How to date your Hammond Console

I’ve compiled a list from  information available on the internet that may help date a Hammond console (A-100, C3, B3, D-100, RT-3)

1958 – Vibrato line box changed from wood to metal

1960 – Side blocks change from wood to plastic

1961 – Pilot lamp added

1962 – Vibrato knob changed from smooth to ribbed (‘fluted’)

Mid-1962 – AO28 transformer colour change from silver to black

Spring 1964 –  Start of using red caps

1965 – Hammond script changed from small to large with new logo

1965 – Foam replaces felt

1965 – Introduction of R/C (resistor/capacitor) networks to tones 37-48 to reduce hum and crosstalk

1969 – Drawbar plastic knob style change to have engraved tones

Additional information can be gleaned from the components in the organ. Speakers (A-100 series) are usually stamped with a production date; the same applies for tubes / valves as well as capacitors.

Tubes overview

Here’s some information I found on the tubes / valves in Hammond consoles (A100-series, D100-series, B3,  C3,  RT3)

A0-28 pre-amp:  6X4, 12AX7/ECC83, 12AU7/ECC82, 12BH7, 6AU6 (2), 6C4 (2x)

A0-35 reverb-amp: 6X4, 12AX7/ECC83, 12AU7/ECC82, 12BH7, 6AU6 (2), 6C4 (2x)

A0-44 reverb-amp: 6CA4/EZ81, 6GW8/ECL86(2x)

A0-39 power-amp: 5U4GB, 12AX7/ECC83,  6BQ5/EL84/6P14 (2x)


Headphone amp

Jut added an Audioengine D1 to my setup. This makes such a difference, the sound quality is so much better than using either the Steinberg CI2+ headphone output, and it also leaves the output from my Macbook Pro in the dust. Granted, I’m using an AKG – K-701 which is notoriously tricky to drive, but this little DAC / Headphone amp does it really well.

Most of you will know that I am quite an active contributor to Wikiloops, which involves download mp3 tracks and adding additional stems, and I really had a hard time hearing the previously recorded tracks – with the Audioengine D1, this problem is now solved.

Only downside is the it takes only the small 1/8 ” mini plug size (3.5 mm), but with the appropriate adapter it will also drive headphones that use the larger 1/4” plug, like the AKG K-701.