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1)
Inspect board.
2)
Observe the following: variac at 0, no load, speaker load on, cabinet speaker off, tones on 10, master on 0, R5 clockwise, R291 Counter-
clockwise, all switches out.
3)
Gradually adjust variac to 20Vrms.
U23/8= 3.2V +or - .5V, U23/4= 1.3V +or - .5V.
Reg. Supplies 4V +or - .5V ,-2.6V +or - .5V.
4)
Gradually adjust variac to 70Vrms. Watch variac (amps), scope and listen to speaker. Amp should not draw current. Output will go –4V, then
6V, then snap to 0 between 30-40Vrms.
U23/8= 11.5V +or - .5V, U23/4= -11.5V +or - .5V.
Reg. Supplies 14.5V +or - .5V ,-14.5V +or - .5V.
5)
Continue to adjust to 120Vrms. Supplies + or- 45V + or - .5V.
6)
Turn speaker load off.
7)
Adjust bias. Adjust R224 to get a 5mV bias across R214, 225 (most positive of the two), and R240, 241 (most negative of the two).
8)
Set the following: 400Hz sine wave 500mVrms at piano input, master 10, limit switch on.
9)
Limiter adjust. Adjust R191A to get a flat response at U24/2. Compare to limiter response figure. Turn off.
10) Set the following: master 0, 4 ohm load.
11) Full power, limiter, and current limiter test. Gradually turn up master until clipping. Output = 20Vrms and clip evenly. Turn up master to 10.
Output should hit the rails hard. Engage limiter. Output should swell down from heavy clipping then swell up to full power without clipping
or bouncing. Change to 2 ohm load- output should be a clean sine wave without clipping and = 12Vrms. Change to no load and disengage
limiter.
12) Set master to 5.
13) Output should = 35Vrms. Plug into Synth. 1, then 2. Output should remain the same for all 3 inputs.
14) Plug into Monitor In. Output should = 27Vrms.
15) Plug back into Piano Input and measure direct outs = 8Vp-p.
16) Check line out. Should be clean sine wave and = 750mVrms.
17) Check headphones. Should have slight clipping with 15Vp-p.
18) Compressor test. Engage compressor. Output will attenuate and = 19Vrms without clipping. Turn up input signal 10dB. Output = 33Vrms
without clipping. Turn signal down 20dB. Output = 10Vrms without clipping. Disengage compressor.
19) Chorus adjust. Engage chorus. Amplitude will vary up and down at output. Check direct out in stereo mode. D.O.'s should look different
but at same frequency. In mono mode, D.O's should look same. Repeat (18)- (compressor test) for Synth. 1 and Synth. 2 inputs.
20) Echo adjust. Engage echo. Adjust R84 to get 400mVrms at U10/6.
21) Change the following: square wave input 400Hz 500mVp-p, tones at 5, master at 9 o'clock position.
22) Check tone controls for each input and compare to figures.
23) Engage echo and compare to echo figure for each input channel.
24) Turn on speaker cabinet and do quick audio test with echo on, then chorus on for each input channel.
25) Noise and tap test.
Tones 10, Master 10, switches in – noise < 20mVrms.
Tones 10, Master 0, switches out – noise < 2.2mVrms
Noise should be clean without popping or crackling. Sharply tap the amp on the bench a few times to make sure nothing fails.
Ready For Burn-in
200MK / 200RK TURN-ON PROCEDURE
2/1/88 Rev. 9/28.99-SW
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