Millett Hybrid MiniMAX - Design/Layout by Colin Toole Last revised:
1/10/2014
BOM by
Tom Blanchard
   
PART ID  DESCRIPTION QTY SOURCE PART NO EACH TOTAL SOURCE PART NO  EACH   TOTAL 
                     
BASIC MILLETT                    
RA1L/R 5K Ohm Trim Pot 2 Mouser 72-T93YA-5K $1.85  $     3.70 DigiKey 490-2888-ND  $         1.51  $      3.02
RA2L/R, RA4L/R 1K ohm 4 Mouser 71-RN55D-F-1.0K $0.08  $     0.32 DigiKey CMF1.00KHFCT-ND  $         0.17  $      0.49
RA7L/R 1M ohm 2 Mouser 71-RN55D-F-1.0M $0.08  $     0.16 DigiKey CMF1.00MHFCT-ND  $         0.17  $      0.49
CA2L/R* 1000uF 16V Nichicon MUSE ES[1] 2 Beezar.com ES-1000-16 $1.75  $     3.50 Beezar.com ES-1000-16  $         1.75  $      6.13
CA4L/R, CA5L/R[2] 1000-1800uF 35V Electrolytic (18mm dia. max, 15mm leads max)[3] 4 Mouser 647-UPW1V182MHD $1.44  $     5.76 DigiKey P12410-ND  $         1.36  $      5.44
CA3L/R, CA6L/R, CA9L/R 0.22uF Film Cap 15mm leads[4] 6 Mouser 505-M10.22/250/10 $1.11  $     6.66 DigiKey P3224-ND  $         1.28  $      7.68
CA8L/R* 0.33uf 200V Sonicap Gen II 2 Beezar.com Sonicap Gen II $4.00  $     8.00 Beezar.com Sonicap Gen II  $         4.00  $      8.00
CA7L/R* 470uF 35V Electrolytic* (16mm dia. Max)[5] 2 Beezar.com ES-470-35 $2.00  $     4.00 Beezar.com ES-470-35  $         2.00  $      4.00
                     
                     
CCS:                    
QA1L/R, QA2L/R 2N5087 PNP small signal[6] 4 Mouser 512-2N5087_J18Z $0.08  $     0.32 DigiKey 2N5087-ND  $         0.19  $      0.76
RA8L/R 1.13K ohm   Mouser 71-RN55D1131F $0.16  $         -   DigiKey CMF1.13KHFCT-ND   $         0.17  $         -  
RA9L/R 11.3K ohm   Mouser 71-RN55D-F-11.3K $0.16  $         -   DigiKey CMF11.3KHFCT-ND  $         0.17  $         -  
Optional selection: results in CCS current of 0.565 ma                  
RA8L/R 1.15K ohm 2 Mouser 71-RN55D1151F $0.08  $     0.16 DigiKey CMF1.00KHFCT-ND  $         0.17  $      0.34
RA9L/R 11.5K ohm 2 Mouser 71-RN55D1152F $0.08  $     0.16 DigiKey CMF10.0KHFCT-ND  $         0.17  $      0.34
                     
MISC:                    
R1 10 ohm, 1W resistor[7] 1 Mouser 282-10-RC $0.19  $     0.19 DigiKey 10W-2-ND  $         0.18  $      0.18
RA5C/L/R (RLED's) 2K ohm 1W[8] 3 Mouser 594-5073NW2K000J $0.16  $     0.48        
  2K ohm 1/2W (alternate)[9]   Mouser 293-2K-RC $0.09  $         -   DigiKey 2.0KH-ND[10]  $         0.26  $      0.78
                     
LED1 Center LED, 3mm, 4000 mcd - Color Change 1 Beezar.com BzrLED-RGB $0.75  $     0.75 Beezar.com BzrLED-RGB  $         0.75  $      0.75
LEDL/R Tube LED's, 3mm SuperBrite, 4000 mcd[11] 2 Beezar.com Varies $0.25  $     0.50 Beezar.com Varies  $         0.25  $      0.50
              Beezar.com Varies  $         0.25  
POT 50K AUDIO TAPER POT 1 Beezar.com ALPS RK27 $16.00  $    16.00 Beezar.com ALPS RK27  $       16.00  $    16.00
                     
