Yamaha SF series

Well well, I am becoming quite the forum spammer lately

Just wondering if anyone has any experience with the yamaha sf series. I gather they were made in Japan during the 70s 80s and that they have become very hard to find. That's all I know. They look nice too!

Good looking geetar. Looks a lot like the Takamine GX-200! Wonder if the same Japanese plant grew these?

Wow Chad, never knew takamine made electrics. Looks alot like these yam' SFs though, maybe same factory.

I must say the takamine's look a little tacky (gosh, that was an easy pun), but I am surely mistaken.

Ok, well what do you know... Some might have seen it coming, but here it is anyway, my new old MIJ Yamaha:





Wouldn't have minded paying a tiny bit less, but it was fair enough. The sad part is I managed to blow the bridge volume pot by trying to pull the plastic knob off, the whole shaft came out... So I now have to guitars with bridge pup problems (this and my dim IV). I am just so stupid sometimes (too often lately).
As you can see, the electronics are ultra neat. The only problem is that it's going to be a real killer to replace the selector switch for instance. The guitar does quite a bit of feedback, even without the coil split. Guess I will try to add a strype of aluminium foil when I replace the vol pot.
Another slightly disappointing thing is the wood you see is actually just a surface layer, sort of a decoration layer.
The scale is somewhate shorter than a 25.5, reaching only 630mm, which is a nice alternative. The neck feels good, though I tend to like the jumbo frets better. The pups (that is the neck, and the bridge before I blew the pot) are ok, low output humbuckers with slightly too much treble and undefined lows and mids (with the same eq and sansamp settings I use for the rest of my guitars). The guitar is very light, as if it were made out of plywood, but it looks like it's made out of real wood.

All in all, a nice looking, sweet playing instrument, easy to handle, great looking electronics but would have liked some warmer pickups with bigger balls in the lows and mids. Will willingly try to upload audio samples if anyone is interested (though you might want to wait til I fix the bridge vol pot).

Lovely looking guitar even if the top is a veneer.
I prefer to coat the cavity with silver loaded paint if taking apart rather than foil.

This sort of stuff, wont change your feedback tho
silver paint

Cool, but isn't that black paint in the cavity supposed to be conductive stuff already?

Oh, and veneer is the word

The black paint is already conductive and serves to boost the ground potential.
The foil shielding further boosts that potential and traps stray signals which can get into the signal chain and be amplified as noise or hum. The most effective material to use is copper, but it can be pricy. Aluminum foil is an OK alternative, and easier on the pocket book!

If you are going to use foil you'd best take time and make sure that you do it correctly (might take some soldering of edges for example). In order to be completely effective the conductive layers need to be in solid contact with each other or the continuity will be compromised.

Copper/silver paint is a good alternative is if soldering is not your thing. That makes it easy to cover everything and keep it it electrically sound, which is why the black paint is there in the first place.

Thanks for the very clear info Barry.

But why does the whole cavity have to be shielded? If I remember my science class correctly (ahem), it should suffice to have only one pot linked to the cavity shielding as all the pots are electrically interconnected? Hence the presence of only a simple aluminium foil stripe in my dim IV I guess.

beavis wrote:Wow Chad, never knew takamine made electrics. Looks alot like these yam' SFs though, maybe same factory.

I must say the takamine's look a little tacky (gosh, that was an easy pun), but I am surely mistaken.

A buddy of mine has a Takamine electric which is made of Koa wood and he said there were only 500 made, awesome guitar!

beavis wrote:But why does the whole cavity have to be shielded?...

As I said, it increases the ground potential which should help reduce any persistent hum. No guarantee though, and as Grogg said, it likely won't affect any feedback issues you might have.

Barry wrote:

beavis wrote:But why does the whole cavity have to be shielded?...

As I said, it increases the ground potential which should help reduce any persistent hum. No guarantee though, and as Grogg said, it likely won't affect any feedback issues you might have.

Ok, might give it a try, might not, we'll see. I am just a bit surprised that the humbuckers produce some (very slight though) amount of hum, but the electronics do look properly done on this yamaha and I doubt any contribution of my own making would improve anything.

