High Powered Version (100w/8ohms, 150w/4ohms) Detailed Parts List:

The list below uses the part numbers that correspond to the PCBs that were part of the original group purchase back in December of 2002 from DIYAudio.com. This list was developed by Chad, John, & William and contains everything that you need to populate the circuit board. Below this list is a bill of materials that indicates sources for these parts, including nearly everything that you need to build a completed amplifier.

Designation
My Aleph-X
Original Part
Notes & Description
C1 220uF/25V 220uF/25V panasonic FCplus 10nF FKP2
C2 3pF 10pF 1pF results in spikes in leading edge of square waves, 5 pF results in rounded leading edges of square waves. 3pF is a good compromise situation here. You should probably try different values (0pF to 10pF) to see how your amp behaves best, this will vary with the speaker load (4ohms vs 8ohms).
C3 220uF/25V 220uF/25V plus 10nF FKP2 (polypropylene film & foil bypass)
C4 3pF 10pF see comments for C2 above
C5 220uF/25V 220uF/25V plus 10nF FKP2
C6 220uF/25V 220uF/25V plus 10nF FKP2
C7 omitted omitted Optional lag capacitor / Miller capacitor / Cdominant - limits the slew rate of the amplifier for a given drive current from the diff pair. Usually set at a value which ensures that it forms the dominant open-loop pole, ideally at least one decade lower in frequency than the next pole. This capacitance is in parallel with the power transistor's own parasitic capacitance.
C8 omitted omitted see comments for C7
C9 omitted 1nF to 3nF Optional cap used to cure high frequency oscillation problems in your completed amp - only install these if you are experiencing HF oscillations (this is apparent at the speaker as a "motorboating" sound, and can be confirmed with a scope). With these installed, you should expect to see high frequency roll-off in your power bandwidth, so there is a tradeoff associated with installing these. See notes about power bandwith back on main web page
C10 omitted 1nF to 3nF see comment for C9 above
C11 omitted omitted Optional bypass capacitor for voltage reference. May improve voltage reference noise, but may also cause turn-on / turn-off thump problems.
C12 220uF/25V 220uF/25V Local power supply coupling cap (+Rail) panasonic FC 220uF plus WIMA FKP2 10nF
C13 220uF/25V 220uF/25V Local power supply coupling cap (-Rail) panasonic FC 220uF plus WIMA FKP2 10nF
D1a 1N5239B 1N5239B selected zener for actual 9.1V
D1b omitted LM329 Alternate voltage reference for diff pair current source. Install one of either D1a or D1b. Be sure to adjust values for VR2, R24 and R26 based on choice of D1 and Q6.
D2 1N5239B 1N5239B  
D3 1N5239B 1N5239B  
D4 1N5239B 1N5239B  
D5 1N5239B 1N5239B  
J1a jumper installed jumper installed Jumper to connect R17 to ground as in Grey's original schematic. Use J1b to connect R17 to the negative rail. Install only one of either J1a or J1b
J1b jumper omitted jumper installed used this one for more voltage over resistor
Q1 IRFP240 IRFP240 need 3 in parallel, matched to within 0.01v and loosely matched to Q10
Q2 IRFP240 IRFP240 need 3 in parallel, closely matched to Q11 within 0,01V at wanted bias current
Q3 MPSA18 BC550 if using BC550 instead of MPSA18, put in the other way around
Q4 MPSA18 BC550 if using BC550 instead of MPSA18, put in the other way around
Q5 IRF9610 IRF9610 match to Q7 at 10mA to 0,001volt for 5 minutes or more. Purchasing 10+ at the same time will typically yield 2 pairs of matched devices. Use Mouser #534-3049 Shoulder Washer #4 for back to back mounting to isolate transistor from metal screw.