VTL/R TUBES 2 Beezar.com 12AE6/A (gain of 14) $5.00  $    10.00 Beezar.com 12AE6, 12AE6A  $         5.00  $    10.00
    2 Beezar.com 12FK6 (gain of 7) $5.00  $    10.00 Beezar.com 12FK6  $         5.00  $    10.00
      Beezar.com 12FM6 (gain of 10) $8.00  $         -   Beezar.com 12FM6  $         8.00  $         -  
SOCKET 7-PIN MINI TUBE SOCKET 2 Beezar.com GZC7-Y-G $2.00  $     4.00 Beezar.com GZC7-Y-G  $         2.00  $      4.00
Terminal Block 3pos 5mm (or 5.08mm) 2[12] Mouser 571-2828363 $1.12  $     2.24 DigiKey ED1931-ND  $         1.30  $      2.60
1/4" Stereo Jack Neutrik NMJ6HCD2 1 Mouser 550-22302 $2.10  $     2.10 Beezar.com Neutrik NMJ6HCD2  $         2.10  $      2.10
Tip Jacks Emerson [13] 3 Mouser 530-105-0602-1 $1.82  $     5.46 DigiKey J106-ND  $         1.54  $      4.62
RCA Jacks Philmore MTG12 1 Beezar.com MTG-12, BL + RD $6.00  $     6.00 Beezar.com MTG-12, BL + RD  $         6.00  $      6.00
Fuse Clips, PCB mount 5x20 fuse clip, 0.2" horiz. lead spacing 2 Mouser 534-3519 $0.13  $     0.26 DigiKey 486-1173-ND  $         0.15  $      0.30
Fuse 5x20mm - 1A slo-blo optional, your choice[14] 1 Mouser 576-0218001.HXP $0.61  $     0.61 DigiKey F2419-ND  $         1.00  $      1.00
                     
PCB Circuit Board 1 Beezar.com MiniMAX PCB $15.00  $    15.00 Beezar.com MIniMAX PCB  $       15.00  $    15.00
                     
                     
POWER SUPPLY                    
RR1 120 ohm 1/4W 1 Mouser 71-RN55D-F-121 $0.08  $     0.08 DigiKey CMF121HFCT-ND  $         0.17  $      0.49
RR2 2K ohm 1/2W 1 Mouser 71-RN60D-F-2K/R $0.09  $     0.09 DigiKey P2.0KW-1BK-ND  $         0.23  $      0.23
RR3 1K ohm trimmer pot 1 Mouser 72-T93YA-1K $1.85  $     1.85 DigiKey 490-2874-ND  $         1.51  $      1.51
PF1 Polyfuse, resettable radial 0.5A 72V 1 Mouser 650-RXEF050 $0.38  $     0.38 DigiKey RXEF050-ND  $         0.32  $      0.32
CR1A, CR1B 1000uF 50V Electrolytic (18mm dia max) 2 Mouser 647-UPW1H102MHD $1.46  $     2.92 DigiKey P12393-ND  $         1.39  $      2.78
CR2 1uF 63V Box cap 1 Mouser 75-MKT1817510064 $1.50  $     1.50 DigiKey 478-3367-ND  $         0.45  $      0.45
CR3A, CR3B, CR3C, CR3D 100pf C0G Axial Ceramic 4 Mouser 581-SA102A101JAR $0.11  $     0.44 DigiKey 478-3141-1-ND   $         0.19  $      0.76
  100pF NPO Ceramic Disc (alternate)   Mouser 140-50N5-101J-RC $0.08  $         -   DigiKey 399-4199-ND  $         0.28  $         -  
                     
CR4 82uf 35V Electrolytic (6.3mm dia max) 1 Mouser 647-UPW1V820MED $0.26  $     0.26 DigiKey 399-3579-ND  $         1.50  $      1.50
                     
DR1A, DR1B, DR1C, DR1D Schottky MBR360, 60V 3A Rectifier - AXIAL 4 Mouser 863-MBR360RLG $0.42  $     1.68 DigiKey MBR360-ND  $         0.64  $      2.56
DR2, DR3 1N4002 2 Mouser 512-1N4002 $0.07  $     0.14 DigiKey 1N4002/54GICT-ND  $         0.69 [15]  $      1.38
VREG LM317T 1 Mouser 511-LM317T $0.70  $     0.70 DigiKey LM317TFS-ND  $         0.48  $      0.48
Heat Sink Wakefield #647-10ABP (1"h.) 1 Mouser 567-647-10ABP $2.90  $     2.90 DigiKey 345-1031-ND  $         1.66  $      1.66
Heat Sink Kit w Shldr Wshr for LM317 Voltage Regulator 1 Beezar.com HtSkKit-1 $1.50  $     1.50 Beezar.com HtSkKit-1  $         1.25  $      1.25
                     
