T.R | Title | User | Personal Name | Date | Lines |
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2209.1 | Dirty Slider?? | WEFXEM::COTE | Call *who* Ishmael??? | Wed Dec 20 1989 14:43 | 1 |
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2209.2 | hmmm... | NRPUR::DEATON | | Wed Dec 20 1989 16:13 | 8 |
| RE < Note 2209.1 by WEFXEM::COTE "Call *who* Ishmael???" >
> -< Dirty Slider?? >-
But would it do that if the slider is not moving?
Dan
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2209.3 | Worth a squirt of cleaner to find out... | DCSVAX::COTE | Call *who* Ishmael??? | Wed Dec 20 1989 16:50 | 7 |
| It's been my experience that it would, or at least *can* cause the
output signal to break up.
I've seen it on my Mirage, and on one of the input trimmers on my
board...
Edd
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2209.4 | | NRPUR::DEATON | | Wed Dec 20 1989 17:06 | 4 |
| What kind of cleaner?
Dan
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2209.5 | | STROKR::DEHAHN | | Wed Dec 20 1989 17:14 | 5 |
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Rat Shack ozone depleter followed by compressed air
CdH
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2209.6 | Methinks they doth protest too much.... | WEFXEM::COTE | Call *who* Ishmael??? | Wed Dec 20 1989 17:15 | 10 |
| I've used Color TV tuner cleaner with totally acceptable results,
however, I've heard that this maybe too 'abrasive' for pot use. (?)
Again, I keep a can handy and use it freely.
Rat Shack undoubtedly sells a switch cleaning fluid.
If it clears it up, you may want to consider treating your pots and
sliders with a 5% Cramolin solution...
Edd
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2209.7 | | NRPUR::DEATON | | Wed Dec 20 1989 17:30 | 1 |
| I'll pick up a can of cleaner tonight and see what happens. Thanks all.
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2209.8 | | NRPUR::DEATON | | Wed Dec 27 1989 12:21 | 4 |
| No improvement. Any other suggestions?
Dan
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2209.9 | Suggestions | DRUMS::FEHSKENS | | Wed Dec 27 1989 13:03 | 10 |
| Have you done the requisite experiments to confirm that the distortion
is originating in the unit itself and not downstream? If it is
in fact within the unit, can you adjust some programmable gain
parameter? It's relatively easy to drive just about any synth into
distortion with a suitable combination of parameters and the VCA
gain topped out. If the distortion seems to be patch specific,
that could be an indication of this kind of problem.
len.
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2209.10 | | NRPUR::DEATON | | Wed Dec 27 1989 13:38 | 18 |
| RE < Note 2209.9 by DRUMS::FEHSKENS >
Well, the RD200 is an entirely pre-set instrument. The only controls
over patches I have is master volume, chorus (on/off) and tremelo (on/off/rate/
depth). As I said earlier, the problem may be mostly in the chorus circuitry,
as the distortion is magnified when it is turned on. Or it could be that the
chorus circuitry adds the kind of modulation that amplifies the distortion in
the output stage.
Oh, there is a three postion switch in the back (as in most Roland
products) to control output level. It appears that the distortion is happening
before it reaches this attentuator, since it distorts at any setting.
And yes, I have traced the distortion to the RD200 and not in other
components (mixers/amps/etc.).
Dan
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2209.11 | Oh No, Roland Field Servcie Required | DRUMS::FEHSKENS | | Wed Dec 27 1989 15:20 | 6 |
| Well, that uses up my supply of standard answers. Sounds like
something's broke. I suspect the chorus is just making it worse
rather than being the source.
len.
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2209.12 | It's only half broke | NRPUR::DEATON | | Wed Dec 27 1989 16:47 | 8 |
| RE < Note 2209.11 by DRUMS::FEHSKENS >
Well, I don't know how anxiously I will pursue sending it out. As I
said, it works o.k. if I leave the volume fader at "half mast". I was just
hoping to find some "useful tips" here (which I did, but to no avail).
Dan
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2209.13 | Bad PSU??? | AYOV16::ABELSEY | | Tue Jan 02 1990 12:10 | 15 |
| I had a similar problem with a Yamaha sound module (EMT-10). The piano
sounds had distortion when I hammered the keys during playing. I traced
this to a bad power supply (it uses what you guys call a wall bug)
which was not providing enough guts to drive the output stages cleanly
when high volume was being output. This resulted in clip distortion.
I know that the RD200 doesn't use wall bugs but you could check the
PSU part of it if you were feeling brave. Perhaps there is a suspect
smoothing capacitor, &c.
Try putting a 'scope across the audio out and see if you can see any
clipping of the output signal (probably require many hands to do
this!).
Andy
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2209.14 | ... but I listen well... | NRPUR::DEATON | | Tue Jan 02 1990 12:22 | 19 |
2209.15 | Power Supply | ROYALT::TASSINARI | Bob | Thu Jan 04 1990 11:28 | 8 |
|
I have a less-expensive keyboard that I use a wall bug with. I can run
on batteries which causes the keyboard sound to distort as the volume
increases.
It does sound like a power supply.
- Bob
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2209.16 | Some improvement! | MAIL::EATOND | In tents | Wed Aug 29 1990 15:04 | 16 |
| Just to put a closing note to this topic...
Shortly before I moved down to misery - er - Missouri, I brought the
piano into Union Music to have them look at it. It was there for quite
a while and it seems that the tech there tried a lot of different
angles. It seems that this is not a common bug as he went through a
number of ROM changes and such to uncover the difficulty. He finally
gave it back to me at no charge saying he did the best he could.
What is intersting about it all is that whatever he did actually
*did* seem to help out. There's still some distortion there if you
turn it up really high, but it seems to be less than what was there
before he worked on it. I am please, and it cost me nothing.
Dan
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