PAIA Tube Mic Preamp 电路图.pdf

Name:Manufacturer / Designer:Revision:Model # + + + + - + - + - + + + + + + + + + - + + + + + + PAiA Electronics Original circuit from Recording Magazine January 1995 Tube Mic Pre9407 S1 330 D2100 25v 100 Vcc D1 0.05uf 0.5A 12VAC 25v 470uf 470uf 220uf 220uf 25v 25v +15v -15v Mic In Output Bal Out 4.7uf 4.7uf IC1f 100 10k IC2b 47k 2k7 220 82k 470 10k IC3b IC3a 10k 2201k 10k D10 10k Drive Tube 12VAC 2k7 22k 0.01uf1uf 270k270k 1uf 100k 1uf Blend 10k 100k33k1k D8 D9270k 270 100k 1uf 1uf 82k 470k4k7 Polarity IC2a 10k D11 D13 D12 150k 10k 47uf # 5pf PP On +48v Drive Power Phant. 10k 470 33uf 33uf 10k Output D3D4D5D6D7 33uf 33k33k 220pf 33uf 33uf33uf33uf Vcc - Pin 1 IC1 - Pin 8 IC1 IC1 - 4049 CMOS Hex Inverting Buffer +15v - Pin 8 IC2, & IC3 -15v - Pin 4 IC2, & IC3 IC2, & 3 - 5532 Dual Low-Noise OpAmp +48v IC1c IC1b IC1d IC1e IC1a D1, D2 - 1N4001 D3 to D8 - 1N4148 12AX7 470k470k # # # # # # 33k # D10 to D13 - 6.8v Zener Diode D9 - 51v Zener Diode 6k816k81 All 33uf caps 16v all others 50v unless marked othewise. Resistors marked with # are 1% film type. The Drive LED indicates how hard the tube is being driven. The Blend control allows for a mixing of SS and tube coloration. Symmetry controls the relative amounts of even and odd harmonics, CCW the 6 8 3 945 1 27 7 5 6 3 2 1 7 5 6 100k 2 3 1 1415 7 6 5 4329 10 1211 Symmetry should be connected to point A. A G 2 3 1 2 3 1 Tube Mic Pre may sound punchier, while CW it may sound warmer. The 12VAC needed for pin 5 of the 12AX7 can be obtained from point G while pin 4 1 / 2 11/11/95RadioFans.CN 收音机爱 好者资料库 Name:Manufacturer / Designer:Revision:Model # 2 3 1 This mod converts the XLR jacks to 1/4 balanced stereo jacks. However, when a mono plug is used with this new jack the inverting input of the differential amp is grounded, this single-ends the balanced input so standard phone plugs on dyanmic mics can be plugged in directly. Additionally the polarity switch still works, even for unbalanced inputs. If phantom power is not turned off while using a singled ended input the performance of the TMP will not be up to par but it wont damage the TMP either. USING STERO PHONE JACKS FOR INPUT Mic In 3 1 2 47k 47k # # Low / Line Level USING THE TMP WITH LINE LEVEL SIGNALS There are two options for line level signals. First if you know that youll be using line level signals all the time with the TMP then you can change the two 33k 1% resistors to 1k 1% types and your done. Alternatively if you want the option of line level or low level signals then you can sacrifice the polarity switch and and rewire it here as shown. Notice that the 47k resistors are again of the 1% variety. + + + + + S1 330 D2100 25v 100 Vcc D1 0.05uf 0.5A 12VAC 25v 470uf 470uf 220uf 220uf 25v 25v +15v -15v Power 1000uf 25v 1W 15 Pin 5 12AX7 Pin 4 12AX7 USING DC TO POWER THE HEATER FILAMENTS This mod can make the TMP quiter. Insted of using the 12VAC to power the heater filaments rectified and filtered DC can be used. This is accomplished as shown. The new resistor added is a 15 ohm 1W type, the new cap is a 1000uf 25v as shown. It is critical that pin 5 of the 12AX7 connects to the ground point shown. PAiA Electronics 2 / 2 Tube Mic Pre (Mods) 11/11/95RadioFans.CN 收音机爱 好者资料库