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Martin CPCPA4 needs help
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10137&t=49807		 Page 1 of 1
Author:  SteveSmith [ Wed Oct 11, 2017 7:50 pm ]
Post subject:  Martin CPCPA4 needs help
One of my best customers brought one of these in and wants it setup. He's a very good electric player but isn't real impressed with the sound of this one (I agree-it sounds overbraced, for a start). I considered telling him to trade it for a better sounding guitar-ha. Anyway I'm looking for suggestions/ideas.

It's a cutaway dred, sapple/sitka, 25.4", richlite fretboard & bridge, corian nut and tusq saddle. Has Fishman F1 Analog system.

I am especially unimpressed with the bridge (large and clunky) and the UST.

Ideas?? I have some but would rather hear yours. Image
Author:  Freeman [ Wed Oct 11, 2017 9:03 pm ]
Post subject:  Re: Martin CPCPA4 needs help
What I'm seeing is a pretty low saddle that has been shimmed, plus the UST. That would worry me about the stability of the saddle in the slot. The shim is a particularly bad idea, the saddle needs to sit perfectly flat on the UST and make good contact. I would seriously consider making a new saddle without the shim (and with a perfectly flat bottom). Also if the neck angle is marginal and you don't have enough saddle in the slot then a neck reset might be in order.

If he is happy with the sound of the Fishman then keep it but there are other transducer options that might be better (you might be locked into that one because of barn door electronics, etc)
Author:  Freeman [ Wed Oct 11, 2017 9:05 pm ]
Post subject:  Re: Martin CPCPA4 needs help
Steve, I'll add one thought to your "sounds overbraced" comment. I own two Martins from the true overbraced era and have had the bridge plates replaced and some scalloping done. It can make a huge difference.
Author:  Hesh [ Thu Oct 12, 2017 12:35 am ]
Post subject:  Re: Martin CPCPA4 needs help
Hey Steve: We won't take in requests such as this one and in our view selling unknown future tone improvements is very subjective and as such risky for any commercial Luthier.

If it can't be quantified by all concerned with a definition of success determined in advance don't even go there.....

Tone can be improved or harmed.... by shaving the braces and the line between either is very difficult to know where it is.
Author:  SteveSmith [ Thu Oct 12, 2017 7:05 am ]
Post subject:  Re: Martin CPCPA4 needs help
Freeman wrote:
What I'm seeing is a pretty low saddle that has been shimmed, plus the UST. That would worry me about the stability of the saddle in the slot. The shim is a particularly bad idea, the saddle needs to sit perfectly flat on the UST and make good contact. I would seriously consider making a new saddle without the shim (and with a perfectly flat bottom). Also if the neck angle is marginal and you don't have enough saddle in the slot then a neck reset might be in order.

If he is happy with the sound of the Fishman then keep it but there are other transducer options that might be better (you might be locked into that one because of barn door electronics, etc)


The saddle was sticking up 0.2"+ over the saddle and leaning forward a few degrees (no surprise there). Strings are about 0.57" over the top and action is about 8 and 8 (argh) or 0.0625" for you decimal folks. So the geometry should be pretty reasonable when I get the bridge right, although I've only eyeballed the neck to make sure it is reasonably straight. As you said though a new bone saddle will be in order for sure

He had no comments on the Fishman, his only concern was with setup and acoustic sound, but my understanding is that the F1 analog UST is real quacky.

- As you noted shims are generally a bad idea and I will put in a new bone saddle. My biggest concern is that the UST is a spongy feeling chunk of coax that goes under the bridge and I'm afraid it is killing the sound - it sure can't help. I might pull it out and do a quicky setup to see if that helps the sound.
Author:  SteveSmith [ Thu Oct 12, 2017 7:09 am ]
Post subject:  Re: Martin CPCPA4 needs help
Freeman wrote:
Steve, I'll add one thought to your "sounds overbraced" comment. I own two Martins from the true overbraced era and have had the bridge plates replaced and some scalloping done. It can make a huge difference.


I checked the bridge plate and it is ok. The Richlite bridge is huge and clunky, probably weighs 40g or more. The top flexes pretty decently but I wasn't planning on shaving braces or doing anything that invasive, I don't think the guitar is worth it.
Author:  SteveSmith [ Thu Oct 12, 2017 7:20 am ]
Post subject:  Re: Martin CPCPA4 needs help
Hesh wrote:
Hey Steve: We won't take in requests such as this one and in our view selling unknown future tone improvements is very subjective and as such risky for any commercial Luthier.

