Cause Spring Breakage

Older style keyboards (3604P) can be converted to the new 3620. These modifications are only available at the Factory by appointment only cost 350. Included with the modification is a portamento interval footswitch and a one full year warranty. Call the Factory for more details. The 4012 to 4072 Filter conversion is available for all 2600's. See Section 5 page 12 for installation information. 1. Remove the 115 V wire from the terminal strip. 2. Solder the 220 V wire to the terminal strip. 3....

Ervice Motes

PROBLEM The wires in the reverb unit break causing the reverb to be dead. CAUSE The wires connecting the input and output jack to the reverb pickup and driver are flexed by the movement of the spring mounted reverb assembly. SOLUTION Apply RTV silicone rubber to the wires on the input and output jacks and the reverb driver and pickup coils to prevent the wires from flexing. .

Inverted Output

Fzam P .n pn p F R r *a KHS f-K - r'. if 2 I < SUBJECT 2600 SERVICE MANUAL CORRECTIONS THE FOLLOWING CORRECTIONS SHOULD BE MADE TO YOUR 2600 SERVICE MANUAL PAGE 43 Linear input to the VCA should be shown with the input slider fully UP on steps 8 through 10. PAGE 98,33 & 37 A 10K resistor should be shown from pin 2 of A20 (AR circuit) and A1 (ADSR circuit) to ground. PAGE 100 The keyboard connecting cable pin connections should be shown, the power supply filter capacitors should be shown...

Keyboard Contacts Access

5.1 Types of Voltage Controlled Filter Modules 4012,4072 The later model 2601's use a 4072 filter module. This module is physically larger than the 4012 and is not encapsulated. In order to use the newer style filter in an older unit, modifications are required to the control input as shown on the circuit below. The newer 4072 module is identical in operation to the 4012.

Shunt

1 ) Care should be taken not to bend the tip of the jack when mounting replacement jacks to the front panel. 2) When removing the printed circuit boards for servicing, take care not to break the jumper wires connecting the jacks to the PC board. 3) Be sure to remove the two screws holding the printed circuit board in place near the bottom of the board when servicing the electronics.

251 Voltage Controlled Amplifier

The VCA controls the amplitude of a signal passing through it. When the initial gain slider on the front panel is at maximum, the signal will pass through the VCA with no change in amplitude (unity gain). If the gain slider is at a minimum, no signal will pass through the VCA unless a positive control voltage is applied to either of the two control inputs. The sensitivity of the left control input is linear but the response of the right control input is exponential. The left control input is...

322 Tracking Definition

Oscillators which are tracking together will maintain The 4027-1 replaces all other oscillator modules. If only one module is to be replaced in a unit containing the 4017 or 4027 modules, follow the 4027-1 2.6 Noise Generator, Voltage Processor, Sample & Hold, Internal Clock, Amplifier 2.6.1 NOISE GENERATOR (Module 4022) The Noise Generator provides a +20 volt peak to peak noise signal of about 10 octaves bandwidth. The right Noise Generator slider controls the amplitude of the noise and the...

Servi

SUBJECT MATING 2600 MAIN CONSOLE TO 3604P KEYBOARD PROBLEM All three oscillators on the 2600 are in tune with each other across the whole keyboard but the octaves are incorrcct. CAUSE When the 2600 or the 3604P are serviced separately they may be adjusted tc a slightly different standard resulting in a slightly different interval setting. SOLUTION Reset the fixed interval control or. the keyboard. 2600 CONSOLE AND 3604P MATING PROCEDURE . 1. Put all of the slide switches on the keyboard in the...

Model 2600 Block Diagram

Arp 2600 Diagram

Raise VCO 1 slider into the filter and close VCF initial and fine tune sliders. 2. Raise the ADSR control slider. 3. Select ADSR settings so that a sharp envelope occurs when a key is depressed. 4. Listen to the output of the filter through the Monitor speakers while depressing each key sequentially from left to right. 5. Each key should produce a well-defined sharp pulse of sound. If not, then either the sequence of contact closures is incorrect or the contacts and or bus bar are dirty. 6....