The Retro Lab
New member
- Joined
- Apr 7, 2021
- Messages
- 1
Well folks, it's about that cycle where once in a blue moon, someone comes along with an inquiry on one of these basses. I've done as much research as I can, all of which turn up dry, no results. Then why am I posting again? In hopes that *SOMEONE* out there has an answer / solution / *something* to get this thing up and running again. And that perhaps sometime between the last time someone posted something like this and now, *someone* has some info / solution!
SO, here's what I'm dealing with, as I acquired it:
I have a '74 Sunburst Les Paul Signature bass that came to me essentially as an empty hull with all hardware (and a fresh re-fret), and a baggie full of parts, consisting of the original pickup, an input jack, 1 potentiometer, a period correct looking unused 3 way selector switch for the 50/250/500, and some wire. THATS IT. Eager to try this thing out, I put the pickup in, wired it up straight to the input jack, hoping I could be in business. Well, kinda. Just whisper quiet. I know I know I know... it's because of the low impedance thing, which is why I'm here. I need to know what that is. Or what it can be. Ideally what it was. Preferably what I can put in there, mmm, now?!
I've seen a photo on Chicago Music Exchange's listing for a Les Paul Signature Model bass, which shows the transformer that I speak of. I will go to my grave that I've seen a photo of what this transformer was, and it was made by UTC, but for the *life* of me I can not find that photo again (shakes fist), and I do know that said photo did NOT have any further into illustrating what model UTC transformer it was.
Yes I've seen the schematic, yes I have spoke to Gibson about it, NO they do not have any further info on the 70-991 or 70-043 part numbers on said schematic. I spoke with Walter Carter at Carter Vintage Guitars in Nashville, as well as Tony the lead tech at Gruhn's Vintage guitars. Best take away from those two consultations was the referral of a gentleman by the name of JT Riboloff, whom was the head designer and main liaison between Jack Casady, Gibson / Epiphone on the development of the signature model Epi. Tried to trace him down through all usual suspect online mediums, no dice other than LinkedIn. ...which if he's like me, the last time he logged into linked in was when it was created, a hundred years ago. So, if anyone has any form of passing along JT Riboloff's contact info via email I would be extraordinarily forever grateful. It was expressed to me if that if there was any wizard on the planet with immediate knowledge of everything I'm in need of knowing, it's that gentleman. 9 out of 10 people I speak with have heard of this guy, just no means of connecting with him.
I have seen some folks post something about a Shure impedance balancing transformer used in-line, I would prefer to get to the bottom of whatever was SPEC first, if at all humanly possible. OR, if someone had some kind of practical workaround of permanently installing the guts of said Shure thing inside the bass itself, if that's even possible?
For an added plot twist- I have a friend who owns one of these. Lives in Montana, I'm in Nashville. Medium story short, he recently visited very briefly, and I made an attempt to remove the position potentiometer, to be able to wiggle the transformer thing out. I didn't have much intuitive luck in doing so, and in the interest of not knowing if there was a certain way to remove it, I for the life of me couldn't get it out of there, and had to leave it. SO CLOSE!!!
I do have some photos and video of the inside guts of my buddies LP Signature Bass, if it would be of any help here, I just don't see the ability to host media here within this post?
Cheers in advance everyone!
~Nick
SO, here's what I'm dealing with, as I acquired it:
I have a '74 Sunburst Les Paul Signature bass that came to me essentially as an empty hull with all hardware (and a fresh re-fret), and a baggie full of parts, consisting of the original pickup, an input jack, 1 potentiometer, a period correct looking unused 3 way selector switch for the 50/250/500, and some wire. THATS IT. Eager to try this thing out, I put the pickup in, wired it up straight to the input jack, hoping I could be in business. Well, kinda. Just whisper quiet. I know I know I know... it's because of the low impedance thing, which is why I'm here. I need to know what that is. Or what it can be. Ideally what it was. Preferably what I can put in there, mmm, now?!
I've seen a photo on Chicago Music Exchange's listing for a Les Paul Signature Model bass, which shows the transformer that I speak of. I will go to my grave that I've seen a photo of what this transformer was, and it was made by UTC, but for the *life* of me I can not find that photo again (shakes fist), and I do know that said photo did NOT have any further into illustrating what model UTC transformer it was.
Yes I've seen the schematic, yes I have spoke to Gibson about it, NO they do not have any further info on the 70-991 or 70-043 part numbers on said schematic. I spoke with Walter Carter at Carter Vintage Guitars in Nashville, as well as Tony the lead tech at Gruhn's Vintage guitars. Best take away from those two consultations was the referral of a gentleman by the name of JT Riboloff, whom was the head designer and main liaison between Jack Casady, Gibson / Epiphone on the development of the signature model Epi. Tried to trace him down through all usual suspect online mediums, no dice other than LinkedIn. ...which if he's like me, the last time he logged into linked in was when it was created, a hundred years ago. So, if anyone has any form of passing along JT Riboloff's contact info via email I would be extraordinarily forever grateful. It was expressed to me if that if there was any wizard on the planet with immediate knowledge of everything I'm in need of knowing, it's that gentleman. 9 out of 10 people I speak with have heard of this guy, just no means of connecting with him.
I have seen some folks post something about a Shure impedance balancing transformer used in-line, I would prefer to get to the bottom of whatever was SPEC first, if at all humanly possible. OR, if someone had some kind of practical workaround of permanently installing the guts of said Shure thing inside the bass itself, if that's even possible?
For an added plot twist- I have a friend who owns one of these. Lives in Montana, I'm in Nashville. Medium story short, he recently visited very briefly, and I made an attempt to remove the position potentiometer, to be able to wiggle the transformer thing out. I didn't have much intuitive luck in doing so, and in the interest of not knowing if there was a certain way to remove it, I for the life of me couldn't get it out of there, and had to leave it. SO CLOSE!!!
I do have some photos and video of the inside guts of my buddies LP Signature Bass, if it would be of any help here, I just don't see the ability to host media here within this post?
Cheers in advance everyone!
~Nick
