Category Archives: Instruction

The Hammond A-100 Series tonewheel organ

A great site with a lot of information of the old tonewheel Hammond organs is Captain Foldback. More details on the A-100 can be found at A-100 – Best in its class

Overview

“The best B-3 is an A-100” – this is a statement occasionally found on the web. It seems to imply that a Hammond A-100 organ is really the same organ as the legendary B-3, with additional features added. The A-100 is often considered as the ‘home’ version of the B-3/C-3 tone wheel organs. The cabinets of the A-100 models were targeted for home use: no locking top, the addition of built-in speakers and reverb, and a wider selection of wood finishes and stylings. Today, the A-100 series organs have become increasingly sought after since they are usually well kept and less played than B/C-3 organs often owned by churches or professional musicians. The slimmer profile of the A-100 cabinet is often preferred over the B-style cabinet for taking it on the road, and makes it easier to get into a home by virtue of its smaller depth, which makes it easier to negotiate doors and corners.

History

The first A-100 organs were produced in in the USA in 1959. They used the necklace type reverb. The A-100 was the first tone wheel console to include a built-in reverb. In the early 60’s, different models of the A-100 featuring a different cabinet style were issued:

  • Traditional A-100. Available in red mahogany and light walnut
  • ‘Contemporary’ A-101. Available in grey and brown mahogany and translucent black
  • French Provincial A-102. Available in dark and light cherry. Features curved front legs
  • The C-3 cabinet was adapted to contain the A-100 speaker system, creating model A-105. Available in light oak and dark walnut. Has a back panel and a locking top
  • The A-122 in Patina Walnut (from 1964). Available in aged walnut. A slightly modified version of the A-101
  • The Early American A-143 (from 1964). Available in maple.

Leslie speakers were sold in matching colours and wood types, but not by the Hammond Company, they were sold directly by Don Leslie’s company, Electro Music.

The A-100 series was discontinued in 1965. The A-105 remained in production until the very last tonewheel organs were made in the mid 70’s. Since the A-105 was still around after 1965, the parts needed to make it , like the speakers, power amplifier and other core components were too, so A-100 series organs were being produced until 1975 in the U.K., Denmark, Belgium and Germany. The models produced under license in Europe were adapted to run using the locally prevalent 200V / 50Hz power supply.

My Hammond A-102

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Type: Hammond A-102 (A-100 Series). US Model (117V).

Uses a converter to get from 220V / 50 Hz to the required 117V / 60 Hz.

Likely built in 1963. I figured this out using the information available on                 The Hammond/Leslie Age Determination List available at  Tonewheel General

  •                 Fluted vibrato knob – 1962 and older
  •                 Small Hammond script (very much faded) – 1935 – 1965
  •                 Pilot lamp by the start switches – 1961 and later
  •                 AO-28 transformer color black – from mid 1962 (silver up to mid-1962)
  •                 Non-engraved drawbars. Engraved drawbars are used on organs built from 1969

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The serial number, 22535, slots in between two other organs on the tonewheel general list that were both identified as 1963 production units.

Speaker serial AO-23232-0 18658 285315 shows a ‚3‘ for the last digit of the year. They are Rola speakers, produced in the 15th week of 1963.

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The coding scheme for the speakers is XXXYWW where XXX is the company EIA code (Jensen = 220, Rola = 285, Heppner = 575), Y is the last digit of the production year, and WW is the production week. 285315 would be a Rola speaker made in the 15th week of 19×3 (you have to figure out which decade using other information).

Hammond used  Heppner, Rola, Jensen, and Magnavox alnico speakers as tuned pairs. One speaker has a ribbed cone and is voiced for the low end of the organ’s tone spectrum and the other one has a smooth cone and carries the mid tones.

Color:  Dark Cherry.

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As far as I can tell everything is original, with basic maintenance done, like replacing the original power cord, and the addition of a Leslie kit (6122 with line out written on the added panel with the line-out and 6-pin Leslie 122 connector, labeled as ‘Leslie 428-13 Tremolo Control Terminal Box’, which is mounted inside the organ), half-moon switch (Chorale / Tremolo) and a switch to toggle between the internal speakers or the Leslie, or both. The Leslie socket had been rewired to accept a 220V power connection to power a Leslie set up to European specifications.

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Here’s some more pictures from a few years back that was used in an advertisement to sell the organ locally in 2015.

Building Hammond organs at the Hammond factory

Inspired by my latest Hammond-acquisition, a 1963 A-102 (this is a Hammond A-100 series tone wheel organ in what was called a ‘French-Provincial’ cabinet, the one with the shapely legs), I’ve been trailing the web to find more information about it, and found a really cool video about the manufacturing process of the Hammond organs, probably from the 50-ies or so:

Most revealing I thought (at about 3:55) is where it is explained that the capacitor is matched to the coil using an automatic process; I’ve often heard that this was hand-matched, but this does not seem to be the case, if this video can be used as any reference. You can see that the lady who is installing the caps uses a measurement device of sorts, so it seems to me that the capacity is derived by formula from the measurement made to, presumably, the coils’ characteristics.

This gives some hop to those that want to recap a tone generator. What is being measured, and how this then translates to the proper value selection for the cap I don’t know, would be great to find out.