Hi all: This was my 11th CBG and most of them have been mag p/u guitars just because I've had no luck what so ever with piezos. On this one I thought I'd give piezos another shot. I've tried all kinds of configuations...double taping them to the box...moving them all around to different places on the box lid...encasing them in wood....foam...silicone....I'm about done with ever considering them again.
As a last resort, I thought I'd check with the experts on this forum. On this build I used two Radio Shack buzzer piezos encased them in wood and added a little silicone to brass side and felt to the ceramic side. I wired them paralell and added a volume pot. The treble high end is obnoxious. Does anyone have any ideas on how I could get a little more bottom end?
I always use those standard radio shack piezos that everyone seems to use. Would it make a difference to use larger ones like the one Gitty has? I'm about ready to rip it out if I can't make it happen.
Thanks loads for your expert advice.
Size isn't generally the issue, when it comes to piezos. Are you busting the piezo disks out of the plastic casing the Radio Shack ones come in? That is critical.
We use disk piezos in the shop primarily by encasing them in a big glob of hot glue on the underside of the sound board, on the bass side of the bridge. The results are uniform and quite good. I have found hot glue to be an excellent medium for encasing and cushioning the sensitive disk, which trims off some of the obnoxious highs and seems to help with lows too. Others have various other methods, but we've found this one to work and we are sticking with it. Now I must admit, we haven't done a lot with multiple piezo circuits because frankly I haven't seen/heard any clear reason for doing so. My personal theory is that mounting location and method is the true key to making good use of piezos, and everything else (size, how many you use, how you wire them, etc) all has pretty small impact.
I've used them on over 50 builds. I mount them in a silicon bed just forward of the bridge. I'm no expert but they sound pretty good through my amps. I think as long as they have a bit of bedding they have always worked fine for me.
Thanks you all for the info. CB....yeh I do take them out of the plastic cases. one question for all of you...what side of the piezo do you put against the wood...or does it really matter? Michael...does the sheilded cable help with the ground hum?
I put the brass side to the wood and yes I think using the shielded cable does help.I also ground the strings.
The one in the photo was filled in situ' on the box lid so I didn't have to think about glueing it on afterwards.
You mentioned that you 'ground' the strings.
How exactly do you do that?
Get them out of the box and into a wood bridge base with a suitable bridge saddle
hi michael...did the drain pipe thing and results were much better than Ive had in the past. It definitely took out much of the harshness.
thanks to all of you for the info.