Detailed Parts List 100w into 8 ohms, 150w into 4 ohms:
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 |
Part Type |
Description |
| C1 | 220uF/25V | panasonic FCplus 10nF FKP2 |
| C2 | 10pF | works fine (couldn´t find 5pF and square wave looks alright) |
| C3 | 220uF/25V | plus 10nF FKP2 |
| C4 | 10pF | see comments for C2 |
| C5 | 220uF/25V | plus 10nF FKP2 |
| C6 | 220uF/25V | plus 10nF FKP2 |
| C7 | 0 | 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 | 0 | see comments for C7 |
| C9 | 3n3 | tried 4n7 first but this makes a nicer square wave |
| C10 | 3n3 | tried 4n7 first but this makes a nicer square wave |
| C11 | 0 | Optional bypass capacitor for voltage reference. May improve voltage reference noise, but may also cause turn-on / turn-off thump problems. |
| C12 | 220uF/25V | panasonic FC 220uF plus WIMA FKP2 10nF |
| C13 | 220uF/25V | panasonic FC 220uF plus WIMA FKP2 10nF |
| D1a | 1N5239B | selected zener for real 9.1V |
| D1b | 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 | checked |
| D3 | 1N5239B | checked |
| D4 | 1N5239B | checked |
| D5 | 1N5239B | checked |
| J1a | 0 | 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 | 0 | used this one for more voltage over resistor |
| Q1 | IRFP240 | need 3 in parallel, matched to within 0.01v and loosely matched to Q10 |
| Q2 | IRFP240 | need 3 in parallel, closely matched to Q11 within 0,01V at wanted bias current |
| Q3 | BC550 | substitute for IRF9610, put in the other way around |
| Q4 | BC550 | put in the other way around |
| Q5 | IRF9610 | match to Q7 at 10mA to 0,001volt for 5 minutes or more |
| Q6a | IRF9610 | Vgs very close to Q5 and Q7 |
| Q6b | ZVP3310A | Alternate current source transistor. Install one of either Q6a or Q6b. |
| Q7 | IRF9610 | match to Q5 at 10mA to 0,001volt for 5 minutes or more |
| Q8 | BC550 | put in the other way around |
| Q9 | BC550 | put in the other way around |
| Q10 | IRFP240 | need 3 in parallel, matched to within 0.01v and loosely matched to Q1 |
| Q11 | IRFP240 | need 3 in parallel, closely matched to Q2 within 0,01V at wanted bias current |
| Q12a | 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 | SST505 | see comments for Q12a |
| R1 | 78 | 5 x 390ohm 1%/1 watt |
| R2 | 0.083 | 12 x 1 Ohm/1watt 1% |
| R3 | not used, accounted for in R2 | |
| R4 | not used, accounted for in R1 | |
| R5 | 0.33 | 3 x 1 Ohm /1 watt 1%, duplicate for each paralleled FET |
| R6 | 0.33 | 3 x 1 Ohm /1 watt 1%, duplicate for each paralleled FET |
| R7 | 220 | duplicate for each paralleled FET |
| R8 | 1.0K | Q1 sense, connected to first output mosfet only, not duplicated |
| R9 | 220 | duplicate for each paralleled FET |
| R10 | 220 | Q2 sense, connected to first output mosfet only, not duplicated |
| R11 | 27k | Sets Bias. A bit lower than the original value, works fine. |
| R12 | 1k3 | gives almost 55% @8A, 58% @7.2A, 1k5 is below 50% |
| R13 | 100 | |
| R14 | 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 | 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 | 100K | 0.10% |
| R17 | 10k | gives 3mA at 31V (rail minus zener) |
| R18 | 10K | 0.10% |
| R19 | 10K | 0.10% |
| R20 | 220 | |
| R21 | 1 | used a1 ohm 0,25w here |
| R22 | 220 | |
| R23 | 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 | |
| R25 | 390 | 0.10% |
| R26 | 330 | |
| R27 | 220 | |
| R28 | 10K | 0.10% |
| R29 | 10K | 0.10% |
| R30 | 100K | 0.10% |
| R31 | 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 | 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 | see R11 |
| R34 | 1k3 | see R12 |
| R35 | 100 | |
| R36 | 220 | duplicate for each paralleled FET, see R7 |
| R37 | 1.0K | |
| R38 | 220 | duplicate for each paralleled FET, see R9 |
| R39 | 220 | |
| R40 | 0.33 | Same as R5 - 3 x 1 Ohm /1 watt 1% - duplicate for each paralleled FET |
| R41 | 0.33 | Same as R6 - 3 x 1 Ohm /1 watt 1% - duplicate for each paralleled FET |
| R42 | 0.083 | 12 x 1 Ohm/1watt 1% |
| R43 | omitted, accounted for in R42, see R3 | |
| R44 | 78 | 5x390 Ohm 1W/1%see comments for R1 |
| R45 | omitted, accounted for in R44, see R4 | |
| R46 | 3k3 | 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: Lower may be better, perhaps as low as 2k7 or 2k0 |
| R47 | 3k3 | see comments for R46 |
| R48 | 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 | 0 (jumper) | optional ground lift resistor for XLR input jack shield / ground connection. Typically 0ohms, but can be increased to supress ground loop problems. |
| VR1 | 100K | Sets output stage bias current. Adjust first, then set VR2. |
| VR2 | 200 | Sets diff pair bias current. Absolute DC offset of outputs can also be adjusted using this trimpot. |
| VR3 | 100K | Sets output stage bias current. Adjust first, then set VR2. |
| XLR | input from balanced line jack. | |
| Power supply | ||
| 2x18V 800VA transformer | ||
| 4 x STPS 80 H100 TV schottkys | ||
| 2x 15 x 3300uF / 35V | ||
| 2x 2.2mH torobar choke | ||
| 2x 22 x 4700uF / 25V | ||
| for 22V@7.2A @232V | ||
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 |
| 10pF | 2 | C2, C4 | Mouser 5982-15-500v10 | $0.55 | $1.10 |
| 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 | V1, V3 | Mouser 72-t93ya-100K | $1.20 | $2.40 |
| 200 | 1 | V2 | 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 | Mouser 534-3049 | $0.04 | $4.00 | |
| 1 | 14ga power cord 6' | Newark 37F3337 (Volex 17604) | $6.32 | $6.32 | |
| 1 | 800VA toroid 2x18 secondaries | Victoria Magnetics | $110.00 | $110.00 | |
| 2 | Hammond Chokes | 156B Parts Connection | $10.00 | $20.00 | |
| 2 | RCA inputs | Parts Express 091-1120 | $5.30 | $10.60 | |
| 1 | Speaker binding posts | Parts Express 091-1150 | $4.95 | $4.95 | |
| Power Supply Caps | local source | ||||
| Heat sinks, 0.06c/w per channel | local source | ||||
| 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 $500 to $600 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 everything that you need to create your own 100w Aleph-X amp.