Tuesday, September 4, 2007

Concertina Progress

Some of the woodwork is finally done. Here are progress photos:

Treble end:

The edges have been routed to receive guitar bindings. Unfortunately the router took off some chips of the surface veneer which will have to be repaired before the bindings can be attached. Holes on front will receive grommets.

Bass end:

Bellows frame:

Treble end with bellows frame, handle and palm rest (mock-up).


Treble valveboard & reedblocks (mock-up):

Bass valveboard & reedblocks (mock-up):

Tuesday, July 17, 2007

First Amplifier Project, The Lama Kazu 8SE

It started as an attempt to create something like the Kalamazoo Model 1, but with more gain, better tone control and a master volume.

  • Single-ended, ~8W RMS (Clean); ~11W (Full distortion).
  • Preamp tubes: 2×ECC83. Power tube: 1×7591.
  • Speaker: Jensen C8R

Cabinet is FSC-certified pine, finished with Tried & True wood finish (hand-rubbed Linseed & Beeswax product). Grill cloth is Marshall "cane".

(Partly-visible bottom shielding is 6" wide aluminum flashing tacked to cabinet.)

Built in a Hammmond 13.5" × 5" × 2" aluminum chassis box. I forgot to take a picture of the circuit before final assembly, so here is an early image with just the power supply underway, and heatsink hemostats protecting a diode:

Thursday, March 22, 2007

The concertina project so far, part 1

The project began in 2000 with the closing of Star Concertina in Cicero, IL. Much dreaming ensued about carrying on the tradition of [Chemnitzer] Concertina manufacturing in Chicago.

A bit of tinkering with old boxes followed.

Some conversations were had with John Bernhardt:
  • What was done by Star in-house.
  • What was outsourced.
  • How some construction details were realized.
  • Where materials were sourced.
  • The marketplace for concertinas and the place held by Star, Hengel, Echo, etc. in the market; also the nature of buyers in Chicago vs. Wisconsin, Minnesota, etc.
Some old parts were purchased from Bill Brown:
  • Reed sets removed from instruments that had been converted to his "Buttontina" product.
  • Threaded brass bushings (with nuts) for key lever pivots. (Turned out to be long: They must be cut down on a lathe to be useful.)
  • L-screws for reed plates in a "pin" reed instrument (smaller than the ones used for long-plate reeds).
  • Grommets for "sound holes" at front of instrument.
Some experimentation with various action arrangements and CNC manufacturing techniques was done:
  • Wood (solid, aircraft plywood).
  • Sheet plastic.
  • Molded plastic.
  • Wire (similar to some English-construction concertinas).
  • Various bushings and pivot methods.
Some experimentation with reedblock arrangements and CNC manufacturing techniques was done.

Suppliers were located for materials.