1920 (?) ajr, #68884

[Martin Jonas]

Well, I've just bought my first Gibson -- it's a nicely battered Ajr, much played, great sound, great playability. I'm very pleased indeed, especially as I got a great price!

As the two previous owners are both active on the Cafe (and in the London mando scene), there are already some nice pictures up in the archive:

68884 (http://www.mandolinarchive.com/perl/show_mando.pl?2916)

I'm a bit confused by the year given in the archive: it says 1920, when every Ajr with lower serial numbers that has a year listed at all says 1921, and every one with higher serial number has 1922 or younger. Shouldn't mine be a 1921 or 1922? Were there even any juniors in 1920? Or is there some subtlety I'm not aware of?

In addition to the photos in the archive, here are some more taken today, starting with the front. Even compared to the other sheraton brown Ajrs in the archive, mine seems very dark, but I guess that it's difficult to compare from photos taken in different light.

Martin

[Martin Jonas]

Here's the back. There's no finish left on the neck, although this may well be from much wear, rather than a deliberate stripping. Either way, it's very comfortable to play.

Martin

[Martin Jonas]

The front from another angle. Difficult to make out in the photos, but this one has fairly tight and regular grain, unlike some Ajrs one sees.

Martin

[Martin Jonas]

The archive entry says "replaced tuners & fingerboard". The fingerboard is obviously fairly recent, and well made (hearing of intonation problems with original boards from others, I'm glad about it, too). The tuners, however, look pretty much as I would expect them to -- maybe the Gibson experts here can say whether these look non-original?

Martin

[Martin Jonas]

A couple of slight structural concerns. The first is the top, which has a slightly flattened arch in longitudinal direction. Transverse, its fine. I have felt for the ends of the brace through the soundhole, and it feels firmly attached with no gaps on both sides, so I guess this is just how it has settled. Does this look worrying to anybody? It's currently strung with J62 strings and I'm thinking of going up to J74 (or maybe J73) -- does that seem ill-advised or should it be OK?

Martin

[Martin Jonas]

The neck joint seems to have moved at some stage: There's a narrow gap between the backplate and the end of the heel, and the lower part of the heel has a gap of about half a millimetre from the rib/neck block (less on the other side). On the other hand, the fretboard itself is completely flat without any lifting or angle at the joint. I suspect that the neck joint has looked like this at least since the new board was put on, and that it is stable -- does this look OK or alarming to those who have seen more of these?

Martin

[Martin Jonas]

Finally, here is the bridge and part of the soundboard, showing the tight grain. This shows nicely that the transverse arch hasn't flattened out. It also shows that the bridge has a shim. For a slightly sunken top, that would of course be not particular suprising, except that in this case, the action is if anything higher than I prefer. I've measured the height of the shim and reckon that the action will be pretty much where I would like it if I just remove the shim. It's glued on, unfortunately, but I guess I can just shave it away. As the photos in the archive show no shim, it looks to me that the shim was put in because of different preferences in action between consecutive owners, rather than to counteract any sinkage.

Martin

[Jim Garber]

Martin:
That neck joint looks a little scary to me. I would have it checked out. It occurs to me that the shim was put in to compensate for the neck angle change which would also cause the action to go up. Hmmmm...

In any case, it makes me nervous and I would not put any heavier gauge strings until the doctor takes a good look at both the neck joint and the braces.

Jim

[Jim Garber]

BTW if you think your A Jr. looks beat, take a look at my 23 (next to my 23 A2). You can't see the top wear under the pickguard which is really worn. Lots of character, right?

Jim

[pickinNgrinnin]

These old Gibson Jr's are a great value and may be among the best sounding A style ovals they made. I regret selling the one I had.

[Martin Jonas]

Martin:
That neck joint looks a little scary to me. I would have it checked out. It occurs to me that the shim was put in to compensate for the neck angle change which would also cause the action to go up. Hmmmm...
Jim, thanks for your comments. I'll certainly check with the previous owners if they've ever had the joint looked at, and will probably have a luthier look at it, too.

I can't see it having anything to do with the shim, though, as it's a corrective remedy in the opposite direction. A shim is used if the action is too low. If the joint had moved, wouldn't that have increased the action, rather than lowered it?

Martin

[danb]

oops!
I got the date wrong and have corrected it. I do know 2 previous owners- I'll ask Craig where the replaced fingerboard and tuners description came from, I don't see that in the pictures now!

[Jim Garber]

I can't see it having anything to do with the shim, though, as it's a corrective remedy in the opposite direction. A shim is used if the action is too low. If the joint had moved, wouldn't that have increased the action, rather than lowered it?
Exactly my point -- that the neck joint caused the action to loosen which, at one point, was too low and is now too high. In other words, the shim was addded before the problem with the neck occurred.

Jim

[Martin Jonas]

Oh, I see what you mean. I'm trying to find out at the moment when the shim was added, and why. I think it was recent, as it wasn't there when Dan took the photos for the archive. The action at the moment is not all that high, by the way: I know many players who like it like that, it's just a little bit higher than I prefer it.