Q6a IRF9610 IRF9610 Match Vgs very close to Q5 and Q7. Install one of either Q6a or Q6b, not both.
Q6b omitted ZVP3310A Alternate current source transistor. Install one of either Q6a or Q6b.
Q7 IRF9610 IRF9610 Match to Q5, see notes for Q5
Q8 MPSA18 BC550 if using BC550 instead of MPSA18, put in the other way around
Q9 MPSA18 BC550 if using BC550 instead of MPSA18, put in the other way around
Q10 IRFP240 IRFP240 need 3 in parallel, matched to within 0.01v and loosely matched to Q1
Q11 IRFP240 IRFP240 need 3 in parallel, closely matched to Q2 within 0,01V at wanted bias current
Q12a jumper installed J505 Optional biasing method for D1a/D1b. Install one of either Q12a or Q12b. If neither Q12a nor Q12b is installed, place a wire jumper between pins 1 and 3 of Q12a.
Q12b omitted SST505 surface mount, see comments for Q12a
R1 78 78 5 x 390ohm 1%/1 watt in parallel
R2 0.073 0.083 output to ground resistor (12 x 1 Ohm/1watt 1%) -or- (3 x 0.22 ohm) - just be close here. original Aleph amps range from 0.083 ohms to 0.10 ohms
R3 omitted   not used, accounted for in R2 above
R4 omitted   not used, accounted for in R1 above
R5 0.33 0.33 3 x 1 Ohm /1 watt 1%, duplicate on the Source pin for each paralleled FET. Aleph2 uses 1R0 here, Aleph 30 uses 0R47. Looks like higher power output amps uses higher resistor value.
R6 0.33 0.33 see notes for R5
R7 220 220 duplicate on the Gate pin for each paralleled FET
R8 1.0K 1.0K Q1 sense, if using parallel output mosfets for high power output, connected to first output mosfet only, do not duplicate for each fet
R9 220 220 duplicate on the Gate pin for each paralleled FET
R10 220 220 Q2 sense, connected to first output mosfet only, not duplicated for paralleled mosfets
R11 27k 27k Sets Bias. A bit lower than the original value, works fine. Start with trim pot VR1 adjusted to 0 ohms. This should provide close to 4A bias to begin with.
R12 1k3 1k3 This governs the power factor (also called AC Current Gain). 1k3 gives almost 55% @8A, 58% @7.2A. If you change the bias point, the power factor will also change, so if you are targeting a specific power factor, this will need to adjusted after changing the bias point. In my design, 1k3 provided exactly 50% AC Current Gain. I increased this resistor to 1k6, resulting in 60% AC Current Gain. While this increases output in to 4 ohms, it comes at the cost of somewhat degraded sound quality.
R13 100 100  
R14 1k2 1k2 value from Aleph 3/60 adjusted for lower rail (used 1k5 in post from 3/15/2005 http://www.diyaudio.com/forums/showthread.php?postid=594650#post594650)
R15 1k2 1k2 value from Aleph 3/60 adjusted for lower rail (used 1k5 in post from 3/15/2005 http://www.diyaudio.com/forums/showthread.php?postid=594650#post594650)
R16 200K 100K feedback resistor - sets feedback level for the amp which in turn determines the input sensitivity. In my completed amp, 100kohm results in needing 2.5v RMS to drive the amp to full output (corresponding bandwidth is approx 210kHz). Increasing this to 200kohm increases input sensitivity, thus needing 1.4v RMS to drive the amp to full output (but reduces power bandwidth to about 100kHz). Match to 0.10% with R30.
R17 10k 10k gives 3mA at 31V (rail minus zener)
R18 10K 10K Sets input impedance of the amp: 10kohm unbalanced and 20kohm balanced. Match to R28 at 0.10%
R19 10K 10K 0.10%
R20 220 220  
R21 1 1 used a 1-ohm 0.25w here
R22 220 220  
R23 390 390 0.1% this resistor sets gate drive voltage for Q11, and can be tweaked to help achieve zero DC across the speaker.
R24 470 470 together with R26 and VR2, sets current through Q6 which biases Q5/Q7 and impacts absolute DC offset