A buddy of mine has a Takamine electric which is made of Koa wood and he said there were only 500 made, awesome guitar!

If it's anywhere near the quality of their old accoustics, must be a killer.

You'll never get rid of hum entirely, it's just a matter of how noticeable it is. A humbucker doesn't eliminate hum it just, um, bucks it. Wax potting helps quiet things down considerably too.

Oh, and don't stand directly in front of the amp!

Barry wrote:Oh, and don't stand directly in from of the amp!

Gosh, have I made that bad an impression on this forum?
Rest assured Barry, I will not stand right in front of the amp and complain about hum .

Hadn't thought about the potting of the humbuckers though. Might indeed be the cause.

Didn't mean to be condescending beavis, but you'd be surprised how many times I hear guys (young fellers mostly) in the shop complain about 'hum' or other noise, only to determine that they've been standing directly in front of their amp---even in the store! Or worse yet they whine about the noise from the Gibson or Fender that they're playing, only to be told they're playing a P90 or a single coil pup model! Education talk ensues.

Just kidding But the hum and amp-facing thing is an easy mistake. Jolly oh, I'm a senior member! What do you know Tokyo!

beavis wrote:But why does the whole cavity have to be shielded?

It doesnt but the issue for me is eliminating as much interference as possible. The more shielding the better.

beavis wrote:
If I remember my science class correctly (ahem), it should suffice to have only one pot linked to the cavity shielding as all the pots are electrically interconnected?

Thats true

beavis wrote: Hence the presence of only a simple aluminium foil stripe in my dim IV I guess.

They put this stuff where they absolutely have to. If you want to eliminate interference (radio, mobiles etc.) as much as possible you need what is called a Faraday cage. All wiring inside your guitar acts as an aerial (antenna) and will pick up radio frequencies, these can be significant given the low level signals from your pups. To create a Faraday cage, albeit imperfect, you need a shield around where all the wiring is hence a grounded conductive coating or use screened wires throughout (like your lead to the amplifier).
If you look at your microwave oven this will have a very effective Faraday cage to stop the rf getting out rather than in as for a guitar.

Hum is a bit different, this is caused by mains interference and is usually an earth imbalance. Your body is good at picking this stuff up e.g. standing in front of the amplifier or even worse an old fluorescent light and in turn coupling this to the pickups. Humbuckers were designed to try and eliminate this because they have 2 windings in opposite phase thereby each cancelling out the hum, coupling and coil imperfections doesnt make this system perfect though.

Tried to explain this in a few words and not sure Ive succeeded, anyway the gist is more shielding and good electrical grounding is good. I think silver loaded paint is better than most things in a guitar cavity, certainly a lot better than the black stuff.

PS a long time ago I rewired my old bass using screened cable throughout, fiddly but did it, in the studio the recording engineer remarked it was the quietest bass he had ever recorded (noise that is not my playing).

Thanks Professor Grogg for that intelligent explanation.

Wow, yes, thank you very much, this is priceless! And the Faraday cage does ring a bell (something about cars and lightning I think) .

Were I a more enterprising fellow, I would try rewiring with screened cable, but I have yet to learn how to solder, so first things first.

It's already got screened cable on the pups and coil tap(not coil split) wires

Oh, cool!

I wouldnt bother with the screened wires, might make your guitar bomb proof but then theres always the next weakest link. The other thing to think about while Im being a prof is wire length, all wires are dipole antennas, the longer they are the more interference they will pick up hence why your guitar lead has to be screened whereas the short stuff inside the guit doesnt have to be.

Heres a pic of what I did in my Thunder 1A bass.



Strange this thread cos last night a mate was round and we had a footle but only have 1 chair in my small study and I started getting loads of hum, flicked my T1 from single to humbucker problem solved, I was inches from the valve amp!

PS Damian I meant all the other wires.

[quote="grogg Damian I meant all the other wires.[/quote]

I know that but does beavis? with his admitted knowledge.

Whats that grogg paint or foil?

Grogg

I have read and tried to understand your Faraday thingy and I have come to the conclusion that you are either very clever or completely mental.