Martin

[danb]

Martin- Craig took those photos. I'll pop him a note to check this thread out. I saw the instrument in London when the previous owner had it, I didn't notice the shim. At the time I helped him intonate it one late night session http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

[Martin Jonas]

Dan -- thanks, I've already dropped Craig a note.

I think I was there at the session you're talking about... (although, alas, I didn't make it to the late night part of it, as I had to catch the last train).

Martin

[Darryl Wolfe]

I do not see anything that would make me say the FB and tuners are not original. (particularly the tuners)

[craigtoo]

Hi! I had a violin builder add the shim for me. It's attached with hide glue to the bridge. I added it to get the string height a bit higher in order to compensate for the top sinking a bit. The good news is, the mando looks exactly now as it did when I had it.


The heel looks the same, the top looks the same. Just as it was when I bought it. I'll try and post some pics. That's a good Ajr. I bought it from Charles Johnson at Mandolin World Headquarters. Great Guy...

craig

[craigtoo]

Here's a pic taken 3 years ago tomorrow.
http://homepage.mac.com/craigtoo/.Pictures/Photo%20Album%20Pictures/2007-04-11%2015.29.46%20-0700/Image-D58272EFE87B11DB.jpg

[craigtoo]

Another one of the tuners.

Oh, I should mention that the shim is mahogany. If you'd like to remove it, simply loosen the strings remove the bridge and it should "pop off" if not, use a moist towel or hold it (sparingly) over some boiling water for a bit. Remember the orientation because it's carved to fit the top.

http://homepage.mac.com/craigtoo/.Pictures/Photo%20Album%20Pictures/2007-04-11%2015.29.46%20-0700/Image-D583154AE87B11DB.jpg

[Martin Jonas]

Craig -- many thanks for that. It's very reassuring to know the top and the heel haven't moved in all the time that you and Aidan have played it. And yes, it's indeed a good Ajr -- I love it. Just trying to make sure it survives the experience of being owned by me...

Martin

[craigtoo]

Cool Shot...

http://homepage.mac.com/craigtoo/.Pictures/Photo%20Album%20Pictures/2007-04-11%2015.29.46%20-0700/Image-D583C448E87B11DB.jpg

[Fliss]

Congrats, Martin! It's nice that you have acquired an instrument where you know something of its history, I think it adds to the character http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

Regarding the question you asked about strings, I'd be interested to hear people's views on that. When I was considering a vintage Gibson, one person who knows a lot more about these things than I do said he always puts J75s on his, which surprised me.

Fliss

[Jim Garber]

Maybe I am too fearful of these things, but I would still have a luthier check it out before putting heavier strings on it. There is some shifting, however slight going on, I believe. I have had quite a few Gibsons and tho they can take the heavier strings -- I usually use J-74s or EXP 74s -- they need to be monitored to avoid Gibson disease (separation and warpoage of the rim from the back.

Jim

[Martin Jonas]

Thanks Jim, I will take it gently and have a luthier look at it before going up to J74. Looking again closely at the neck joint, I think it has actually moved slightly sideways rather than pulled up: the gap between the heel and the neckblock is only there on the treble side and not the bass side, and the bottom of the heel is slightly misaligned (by about 0.5mm) with the little extension of the backplate that covers it. I wonder whether it may have spent some time in storage with only the bass strings tuned up to pitch.

I'm going to take out my Vernier calipers on the weekend and check the action and the height of the shim to get some precise measurements. Using those as a starting point, I can then monitor any future movement, and also make a judgment on whether to take the shim off.

Martin

[Martin Jonas]

I'm going to take out my Vernier calipers on the weekend and check the action and the height of the shim to get some precise measurements.
So. I've done my measurements now, and (deliberately or not), the action is quite a bit lower on the treble strings than on the bass strings. On the G string, it's 2.3mm (a bit under 3/32") and on the E it's 1.6mm (2/32") at the twelfth fret. I thought it's higher just from looking and playing. Action at the nut seems fine. I would normally keep my action around 1.5mm all over, so the E is about right but the G a bit high.

Does this sound roughly what the action was when you had it, Craig? The shim is 1.5mm high all over, so taking it out will reduce the action at the 12th fret by 0.75mm, to 1.5mm on G and 0.8mm on E. That sounds very low indeed. I need to think about this a bit.

Martin

[danb]

Martin- take it to Dave King, he has a shop on Denmark st. Sounds like there's a bit of set-up she could use!

[Martin Jonas]

Thanks, Dan -- wrong end of the country for me, but I'll have it checked over locally in any case, because of the neck joint. For now, I'm just getting to know the instrument and see what the options are.

I think I have it cracked now, anyway: I had an old adjustable bridge around that happens to have almost exactly the right curvature. So, I popped it on, turned the action down to where it would be without the shim, and from that test run decided that it's going to be playable with that action.

Thanks to Craig for confirming that the shim was fixed with hide glue. I've taken the bridge off and gently heated it, and it popped off cleanly. I reckon if I want to put the shim back on, I can do so without glue, just string tension should be enough. For now, I've strung her up without the shim, and have 1.0mm on E/1.6mm on G. That's more comfortable to play than it was, and there is no buzzing.

Martin