Rodgers 740 low volume

[Esteban Enrique]

Hello all,

I have a Rodgers 740 organ I acquired for my church as a donation from a convent. The organ is great, it comes with the P32 sub but no other speakers. I have added two large full range Jbl L5 speakers for the other two channels. However, there is a huge problem.

The volume is really low. The expression and crescendo pedal work really well, but everything is low volume. Minimum volume is barely audible, max is enough to practice but certainly not for congregational singing. I don't know what to do. I don't know almost anything about electric organs, and likewise with electronics.

The two speakers don't seem to be the problem, I attached other 6 ohm speakers which worked the same way, same volume problem. When on max volume, one of the channels has decent white noise - it sounds like max volume. But the actual output is meh.

I compared to our Conn 640 with an incredible internal speaker that can get to be almost deafeningly loud.

Please let me know what I should do. I am willing to learn if someone can teach.

Thanks,

Esteban

[myorgan]

Esteban,

There are amplifiers inside the organ which can probably be turned up. We have other members who can give you more specific advice on how to access those and turn them up. That should solve your problem. They will weigh in within a day.

Welcome to the Forum!

Michael

[Esteban Enrique]

Thank you so much Michael! Even though I still don't know what to do, hearing that there is a probably solution gives me a sigh of relief. I found the amp today while I was looking at this inside. Other than identifying what it is, I don't know what else to do. But I will wait patiently!

Thanks, I feel welcomed already!

[toodles]

The Rodgers dealer in your area is Organ Power and they are very familiar with the Rodgers analog organs. You can contact them--see their website at: http://www.organpower.com/contact

The 740 has numbers volume adjustments--they are all located on the output preamp board, but there are so many controls on that board it is a bit confusing. You can get into trouble with the settings if you don't know what yu are doing. It's probably worth a call to Organ Power to set up a service call since they are close to you.

[Esteban Enrique]

The Rodgers dealer in your area is Organ Power and they are very familiar with the Rodgers analog organs. You can contact them--see their website at: http://www.organpower.com/contact

The 740 has numbers volume adjustments--they are all located on the output preamp board, but there are so many controls on that board it is a bit confusing. You can get into trouble with the settings if you don't know what yu are doing. It's probably worth a call to Organ Power to set up a service call since they are close to you.

I left them a voicemail yesterday so I'm trying to get them to come over and help out. Any idea as to why the organ is so quiet in the first place? Could it have to do with the place it was in before, which was a smallish chapel?

[toodles]

When installed, levels are adjusted for the specific installation. In a small chapel that is used for quiet service, it might be appropriate to set the volume levels low; in addition, the speakers normally used are quite efficient, so that would have been taken into account when setting it up.

[Esteban Enrique]

Going off of this forum post, I have a rough idea of what I can do on my own.
https://organforum.com/forums/forum/...ing-repurposed

Is there any diagram or chart I can work with to turn the correct pots for the correct volume? I really want to see if I can do this on my own without risk of damage. I think as long as I can find the preamp and know how to turn the pots back to factory , this should work?

Thanks!

[myorgan]

Esteban,

There is no such thing as "correct volume." In the process of installing an organ (as Toodles has so aptly stated), an organ is adjusted to fit the space. For that reason, it helps if the person installing it has a good ear, and an experienced knowledge of how to make the organ fit the space. In my early days with Allen, I had some difficulties in this area. You might as well with your Rodgers.

Just a couple of thoughts.

Michael

[toodles]

Here's the voicing guide that covers the 740.

Voicing Procedure.pdf

[Esteban Enrique]

Here's the voicing guide that covers the 740.

Toodles,

Thank you so much for this, this is exactly what I was looking for. From a basic look through, my goal would be to find the main channel pots and adjust them accordingly.

From my quick read, this should be done with two people:

1. Organ on
2. Full expression pedal
3. Using 8 ft stops while adjusting?

Or am I missing something, and this should all be done off power?


I will update my findings hopefully by tomorrow or the day after that.

God bless you

[toodles]

Two people makes things easier--one can play and the other adjust, but it can be done with just one person and some sort of a key wedge to hold the note on.

Full expression is correct, and use 8 ft stops to adjust the balance between voices; then check overall volume with full registrations to make sure the organ isn't too loud.

[myorgan]

From my quick read, this should be done with two people:

1. Organ on
2. Full expression pedal
3. Using 8 ft stops while adjusting?

Or am I missing something, and this should all be done off power?

Organ on. Otherwise it's quite difficult to hear what you're adjusting-especially if you adjust the wrong setting! Of course, none of us have ever done THAT before.:embarrassed:

Michael

[Esteban Enrique]

Hello,

Went to the church today to work out the voicing. I was able to find the panel and change some of the master settings! Basically moved them to factory, and so far its a bit better, though I still need to do more detailed work. Hard to do by myself without an assistant holding notes and stuff, maybe I can get my brother to help.

