Hey all,
I recently completed my first CBG and decided to try a rod piezo under the saddle -vs- using the disc type glued in the box somewhere. From all I read, the under the saddle pickup was the way to go. However, I'm pretty disappointed in the sound.
Did some more reading and discovered that if I'm plugging into a standard electric guitar amp, a piezo "buffer", or preamp is a good thing to have, so I whipped up a little J-FET, impedence matching, buffer with only marginal improvement . OK, it's easier to drive the amp, but the sound really lacks depth and is shrill, sharp, scatchy, clacky... just generally unpleasant.
So I'm thinking to myself that maybe, just maybe, something is amiss with my pickup or wiring, so I do a little experiment and stick a disc piezo to the box with a gob of Silly Putty and run that directly into my little buffer and into my amp. Wow, what a difference - now it sounds more like what I expected. If I use double sided foam tape to stick the disc to the box the sound improves even more. Hmmmm....I then had a Eureka! moment - could it be that my rod piezo is just fine, but it's more likely the relative placement to the string terminations?
You see, I'm using a home-made tail piece to terminate my strings and the saddle is only about 1.5" away from the tailpiece. Is it possible that there's too much pressure on the pickup and that's why the sound quality is surpassed by the lowly, hastily applied, disc piezo?
Before I cut into the box and glue in some discs (yes, the box is glued shut) , I thought I'd run my theory by you all. What do you all think? Did I screw up with my basic geometry?
Oh, but wait, here's the interesting part... took the CBG to my local Guitar Center to test drive some amps in it's current configuration... although it was well received visually, it had that same nasty, shrill, scratchy, clacky, sharp, unpleasant tone... that is until we plugged it into a $360 Fishman Loudbox Mini ACOUSTIC amp, then and only then did it sound friggin' amazing - very much like a nice amped acoustic guitar. Do these amps have a lot of filtering and signal manipulation to deal with this? I mean it was a whole different guitar and the one guy played it for 20 minutes and I stood there in awe.
Sorry for the long post, but I'm really lost here - please, somebody, show me the way to CBG nirvana.
Replies
I appreciate this discussion. Could anybody point me to (or provide) a cross-section diagram of the optimal rod piezo/bridge/saddle configuration?
I'm trying to figure out if the rod piezo is laying in a rounded-bottom slot in the bridge, and if the bottom of the saddle also has a radius to match the rod... or is it OK for one or both to be flat? And I guess I'm trying to see if the rod is in contact with the soundboard or has bridge material between it and the soundboard. (etc).
A picture is worth a thousand words, and all that....
Thx in advance!
I,too,am working with the rod piezo and have been somewhat disappointed ,, but followed this thread and I must say when u put in that bone bridge it lit up like a Christmas tree ,,,,,,, I am taking a lot away from this one guys ,, tks to all that jumped in,, I got a little something from all of you.
Q Joe ,, man U gonna b a good builder with the tenacity u showed working this out !!! Good on Ya !!!!!!!!!
Could the bottom of the saddle be coved to match the radius of the rod piezo and there by creating more surface contact? ( sorry if i missed this being mentioned before)
Bert, I doubt it would matter
Ok. Thought maybe with more contact surface :)
you just have to mess around with each guitar with these kinda pickups they will never sound like a mag but you can get a good cbg sound if you want.
One thing I read Oily is right about your bridge and saddle , mass eats vibration.
You don't won't a wide flat saddle if it's just a little bit high in the back it will mute the strings.
You want a clean edge going to the nut. many guys use banjo or fiddle bridges with good results. I like mando or arch top floating bridges no mater what string you use and can get the intonation right.
Sounds like you are getting output. I have noticed if my tone pot has a smaller cap (22 or 47 nf) I don't like it as much as if I have a 100nf (.1uf). It takes a lot of the high / shrill noise out leaving a richer bassier sound. Might be worth a try.
Hi Jim - yea, I have a .047uf cap on the tone pot now... It certainly could be a combination of things, so when I cut the access for the jack / pots I'll go ahead and try that. What the hell right? To be frank though, I wish I didn't even bother with a tone pot (especially on a first build) as it's just one more thing to troubleshoot. The next build is back to basics!
I have one more trick up my sleeve before I start cutting on this one - I'm going to replace that hard plastic saddle with bone, but I"m not holding my breath.
I rarely put pots on the git. For what I do, making adjustments at the amp is easy enough.
Well guys... it just goes to show just how much I know. I made a new BONE saddle today, carefully fitted it to the slot. Polished the sides, cut string notches, made sure the bottom was dead flat - heck I even put a tiny chamfer on the bottom edges to ensure it wasn't hanging up in the slot..
So did it work? Well, you the judge (amp on "2" & tone controls set to mid position & no pre-amp) :
-
1
-
2
-
3
-
4
-
5
of 5 Next