Converting 6-string dobro to 7-string

Mike Harris · From: Texas, USA

Has anyone done this?

I'm guessing it involves a drill, a spare tuner, a new nut and a new saddle. I'm curious to hear from anyone who has tried this as I have concerns about the effects of the added tension on the headstock and the bridge/cone assembly.

Also, after posting this I realized I was in the Steel Players section--please move to Steel Without Pedals if that's a better place for it.

thanks,

Mike

Ulric Utsi-Åhlin · From: Sweden

I recently converted my Dobro to 8-string,but in my
case that meant building a new neck,but,from what
I gather,You plan to keep the neck...first issue
would be the head,is it a slot-head?Where do You
plan to fit the 7th tuner,and what type?BTW,it´s
not a vintage Dobro,is it?If so,don´t do it.Keep us
informed...McUtsi

Mike Harris · From: Texas, USA

McUtsi,

no, sir, it's a paddle head (Goldtone PBSM), definitiely not a vintage instrument, and it's slightly damaged already--I got it rather cheap, but it sounds fine.
I might have to remove the strap button on the head depending on the tuner type.

Going from 6 to 7 with the original neck I think I could easily live with the slight reduction in string spacing. I am a little uneasy about putting a hole in the head, though--you can't really "undo" that sort of thing.

chris ivey · From: california (deceased)

also...where are you going to run the extra string in the middle of the bridge? i often wondered how and where to offset that problem.

AJ Azure · From: Massachusetts, USA * R.I.P.

get banjo tuners and drill the extra hole dead center. You may want to look at a Beard spider bridge and a Randy Allen tailpiece. Not the cheapest way to go but, it will work better than just modifying the standard bridge and tailpiece..

Billy Gilbert · From: Texas, USA

I don't think the extra string would hurt the neck, but there are other problems. You can't allow your "saddle" aka bridge inserts to cover the center screw. If you do you can't adjust the tension on the cone with it tuned up and ready to play. An offset bridge would cure that problem but create another. It would make your scale either a quarter inch shorter or longer, depending on which way you installed it. I would go for 8 strings, and make the new nut wider than the neck. It you miter the ends of the nut so that the bottom of the nut is the same width as the neck it looks okay. You may have to cut off the handrest for string clearance at the bridge. Forum member Sonny Jenkins converted a reso that way and it looks pretty good. He put both extra tuners at the top of the peghead. YMMV

Ulric Utsi-Åhlin · From: Sweden

Yeah,8 strings permits 4-on-each-insert,and IF You
can live with(or even prefer)"PSG-spacing" even the
rest could survive,it´s a close shave,though ; time
may have been on someone else´s side but not mine when I assembled my project so,regarding the TP,I
simply cut a hole middish + two angled slots...
McUtsi

Howard Parker · From: Maryland

The Beard shop has done these conversions on Gold Tones. It involves swapping the original spider for an offset one and using a single piece tricone bridge insert. The screw sits behind the bridge. Beard also has an appropriate 7 string tailpiece.

The 7th machine is mounted dead center at the end of the headstock. The shop has also done 8 string conversions in a similar fashion, except you can use the standard spider in that case.

Hope this helps.

h
_________________
Howard Parker

03\' Carter D-10
70\'s Dekley D-10
52\' Fender Custom
Many guitars by Paul Beard

Mike Harris · From: Texas, USA

It does sound as if 8 is easier and/or cheaper, and better in the long run, than 7. I'd rather not invest heavily (as in a new spider and a 50 dollar tailpiece). McUtsi's solution on the tailpiece seems smart and do-able.

I'm wondering if the string spacing between #5 and #4 will be inordinately greater than the other pairs. I'm also wondering if I should get non-slotted inserts, it seems there might be more real estate to work with that way--can that be done?

I did find this link to a Regal which was converted to 7-strings. He routed both of the two highest-pitched strings through the same hole in the tailipiece. He also did a bit of plugging/filling on the headstock, putting 4 on one side.

http://www.suduva.com/7string_dobro.htm

chris ivey · From: california (deceased)

that's interesting on the regal 7string conversion. the guy says..the cone tension screw was already adjusted so access to the screw wasn't necessary. that seems a little like, 'well they tuned it at the factory...' etc.

Jeff Watson · From: Anza, CA. USA

I did pretty much the same thing as the linked Regal project. I used 4 on a plank mandolin tuners on one side of the headstock, a one piece bridge insert and drilled a center hole in the tailpiece. Worked great.

Mike Harris · From: Texas, USA

Jeff,

you didn't need to change the spider bridge? And how do you adjust the tension now?

Jeff Watson · From: Anza, CA. USA

Mike,

No need to change the spider. I simply fit a longer bridge insert into the existing spider slot. This was a one day project that cost me nothing more than the cheapo mandolin tuners. The bridge insert was fashioned from a junk piece of aluminum bar I found that just happened to fit the spider slot. It was meant to be a temporary one while I checked the whole idea out (including the tension aspect of it) and then I would get a proper insert made. As it turned out the aluminum insert worked and sounded fantastic and the tension hadn't changed enough for me to notice so I just played it that way for years until I sold it

Mike Harris · From: Texas, USA

It seems that with a metal insert you might be able to cut away some under the center, enough to allow a right-angle screw driver to adjust the tension...
I don't know if a hard wood insert would hold up in that situation.

Forum Index > Steel Without Pedals		Next oldest topic :: Next newest topic

All times are GMT - 8 Hours	Jump to: