D-Comp Compressor 电路图.pdf

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1、D will work with 2N3904 or 2N4124. Diodes 1N914 or 1N4148. Parts not in the original but included for modern pedal practices. Electro Cap Polarity D-Comp Compressor 2 3 4 5 6 7 Vb Vb Vb R5 TRIM 1 9V In Out Copyright 1999 R.G. Keen All rights reserved. Fair use only if this notice is reproduced. No p

2、ermission to serve from web pages other than Shown with True Bypass switching for the Millenium Bypass. Connect this point to the conrol pad of the MB to get an LED indicator with the same DPDT switch. Shown with True Bypass switching for the Millenium Bypass. Connect this point to the conrol pad of

3、 the MB to get an LED indicator with the same DPDT switch. R-Comp Compressor Not in original pedal U1 U1 C9 C9 SUST SUST LEVEL LEVEL R20 R20 R18 R18 C16 C16 R17 R17 C15 C15 C14 C14 Q3 Q3 Q4 Q4 Q2 Q2 R16 R16 D2 D2 D3 D3 C13 C13R19 R19 Q5 Q5 R21 R21 R12 R12 C11 C11 C12 R14 R14 TRIM1 C10 C10 R11 R11 C8

4、 C8 R15 R15 R13 R13 C3 C4 C7 C5 R9 D1 D1 R10 R10 R6 C6 C6 R8 R8 R5 R7R7 C4 R4 Q1 Q1 R3 R2 R2R3 C1 C1 R1 R1 C2 RadioFans.CN 收音机爱 好者资料库 D-Comp and R-Comp Compressors 2 Copyright 1999-2001 R.G. Keen. All rights reserved. input currents of the differential inputs and balance out any control voltage nois

5、es as the gain of the OTA changes. In the R-Comp, R6 is added in series with R10, and the junction of the two are bypassed to ground by C5. The maximum gain of the OTA is set by the R14 load resistor attached from pin 6 to the bias voltage, and the high frequency rolloff is set by the parallel combi

6、nation of R14 and C11. From pin 6, the signal goes to the base of Q2. Q2 performs two tasks - it acts as an output buffer to drive the output signal, and also as a phase inverter to help derive the DC level signal which controls the gain of the whole circuit. The output signal is tapped from the emi

7、tter of Q2, while both the emitter and collector of Q2 provide out-of-phase signals to a rectifier-filter arrangement built from Q3 and Q4. The most negative peak of the both phases of the signal from Q2 is clamped to ground by the diodes at the bases of Q3 and Q4, providing a rectified signal that

8、is as large as the peak-to-peak Q2 signal. Since there are two of these working on the two out-of-phase signals from Q2, the signal is effectively full wave rectified. Q3 and Q4 invert; that is, higher signals cause them to pull their collectors to a lower voltage. The collectors pull this current f

9、rom R18 to +9V, pulling down on the voltage of C16. In the absence of a signal, C16s voltage rises to nearly the supply voltage. When large signals are passed through, Q3 and Q4 pull the voltage on capacitor C16 lower. The voltage on this capacitor is buffered by Q5, and in turn drives the bias curr

10、ent of the OTA through the 500K sensitivity control and the 27K resistor. So as a result, if there is a very small or no signal at the input, Q3 and Q4 do not pull down on C16, and the voltage at the emitter of Q5 is high; this supplies a current to the bias pin which is determined by the voltage at

11、 Q5s emitter and the Sustain control in series with R12. With a high voltage at Q5s emitter, the bias voltage into Pin 5 of the OTA is high, and the gain of the OTA is high. As the signal level rises, Q3 and Q4 pull the voltage on the 10uF capacitor down, so the voltage across Sustain and R12 are lo

12、wer, and current is reduced to the bias pin so the OTA gain goes down. Note that the sustain control can vary the current over a wide range as it varies from 0 to 500K. This setup effectively forms a negative feedback loop which attempts to adjust the signal level at the output of Q2 so it is almost

13、 constant. When a note is first hit, it is loud and the level feedback adjusts the OTA to a low gain. As the note trails off, the feedback circuit lets the gain come up to hold the output signal almost constant until the maximum gain of the circuit is reached and the OTA can no longer keep the tiny

14、signal up to the desired level. The stomp switch on the vintage units is a DPDT switch, but not wired for true bypass. The guitar always connected to the input of the effect unit. Because the input signal must go through a 10K resistor at the input to the effect, the loading may be bad enough to cau

15、se tone sucking. I have drawn the circuit with true bypass switching to get around this. I have also shown how to wire the units for true bypass with an LED status indictor; see the Millenium Bypass at GEO, for how to build the circuit to do that. Building it: While neither circuit is complicated, a

16、nd the use of a printed circuit board (PCB) does make things much easier, you will need to pay attention to the differences between the D-comp and R-comp versions. In the Parts List that follows, I have shaded the entries where the D-comp and R-comp versions are different. The R-comp version uses mo

17、re parts, but the D-comp version needs jumpers strategically placed. Its probably a good idea to study the differences in the two population diagrams before beginning building, or in fact before ordering your parts, just to be sure that you get the right set of parts. I like to build things in a spe

18、cific order: clean the copper side of the board to ensure easy soldering. Acetone, kitchen scrubbing powder or just 0000 steel wool all do a good job insert and solder in any jumpers; the jumpers on this board all replace resistors, so they are on the same 0.4 spacing as the resistors. insert resist

19、ors; all the resistor holes are on 0.4 centers, so you could make a piece of wood or plastic thats the right width to bend many of them to the right spacing at the same time; I also use a lead bender gadget that I got at Mouser. Very, very handy. Bend the resistor leads slightly to hold them in the

