L100 to M100

[Guest]

Hi, this thread is going to be a little "photo blog" about my modifications - Hammond L100 to M100 conversion - installing AO-29, making an electronic emulation of scanner, etc. I have done basic things like TG recallibration etc.</p>

Please comment, make suggestions, ask questions etc.</p>

13-04-2008</p>

1.Matching transformer from B3 installed, with one half removed (no split vibrato - I was too lazy to cut the drawbar busbars) - to get rid of hum present in L100
</p>

2.Eight 1 ohm resistors between drawbar busbars - to avoid shorts between matching transformer taps while setting the drawbars in intermediate positions - like 4,5 (there are 17 - position drawbars in L100)</p>

3.Percussion wired in 50% - harmonic and keying (no decay and volume control yet)</p>

4.AO-29 placed</p>

next steps: vibrato, expression control etc.</p>

</p>

poor organ - german made L100</p>

</p>

matching transformer wired but not yet screwed</p>

</p>

the amp - manuals and percussion partially wired.</p>

please comment </p>

Jon</p>

[johnny b3]

Re: L100 to M100



Vibrato and Percussion are all built into the A0-29, correct? </p>

The TG, once re-callibrated will be identical to the M-100? What are the factory differences between the 2 models...I know they cut costs with the L by using cheaper wood cabinets as well as the different vibrato. Separate amps for vibrato/percussion...etc.</p>

</p>

Looking forward to more pics!</p>

</p>

[Guest]

Re: L100 to M100



Hi Johnny,</p>

L100 have increased higher notes output voltage to hide the keyclick.</p>

L100 and M100 have identical case, manuals etc.</p>

The AO-29 have percussion built-in - better sounding then the L100 one. In M100 vibrato is produced by delay line and scanner. I have no idea how to attach the scanner to TG. Any ideas?</p>

jon</p>


</p>

[Guest]

Re: L100 to M100



</p>

First attempt to couple the exp. pedal with swell capacitor - with ruler. [:D]</p>


</p>

First idea of vibrato - Hammond M3 delay line (recapped) and 16:1 multiplexer (NE555, CD4520, DG406B) - sounds really like ****!</p>

</p>

B3 matching transformer installed.
</p>

[Guest]

Re: L100 to M100



Sounds like a similar project I've been working on. Only I'm using the AO-29 as a preamp for the stock L-100 amp. Not going for the B3 sound here, mind you. </p>

This pic is in the early stage of fitting. A lot of cuts to the L-100 case needed to be made and holes drilled, but it fits like a glove. Just need to strip it down and make it beautiful.  </p>

 </p>

  </p>

[Guest]

Re: L100 to M100



Nice project, Nathan.</p>

Would you use the original LDR expression pedal from L100 in this organ?</p>

Jon</p>

[Guest]

Re: L100 to M100



That's the plan. Basically a stock M3 up to the output, which I will pad down and send to the input of the L-100 amp. Then I'll control the expression from that point. </p>

 </p>

 </p>

[Guest]

Re: L100 to M100



Why don't you simply use the AO-29 6V6 amp for driving speakers?</p>

Jon</p>

[Guest]

Re: L100 to M100

I have my reasons. Customized output stage and spring reverb for starters. Like I said, I'm not trying to emulate a Hammond, rather, create my own. 

[Guest]

Re: L100 to M100



Nice idea, spinets are great to customise.</p>

About the reverb, can you measure the reverb tank coils resistance Nathan? I don't have an ohmmeter here [:S]
</p>

I sucessfully replaced the 6AU6 with dirty-cheap russian beam tertodes 6SH5P (6Z5P). Works nice.</p>

Jon
</p>

[Guest]

Re: L100 to M100



14.04.08
</p>

Percussion "fast decay" and "percussion soft" operational as well as organ "volume soft" tab. No idea what to do with "brillance" anyway.
</p>

[Guest]

Re: L100 to M100



</p>

Full foldback added. Thanks for the contacts Johnny!</p>

New reverb amp in place. This cord with black/yellow wires supply plate and filament voltage for 12AX7 and 12AT7 (not in place now anyway...)</p>

AO-29 with wiring. 6SH5P tube instead of 6AU6. It gives a better sound IMO.</p>

</p>

Matching transfomer with cover removed showing the... matching transformer! [:D]</p>

Jon</p>