Parts Sources for the Leach Amp

This list of parts with sources and prices was prepared by Craig Truesdell and Jim Musial. Craig built a 6 channel version of the amplifier in the fall of 1995. Jim built a 2 channel version in the spring of 1996. In many cases, the parts can be bought cheaper than the prices listed here. The abbreviations used for the sources are as follows:

DK   -	DigiKey
ACK  -	Ack Radio, 554 Deering Road NW, Atlanta, GA 
        Inside Atlanta: 404-351-6340
        Outside Atlanta: 800-282-7954
MCM  -	MCM Electronics
NEW  -	Newark Electronics
MARK -	Mark V Electronics
ACE  -  Ace Hardware

								
	Must
Quan.	Buy	Source	Part Description		$/Unit	$Total
_____	____	______	________________		______	______

Transistors
12	12	DK	2N5210 NPN			0.36	  4.32
10	10	DK	2N5087 PNP			0.48	  4.80
 4	 5	MCM	2N3439 NPN			1.85	  9.25
 4	 4	MCM	2N5415 PNP			2.13	 10.65
 2	 2	MCM	MJE15030 NPN			1.94	  3.88
 2	 2	MCM	MJE15031 PNP			2.23	  4.46 
 4	 4	MCM	MJ15003 NPN			4.91	 19.64
 4	 4	MCM	MJ15004 PNP			4.91	 19.64
								_______
Total								$76.64

Alternates for the MJE15030 and MJE15031
 2	 2	ACK	2N6474 NPN			1.15	  2.30
 2	 2	NEW	2N6476 PNP			1.32	  2.64

Diodes
12	20	DK	1N4004 Diode				  1.44
12	20	DK	1N4148 Diode				  1.28
								______
Total								$ 2.72

Capacitors
 2	 2	ACK	SM15J391 390 pF mica		1.01	  2.02
 2	 2	ACK	SM15J181 180 pF mica		0.65	  1.30
 2	 2	ACK	SM15J470 47 pF mica		0.48	   .96
 4	 4	ACK	SM15J100 10 pF mica		0.48	  1.92
 2       2	ACK     Mallory CGS103U075V3C
			10,000 uF 75V		       19.40	 38.80
 8	10	DK	P4525 0.1 uF 50V			  1.65
12	12	DK	P6283 100 uF 63V			  2.77
 2	 2	DK	P1120 220 uF 16V		1.03	  2.06
 4	10	DK	P4513 0.01 uF 50V			  1.20
14	20	DK	P4725 0.1 uF 100V			  4.38
 1	 1	DK	E2104 0.1 uF 250V		 .25	   .25
								______ 
Total								$57.31

Resistors, 1/4 Watt unless otherwise specified.
 2	 2	DK	20k		20 kohm
 2	 2	DK	2k		2 kohm
16	16	DK	300		300 ohm
 4	 4	DK	330		330 ohm
 6	 6	DK	1.2k		1.2 kohm
 4	 4	DK	11k		11 kohm
 4	 4	DK	12k		12 kohm
 2	 2	DK	22k		22 kohm
 4	 4	DK	360		360 ohm
 4	 4	DK	270		270 ohm
 6	 6	DK	82		82 ohm
 2	 2	DK	220		220 ohm
 2	 2	DK	1.1k		1.1 kohm
 4	 4	DK	30		30 ohm
 4	 4	DK	1k		1 kohm
 8	 8	DK	470		470 ohm
 4	 4	DK	2.2k		2.2 kohm
 8	10	DK	0.33W-5 0.33 ohm 5W			  3.41
 2	 2	DK	3386P-202 2 kohm pot			  2.00
 8	20	MCM	3.3 ohm 1/2 W	3.3 ohm			  1.15
 4	 4	ACK	Y-50 CII 3.9k 1/2 W			   .56
 4	 4	ACK	HB-2-2%RES 10 ohm 2W Carbon		  4.80
								______
Total								$11.92
 
