Modern Gretsch Guitars

Fishman Prefix Pro in Rancher cutting out

1

Before I spend hours coming to a conclusion that someone else already has:

My Rancher with a Prefix Pro has recently taken to cutting out now and again during the middle of a performance. Simply unplugging the cord from the guitar and plugging it back in fixes the problem temporarily. I've sprayed contact cleaner into jack and did the plugging and unplugging trick, used different cords and changed the battery-none of which has made any change. My next step is to take the jack out and inspect it and take some emory cloth to the contacts, inspect the harness, etc.

But before I do, does anyone know of any specific issues with the circuitry inside the Prefix Pro that may cause this intermittent phenomenon? I am mostly puzzled by the fact that unplugging and re inserting the cord temporarily fixes the issue. Everything is secure and simply wiggling or turning the cord in the jack doesn't do anything. The cord needs to come all the way out and back in.

Thanks,

Zig

2

Stew-Mac sells a contact cleaning tool that does male and female 1/4" connectors---$20 range if I recall correctly. It's a very mild abrasive. Ethyl alcohol or De OX IT would be the chemical cleaners of choice. It could also be something like a bad solder joint, too. Good luck!

3

Jack out. Solder joints look good. Did my best with contact cleaner. I'm not thinking this will do it though, based on the fact it is so intermittent.

4

Greg-- I had this problem briefly on my 2005 Rancher, and it was very sporadic. The 2005 Rancher has a Fishman Prefix, but it is the older version. I thought the jack was going bad-- and I couldn't reproduce the intermittent cycle on demand... Like you, no amount of twisting, jiggling, etc of the plug would fix it-- only complete removal and reinsertion of the plug would work.

Finally, I used the same cord with another instrument-- my Gretsch Park Avenue mandolin (which has a passive pickup, no preamp system). Same intermittent problem. I switched to a new cable, and the problem was gone. Suspecting something but not knowing exactly what, I measured the plug barrel diameter with my micrometer and compared the measurement with the new cable. There was enough of a difference in sleeve diameter that apparently the ground portion of the plug (the sleeve portion) was not making solid contact with the ground/ring portion of the jack-- the tip was connecting OK with the jack, but not the sleeve. I tossed the older cable and haven't had a problem since. Also, the endpin jack on the rancher has an internal spring-loaded connector switch which activates the preamp when the plug is inserted and turns it off when the plug is removed... this could be the problem, particularly if the switch portion is going bad.

Not saying this will work for you, but it's worth a shot. Also, if you need to replace the jack itself, the Fishman Switchjack is the one you want. Nothing more frustrating than having it go out in the middle of a song.

5

I MAY have accidentally figured out the problem. Put the guitar back together and after a while it cut out -only this time I was sitting at my desk and reached over the top of the guitar to use the mouse. My elbow hit the Prefix unit and I got a little static and sound. I started going through the unit and found that the phase switch may not have been switched entirely to one side or the other as the unit came alive when I fully switched it either way. I sprayed a little contact cleaner and manipulated the phase switch a few times. Hasn't cut out yet since then. Interestingly enough, I haven't recently had occasion to change the phase, but I may have knocked the switch ever so slightly while handling the guitar. I will post more if the problem returns.

6

Ok thanks, I had to abandon playing my Rancher today because of what sounds very much like this problem! I'll try your tests and solutions. Thank you so much!

7

Glad to see you seem to have it traced down, Greg. Also nice addt'l tech info Rob, thx for posting it.


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