was a B-Band, which isn't a piezo system but was described as a capacitive system, 'like a microphone'.

That's interesting, I had noticed the B-Band connection in discussions but hadn't appreciated the finer details.

Looks like the passive option is looking more favourable, maybe I'll just slap a bit of plasterboard over the hole.

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 5:01 pm
by shufflebeat
Sam Spoons wrote:That may be because I just haven't got the 'training' right yet though.

Aside - I've updated the f/w recently to access the bigger, better, faster training but keep coming back to my old wavemap done with an sm57 (I have others available) and the soundhole plug fitted.

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 5:06 pm
by Sam Spoons
A bit of cement render on top an it'll be like new ;)

I was wondering about having a plate for a passive volume 3D printed to replace the B-Band in the Emerald something with a recess for a conventional pot which leaves 4-5mm of the knob protruding. They stick up too far in that position otherwise and both look and feel ungainly. Problem is what value pot to not mess too much with the piezo's impedance and the preamp. I recently bought some Fishman style flexible piezo USTs to convert some guitars to, hopefully, work better with the TD. About £3 to you if you need one Mr Beat.

Might try the new FW. Wouldn't it be nice if you there was an app to allow you to fine tune the wavemaps so you could switch instruments without having to adjust the gain, tone and output settings.

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 5:16 pm
by shufflebeat
Sam Spoons wrote:Might try the new FW. Wouldn't it be nice if you there was an app to allow you to fine tune the wavemaps so you could switch instruments without having to adjust the gain, tone and output settings.

I've just been experimenting with that in Reaper with modest but encouraging results.

Thanks for that offer, Sam, keep.me posted on your results.

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 5:31 pm
by Sam Spoons
Will do, I've just emailed Audio Sprockets asking about the possibility of tweaking TD Wavemaps. They mention doing this when they made their Yamaha Silent guitar and electric guitar wavemaps. The former might be useful for the likes of my Emerald so I'll download them later (hmmm wonder if the nylon one would improve my mates electro classical........).

And now I'm thinking I need a piezo bridges for my assorted electrics....... This could get expensive :blush:

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 5:58 pm
by shufflebeat
Sam Spoons wrote:And now I'm thinking I need a piezo bridges for my assorted electrics.......

...or possible some piezo discs on the body at the bridge? I remember having a play with this (SG copy) when my double bass playing buddy stuck some £0.10 buzzers on his Big Friend which sounded great.

We were 20yrs ahead of the game, idiots!

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 6:16 pm
by Sam Spoons
That's all the super expensive K&K pickups are, these guys do something pretty much identical for about ⅓ the price. http://jjb-electronics.com/prestige-220.html

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 6:30 pm
by Wonks
Wrong link, I think. (link now edited)

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 6:36 pm
by Sam Spoons
Very nice though. Anyway, edited, that one should be better

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 6:42 pm
by Wonks
Available in the UK or do you have to get them from the US?

Re: Yamaha preamp out of retirement

PostPosted: Fri Jan 10, 2020 7:00 pm
by Sam Spoons
I think I bought it from the US, pretty sure they were cheaper still too. I've never got around to using it but will try it in one of my guitars at some point.