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Millett Hybrid		  PCB Design/Layout
 by Dsavitsk		 Last revised:
01/23/10		 BOM by
Tom Blanchard
PART ID  DESCRIPTION QTY SOURCE PART NO EACH TOTAL SOURCE PART NO  EACH   TOTAL 
                     
Please read the comments! (little red triangles in the upper right corners)
                     
BASIC CIRCUIT                    
Please note - the caps are limited to 20mm height if the "L" case is used.                
C1/C6 680uf 63V Electrolytic (18mm dia max)[1] 2 Mouser 647-UPW1J681MHD3[2] $0.80  $     1.60 DigiKey P11276-ND[3]  $     2.65  $     5.30
C2/C4 0.22uf 250V Film Cap (10 or 15mm leads)[4] 2 Mouser 505-M10.22/250/10 $1.11  $     2.22 DigiKey P3224-ND  $     1.28  $     2.56
C3/C5 470uf 63V Electrolytic (18mm dia max)[5] 2 Mouser 647-UKW1J471MHD[6] $0.73  $     1.46 DigiKey P10352-ND  $     1.36  $     2.72
C3a/C5a* 0.22uf 250V Film Cap (10 or 15mm leads)[7] 2 Mouser 505-M10.22/250/10 $1.11  $     2.22 DigiKey P3224-ND  $     1.28  $     2.56
C7/C8* 220uf 16V Nichicon Muse ES[8] 2 Beezar.com Muse ES, 220uf 16V[9] $1.00  $     2.00 Beezar.com Muse ES, 220uf 16V  $     0.90  $     1.80
                     
                     
R1/R7 33K ohm[10] 2 Mouser 71-RN55D-F-33K $0.16  $     0.32 DigiKey CF1/433KJRCT-ND  $     0.20  $     0.40
R2/R8, R4/R10 220K ohm[11] 4 Mouser 71-RN55D-F-220K $0.15  $     0.60 DigiKey CF1/4240KJRCT-ND  $     0.20  $     0.80
R3/R9, R5/R11, R6/R12, R13 2K ohm[12] 7 Mouser 71-RN55D-F-2.0K $0.08  $     0.56 DigiKey CF1/42KJRCT-ND  $     0.20  $     1.40
R14/R15* 1K ohm[13] 2 Mouser 71-RN55D-F-1.0K $0.08  $     0.16 DigiKey CF1/41KJRCT-ND  $     0.20  $     0.40
R16/R17* 50K - 1/4W [14] 2 Mouser 71-RN55D5102F $0.19  $     0.38 DigiKey CMF49.9KQFCT-ND  $     0.29  $     0.58
R16R17* - low gain 100K - 1/4W[15] 2 Mouser 71-RN55D-F-100K $0.08  $     0.16 DigiKey CMF100KQFCT-ND  $     0.29  $     0.58
                     
                     
RV1
(please read comments)[16]		 Alpha 50K Audio Taper Stereo Pot
RV122F-20-15F-A10K[17]		 1 Mouser 313-1240F-50K $3.16  $     3.16 DigiKey N/A    $         -  
Q1/Q2 MOSFET, IRF510, TO-220 case 2 Mouser 844-IRF510PBF $0.53  $     1.06 DigiKey IRF510PBF-ND  $     1.12  $     2.24
Tubes** 19J6[18] 2 Beezar.com 19J6 $6.00  $   12.00 Beezar.com 19J6  $     5.00  $   10.00
Tubes Tested/Matched within 10% Per tube, two triodes each 2 Beezar.com Testing/Matching $2.00  $     4.00 Beezar.com Testing/Matching  $     2.00  $     4.00
                     
                     
MISC:                    
Headphone Jack Neutrik NMJ6HCD2 1 Mouser 550-22302[19] $1.13  $     1.13 DigiKey N/A    $         -  
RCA jacks HiQ gold-plated copper, 1 pair 1 Beezar.com RCA-1 $3.50  $     3.50 Beezar.com RCA-1  $     3.50  $     3.50
Tube Socket 7-pin PCB Ceramic, tin-plated 2 Beezar.com GZC7-Y-T $1.00  $     2.00 Beezar.com GZC7-Y-T  $     1.00  $     2.00
Terminal Block, 3-pos 5mm (or 5.08mm) 1 Mouser 571-2828363 $0.66  $     0.66 DigiKey ED1931-ND  $     0.93  $     0.93
Terminal Block, 4-pos 5mm (or 5.08mm) 2 Mouser 571-2828364 $0.76  $     1.52 DigiKey ED1930-ND  $     0.62  $     1.24
Standoff Kit, for 3rd slot SSHM Standoff kit, screws, etc. 1 Beezar.com SSMH Standoff Kit $1.00  $     1.00 Beezar.com SSMH Standoff Kit  $     1.00  $     1.00
SSMH PCB Heat Sink Kit Bergquist pad, shldr washer, screws, etc. 2 Beezar.com Heat Sink Kit $2.00  $     4.00 Beezar.com Heat Sink Kit  $     1.50  $     3.00
Heat Sink TO-3 style, Aavid #569003B00000G 2 Mouser 532-569003B00 $2.53  $     5.06 DigiKey HS110-3-ND  $     3.04  $     6.08
Knob Silver anodized Al, 1.25" dia, 1/4" shaft 1 Mouser 450-6007 $3.02  $     3.02        
                     
RLED*** 2.4K, 2W metal oxide resistor[20] 1 Mouser 282-2.4K-RC $0.19  $     0.19 DigiKey P2.4KW-2BK-ND  $     0.28  $     0.28
LEDL/R Tube LED's, 3mm 5000 mcd - Blue[21] 2 Beezar.com 604-WP7104QBC/D[22] $0.25  $     0.50 Various 754-1248-ND  $     0.42  $     0.84
                     
