At times during a performance the organ sounds drops significantly compared to the ensemble sounds, what could be the problem?

Hi....The best places so far to find that manual is here:
http://organforum.com

and here:
http://www.compare99.com/compare.html?q=used-allen-organs&ort=Baldwin-Organs-Sale&adid=iaCkp56kxJ2WqsrQkICkmsLQ1lehnp6kxJ2WqsrQkICkmsLQ1lelcMjD2KRYlsnD1W6U&adver=5&gclid=CJmUpeWD4MoCFZJffgodT-YILw

Need more info.... using line out or does it have built in speakers, make sure if it uses an ac power adapter that it is the correct one (AC vs DC output and voltage\amp rating makes a difference). Is it moved often, was anything dropped or spilled on it, etc? Age... model number and you say organ I'm guessing it's actually an electronic keyboard?

i use korgpa50sd i had some voices by default but once when i inserted my sd card into the arranger every voices got deleted and now everything is new...so can you please help me to get back the old voices?

"sounds flat" ... What are you comparing this to? Pianos at that range are sharped due to stretch tuning so this would appear flat compared to the piano. Use a Korg or other brand tuner to verify. If it is flat, my educated guess is there is a crack in it. Dip it in a vegetable dye water mixture and usually cracks will show up. This is almost like Magnafluxing they use in the aircraft industry. These are likely made of aluminum and repair if cracked would be hard... one could try to have it welded and then filed down to tune it. I have done this with sleigh bells on a pipe organ, but those were brass.

Not likely iit is a fuse. The keys are likely scanned as a matrix with two contacts per key. You need to get a maintenance manual for thee organ. Contact Yamaha America parts for music products. They may have the service manual on CD... they used to get $15 for the CD of the manual. Unless you can find something simple like a cable knocked off this could be hard to troubleshoot.

This may be he characteristic of mixing of the delayed when high distortion is present...

I would go to music store and compare... I tend to think this is the nature of the beast.

If you consider what the waveforms look like with distortion and then add them delayed... they limit out and when added there is a significant difference when adding or mixing waves that are delayed when squared compared to nice sine waves.

Try this link:http://www.organservice.com/ Here's another one:http://www.combo-organ.com/Schematics/index.htm Join this one for free and post:http://organforum.com/forums/thread/73735.aspx This site is good too:http://www.combo-organ.com/spares_and_repairs.htm#Electrolytics Hope these help.

Try posting on the organforum.com.

It sounds like the power amp has a problem. Probably filter capacitors have gone bad.