                     
Walwart 24VAC, 750-1000ma Walwart 1 Mouser 553-WAU24-750 $16.40  $    16.40 DigiKey ----  $       16.40  $    16.40
Power Socket 2.1mm Insulated Socket
(must be isolated from case)
1 Mouser 163-4302-E $1.92  $     1.92 DigiKey CP-011A-ND[16]  $         1.49  $      1.49
SPST Switch Red Pushbutton w/round body & thread 1 Mouser 10PP422 $4.96  $     4.96 Radio Shack 275-1565  $         2.99  $      2.99
  Red Pushbutton w/square body & thread   Mouser 10PP432 $2.80  $         -          
Knob Silver, Solid Aluminum, 30mm dia 1 ebay/Partspipe   $5.99  $     5.99 ebay/Partspipe    $         5.99  $      5.99
                     
                     
RELAY-DELAY                    
RM1 3.32K ohm 1 Mouser 71-RN55D-F-3.32K $0.08  $     0.08 DigiKey CMF3.32KHFCT-ND  $         0.17  $      0.49
RM2 1M ohm[17] 1 Mouser 71-RN55D-F-1.0M $0.08  $     0.08 DigiKey CMF1.00MHFCT-ND  $         0.17  $      0.49
CM1 47uF, 25V Electrolytic  1 Mouser 140-HTRL25V47-RC $0.08  $     0.08 DigiKey 493-1300-ND  $         0.14  $      0.14
                     
CM3 470uF 16V Electrolytic (10mm dia. Max)[18] 1 Mouser 140-HTRL16V470-RC $0.17  $     0.17 DigiKey 493-1286-ND  $         0.29  $      0.29
DM1 1N5242B Zener 1 Mouser 78-1N5242B $0.06  $     0.06 DigiKey 1N5242B-TPCT-ND  $         0.75  $      0.75
DM2 1N4148 1 Mouser 78-1N4148 $0.04  $     0.04 DigiKey 1N4148FS-ND  $         0.07  $      0.07
QM1 BD139[19] 1 Mouser 512-BD1396STU $0.54  $     0.54 DigiKey BD13916STU-ND  $         0.42  $      0.42
QM2 MPSA14 1 Mouser 512-MPSA14 $0.50  $     0.50 DigiKey MPSA14-ND  $         0.29  $      0.29
G6A Omron 12V DPDT Relay G6A-234P 1 Mouser 653-G6A-234P-DC12 $8.06  $     8.06 DigiKey Z106-ND  $         6.08  $      6.08
                     