20、board as you insert them, and clip them off, leaving about 1/16 of lead protruding above the copper. Solder in the resistors. Place the capacitors next, clenching the leads slightly and then clipping and soldering. RadioFans.CN 收音机爱 好者资料库 D-Comp and R-Comp Compressors 3 Copyright 1999-2001 R.G. Keen

21、. All rights reserved. Once all the passive parts are in place, double check the values and correct any placement mistakes. I often mistake 4.7K for 47K, as I confuse the red with the orange bands. Double check the pinouts of the transistors, then insert them and solder them into position Finally, s

22、older the IC in. I like to tack-solder pins 4 and 8 to get the IC placed and flat on the PCB, and once its all in position, solder the rest of the pins. Youre probably wondering if there is any difference in the sound of the D-comp and R-comp versions. There is. Its not big, but there is a slight ad

23、vantage in smoothness of compression in favor of the R-comp. Notes on the parts list: 1. The original transistor type number is not know. 2N5088s worked well in the prototype. You can probably get away with 2N3904 and 2N4124 as well. 2. The D &R Comp PCB is designed to fit into the Hammond 1590BB di

24、e cast aluminum box. This is a sturdy unit, and with care in fitting parts into it, you can make a pedal which will stand up to the rigors of road gigs. 3. Parts different between the two versions are shown shaded gray in the parts list. Be sure to check and buy the right parts for the version you w

25、ant. 4 Part numbers and prices listed were current when this was written. Since part numbers and prices change all the time, do not be surprised if some of them have changes. Just ask the sales rep to help you find a replacement part that they do have. D-Comp and R-Comp Compressors 4 Copyright 1999-

26、2001 R.G. Keen. All rights reserved. Parts List Part D-Comp R-Comp Description Mouser Stock No. Est. $ U1 CA3080 CA3080 Operational Transconductance Amplifer 570-CA3080E 0.68 Q1-Q5 2N5088 2N5088 High gain, low noise NPN transistor 610-2N5088 0.26 D1-D3 1N914/4148 1N914/4148 Signal diode 625-1N914 0.

27、06 R1 4.7M 4.7M W carbon film resistor 29SJ250-4.7M 0.07 R2 10K 10K W carbon film resistor 29SJ250-10K 0.07 R3 1M 470K W carbon film resistor 29SJ250-1M or 470K 0.07 R4 jumper 470K W carbon film resistor 29SJ250-470K 0.07 R5 10K 10K W carbon film resistor 29SJ250-10K 0.07 R6 jumper 220K W carbon fil

28、m resistor 29SJ250-22K 0.07 R7 1M 1M W carbon film resistor 29SJ250-1M 0.07 R8 1M 1M W carbon film resistor 29SJ250-1M 0.07 R9 jumper 10K W carbon film resistor 29SJ250-10K 0.07 R10 470K 220K W carbon film resistor 29SJ250-470K or 220K 0.07 R11 15K 15K W carbon film resistor 29SJ250-15K 0.07 R12 27K

29、 27K W carbon film resistor 29SJ250-27K 0.07 R13 56K 56K W carbon film resistor 29SJ250-56K 0.07 R14 150K 150K W carbon film resistor 29SJ250-150K 0.07 R15 27K 27K W carbon film resistor 29SJ250-27K 0.07 R16 1M 1M W carbon film resistor 29SJ250-1M 0.07 R17 1M 1M W carbon film resistor 29SJ250-1M 0.0

30、7 R18 150K 150K W carbon film resistor 29SJ250-150K 0.07 R19 10K 10K W carbon film resistor 29SJ250-10K 0.07 R20 10K 10K W carbon film resistor 29SJ250-10K 0.07 R21 10K 10K W carbon film resistor 29SJ250-10K 0.07 C1 0.01uF 0.01uF Film capacitor 140-PF1H103K 0.11 C2 not used 0.0022uF Film capacitor 1

31、40-PF2A222K 0.10 C3 1uF electro 1uF electro Radial package aluminum electrolytic cap 140-XRL25V1.0 0.05 C4 not used 1uF electro Radial package aluminum electrolytic cap 140-XRL25V1.0 0.05 C5 not used 1uF electro Radial package aluminum electrolytic cap 140-XRL25V1.0 0.05 C6 1uF electro 1uF electro R

32、adial package aluminum electrolytic cap 140-XRL25V1.0 0.05 C7 not used 1uF electro Radial package aluminum electrolytic cap 140-XRL25V1.0 0.05 C8 1uF electro 1uF electro Radial package aluminum electrolytic cap 140-XRL25V1.0 0.05 C9 10uF electro 10uF electro Radial package aluminum electrolytic cap

33、140-XRL25V10 0.05 C10 0.01uF 0.01uF Film capacitor 140-PF1H103K 0.11 C11 0.01uF 0.01uF Film capacitor 140-PF1H103K 0.11 C12 optional 0.1uF cer. Ceramic capacitor 21RZ310 0.08 C13 0.01uF film 0.01uF film Film capacitor 140-PF1H103K 0.11 C14 0.01uF film 0.01uF film Film capacitor 140-PF1H103K 0.11 C15

34、 0.047uF film 0.047uF film Film capacitor 140-PF1H473K 0.17 C16 10uF electro 10uF electro Radial package aluminum electrolytic cap 140-XRL25V10 0.05 Sust 500K lin pot 500K lin pot Potentiometer 313-1000-500K 1.21 Level 50K log pot 50K log pot Potentiometer 313-4000-50K 1.74 Part Description Mouser Stock No. Est. $ enclosure Hammond 1590BB or eq. stomp switch DPDT stomp switch. Preferably Carling 317PP Not stocked by Mouser knobs to your own taste. batt clip PP3 / 9V battery clip D-Comp and R-Comp Compressors 5 Copyright 1999-2001 R.G. Keen. All rights reserved.