Questions on a Dobro Mandolin

[JimKo]

I have borrowed this dobro mandolin from a friend and may be interested in trading for it. It is really sweet and I enjoy playing it. I haven't had much luck finding info on it so I thought I would put out a few questions to Cafe members.
Any ideas when it might have been built? Serial number is 8 106 2M. The case looks like it might be from the 70's but I don't know if it is original.
What is the approximate value? Since I am dealing with a good friend I would like to make sure it is a fair, or slightly better than fair, trade.
What type of stings are usually used on these instruments?
Is there a way to adjust the intonation? Plays sharp up the neck. There is no truss rod.
Thanks ahead of time to anyone who might take the time to answer. The Cafe is, without a doubt, the best thing ever on the internet. Jim

[Tom C]

Those are known for intonation issues. Sam Bush uses a slide for that reason. That being said and knowing it needs work. $600 would be a better than fair price I believe. It's not something somebody needs but can be fun to have.

[pops1]

Sometimes you can move the cone back to intonate better. Worst you can remove the fingerboard and move it so it intonates and glue it back on. These are sweet sounding and loud enough to use a flatwound string and still have some volume.

[fentonjames]

That Dobro is from 1982.

Sam Bush plays a 1938 National, which 4 strings has been removed and the holes on the headstock filled, new nut, etc.

[Barry Wilson]

I have the same dobro. its an 80s model as mentioned above. I love the sound but find it a little cramped

[Ray(T)]

Sometimes you can move the cone back to intonate better. Worst you can remove the fingerboard and move it so it intonates and glue it back on. These are sweet sounding and loud enough to use a flatwound string and still have some volume.

Unlike Dobro v National Guitars, I assume it has a biscuit rather than a spider then?

[DavidKOS]

Unlike Dobro v National Guitars, I assume it has a biscuit rather than a spider then?

No, it has a spider like the dobro, you can see in the picture. That's what makes it hard to intonate, the spider has to be set for tone and no rattles, but often the bridge is not in the EXACT right place to play in tune up the neck.

But heck, there's no money above the 7th fret anyway, right?

[JimKo]

Thanks to all who replied. Played it at a jam last night and it sounded sweet, below the 7th. The saddle is a little high. I was wondering if lowering that might help a bit.
David, I know there is no money above the 7th fret but I am pretty sure there isn't much below it either.

[pops1]

If the saddle is high lowering it will help it not to play so sharp somewhat, depending on how much you are talking of lowering.

By sliding the cone back I meant the cone, spider and all. Sometimes there is room in the well to put it to the very back and gain some string length. We are not talking a lot here. It can also be slightly turned in the well so the saddle angles helping intonation.

[foldedpath]

If the middle strings are reasonably intonated and the high and low strings show a stronger difference, you might be able to do what pops1 mentioned and slightly rotate the spider so the bridge is angled. Just a little bit. I've done that with Dobro guitars to improve intonation.

Also make sure you're checking intonation with fresh strings. If those strings have been on there for a year, they'll be causing their own intonation issues.

[DavidKOS]

By sliding the cone back I meant the cone, spider and all. Sometimes there is room in the well to put it to the very back and gain some string length. We are not talking a lot here. It can also be slightly turned in the well so the saddle angles helping intonation.

If the middle strings are reasonably intonated and the high and low strings show a stronger difference, you might be able to do what pops1 mentioned and slightly rotate the spider so the bridge is angled.

It could work, both the moving the whole assembly and/or rotating it.

[JimKo]

Sliding the cone sounds worth a try. If it is OK with the owner, I will give it a try this weekend. I will let you know how it come out. Any other opinions on fair trade value?

[mandroid]

spider bridge over the cone/? I had one for a while (made by rigel) [not an old Dopra bros one ..they often needed a neck reset, yours may be the exception ] .
..even needing the reset asking $600+ is not unusual

the replacement of the straight thin maple bridge piece technically could be made in the same thickness
as Gibsons to get the intonation offsets hand made tongue and groove sort of thing..

FWIW, people seem to like the new biskit cone National RM1

[Verne Andru]

Is that a biscuit or spider bridge? My Republic Mandolian is biscuit.

Intonation is hit or miss. Mine is good. You learn not to be too fussy and just enjoy the reso sounds.