Two problems:
1.My subwoofer is in serious need of refoaming. It is the monstrous Rodgers P32 and it sounds like a very low frequency burp when it plays. But it does work and its pretty loud. Just needs to be refoamed.

2. It seems like one of the channels is simply not sounding. I only could hear one of my two speakers, the other one is practically mute. I will play around to make sure it's not a speaker issue, but I think I already checked that and it seems to be that the channel isn't working for some reason. Given that the speakers are fine, what could be the issue here? The main 'organ' sounds are heard through one of the channels, but the other is not working. I'll have to take a closer look. Could it have to do with power amp volume controls? I can take a look at those as well.

I ran out of time before the mass and other activities, so will have to return in a few hours. However, if you guys have any advice on either of these two points, please let me know. I especially need help with #2. I'm pretty confident I can refoam following a tutorial on the internet.

Peace

[myorgan]

Esteban (or is it Enrique?),

How do you know the subwoofer needs refoaming? Is the surround deteriorated, or is it just the sound? If it is just the sound, perhaps it is an amplifier issue or the speaker is being overdriven. A low-frequency "burp" could be the speaker responding to frequencies below your hearing range, and you're not hearing it because you're not far enough away. A surround will generally have losses (gaps/cracks) in the surround, which means it needs to be re-foamed.

To diagnose the speaker issue, try switching one thing at a time in the audio chain:

1. Switch the wires from the silent speaker to a known, good speaker and see if you can hear something.
2. If that doesn't result in sound, with the known, good speaker still connected, try a different set of wires (ones you know work).
3. If that doesn't work, then switch things inside the organ.

By eliminating one thing at a time, you can narrow the issue down to what is causing the problem and then concentrate on that one issue.

I've found that when working alone, I can use a car key or a pen cap to wedge down keys in a 3-note chord while you work in the back of the organ. When leveling the treble and bass, I then move a couple of the wedged notes to either end of the keyboard so I can hear the balance.

Hope this helps.

Michael

[Esteban Enrique]

Hi Michael,

Esteban is the first name, Enrique the last. Many people get confused about this :)

Very helpful. The speaker needs to be refoamed because there is scarcely any foam left! Pieces fall every time I play it. I'm not sure whether to get foam or rubber, I'm leaning toward foam which is what it originally had. The sound is actually good in the higher frequencies and muddy in the lower, again, I think bc the speaker is rubbing with the voice coil since the surrounds are virtually gone.

For the channel issue, I will do just that. I'll also look at the connections inside and see if everything is in order.

Thanks

[myorgan]

Esteban,

Thank you for the name clarification. I've had the same problem with many students who have names that can both be first and last names!

In the case with the speaker, I'd recommend not playing it at all because if you continue to play the speaker, you can damage the coil and that's a much more in-depth repair. I had that problem with my first organ, purchased from a member of the Forum in NC. I only discovered the issue when I was playing a rehearsal for the Symphony, and the audio fellow from Radio City Music Hall pointed out the issue to me. I had to learn to switch woofers, and to solder in a hurry!

There are accordion surrounds available as replacements, but IIRC they don't allow as much excursion as a rubber surround.

Michael

[cinnamon]

I'll echo what myorgan is saying. Don't use a speaker with very little foam left.

With scarcely any foam left, it is very likely that the voice coil is rubbing as it moves in and out, and thus is getting some of the coating on those wires worn off. Eventually this may cause a short. Even if it doesn't short, you may still need to replace the voice coil (or re-wind it if you have the facilities) if you continue using the speaker without the voice coil being fully supported.

[Esteban Enrique]

New discovery

The channel that doesn't work is channel 1. Cables all work, speakers all work. Something is wrong inside then, but I don't really know where to start.

Interestingly, when I increase expression pedal, it quiets even more! Yes, there is sound being transmitted and it actually sounds normal, but so so faint and quiet. I feel like the solution is close by but I don't know what. Another interesting fact, the preamp for channel 2 is what changes the volume. But even the max preamp volume is peanuts.

Thoughts? Thanks so far for the help!

[myorgan]

Quick question: Does that division/speaker have its own expression pedal separate from the others?

If so, it could be a bad lamp inside the pedal has either blown, or sometimes there is a black dot placed on the bulb (to control the amount of light available to the sensor), and that could have come off.

Alternately, you could check the physical connections of everything in that channel to make sure the connections are solid and secure.

Other than those suggestions, I'm at the end of my ability to help with a Rodgers simply due to my ignorance of how they work. Hope this helps.

Michael