ARP 1004-T/P VOLTAGE CONTROLLED OSCILLATORS

Both the ARP 1004-T and 1004-P Oscillators consisted of 2 boards: the 1004 main VCO board and a waveform selector ("T") board or a waveform mixer ("P") board, respectively. The same main VCO board is used in 2 other modules:

  • the 1023 Dual Oscillator (which has 2 of these boards) and the
  • 1045 Voltage Controlled Voice module.
    •  Most synthesizer VCOs are either based on a triangle core or a sawtooth core. The 1004 oscillator consisted of both a triangle and a sawtooth core, the sawtooth generator being reset by the square wave generated from the triangle. There was also a panel switch which reset the oscillator, used as an "inhibit" switch. This was essentially a manual sync. Oddly enough there was no provision for doing this via an input.

    Some more usefull information can be found at the HKU Hilversum website - some 1004-T circuit board photos and the 1004-T spec sheet

    SCHEMATIC - Main VCO Board - (click on image to download full-sized version)

    PARTS LIST - Main VCO Board
    Resistors1/4 watt, 10%, carbon composite
    47 OhmR97, R98
    100 OhmR30, R31, R48
    220 OhmR39
    390 OhmR67
    560 OhmR47
    1 KR49, R56, R62
    1.5 KR32, R33, R82, R95
    1.8 KR50
    2.2 KR51, R52, R57, R58, R69, R70, R79, R91, R93
    3.3 KR80, R83, R96
    4.7 KR46, R53, R87, R88
    5.6 KR61
    10 KR68, R72, R74, R77
    15 KR89, R90, R92
    33 KR75
    47 KR40, R45
    68 KR60
    100 KR71, R76
    120 KR78
    150 KR65
    1.5 MegR73
    8.2 MegR42, R44
    Tempco Resistors1/4 watt, 3%, +3500ppm
    100 OhmR34
    Resistors1/4 watt, 1%, metal film
    5.36 KR26, R27
    10 KR22, R23
    15 KR28, R29
    40.2 KR63, R64, R100
    68.1 KR84
    97.6 KR19
    100 KR14, R15, R16, R17, R18, R99
    121 KR85
    196 KR10
    787 KR9, R12
    Trim PotsLinear Taper
    5 KR6
    50 KR1, R41, R43
    1 MegR59
    Capacitors20%, 50 volt, ceramic disc
    10 pFC10, C19
    20 pFC2
    100 pFC7
    220 pFC1, C4, C16
    680 pFC15
    2200 pFC25 (2.2 nF)
    Capacitors5%, 500 volt, silver mica
    330 pFC11
    1300 pFC20 (1.3 nF)
    Capacitors10%, 50 volt, polycarbonate
    0.15 uFC13 (150 nF)
    0.56 uFC22 (560 nF)
    Diodes
    1N4148CR1 thru CR11
    Transistors
    TZ-81 *Q4, Q8, Q10, Q12, Q13, Q16, Q17
    TZ-581 **Q3, Q11, Q14, Q15
    TZ-81Q5, Q6 (matched pair) Q7, Q8 (matched pair)
    2N5460Q1, Q2 (FET P-channel)
    Integrated Circuits
    1339A5
    LM301AHA1, A2, A3, A4
    Potted Modules
    4001-003Exponential Module
    4002-003Exponential Module

    * - TZ-81 alternate part was the 2N5249, also defunct. 2N3904 would be a modern equivalent.

    ** - TZ-581 alternate part was the 2N5367, also defunct. 2N3906 would be a modern equivalent.

    SCHEMATIC - "T" Board - (click on image to download full-sized version)

    PARTS LIST - Waveform Select Board
    Resistors1/4 watt, 10%, carbon composite
    390 OhmR19, R20, R27
    1 KR29
    10 KR21, R22, R28
    47 KR11, R12, R23, R24, R25, R26
    100 KR1 thru R10
    Capacitorsceramic disc
    2200 pFC1, C2, C3 (2.2 nF)
    Capacitors500v ceramic disc
    .01 uFC6, C7 (10 nF)
    Transistors
    2N5460Q1, Q2 (FET P-channel)
    Integrated Circuits
    1339A1, A2, A3

    SCHEMATIC - "P" Board - (click on image to download full-sized version)

    PARTS LIST - "P" Board
    Resistors1/4 watt, 10%, carbon composite
    390 OhmR12, R22
    1 KR24
    1.5 KR19
    3.9 KR18
    10 KR13, R23
    22 KR17
    47 KR20, R21
    100 KR6, R7, R8, R9, R10
    120 KR15
    PotentiometersAudio ? Taper
    100 KR1, R2, R3, R4, R5, R11
    Capacitorsceramic disc
    2200 pFC2, C4 (2.2 nF)
    .01 uFC5, C6 (10 nF)
    Transistors
    TZ-81 *Q2
    Integrated Circuits
    1339A1, A2

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