Roland Vocoder SVC-350 Service Notes page 11

.5. 7GCGBER JCUND 3GMP.HBSJCR JAI3
ADJUSTMENT
1. MIC :CMPR-3SSCR JAIN
licH 3ine -50d3m
oscilloscope
LEVEL: 9
Make 3UT9 th~at the Red LED on the MICRCPHCNB
section goe3 on and stays on in above 3et-up.
Adjust TR-l for 20V?p at TP-2.
2. GUITAR COMPRSS30R GAIN
Peed a 3igna-l, 1kHz, sine -lOdBm
into JUITAR Input jack.
The Red LED on the GUITAR
section shou-Ld light and stay on.
Adjust 7R-2 for 2OVpp at TP-6.
Vlavefora Che-eking
With HARMCNECS knob turned fully clockwise,
a waveform similar to the waveforms in the figure
bellow 3hou2_i be seen at TP-2O.
Peed a signal,IkHs,Jir.e, J[p 12
OdBm, into TP-35.
Adju3t 7R-3 for 2C7=p
at TP-12.
•11": top
""vertical
—LqINPUT
To make 3ure of the compressor function, slide /j.cb "11" lown to
lowest. -he waveform has just reduced to a acme extent
(,depends on knob'3 traveling 3peed) is ri3ing anc ''ill 3top when
it reaches half an amplitude of earlier.
4. 7CA TRIANGULAR VA73FCRM FR3QU3NCY
Use a 10:1
probe for
trace
clarity.
■/ .:i-.--
ov
Adjust 7R-9 for 5-us per:cd.
5. 7CA CUT-OFF 3IA3
Feed white nci3e, lVpp into GUITAR
input jack.
31ide up JtURACrOR CONTROL FREQUENCY
knobs "1" to "1C" to the top.
Adjust 7R-3 until the noise signal just
disappears. Excessive turn will result
in low 7CA output.
MOTS
If this adjustment failed noise reduction, slide io-m the knob3
individually. The signal leaking through a filter will decrease
as the corresponding knob being 3iided down. Che ck tne Analyser
and Synthesizer filters in that frequency cr.3ir. r or malfunction.
OSCILLOSCOPE
O
VERTICAL
INPUT
Place a grcund on TP-15•
Plug a clank plug into
SN3EMBL2 ^acic to open the
jack circuit.
a. Connect TP-16 to a ground.
Adjust 7R-J. 30 that TP-17
becomes Z7 DC.
b. Connect IP-19 to a ground.
Adju3t 7R-= 30 that TP-13
beccme3 j'I DC.
7. 3XPAN32R JAIN
Feed a signal, 1kHz, sine
-3d3m ir.tc TP-15.
Connect Tr-lo ar.d TP-1? to
the grcur.i.
a.Adjust 7R-5 for 3Vpp at TP-17.
b. Ad just 7R-;- for 3V?p at TP-13.
VERTICAL
—pO INPUT
3BD M0DULATI3C 7C0 iA7E?0RM CHEKING
T = 4.-5sec vapprox.)
at TP-;C ov
_ -107
T = 0.2-0.2?sec
at TP-31
B = 177?? a: IP-33
OV
T = ijus-lrus (apprcx;
at r?-:5, tp-29
<•••>< i •••••• |
Being modulated by the composite sigr.aiiair.e and triar.glular
waveforms), the waveforms at TP-2= ar.i TP-i9 3wee? 3lowly
with :3gslir.g.