View Full Version : Restored Gelas Flatback
Probably the worlds weirdest mandolin:
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This one is dated 1931, and is numbered in the 8000's - frankly who knew they made so many?
They were made with their own rather cool fitted cases though:
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Unfortunately they're almost impossible to repair and/or set up, this one is playable now though with a new fretboard, and much to my relief, playable in tune as well (most of them aren't as far as I can tell!):
https://www.youtube.com/watch?v=YBXWrD3u_GY
derbex
May-26-2016, 9:42am
That's a nice sounding instrument Paul, well done for bringing it back to life.
JeffD
May-26-2016, 10:10am
Its hard to understand what problems are solved by a double sound board like that.
Its hard to understand what problems are solved by a double sound board like that.
Well... no one in their right mind (and I suspect Monsieur Gelas had been sipping from the same cup as Monsieur Dali) is going to copy you, patent or no patent.
Jim Nollman
May-26-2016, 1:09pm
a friend of mine just restored one of these, so we know there are at least two of them in the world. I thought the sound of it was well worth the many hours he spent to reset the two sound boards. .
Martin Jonas
May-26-2016, 1:52pm
Unfortunately they're almost impossible to repair and/or set up, this one is playable now though with a new fretboard, and much to my relief, playable in tune as well (most of them aren't as far as I can tell!):
Oh yes, indeed. I still have one sitting around waiting for me to pick up the energy to sort out the set up. When I got it, the action was way too high and although I figured out a way of lowering it (in short: very difficult indeed as it involves drilling new holes through the base of the fixed bridge directly next to the soundboard!) I didn't make a large enough adjustment. It's playable now, but not comfortable. I need another 1 to 1.5 mm lower action, and can't face having to fill my initial holes and drilling new ones...
It does sound quite nice, though, and it's not as weird to play as one might think.
Martin
Jake Wildwood
May-27-2016, 1:28pm
Thanks for showing us!!!
I was also going to say -- this looks like an obnoxious thing to setup.
I've encountered a lot of weird instruments and whenever I see tension handled like this on a bridge (even on single-top instruments) I wince because I know the setup will take twice or three times as long due to all of the design issues -- and the customer will be wondering "what's taking so long?"
(grrr)
Thanks for showing us!!!
I was also going to say -- this looks like an obnoxious thing to setup.
I've encountered a lot of weird instruments and whenever I see tension handled like this on a bridge (even on single-top instruments) I wince because I know the setup will take twice or three times as long due to all of the design issues -- and the customer will be wondering "what's taking so long?"
(grrr)
Is the point where I admit to fitting 3 new fretboards before I got one that worked... I can't tell you how many times I nearly smashed this one against the nearest wall just to be rid of it!
Utterly horrible to work on...
Jake Wildwood
May-28-2016, 10:07am
Utterly horrible to work on...
Been there, done that!
I had a double-backed mandolin that was really more "double-bodied" as it sat in a full secondary body/resonator but it'd been built in such a way that it was nearly impossible to take it all apart to repair all the loose braces, loose back, etc. going on. I started disassembling it and after a while I said -- "Ya know, it's not worth me spending $1500 of my time to fix this instrument that will sell for $350, tops."
Needless to say I gave my $175 into it away so it could decorate someone's wall and I wouldn't have to look at it anymore.
brunello97
May-29-2016, 5:01pm
.....and although I figured out a way of lowering it (in short: very difficult indeed as it involves drilling new holes through the base of the fixed bridge directly next to the soundboard!)
I'm trying to wrap my head around the bridge work you fellas have done.....
A question to John and Martin viz the Gelas style bridge:
Are all three "bridges" in the assembly (front w saddle, middle with holes and rear w triangular profile) fixed to the bottom, flat bridge plate?
Martin, did you lower the height of the front bridge and then lower the position of the holes in the middle "bridge" to keep the same amount of "break" over the bridge assembly?
Mick
All the fussing aside, the video clip you supplied, John, does sound pretty good. :)
I'm trying to wrap my head around the bridge work you fellas have done.....
A question to John and Martin viz the Gelas style bridge:
Are all three "bridges" in the assembly (front w saddle, middle with holes and rear w triangular profile) fixed to the bottom, flat bridge plate?
