1950s Kay 4/4 Cello to 1/8 Bass Conversion




My friend Ivan brought this full-size, plywood-special Kay cello in the other day. He'd been using it as a "bass" with electric bass flatwound strings fudged onto it. He sort-of wanted to sell it... or trade it... or something! It sounded, well -- bad -- with the electric strings. As you'd expect, they just don't sound right. It's a bit like piano wire twang with no warmth. His plan, however, was good. I've done similar stuff with Kay cellos for local musicians in the past. I wanted to do this up my way, however, with "all the good stuff" added to make it function and sound its best in this "mini-bass" role.

The instrument itself was in good order, really, so all of my changes were mostly "setup-side." I wanted to lengthen the scale to at least 30" so the lower-frequency notes would have some breathing room. I also wanted geared tuners at the headstock, a decent German-style bow, and real strings on it. I can't help but want to solve "problem projects" like this.

After work, it plays great and has a sound and carrying-power that's above what you might expect for its size. This is perfectly usable for small-group acoustic work, especially when bowed, though it'd probably get lost in a large jam. It's great for recording, as it sounds like a big, ply-Kay guy on mic but isn't physically big, so it's happy to hang out in a corner of a studio space. It's also small enough that one can sit it on the lap like a bass guitar and pluck it that way, too. I've done both and, of course, there are advantages/disadvantages to both methods.

Work included: installing a fresh set of Japanese-made Gotoh bass tuners at the headstock, fitting and installing a new bridge, resetting the soundpost lower on the instrument (about 3/8" south of the treble bridge foot), a new (old-stock) ebony tailpiece install, addition of a fancy "big rubber ball rest" to the old Kay endpin, side dots aligned to the new 30" scale length for reference (I moved the bridge south about 4"), and most importantly -- stringing-up with a fresh set of Corelli 1/8 (fractional) double bass strings with steel rope cores. These Corellis are my favorite upright strings as they're easy on tension, pitch-stable, sound fantastic plucked or bowed, and are easy to bow. At about $115 a set, they're also on the cheaper (!) side for upright strings, too. Finally, after all these changes, a good setup brought the action down to "fast and easy."

Scale length: 30"
Nut width: 1 5/16"
String spacing at nut: 1"
String spacing at bridge: 2 1/4"
Body length: 29 3/4""
Lower bout width: 17 3/4"
Upper bout width: 13 1/2"
Side depth at endpin: 5"
Top wood: ply maple
Back/sides wood: ply maple
Neck wood: maple
Fretboard: rosewood
Neck shape: steep radius with medium, C-shaped rear
Bridge: maple
Nut: rosewood
Weight: 8lb 20z

Condition notes: there's minor wear and tear throughout (with a few tiny chip-outs of first-layer ply here and there along the edges) but overall it's in good shape. The neck is nice and straight with only 1/32" of relief overall. Much original equipment is missing -- the bridge, tailpiece, and tuners are replacements.

It comes with: a new, 1/4-size German-style upright bass bow.



Double dots mark out "frets" 3, 5, 7, 9, 15, and 17. The octave (12th "fret") has three dots.



Interestingly, Kay used figured/flamey maple veneer on the sides, back, and top.





The new Gotoh tuners don't fit perfectly at the headstock, but they certainly beat the original friction pegs and are quite nice quality-wise.


While these "endpin balls" are a little pricey for what they are, they're perfectly designed. I learned long ago that no other endpin gadget is more useful than one of these as they keep the instrument in place and save the floors, too, from random spike-throughs of cheaper "balls."

Comments

lincoln said…
If you were charging for this conversion, what would the cost be?
Oscar Stern said…
That looks super cool. Even if you used it as a Plain Old Cello, the Machine Head tuners will still beat those old Friction Pegs because they're basically pegs & fine tuners all in one. Those machine head tuners allowed us to get rid of the Fine tuners from the Tailpiece.
Tarkun said…
Hi, don't you have a picture of the front of the head/tuning pegs?

I'm planning to do it on one cello too but the tuning peg I have look to short, that it doesn't reach the hole from the other side of the head...

Thanks for this awesome post!!!
Oscar Stern said…
They do make Brass Tuners for Cello too