                     
BJT Diamond Buffer                    
RB1L/R 1K ohm 2 Mouser 71-RN55D-F-1.0K $0.08  $     0.16 DigiKey CMF1.00KHFCT-ND  $         0.17  $      0.34
RB6L/R, RB7L/R 220 ohm 4 Mouser 71-RN55D-F-221 $0.08  $     0.32 DigiKey CMF221HFCT-ND  $         0.17  $      0.68
RB2L/R, RB3L/R 10 ohm 4 Mouser 71-RN55D-F-10.2 $0.10  $     0.40 DigiKey CMF10.2HFCT-ND  $         0.17  $      0.68
RB10L/R, RB11L/R 2.2 ohm 2W Metal Film 4 Mouser 594-5083NW2R200J $0.32  $     1.28 DigiKey P2.2W-2BK-ND  $         0.28  $      0.98
RB12L/R 2K ohm Trimmer Pot - different value 2 Mouser 72-T93YA-2K $1.85  $     3.70 DigiKey 490-2880-ND  $         1.51  $      3.02
RB4L/R, RB5L/R, RB13L/R 100 ohm 6 Mouser 71-RN55D-F-100 $0.08  $     0.48 DigiKey CMF100HFCT-ND  $         0.17  $      1.02
RB8L/R, RB9L/R NOT USED - for MOSFET ONLY - jumper out                  
RB14L/R jumper[20] 2 -   $0.00  $         -   -    $            -    $         -  
  Kiwame 10R (alternate)[21] 2 Beezar.com KOA/Kiwame 10R 2W $1.00  $     2.00 Beezar.com KOA/Kiwame 10R 2W  $         1.00  $      2.00
QB1L/R PN4392 Matched for current[22] 1 Beezar.com PN4392pr $2.50  $     2.50 DigiKey PN4392FS-ND  $         0.60  $      0.60
QB2L/R, QB4L/R, QB6L/R 2N5087 PNP small signal[23] 6 Mouser 512-2N5087_J18Z $0.11  -  DigiKey 2N5087-ND  $         0.19  $      1.14
QB3L/R, QB5L/R, QB7L/R 2N5088 NPN small signal[24] 6 Mouser 512-2N5088TA $0.07  -  DigiKey 2N5088BU-ND  $         0.18  $      1.08
  Matched Small Transistors
(preferred alternate)
1 Beezar.com Matched Transistors $2.50  $     2.50 Beezar.com Matched Transistors  $         2.50  $      2.50
QB8L/R MJE243 NPN power transistor[25]   Mouser 863-MJE243G $0.76  $         -   DigiKey MJE243GOS-ND  $         0.73  $         -  
(default option) BD137 NPN power transistor[26] 2 Mouser 512-BD13716STU $0.42  $     0.84 DigiKey non-stock  $         0.73  $      1.46
QB9L/R MJE253 PNP power transistor   Mouser 863-MJE253G $0.58  $         -   DigiKey MJE253GOS-ND  $         0.72  $         -  
(default option) BD138 PNP power transistor[27] 2 Mouser 512-BD13810STU $0.42  $     0.84 DigiKey non-stock  $         0.72  $      1.44
Special Alternates for Q8/Q9                    
a 2SC3421 NPN power transistor[28] 2 Beezar.com 2SC3421 $1.50  ***         
a 2SA1358 PNP power transistor 2 Beezar.com 2SA1358 $1.50  ***         
b 2SC3422 NPN power transistor[29] 2 Beezar.com 2SC3422 $1.75  ***         
b 2SA1359 PNP power transistor 2 Beezar.com 2SA1359 $1.75  ***         
c 2SC2344 NPN power transistor[30] 2 Beezar.com 2SC2344 $1.25  ***         
c 2SA1011 PNP power transistor 2 Beezar.com 2SA1011 $1.25  ***         
d 2SC2238 NPN power transistor[31] 2 Beezar.com 2SC2238 $2.00  ***         
d 2SA968 PNP power transistor 2 Beezar.com 2SA968 $2.00  ***         
                     
Heat Sink Aavid #531002B02500G (1"h.) 4 Mouser 532-531002B25G $1.92  $     7.68 DigiKey HS351-ND  $         1.19  $      4.76
Heat Sink Kit w/o Shldr Wshr for Toshiba 2SC3422/2SA1359 4 Beezar.com HtSkKit-2 $1.25  $     5.00 Beezar.com HtSkKit-2  $         1.25  $      5.00
                     
ACCESSORIES                    
Digital Multimeter Centech Digital Multimeter 1 Beezar.com Centech DMM $7.50  $     7.50 Beezar.com Centech DMM  $         7.50  $    56.25
Trimmer Adjustment Tool Bourns Trimpot Adjustment Tool 1 Beezar.com H-90 $2.80  $     2.80 Beezar.com H90-ND  $         1.29  $      3.61
                     
ENCLOSURE***                    
PCB: approx. 5" x 6" Lansing   Lansing-Clear DT1A60-06A1 $21.37  $         -   Lansing-Black DT1K60-06B2  $       23.07  $         -  
  Custom Machined Beezar/Lansing MiniMAX Case 1 Beezar.com MiniMAX Case - Black $65.00  $    65.00 Beezar.com MiniMAX Case - Black  $       65.00  $    65.00
Center Standoff Kit For Custom Beezar/Lansing case 1 Beezar.com Beezar Cskit $1.50  $     1.50 Beezar.com Beezar Cskit  $         1.50  $      1.50
        TOTAL   $264.15   TOTAL    $  314.84
                     
* These are consensus boutique electrolytic cap positions, the selection choices are many.
** These are consensus boutique film cap positions, the selection choices are many.
*** Fully machined case, punched endplates, cooling slots, and silkscreened labeling

[1]
Cathode Bypass Cap - in the signal path, so boutique cap may benefit.  Also - CA9L/R is the film bypass cap for this position
[2]
Suggest 1000uF for "symmetry"
[3]
You can go up to 1800uf 35V with these and still stay under 1" height with FM's and the newest UPW's (2200). 1000uf should be viewed as a minimum.

