A100 Frequency 90 and 91.

[Crewser]

Good Morning Everyone.

This forum has been a wealth of information for me while I have been going through this A100 I purchased. I try to search all questions before asking questions but I cant find any info on this problem.

My problem is that any time a draw bar is out # 5 through #9, the note that frequency 90 and 91 is associated with seem to be off key or maybe an octave higher.
Other than that I think I have this thing working pretty good.

Any suggestions would be greatly appreciated.
Thanks in advance.

Jim C

[enor]

Good Morning Everyone.

This forum has been a wealth of information for me while I have been going through this A100 I purchased. I try to search all questions before asking questions but I cant find any info on this problem.

My problem is that any time a draw bar is out # 5 through #9, the note that frequency 90 and 91 is associated with seem to be off key or maybe an octave higher.
Other than that I think I have this thing working pretty good.

Any suggestions would be greatly appreciated.
Thanks in advance.

Jim C

This is one of those cases when a short video clip illustrating the issue would be very helpful - it's not easy to comprehend the exact nature of your problem.

[Crewser]

This is one of those cases when a short video clip illustrating the issue would be very helpful - it's not easy to comprehend the exact nature of your problem.

Hi Enor

https://www.youtube.com/watch?v=bFyc85b5Mic

This link is to a short video of the upper scale with the 4th drawbar out only.

https://www.youtube.com/watch?v=Se7d5jeYAZ0

This second link is to a short video of the upper scale with the 7th drawbar out only and the C# and D notes sound distorted seem to go to a higher note when played.

Jim C

[enor]

Hi Enor

https://www.youtube.com/watch?v=bFyc85b5Mic

This link is to a short video of the upper scale with the 4th drawbar out only.

https://www.youtube.com/watch?v=Se7d5jeYAZ0

This second link is to a short video of the upper scale with the 7th drawbar out only and the C# and D notes sound distorted seem to go to a higher note when played.

Jim C

What you're hearing is called "harmonic foldback". This D key, on drawbar 7, carries frequency #91 on it which is the last frequency in the generator. So, when you continue upwards the organ repeats the frequencies from the octave below. It's a feature, not a bug!

You'll notice the same thing on the transition between top octave F#/G notes on drawbars 6 and 9 (even two times on #9). And, between B/C on drawbar #8.

[Crewser]

What you're hearing is called "harmonic foldback". This D key, on drawbar 7, carries frequency #91 on it which is the last frequency in the generator. So, when you continue upwards the organ repeats the frequencies from the octave below. It's a feature, not a bug!

You'll notice the same thing on the transition between top octave F#/G notes on drawbars 6 and 9 (even two times on #9). And, between B/C on drawbar #8.

Thanks Enor,

Guess that's why a could not find anything about it.

I just know when playing above middle C and with the 9th drawbar out the pitch of the 4th F just seemed over powering and higher than I wanted it to. Guess I can just throttle the 9th drawbar back.

Thanks Again.

Jim C