If it can't be quantified by all concerned with a definition of success determined in advance don't even go there.....

Tone can be improved or harmed.... by shaving the braces and the line between either is very difficult to know where it is.


Morning Hesh, you're up early - ha. I absolutely agree. In this case, first of all, I know this guy very well. I've set up his electrics and we've done concerts together over the last 4 or 5 years, plus he is also is the one who ended up with the falcate dred I built a few years ago. What I told him I would do is to make sure there were no structural defects (i.e. broken braces, etc.), ensure the nut and saddle were correct and try a new set of strings. He knows it may or may not do any good. If a few simple changes can open it up then I'll do a full setup on it for him. I'm not real hopeful on this one and I told him that after I did my initial evaluation on it.

Seems like every time I set up a guitar for someone they are usually back within a month or so with another guitar to get it done too 8-)
Author:  SteveSmith [ Thu Oct 12, 2017 11:05 am ]
Post subject:  Re: Martin CPCPA4 needs help
I appreciate the input, looks like I'm essentially on the right path. Anyone worked with one of these coax UST's and had the guitar sound good? It almost seems as if the bridge is sitting on a piece of rubber.
Author:  Freeman [ Thu Oct 12, 2017 11:54 am ]
Post subject:  Re: Martin CPCPA4 needs help
I have seen a couple of the coax looking things in factory guitars (don't remember which ones) but didn't pay much attention to them. As long as I could get the setup done right I figured the owner must be happy with the sound or he wouldn't have bought the guitar.

When I have been asked to install a UST it has always been the Matrix Infinity - that is a flat piezo transducer with the wire coming out at 90 degrees. I believe they are 0.050 thick but I measure them before sanding the saddle. I know you can buy just the transducer if you want to run it passive (with an external amp or DI) - I do not know if that transducer is compatible with the onboard electronics that you will have with your guitar. I've been mostly satisfied with the Matrix but I have had a couple of guitars where there was some imbalance between strings - usually futzing with the bottom of the saddle will fix that (which is why I commented on the shim).

Personally I like the K&K Pure Mini piezo bridge plate transducers and I'm sure they are not compatible with the Fishman preamp (I asked that of K&K tech support one time).

I don't remember the brand of this one but it does solve the problem of the saddle sitting on top of the transducer. However your only option for adjusting the action is to sand the top of the saddle and its pretty expensive if you go too far

Image

One benefit of making a new saddle for yours is that you can correct the intonation - it doesn't look like the stock saddle was compensated and if your customer is an electric player he has probably noticed
Author:  SteveSmith [ Thu Oct 12, 2017 12:17 pm ]
Post subject:  Re: Martin CPCPA4 needs help
Thanks Freeman, I guess he liked the sound when he bought it but he doesn't like it now. Too bad about the K&Ks because they are my favorites too. I do have some old bone saddles laying around so I guess I'll just put one in there, set the height and change out the strings for a start to see how it sounds. If nothing there then I'll temporarily pull the UST and make a new saddle to fit and see how that works. I'm just curious to see if that coax UST is as bad as I think it is.
Author:  Freeman [ Thu Oct 12, 2017 2:19 pm ]
Post subject:  Re: Martin CPCPA4 needs help
I had a guitar with kind of the same problem as yours - someone tried to put a Matrix in it but could never get it balanced, It came to me and we decided to put a K&K in it, I asked them if it would work with the Fishman preamp. As I recall, they said it would work but I probably wouldn't be happy with the balance. I installed it as a straight passive pup and kept the old Matrix for parts - I know it has a good transducer if you would like to try that. The Matrix normally has a small electronics board that mounts just inside the sound hole and a small circuit board in the end pin jack. You could try just hooking it to your preamp and see if sounds better.

If you want to try PM me your snail mail addy and I could drop it in an envelope.
Author:  SteveSmith [ Thu Oct 12, 2017 2:49 pm ]
Post subject:  Re: Martin CPCPA4 needs help
I appreciate the kind offer and may take you up on it. First let me do the with/without experiment; there's probably an even chance that leaving the UST out won't change much. I should be able to get that done in the next few days and I'll let you know how it goes.