[4]
Note that CA9 is the bypass film capacitor for the cathode tube bypass. This cap is normally considered to be in the signal path, but not directly.   Unless you are certain of results, leave this cap as the recommended Wima.  Detrimental effects may occur to the bass response if a quality boutique film cap is used in this position.  Note that upgrading CA3 and CA6 beyond the recommended Wimas is not beneficial.
[5]
Output coupling cap - directly in signal path, boutique cap may benefit
[6]
Note: you should probably purchase about 50 - 100 each of the 2n5087/88 transistors.  Matching for the CCS may be particularly critical.

Also, prices change constantly.  Look for the lowest price specific part numbers at the time of your order.
[7]
Heater Resistor, used to knock down the voltage to the heaters if high supply voltages (30VDC) are used.  10 ohm = -1.5V, 20 ohm = 3.0V.  Optional, but it must be jumpered if not used.
[8]
These resistors are a bit higher-rated than necessary, but will fit within the pads.
[9]
2K puts the power in the 1/2W range and allows the use of cheap and common carbon film resistors, if desired.  However, 1/2W carbon films are too big for the pads and will need to be installed in a "kneeling" posture.
[10]
DigiKey:
Qty of 5
[11]
Since LSDiodes has stopped selling LED's, Team Millett MAX has not found a vendor to recommend for every case.  LED's are plentiful, however.  Simply select the highest-rated MCD LED that uses 20ma current and is a T1, 3mm LED.
[12]
Note: the production MiniMAX board has positions for three terminal blocks - one input at the pot, one output at the headphone jack, and one for power input.
[13]
Pick some different colors - maybe red, white, and black or gray - the 3rd digit in the middle number changes for color: 801 is white, 802 is red, 803 is black.
[14]
There are too many variables to predict what size may be needed.  The fuse is useful for protecting your Class 2 plug-in transformer (AC walwart).  1A SLO-BLO should be your starting point.  If you want to reduce or increase it from there, or experiment with a fast blo, that's up to you.  Be careful, however, or protecting the fuse may become the goal instead of the other way around.
[15]
min qty 10
[16]
Note: this jack is the inverse of the Mouser version - the threads are outside instead of inside.
[17]
Recommendation:
R*C for RM2 and CM3 should equal ~450 or greater. Greater values will result in greater delays.
[18]
Recommendation:
R*C for RM2 and CM3 should equal ~450 or greater. Greater values will result in greater delays.
[19]
Thomas M. Blanchard:
Don't waste one of your expensive output transistors here - even if it's the same type.  The BD139 is very cheap.
[20]
This is the output resistor.  Jumper this position unless you have noise problems or desire greater gain reduction.
[21]
This is the output resistor.  Jumper this position unless you have noise problems or desire greater gain reduction.
[22]
J310 is also acceptable, or other JFET's with IDSS >50
[23]
Note: you should probably purchase about 50 - 100 each of the 2n5087/88 transistors.  Matching for the CCS may be particularly critical.

Also, prices change constantly.  Look for the lowest price specific part numbers at the time of your order.
[24]
Note: you should probably purchase about 50 - 100 each of the 2n5087/88 transistors.  Matching for the CCS may be particularly critical.

Also, prices change constantly.  Look for the lowest price specific part numbers at the time of your order.
[25]
Steinchen:
well balanced, neutral to slightly warm sound. very stable due to moderate bandwidth.

default recommendation.
[26]
Steinchen:
neutral to warm sound, strong bass, yet detailed. cheap and easy to source (at least in Europe).
default recommendation.
[27]
Steinchen:
neutral to warm sound, strong bass, yet detailed. cheap and easy to source (at least in Europe).
default recommendation.
[28]
Steinchen:
strong bass, hard punch, recessed mids. highs tend to sound a little rough and pronounced.
[29]
Steinchen:
strong bass, neutral to warm sound.
good choice if you prefer rocky sound with slam
[30]
Steinchen:
crystal clear and airy, rather bright but not piercing bright. good detail and instrument seperation. well defined bass. sounds clean and analytical.

note reversed pinout!
[31]
Steinchen:
neutral and balanced sound, tight bass. detailed and clear highs without being bright, easy to listen to
excellent choice
note reversed pinout!