R25 390 390 0.10%
R26 330 330 together with R24 and VR2, sets current through Q6 which biases Q5/Q7 and impacts absolute DC offset
R27 220 220  
R28 10K 10K see notes for R18 - match to 0.10%
R29 10K 10K 0.10%
R30 100K 100K see notes for R16 - match to 0.10%
R31 1k2 1k2 value from Aleph 3/60 adjusted for lower rail (used 1k5 in post from 3/15/2005 http://www.diyaudio.com/forums/showthread.php?postid=594650#post594650)
R32 1k2 1k2 value from Aleph 3/60 adjusted for lower rail (used 1k5 in post from 3/15/2005 http://www.diyaudio.com/forums/showthread.php?postid=594650#post594650)
R33 27k 27k see R11
R34 1k3 1k3 Sets Power Factor see notes about R12
R35 100 100  
R36 220 220 duplicate for each paralleled FET, see R7
R37 1.0K 1.0K Sense resistor - if paralleling mosfet, attach only to first mosfet in bank, do not duplicate
R38 220 220 duplicate for each paralleled FET, see R9
R39 220 220  
R40 0.33 0.33 Same as R5 - 3 x 1 Ohm /1 watt 1% - duplicate for each paralleled FET
R41 0.33 0.33 Same as R6 - 3 x 1 Ohm /1 watt 1% - duplicate for each paralleled FET
R42 0.073 0.083 3 x 0.22 Ohm/1watt 1%, see R2 above
R43 omitted   omitted, accounted for in R42, see R3
R44 78 78 5x390 Ohm 1W/1% see comments for R1
R45 omitted   omitted, accounted for in R44, see R4
R46 6k6 1k - 10k Absolute DC offset correction resistor, as applied by Ian MacMillan. This resistor is optional. Either install both R46 and R47 or neither. Values from 1K to 10K should work fine… experiment to find a value which gives acceptable absolute DC offset. Update: While values as low as 2k7 or 2k0 will provide less Absolute DC Offset (as measured from the pos speaker terminal to ground), increasing values (up to about 10k) result in better bass reproduction from the amp.
R47 6k6 1k - 10k see comments for R46
R48 jumper installed 0 (jumper) optional resistor to reduce power dissipation in Q6a or Q6b, and provide additional increase in CCS impedance. Choose a value which will leave sufficient voltage for the input diff pair to operate at peak input voltage.
R49 jumper installed 0 (jumper) optional ground lift resistor for XLR input jack shield / ground connection. Typically 0ohms, but can be increased to suppress ground loop problems.
VR1 100K 100K Sets output stage bias current for left side of amp (Q1 & Q2). Adjust first, then set VR2. See notes on setting bias below. Each full revolution changes resistance by 4k ohms
VR2 200 200 Sets diff pair bias current. Absolute DC offset of outputs can also be adjusted using this trim pot. Use multi-turn pot, each full revolution changes resistance by 10 ohms.
VR3 100K 100K Sets output stage bias current for right side of amp (Q10 & Q11). Adjust first, then set VR2. See notes on setting bias below. Use multi-turn pot, each full revolution changes resistance by 4k ohms
XLR     input from balanced line jack: XLR Jack Pinout: Pin 1= Shield/Ground, Pin 2= + Signal in, Pin 3= - Signal in. When using RCA input, install switch to short Pins 1&3 on XLR input - this will provide 6dB of gain with RCA input.
Power supply
2x19V 1500VA transformer. 18v secondaries and standard C power supply filter results in 21v rails with about 200mV ripple. If using a 0R2 CRC filter, you may want 19v secondaries to keep rail voltage near 21-22v, with about 30mV ripple. 0R2 drops between 1.5v and 2.0v from rails with CRC.
4 x STPS 80 H100 TV schottky's
2 x 15 x 3300uF / 35V
2x 2.2mH torobar choke, choke is optional CLC replacement for CRC power supply. Will reduce PSU ripple
2x 22 x 4700uF / 25V
  for 22V@7.2A @120V