PCB Circuit Board 1 Beezar.com SSMH PCB $10.00  $   10.00 Beezar.com SSMH PCB  $   10.00  $   10.00
                     
                     
POWER SUPPLY                    
Power Supply 120/240V, 48VDC@0.38A, w/power cord 1 Various Cisco PSA-18U $15.00  $   15.00 Various  Cisco PSA-18U   $   15.00  $   15.00
Power Socket 2.5mm Metal Socket, 100VDC 2A 1 Mouser 163-4025 $3.03  $     3.03 Radio Shack 274-1576[23]  $     2.99  $     2.99
SPST Switch Black Rocker w/round hole & thread 1 Mouser 103-R13-135A-02-EV $1.18  $     1.18 Radio Shack 275-693  $     2.99  $     2.99
                     
                     
ENCLOSURE***                    
PCB: approx. 4" x 3" Hammond 1455N1201 - Black[24] 1 Hammond 1455N1201BK $21.27  $   21.27 Hammond 1455N1201BK  $   21.27  $   21.27
  Machining, tube holes, heat sink mounts, and all endplate openings 1 Hammond Hammond machining ($30 total per case) $13.73  $   13.73 Hammond Hammond machining ($30 total per case)  $   13.73  $   13.73
        TOTAL   $118.69   TOTAL    $ 120.19
                     
* Optional parts - Dsavitsk additions over Pete Millett original
** 19J6 tubes at Beezar.com to be sold in tested pairs with PCB, only
*** The LED resistor is treated as a single source to two Tube Light LED's.  If you choose to use a panel LED, either by itself or with the Tube LED's, you will need to calculate your own resistor sizes.  We do not recommend feeding three LED's from this resistor.
[1]
These are the power decoupling caps.  A good quality power cap is all that's necessary.  680uf seems to be the smallest necessary to prevent power startup stuttering in the standard configuration.
[2]
This is a non-stock item at Mouser at 20mm height, unfortunately.
[3]
Also available at Beezar.com
[4]
These are the interstage coupling caps.  Audio quality needed, voltage rating is not important as long as >= 50V.  0.1uf is minimum, but the pads are sized for 0.22uf.  NOTE: Some boutique style film caps may not be accurate down to 0.1uf and loss of bass may result.  0.22uf gives a safety factor.
[5]
These are the output coupling caps.  Their size is directly related to the cutoff frequency seen by the headphones.  470uf is sufficient down to 32 ohm headphones.  Audio-quality is desired, but power caps will work well with film cap bypassing.
[6]
This is a new audio-quality Nichicon at Mouser.  Also available at Beezar.com
[7]
These are optional bypass caps for the output coupling electrolytics.  A good film cap will increase the sound quality over the electrolytics alone, especially in the highs.  0.22uf is a suggested size.  Caution: film cap bypassing is not "scientifically" predictable in all cases.  Deviation from known combinations may yield unpredictable results.
[8]
Cathode bypass cap.  These are optional, but may increase plate resistance, a good thing.  A bipolar cap would probably be best, here - if you use one.
[9]
This should also be a signal-quality cap.  A Nichicon Muse ES would be a great choice here (Handmade Electronics or Beezar.com)
[10]
1/2W size, 10.8mm maximum, but either 1/4W or RN55/RN60 sizes will work.
[11]
1/2W size, 10.8mm maximum, but either 1/4W or RN55/RN60 sizes will work.
[12]
1/2W size, 10.8mm maximum, but either 1/4W or RN55/RN60 sizes will work.
[13]
These are optional grid resistors for the tubes, usually used to quell tube oscillations.  Not found to be needed in the SSMH, they won't hurt, either - install 470 - 1K ohms if you wish.
1/2W size, 10.8mm maximum, but either1/4W or RN55/RN60 sizes will work.
[14]
These are the pot input resistors, used to "push" the pot into a greater adjustment range for volume.  Size for a rating equal to the pot's impedance as a starting point.  7.5mm lead spacing, 1/4W or V-D RN55 size, maximum.
[15]
Use these if you want low gain for low-impedance efficient phones.
[16]
50K is suggested, but 100K or 10K will work just fine, too.  If you use R16 and R17, be sure to adjust their size according to the pot rating you select.  For instance, for a 10K pot, use 10K for R16/R17.  For a 100K pot, use 100K for R16/R17, and so on.
[17]
50K is suggested, but 100K or 10K will work just fine, too.  If you use R16 and R17, be sure to adjust their size according to the pot rating you select.  For instance, for a 10K pot, use 10K for R16/R17.  For a 100K pot, use 100K for R16/R17, and so on.
[18]
Must be purchased with PCB
[19]
Also available at Beezar.com
[20]
This resistor is sized for a single 10ma load.
This resistor is sized to use two LED's under the tubes.  The resulting current should be about 10ma for each resistor, plenty for super-bright LED's.  NOTE: this resistor will need to be installed in tombstone or kneeling fashion.
If you want a panel LED, too - install a separate resistor in the leads for the panel LED; feed it directly from the power terminal block.
[21]
 LED's are plentiful.  Simply select the highest-rated MCD LED that uses 20ma current and is a T1, 3mm LED.
[22]
Mouser Part #
604-WP7104PBC/H
is 3600mcd for $1.97
[23]
Note: this jack is the inverse of the Mouser version - the threads are outside instead of inside.
[24]
Height is not a restriction with this case (within reason), and every boutique cap within the suggested size range will fit.
The downside is that the case doesn't look proportional and the endplate-located parts such as the pot and headphone jack are offset greatly to the top of the case.  Air-wiring the headphone jack and pot will solve this issue, but remove some of the convenience of the PCB.