brad@kontron.UUCP (Brad Yearwood) (01/24/86)
My DX-7 headphone output (nice feature) seems to vary greatly in
quality depending upon the type of headphones I use. With my
old Sennheiser 424's with the now-uncomfortable decaying foam
earpieces, it sounds pretty good. On some newer Bang & Olufsen
phones (which sound great on a stereo system), it becomes more
noisy and harsh. Does anyone else have a similar experience?
Also, there is a peculiar sort of distortion that sometimes rides on top
of the sound (headphone or line output).
I notice it particularly on the mid-bass notes of some of the
factory low brass patches and the Piano-2 patch. It sounds like
a distorted form of phasing/flanging, and makes the overall a little
raspy, particularly in the attack and initial decay. Has anyone else
experienced this, or should I consider repair or tweaking?
Here are my speculations about possible causes of the distortion:
Aliasing due to minimum-cost design or component tolerance
problems in the post-D/A lowpass filter. (Possibly improvable.)
Digital noise coupling to the analog stages. (Possibly improvable.)
Truncation or overflow in the FM synthesis. (Cast in silicon.)
Any comments? Has anyone experimented with any tweaks or improvements?
I am actually very pleased with the DX-7 - it sounds mostly nice and is fun
to use.
Brad Yearwood
Kontron Electronics {voder, pyramid, loral}!kontron!brad
Mountain View, Calif.