Bill of Materials:

The parts indicated above have been more neatly grouped below and listed according to corresponding part number and vendor for easy reference.

Type/Value
Qty/Ch
Component Reference Identification
Part Number
Price @
Ext Price
PCB 1 PCB from Group Purchase diyaudio order $5.00 $5.00
IRF9610 3 Q5, Q6, Q7 Digikey IRF9610-ND $0.58 $1.16
220uF 25V 6 C1, C3, C5, C6, C12, C13 Digikey P10271-ND $0.22 $1.31
3n3 or 3300pF 2 C9, C10 for square wave Digikey P3907-ND $0.30 $0.61
3pF 2 C2, C4 Mouser 5982-15-500V3 $1.06 $2.12
10nF Wima FKP2 6 bypass for C1, C3, C5, C6, c12, c13 Mouser 505-FKP20.01/63/1 $1.08 $6.48
1n5239b 5 D1, D2, D3, D4, D5 Mouser 625-1n5239b $0.06 $0.30
MPSA18 4 Q3, Q4, Q8, Q9 Mouser 610-MPSA18 $0.30 $1.20
J505 1 Q12a (not used) Mouser 781-J505 $1.90 $1.90
0.33 ohm (3x 1 ohm) 36 R5, R6, R40, R41 combined with below
0.083 (12 x 1 ohm) 24 R2, R42 Mouser 71-RS2b-1.0 $0.60 $36.00
1 ohm 1 R21 Mouser 71-RS1A-1.0 $1.19 $1.19
78 ohm 5w (5 x 390 ohm) 10 R1, R44 (+R4, +R45) Mouser 71-RS2b-390 $0.73 $7.30
100 2 R13, R35 Mouser 71-rn60d-f-100 $0.21 $0.42
221 17 R7, R9, R10, R20, R22, R27, R36, R38, R39 Mouser 71-rn60d-f-221 $0.21 $3.57
332 1 R26 Mouser 71-rn60d-f-332 $0.21 $0.21
392 2 R23, R25 - better if 0.1% tolerance Mouser 71-rn60d-f-392 $0.21 $0.42
475 1 R24 Mouser 71-rn60d-f-475 $0.21 $0.21
1k2 4 R14, R15, R31, R32 Mouser 71-rn60d-f-1.2k $0.21 $0.84
1.0k 2 R8, R37 Mouser 71-rn60d-f-1.0k $0.21 $0.42
1.3k 2 R12, R34 Mouser 71-rn60d-f-1.3k $0.21 $0.42
10k 5 R17, R18, R19, R28, R29 - better if 0.1% tolerance Mouser 71-rn60d-f-10k $0.21 $1.05
27k 2 R11, R33 Mouser 71-rn60d-f-27k $0.21 $0.42
100k 2 R16, R30 - better if 0.1% tolerance Mouser 71-RN60D-F-100K $0.21 $0.42
3k3 2 R46, R47 Mouser 71-RN60D-F3.32k $0.21 $0.42
100k 2 VR1, VR3 Mouser 72-t93ya-100K $1.20 $2.40
200 1 VR2 Mouser 72-t93ya-200 $1.20 $1.20
IRFP240 12 Q1, Q2, Q10, Q11 (use three in parallel for each transistor) Mouser 512-IRFP244B $1.98 $23.76
1 EIC power entry Mouser 161-R30148 $2.34 $2.34
4 10A 45v Shottkey Rectifiers Mouser 625-MBR1045 $0.95 $3.80
1 CL-60 10 ohm 5A Thermistor Mouser 527-CL60 $1.24 $1.24
100 Nylon Shoulder Washers for 9610s - accepts M3 size screw for mounting. Mouser 534-3049 $0.04 $4.00
1 14ga power cord 6' apexjr or Newark 37F3337 (Volex 17604) $6.32 $6.32
1 1000VA - 1500VA toroid with 2x18v or 2x19v secondaries see sources on main page $200-300 $200-300
2 Hammond Chokes if using CLC power supply 156B Parts Connection $10.00 $20.00
2 RCA inputs apexjr or Parts Express 091-1120 $5.30 $10.60
1 Speaker binding posts apexjr or Parts Express 091-1150 $4.95 $4.95
Low ESR Power Supply Caps Buy new, don't bother with surplus or computer grade. Look at 35v or 50v Panasonic TUP snap-in style caps, available from both Mouser and Digikey (digikey pricing is lower)
Heat sinks, 0.06c/w per channel see sources on main page
Aluminum for chassis local source

All together, this works out to about $250 per channel for the parts listed. The majority of the cost is in the source resistors and the output to ground resistors. Including power supply caps, heatsinks, and aluminum for a chassis, figure that you are probably closer to $600 to $700 per mono, depending on what you can find and the pricing. When ordering parts, be sure to order extras to allow for matching (especially with 240's and 9610's) or replacement parts. For example, if you need 6 of a particular value resistor, order 10 of them.

This should be just about all of the internals that you need to create your own 100w Aleph-X amp.