| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1419.1 | is this a developement or a revelation? | ANGORA::JANZEN | Tom LMO2/O23 296-5421 | Mon May 30 1988 19:34 | 13 |
| We need to see an oscilloscope trace of the output of the synth.
then the output of the mixer.
Once I had a pre-amp with a dead battery with that symptom in a
live performance. Not a dead battery, just a wounded one.
So the mixer could do that if it had batteries and the
battery-replacement plug were coming out unnoticably.
so that it was using batteries that weren't up to snuff.
An audio chain element with insufficent poop in the power supplies
(low voltage) can do that.
It's a common problem with sharp attack piano sounds, though.
Did this setup ever work correctly?
TOm
|
| 1419.2 | No batteries... | FGVAXZ::LAING | Jim*261-2194*DEC MemorabiliaCollector | Tue May 31 1988 10:03 | 6 |
| No batteries; all runs on AC power. The problem had been noticed
in the past, but is more noticable now due to a new controller with
different touch/velocity characteristics, i.e. I'm sending higher
velocity values more often to the TX-802.
-Jim
|
| 1419.3 | Mixer / keyboard specs? | FGVAXZ::LAING | Jim*261-2194*DEC MemorabiliaCollector | Tue May 31 1988 10:09 | 10 |
| I looked through some brochures on mixers ... sound reinforcement
mixers, recording mixers, keyboard mixers. There seems to be NO
standardization in reporting of specifications! Some talk about
dBV, some about dBm. A greater variety of input impedences than
I'd expected; some with "line level" as the primary input, some
with mostly "mic level with trim" on most inputs. What "level"
do most keyboards put out? What impedence? Couldn't find that
sort of info in my TX-802 manual...
-Jim
|
| 1419.4 | I think I've got it ... | FGVAXZ::LAING | Jim*261-2194*DEC MemorabiliaCollector | Tue May 31 1988 11:17 | 15 |
| Talking with someone, I think I've found the problem. It isn't
my mixer, it's my TX-802! I'll have to experiment, but this seems
very likely to be the cause:
The TX-802 is a max output! It has no VOLUME or OUTPUT control
of its own. I'd need to send MIDI volume messages to reduce its
output. Probably, due to it always being "turned all the way up"
so to speak, it's overloading my mixer's input stage. So, I'm left
with a new problem: how can I attenuate the TX-802 without having
to send MIDI volume messages? I think Yamaha really goofed - every
other MIDI sound module I have has a VOLUME or OUTPUT slider/knob!
Short of buying a pedal or other device to send MIDI volume messages,
how can I control this problem?!
-Jim
|
| 1419.5 | Time to Go Potty | DRUMS::FEHSKENS | | Tue May 31 1988 11:29 | 7 |
| Why not just use a volume pedal on the output? Or a simple resistor
network to pad the output down to an acceptable level for your
mixer's input stages? Doesn't the mixer have a gain/sensitivity
control for the line input?
len.
|
| 1419.6 | Attenuator schematic | IOENG::JWILLIAMS | Zeitgeist Zoology | Tue May 31 1988 11:42 | 22 |
| Here's an attenuator network:
R1
+------+----/\/\/\/----+------+
| |
Z R2 Z R2
Z Z
| |
+------+----/\/\/\/----+------+
R1
Given an input impedance and an attenuation level in percent,
solve for the simultaneous equations:
Ri = 1/((1/R2)+(1/(R1+R1+R2)))
A% = R2/(R1+R1+R2)
If the input is unbalanced, that is, if one terminal is connected
to ground, short one of the resistors and remove one of the R1's
from each equation.
John.
|
| 1419.7 | Misc | FGVAXU::LAING | Jim*261-2194*DEC MemorabiliaCollector | Tue May 31 1988 13:11 | 12 |
| Re .5
My mixer does have a sensitivity control, but as mentioned in .0,
I get distortion/clipping when playing certain patches at high key
velocities ... sure, I can get a pedal, but I wanted to avoid carrying
yet another gadget with cables, etc. The idea of a "Resister pad"
sounds like it might be what I want, although I'm not very knowledgable
in working with electrical components, etc.
Thanks for the hints/suggestions...
-Jim
|