Edit: I just remembered that he had asked me the other day what pickup was in the falcate dred I made (a K&K) and what preamp he needed for it. If he has the preamp then I'll put a K&K in for him, assuming, of course, that the guitar sounds significantly better without the UST.
Author:  SteveSmith [ Sat Oct 14, 2017 8:30 am ]
Post subject:  Re: Martin CPCPA4 needs help
I pulled out the shims and the UST then put in a standard Martin bone saddle which just happened to be about the right height then put on some new D'Addario PB meds. The guitar sounds better, at least it sounds ok but not much volume and I think this is about as good as it's gonna get. Top is 0.122" thick and braces are pretty stout. The owner is supposed to come over tomorrow and check it out. I think he needs to sell it and find something that has the sound he wants, we'll see.
Author:  SteveSmith [ Mon Oct 16, 2017 9:49 am ]
Post subject:  Re: Martin CPCPA4 needs help
Owner came by and checked it yesterday - he's happy with the way it sounds now. A properly made bone saddle, even with the squishy UST in the slot, at least makes it sound good although at a lower volume. Apparently nothing magic here so idunno glad he's happy and now I'll proceed with the setup.
Author:  SteveSmith [ Fri Nov 17, 2017 10:15 am ]
Post subject:  Re: Martin CPCPA4 needs help
An update on this one - it reinforced for me that taking care of the basics can make a big difference in how even a "less than ideal" guitar plays/sounds. The owner came back and tried the guitar with the temporary bone saddle and new strings; he liked it enough to have me go ahead with a full setup including fret level and a new bone saddle. He did decide he wanted to keep the UST (I tried :( ).

Anyway, I did the normal fret level/setup stuff then moved on to the bridge. I got rid of the shims, leveled the slot and also cleaned up some ridges that were on the walls of the slot then made a properly fitting bone saddle. One thing I had noticed was a wood shim below the UST so I got rid of that figuring a clean level slot should do the job better. The setup took care of the action issues and with a well-fitted saddle I was also able to intonate it properly (one of his other complaints). Surprisingly the guitar sounds pretty good now. The overbraced top kills the volume a bit but the tone is nice. The UST is still a UST but with the saddle corrected the sound is now at least balanced and since he runs through a board when he performs they can do some post processing. Interesting note is that the onboard tuner was off by at least 5 cents making it essentially useless. It took the owner a few weeks to come get it since he is not local but it was fun to see the look on his face when he played it - he said he had fully expected to just pick it up and put it up for sale but now he really likes it and plans to keep it.
Author:  truckjohn [ Fri Nov 17, 2017 2:25 pm ]
Post subject:  Re: Martin CPCPA4 needs help
Glad to hear you were able to at least bring it back to the land of the living. Its always surprising what simply returning to solid fundamentals of setup will do....

Tone wise.... One man's "overbraced" is another man's "well behaved on stage when plugged in"... You know how that goes..... There's nothing like the joy of a guitar feeding back and echoing onstage.... Shaving braces on these is already only marginally effective - because you have such a heavy bridge, thick top, and heavy bridge plate... It's hard to undo the design..

As per usual - one of my perennial "solutions" for a stiff guitar is heavier strings... Going up at least one gage always makes a big difference with these... It's especially noticable when an electric guitar player is running lights or extra-lights on a guitar with a 1/8" thick top and 3/4" bracing... Move him back to Mediums and all of a sudden - there is tone...
Author:  Hesh [ Fri Nov 17, 2017 2:38 pm ]
Post subject:  Re: Martin CPCPA4 needs help
Way to go Steve!!! Good going and isn't this a great feeling knowing that you dramatically improved an instrument AND someone's experience with it! That's why I do this and I can't get enough of the smiles you see when folks are positively surprised!

I'll add that many folks have had bad prior work and experiences. When you provide real value and great customer satisfaction although it's sad that this is not seemingly the norm... in our trade nonetheless it just makes your day too. It certainly does mine.

Lastly when the basics are actually addressed correctly nuts, saddles, UST performance the stuff that you don't want to get into, remanufacturing and engineering say an over braced instrument pale and become more tolerable.
Author:  SteveSmith [ Fri Nov 17, 2017 3:36 pm ]
Post subject:  Re: Martin CPCPA4 needs help
John, one of the things I was thinking of as an "advantage" for the stiff top was that it would be pretty much feedback proof :)

Hesh, you are so right about customer responses. I really enjoy watching them pick up their instruments and see them light up when they try them out.
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