Yes, very much so, it's all one piece as far as I can tell, unless Martin knows otherwise... I'm not really sure how he managed to drill lower holes in the central section... the holes in mine were already at the bottom of the "dip". Actually, on second thoughts, I'm not sure how they could have made the bridge in the first place unless it was multiple pieces glued together...
Martin Jonas
May-30-2016, 6:07pm
Yes, very much so, it's all one piece as far as I can tell, unless Martin knows otherwise... I'm not really sure how he managed to drill lower holes in the central section... the holes in mine were already at the bottom of the "dip". Actually, on second thoughts, I'm not sure how they could have made the bridge in the first place unless it was multiple pieces glued together...
The bridge on mine is a slightly different design: chunkier and with a different (though equally Byzantine) path for the strings through the bridge. I had a thread with photos in the builders' section when I did the setup work back in 2010 (Link (http://www.mandolincafe.com/forum/showthread.php?66358-Gelas-mandolin-bridge-jewellers-hand-drills)) -- the photos in the old thread show the differences between mine and John's fairly clearly and should make it clearer what precisely I had to drill on mine. My final posting on the old thread was pretty optimistic, but it turned out that the action was still uncomfortably high so I really need to revisit it.
I think the differences arise because Gelas wasn't really a luthier at all: he held the patent for this weird system and licensed it to at least four different makers, each of which displayed the Gelas name more prominently than their own (although on the ones I've see photos of, the actual makers' name is somewhere on there as well -- John: what precisely does your label say?). Mine was made by Rene Gerome, and does not have the Gelas name on the label, possibly because he didn't pay the license fee. Also, some of the details, including the bridge design, are a bit different from those with the Gelas name on the label. Still, clearly the same system, though.
Martin
brunello97
May-30-2016, 6:19pm
Thanks, Martin. Wow. I participated, briefly, in that conversation.....6 years ago. Yikes, time flies. I didn't realize you have had your Gelas for such a time. Still, the discussion with you and Pablo H was very informative and great to have it linked to this one.
I see the difference in the bridges now, obviously. It looks like there is still significant upwards action on the bridge on yours. John's appears to have two down and one up.
Still super intrigued by these. (We've been watching a super grand size Gerard Depardieu on "Marseille" on Netflix this summer so my Francophilia is in full swing.....)
Mick
Martin Jonas
May-30-2016, 6:26pm
I see the difference in the bridges now, obviously. It looks like there is still significant upwards action on the bridge on yours. John's appears to have two down and one up.
Yes, I think that is the main difference. I suspect that the downward break on the tailpiece side on John's bridge (which I think was Gelas's original design) is intended to cancel out the torque created by the S-shaped string path through the front part of the bridge. I also suspect that the reason my bridge is so much chunkier is that because it does not cancel the torque in this way, it needs to be more substantial so that it doesn't get torn apart (of ripped from the soundboard) by the torque created by the tension wanting to pull the string straight.
Martin
Martin Jonas
Jun-11-2016, 7:04pm
An update on this discussion: I have today found the time and motivation to do something about my Gelas (René Gérôme) mandolin -- I've taken the action down another millimetre or so by going at the bridge with needle files, whittling knife and other assorted kit to beat it to submission. Took some work -- for some reason, buzzes kept popping up at the saddle -- but it plays much more comfortably now and intonates OK. I do however echo John and Jake's sentiment that setup on these is a pig, not least because adjusting the setup at the bridge requires all strings to be taken off completely. After the adjustment, the ends of the strings then need to be threaded through the holes in the bridge, but of course the ends are bent and twisted on used strings. Repeat for every further adjustment...
Anyway, it's playable now and is sounds rather intriguing. The closest comparison I can think of is with a Vega cylinderback which a friend of mine recently bought from TAMCO: like the Vega, the Gelas is a bit quiet but has a very warm soft tone.
I made a recording today, as a duet with my Ceccherini bowlback on a classical mandolin duet by Carulli (Link (http://www.mandolincafe.com/forum/showthread.php?124642-Allegro-for-Two-Mandolins-(Ferdinando-Carulli))) -- illustrates the tone of the two mandolins quite nicely.
Martin