Accessories
  1	  1	DK	MB252 25A 250V Bridge Rect.		  5.40
  1	  1	DK	3536K Fuse Holder (1)			   .77
  1	  1	DK	3539K Fuse Holder (4)			  2.64
  1	  5	DK	F335 8A Slow Blow Fuse			  3.05
  4	  5	DK	F123 5A Fast Blow Fuse			  1.83
  8	 10	DK	J240 3/4" Threaded Spacers		  2.99
  8	 10	DK	J167 1/4" Tubular Spacers		  1.07
  4	  4	DK	HS111 TO-220 Clip-On Heat Sinks		  1.28
  1	  1	DK	VFP018-R75 1/8" x 3/4" Heatshrink Tubing  1.48
  1	  1	DK	VFP316-R75 3/16" x 3/4" Heatshrink Tubing 1.75
  2	  2	DK	Red Binding Post			  3.00
  2	  2	DK	Black Binding Post			  3.00
100	100	DK	H342 Mach. Screws 4-40 x 1/4"		  1.11
100	100	DK	H346 Mach. Screws 4-40 x 1/2"		  1.37
100	100	DK	H216 Hex Nuts 4-40			   .93
100	100	DK	H236 Lock Washer #4			  1.07
  1	  1	DK	KE1102 Solder 21 guage 63/37 RA 11b	 10.10
  2	  2	ACK	3505F SC Switchcraft JAX Phono Jack	  4.16
  2	  2	ACK	Shoulder Washer for Phono Jack
  2	  2	ACK	Flat Washer for Phono Jack
  1	  1	ACK	Pilot Light, 120V AC			  5.69
  2	  2	ACK	VR8 MAL 2" Capacitor Clamps		  3.24
  2	  2	ACK	E520X6.00 IERC Power Transistor
			Heat Sinks				 27.50
  1	  1	ACK	MCLS5-17-9 B/B Moduline Chassis 19x5x9	 53.35
  1	  1	ACK	SPR5-9 Moduline Chassis Side Panels	 19.00
  8	 10	MCM	21-1150	Power Transistor Insulators	  2.69
  8	 10	MCM	Power Transistor Sockets		  9.18
  2	  2	MCM	#18, 50 ft., Hookup Wire		 15.98
  1	  1	ACE	15A Toggle Switch			  3.99
 20	 20	ACE	Terminal Rings				  1.78
 16	 16	ACE	Female Disconnects			  1.98
100	100	ACE	Small Wire Cable Ties			  1.99
  3	  3	SHACK	Rubber Washers				  2.07
  1	  1	MARK	003 Power Transformer			 32.00
  2	  2		Circuit Boards				 25.00
								______
Total							       $252.44

Do not buy Radio Shack hookup wire. It does not solder properly and the insulation shrinks when the wire is heated by a soldering iron. I recommend using a quality brand of stranded hookup wire such as Belden, Alpha, Carol, etc., for the chassis wiring. Digi-Key usually has good prices for wire. I prefer wiring the chassis with 3 colors of wire, e.g. red for +Vcc, yellow for -Vcc, and black for ground. It is probably cheaper to use a single color. In this case, you should use temporary masking tape labels on the wires to identify them.

Do not use Radio Shack solder lugs in the chassis wiring. Solder will not bond to the metal that these lugs are made of. I have seen amplifiers that put out a hum because of bad solder joints to Radio Shack solder lugs. Replacing the lugs with Walco solder lugs solved the problem. One student recently did not follow my advice and he tried to use Radio Shack solder lugs to attach R50 and C25 to the loudspeaker output binding posts. After he almost burned up R50 and C25 trying to solder them to the lugs, he went to Ack Radio and bought Walco lugs which soldered with no problems.

You should not use substitutes for the 1N4148 fast switching diodes. If the diodes which you purchase do not have 1N4148 printed on them, do not use them. I have seen amplifiers not work properly because the vendor supplied a substitute diode that was not a fast switching diode. The slower diodes cause the protection circuit to be activated on the zero crossings of the signal and this produces large amounts of distortion.

Last modified at 11:00 AM 2/3/97.


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