Check your scale length. Mine is around 15" and I found normal mandolin strings put on too much tension as they are optimized for a 13.something scale. I use GHS Ultra Light:

[allenhopkins]

1. Dobro mandolins almost invariably have the "spider" bridge set-up. National mandolins, and their Asian-made clones (Johnson, Republic et.al.) have the "biscuit" bridge (bridge glued directly to the cone), and the longer scale.

2. Mandroid's take on the older Dobro mandolins is spot-on; they have soft-wood neck blocks and often need neck re-sets. The 1980's versions probably don't have quite the same problems. My Dobro mando is from the '30's and needed a re-set.

3. It may be possible to fiddle with the cone/spider placement to improve intonation, and lowering the action will decrease the amount of string stretching and "sharping" as you go up the neck. The wooden bridge saddle sits in a slot on the spider, and I guess one could make a compensated saddle replacement to fit in that slot. I just put up with the intonation, since the instrument's 80 years old and I'm looking for vintage authenticity -- if Yank Rachell (or whoever) put up with inaccurate intonation, who am I to quibble? Not that Yank ever played a Dobro mandolin, to my knowledge...

[JimKo]

Again, thanks everyone for the suggestions. I have decided to watch the Packers today and do mando rehab tomorrow. My approach is probably going to be:
1) Adjust the spider.
2) Sand the base of bridge to lower the action.
3 Learn to live with the intonation.

That is the plan until it changes.

[fentonjames]

Go Packers!

[Verne Andru]

1. Dobro mandolins almost invariably have the "spider" bridge set-up. National mandolins, and their Asian-made clones (Johnson, Republic et.al.) have the "biscuit" bridge (bridge glued directly to the cone), and the longer scale.

Thanks Allen. What are the tonal differences between the two?

[JimKo]

Allen, I remember you have posted about Dobro mandolins before. Any ballpark figure on what this one might be worth?

[pheffernan]

Looking back through the archives, the range seems to be ~$650 for a private sale to ~$850 from a dealer: http://www.mandolincafe.com/forum/sh...Dobro-Mandolin

[allenhopkins]

Responding to the above inquiries:

Verne: While generalizations are dangerous (watch out, there!), Dobro mandolins have a long-sustaining, sweet and "ring-y" tone, in my experience; "silvery" is an adjective that comes to mind. Biscuit-bridge Nationals, and their Asian clones, tend to have a harsher, "bark-y" timbre, very strong and penetrating; I use my '30's steel-bodied National Triolian mandolin almost exclusively for blues. I've heard that the new National RM-1 mandolins, with biscuit bridges, are less harsh than the vintage ones like mine, while still very loud. Perhaps this is attributable to the fact that the RM-1's have wooden bodies, while the old Nationals, and the Asian ones, have metal bodies, either steel or plated brass.

JimKo: I'm a bit reticent about guessing a price for the instrument in question; the old Dobro mandolins, from the '30's and '40's, command the additional "vintage" prices, though they're probably not as well made as the '80's one we're discussing. Back in the '30's, Dobro instruments (Nationals too) often had wooden bodies built by the large-volume Chicago firms like Harmony and Regal, with Dobro basically making only the resonator hardware. As a result, build quality wasn't always the best -- you often find neck re-sets are needed. The instruments made when Dobro was "back in business" 30± years ago, probably were better constructed, in terms of the wooden components.

I paid $250 for mine, about 20 years ago. This one would go for more than twice that, at least $600, and probably $700. I see dealer listings ranging from $699 to a ridiculous $6,000 (!), but those are for "vintage" ('30's) instruments, and an '80's one wouldn't attract the collectors quite as strongly.

You could offer $5-600, and bargain up from that. I wouldn't go to the $850 pheffernan has researched, but I'm basically cheap. You can, sometimes, find nearly-identical "vintage" resonator mandolins marked "Regal" rather than "Dobro," at lower prices. This one looks like a good, solidly made newer instrument, with the major issue being poor intonation -- a problem often found on the older Dobro mandolins as well.

[Turlagh]

I have one of those that I bought new in 1985. I should have cleaned it better before storing it away for 26 years. Some of the chrome is badly pitted. Hopefully I will have new strings on it soon.

Sadly, my musical interests go in cycles.

Oh, the owner of the folk music store where I bought it strongly recommended light guage strings.