I am a fair minded individual and will watch your posts closely before finally making up my mind.

It could be, of course, that I am too stupid to remember O level Physics, but I will not let that interfere with my decision.

Hoax

PML*

*Peeing Meself Laffing

Westbone wrote:
I know that but does beavis? with his admitted knowledge.

Nicely put!

Prof. Grogg, thanks ever so much for the explanations and pics!

hoax wrote:
Grogg

I have read and tried to understand your Faraday thingy and I have come to the conclusion that you are either very clever or completely mental.

I am a fair minded individual and will watch your posts closely before finally making up my mind.

It could be, of course, that I am too stupid to remember O level Physics, but I will not let that interfere with my decision.

Hoax

Could be all of those, ie I am very clever and completely mental, you are fair minded and stupid. These things are not mutually exclusive.

Westbone wrote:

Whats that grogg paint or foil?

Conductive paint, silver loaded, much easier than foil, probably more effective, much more expensive.

OK Grogg

I'll swap you a stupid for a clever and I'll throw in a nice as a deal clincher.

Are you up for it?

Hoax

So that makes me nice, stupid and mental. You clever and fair minded. No.

Ill swap you a stupid for a fair minded and throw in a funny.

OK Grogg - I'll settle for that!

Hoax

Ok final score is evens:-
While the nice Mr Grogg was being fair minded with the guitars he was offering all he saw was the prices of the Westones he desired going mental. Meanwhile the clever Hoax thought there was some funny goings on that resulted in a stupid faux pas.

grogg wrote:Ok final score is evens:-
While the nice Mr Grogg was being fair minded with the guitars he was offering all he saw was the prices of the Westones he desired going mental. Meanwhile the clever Hoax thought there was some funny goings on that resulted in a stupid faux pas.

Okay, my head is now officially spinning.

Clockwise of course being that I'm on the correct side of the equator.

I'm so confused.

https://youtu.be/qKhit2nsoq4

gittarasaurus wrote:https://youtu.be/qKhit2nsoq4

This thread gets more and more confusing!

Think we should send this to the Yamaha Forums.... That'll fook 'em up. What the hell!!!

The Chad wrote: This thread gets more and more confusing!

your confused Chad, you want to come in at the end & back read it

I blame it all on Beavis buying the axe in the first place.

For those that don't understand Faraday's law this is for you though I bet you don't watch it to the end

https://www.youtube.com/watch?v=2OdlVM2sCWU

fish wrote:

For those that don't understand Faraday's law this is for you though I bet you don't watch it to the end

https://www.youtube.com/watch?v=2OdlVM2sCWU

PMP thats brilliant, nice one Fish, tears there are tears.
Happy journey
Go and do best

It isn't that it's crushingly boring....just that it's so s-l-o-o-o-w...

(OK, it was the first thing I said)

Yup Barry

It is so crushingly boring that I am not having any Faradays on any of my axes. Grogg can keep his and have all of mine if he likes.

Hoax

I never roam far without my Faraday sheild, just in case of lightning.

I reckon this is about as off topic you can get, fellas......

corsair wrote:I reckon this is about as off topic you can get, fellas......

... you doubtin' me?? Don't tempt me.

corsair wrote:I reckon this is about as off topic you can get, fellas......

If you understand what grogg was on about in the first place it's not that far off topic. No :idea:

corsair wrote:I reckon this is about as off topic you can get, fellas......

What? You don't think that discussions about knights in gleaming Faraday cages have their place on a westone forum??

Wait and see what happens when someone buys a suzuki guitar!

Westbone wrote:I never roam far without my Faraday sheild, just in case of lightning.

Ah man. Yes, very good for understanding electronics. Or something.

hoax wrote:Yup Barry

It is so crushingly boring that I am not having any Faradays on any of my axes. Grogg can keep his and have all of mine if he likes.

Hoax

Hoax, Ill take you up on that kind offer.
Damian, love the chain ground.
Fish, that youtube link is so funny because its off topic - Faradays law of electrolysis is a different thing.

Off-topic.... on-topic.... a Festivus for the rest of us.... whatever.


Just keep that avatar a'coming, Beav...










**pun intended**