I am going to get a JEM7Vwh at Christmas and I want to put a Fernandes Sustainer in it. To do this, of course, you must remove one of the DiMarzio Evos and I was worried that it would effect the tone and general sound a lot... I guess my question is; will it?

Well, one evo less. I'd be more worried about routing the cavity for the sustainer:
http://theguitarfix.com/db1/00037/th...1570MRR003.jpg

You should first consider if you really need a Sustainer. Just to play some cheap Vai tricks? Most of them can be done without a Sustainer

- If you never did this before, it is very likely you will ruin your guitar.
- If you have it professionally done it will cost...

Will it influence sound: YES

Well I wont be doing this. I know my guitars but I dont know the first thing about tech stuff. I can just about change the strings on my JS lol.

I will be getting the guy at my local guitar store to do it. He fitted my new trem for free and doesn't often cost much for labour (its only a small shop, I guess he doesnt have much else to do).

Does it influence the sound/tonality for good or does it make it sound bad. I suppose with two other EVOs in there it would still be fine...

Does Vai's FLO sound bad to you? How about MOJO?

Personally, I wouldn't let any "guy at my local guitar store" have a shot at hacking a sustainer into one of my guitars. Good luck with that.

YoungGuitarist, there are a couple of great threads on in this forum that have pictures of successful fsk installs. I followed one and the results turned out great. It does take alot of patience and a steady hand with a router though, so I'd probably at least ask your tech if he/she has ever performed major surgery with a 2.5" router bit before. As for the sound, it will affected as all of your pickups will pass through the circuitry whether it is activated or not. You could also consider picking up a 560 or 570 and spare your 7v the chance of being hurt.

That being said, if your looking for a unique sustaining/harmonic effect for a particular piece, a sustainer can provide an effect that cannot be emulated through electronic effects alone. I wouldn't go through with it if your just looking to play "Building a Church" but the effect can be backed down somewhat to emphasize harmonics as well. Anyone noticed that Vai plays "For the Love of God" on Flo now?

Yeah Vai does play FtLoG on Flo now, I saw the video of him in Holland with an orchestra, which was pretty amazing if you ask me

The guy at my local guitar store is a proper tech guy who deals guitars on the side. Basically, its a small guitar shop on the side of his operation theatre Of course, I will ask him if he has ever installed one before because the chances are that he has installed quite a few fsks in his own guitars.

As for why I want it: I have been lacking sustain which may be a result of my crappy marshall cab (which I am now replacing with a 5150 4x12) but Im confused because usually Laneys have awesome sustain. I saw Steve Vai using a fs, obviously and I thought it was a brilliant idea. It would sort my sustain problems out and enable me to play anything I like (with the practice, of course ).

Thanks for the advice though

The sustain issue could very well be a problem with ur guitar's setup more than a problem with the amp or cab. I'd go through the ibanezrules setup before buying new amps/cabs.

Cheers
Themi

Also the Fernandes sustainer has a pretty crap standard pickup, where as the Stealth Sustainiac has a configurable active gain boost so you can match the pickups output when the sustainer is off to your other pickups something I found very useful and the Sustainiac has non of the "odd noises" the Fernandes one can produce when switching modes and the sound fades out when you switch the unit off. The early Fernandes ones simply cut off which is rubbish!

Anyway, good luck an remember there is more than one good sustainer out there and if you have EVOs make sure you pick one that will match up with there output when the sustainers off.