Rodgers Concord 760 program features

[paul2169]

I'm helping a friend tweak his Rodgers Concord 760 with MIDI and Walker Flute and Principal Enhancement Generators. I am unable to engage the Programmable Alternate Level Selections to adjust chiff, etc. I know how to do this on my Exeter 770. The selector switch is in the UP position. With the Concord 760 on, I've pressed and held the SET button and turned the POWER switch. Am I missing something?

Also, we are trying to add reverb with the NANOVERB digital unit. I have one of these on my Exeter which I installed and tweaked. No luck on the Concord. I see signals are being received on the NANOVERB, but no reverberation. Is there another adjustment on the console since there is no knob underneath the desk (there's a knob on my 770). Perplexed.

Also, my friend would like to know if he can run Hauptwerk audio output back into the organ using the Rodgers speakers.

At some point we'd like to replace the dead bulbs on some of the drawknobs and pistons. Will this require surgery? I hope it's a simple bulb replacement but I suspect not.

Thanks everyone in advance for your help and guidance.

Paul

[paul2169]

I'm chewing on this. I don't have all the speakers connected. I think I have channel 1, 2 and pedal connected. Channel 3 is not.

[toodles]

1. MFB switch in the UP position.
2. While pressing the set piston, turn the power switch to the on position, release both. Tutti indicators will start flashing.
3. Press set and any #1 piston. Soft voices will be lighted; loud voices will be off; turn the soft voices off to change to loud, or turn on any off voice to make it light, for soft. If a voice won't turn on/off, it isn't adjusted through this voicing procedure.

If the 760 has factory MIDI, the MIDI panel might have a stereo input pair you could use for Hauptwerk audio; if he wants to run more than the stereo pair, he'll have to tie into the preamp board. There is no simple, easy way to do that.

For the reverb, just follow the signal on the preamp board schematic. I think reverb is on the last page of the schematic. It'll show you where the reverb recovery/injection op-amp connects. It should be U59, a single in-line package op-amp. If it isn't there, the easiest way to inject reverb will be to take the output of the Nanoverb and connect it to the pin that is the output of that op-amp; set the reverb for 100% wet so as not to double up on the dry signal, and adjust reverb volume with the pot on the reverb unit.

I believe at this point in manufacturing the Rodgers LDK bulb has pre-attached wires and has to be re-strung through the drawknob unit. The head attaches with a small Allen wrench, probably on the bottom of the drawknob shank. You'll probably have to detach the drawknob panel to access the drawknobs. Yes, it is a pain.

Pistons are replaced, not re-lamped.

[paul2169]

Thank you for your reply. Sequence of invoking programming still doesn't work per instructions. I'm perplexed. Works on my Exeter.

[toodles]

Try turning the power switch CCW (counter clockwise) per the manual while holding the set piston.

Correction on the reverb: the schematic is on page 4 of 9.

The reverb level if it had a spring installed is R874. That is just to the right of the middle expression LDR rubber cover, and should be labelled Rev Lev.

[paul2169]

CCW worked. The owner's manual is unclear. States "turn the switch". I had the Nanoverb connected correctly with adjustment via R874 (my Exeter has a knob under the keydesk). The input connection is wonky and will stop buzzing when I gently move the RCA plug back and forth. Do I need to re-solder that connection? I might use a separate amp with additional speakers for a better reverb effect.

[toodles]

Your RCA cable might be intermittent, or the connector. I'd try changing the cable first. It might also be that the center pin contact is a little loose--you could try to tighten it a bit with a pair of needle nose pliers if that is the case.

Rodgers analog designs underwent some cost reductions during the late 1980's from what I can see--lots of little things. I suspect the "under the key desk" reverb adjustment pot was one of those. Another example was the wood solids used on their lids--early 1980's production the solids were mitered, later production models, they were butt-spliced.

[paul2169]

Tried switching out cables for RCA jacks and tightened. Still buzzing off and on when I tap the cable. Is there another way adding reverb not using the RCA connectors on the board?

[toodles]

You could try soldering to the back of the connector, I guess. Or, if it has MIDI input jacks, you could use those.

If both your send and receive cables have the shield connected, you might have a ground loop. Disconnecting the shield from one (only one) of the cables would be the solution for that. But it is probably an intermittent cable or connector.

[jlmk]

If you have and decide to use the midi audio input jacks, be aware that jack A goes to one channel, jack B goes to another channel, nothing goes to a third channel (or antiphonal), and A & B both mix down to the bass channel. You might need to adjust your speaker connections accordingly at the amp. On the way to figuring that out, I tried everything under the sun to get audio into the reverb jack on our 760. Nothing ever worked.

I've been using Hauptwerk exclusively with our 760 for the past year, using program changes and midi couplers with reasonable results.