Sourcing electronic components for synth-DIY

"Not discontinued, you understand,
just on a 52-week lead time.
"
—Dan Mills

Hardware

Eurorack frames

AKA Eurocard frames AKA IEC 60297 sub-racks. supermoduul.com have them cheap.

Connectors

0.145" / 3.68 mm pitch

Molex 1625 series. Used in the old Oberheim SEM.

Male pins
Molex 02-06-2103 (Digi-Key WM1000-ND, Farnell 1079887)
Receptacle for male pins, 3-way
Molex 03-06-2032 (Digi-Key WM1221-ND, Farnell 1593638)
Receptacle for male pins, 4-way
Molex 03-06-2042 (Digi-Key WM1222-ND, RS 679-4855)

Switches

Keyboard switches

RS 664-581 (Cherry MX1A-A1NN) does not include a keycap, contrary to what the photo on the web site suggests. The UK site says the keycaps are available as SKU 664-660 which doesn't seem to be available from the French branch. Nice. Presumably, the same applies to RS 664-569 (Cherry MX1A-11NN).

Passives

Capacitors

Dielectrics

Potentiometers

The most common types of shaft are : round, 1/4" (6.35 mm) ; round, 6 mm; "knurled" a.k.a "serrated" a.k.a. "splined" (6 mm with 18 teeth) ; "D" (6 mm with a flat). Round shafts require knobs with a set screw. Splined shafts and D shafts accomodate push-on knobs which are usually made of molded plastic and much cheaper.

Curves a.k.a. laws a.k.a. tapers : the three most common curves are linear, log (a.k.a. "audio") and anti-log (a.k.a. "antilog" a.k.a. "reverse audio"). In France (and, I believe, Europe), "A" means linear and "B" means log. In Japan (and, I believe, North America), it's the other way around. "C" always means anti-log.

One of the best deals there is on pots is the Alpha RV160 knurled shaft carbons. Rapid, Futurlec and Mouser sell them. Futurlec have the best prices. Mike points out that The pots from Rapid have longer spindles than those from Futurlec. If direct panel mounting the ones from Rapid, the spindles need cutting down..

Some people prefer G&H or Song-Huei's 16-mm carbon pots.

Beware of Piher pots. My experience has been that they become scratchy fast.

Anti-log pots

Anti-log pots are relatively hard to find. Banzai, Futurlec, Mouser and Small Bear carry Alpha anti-log pots. Futurlec and Mouser don't seem to have any dual-gang ones, unfortunately for people building or repairing parametric equalisers. Before you embark on a search for an anti-log pot, read these :

Centre-tapped pots

Tom Arnold has Alpha RV16 50 kΩ linear, centre-tapped, 1/4"-shaft pots for sale

Pots with push-pull switch

Mouser order code 313-1601F-500K is the Alpha RV16BF-10-15R1-B500K which is a 16 mm 500 kΩ linear carbon with a 1/4" shaft and a DPDT switch. Jürgen Haible used them in his Korg PS-3200 clone.

Knobs

RS 467-5951 looks nothing like the photo on the web site. It is in fact the same product as Multicomp MCCPMB5 or CP-MB-5 which Farnell used to carry as 766-562. Not a bad knob but no skirt and the indicator "line" is almost 2 mm thick.

Precision resistors

Tempcos

Resistors with specific temperature coefficients (E.G. +3500 PPM/K as needed in exponential converters). See Ian Fritz's Dial-a-Tempco Exponential Converter.

Mfr Model Prec PPM/K W Pkg Reseller SKU Price ea. Notes
1 ? ? ? ? ? ? The Bridechamber link 2.50 USD
1 Panasonic-­ECG ERA-S33J102V 5% +3300 0.1 SMD 0805 Digi-Key P1.0KCDCT-ND 0.552 USD David Brown used them to build an AM4075 ARP 4075 VCF clone.
1 ? ? 1% +3500 ? ? Elby Designs link 6.10 AUD Includes a 42.2 Ω resistor to lower the coefficient to +3300 PPM/K if desired.
1 ? ? ? +3500 axial Oakley Sound Systems link 5 GBP Equivalent to the old Tel Labs Q81
1 Precision Resistor PT146 1% +3500 0.25 axial Eli Manis ? 3.58 CAD Eli Manis Inc.
8515 Place Devonshire
Suite 202A
Montreal Quebec
H4P 2K1
1 Tyco/­Meggitt LT300014T261K0J 5% +3000 0.25 axial Farnell 1174-306 (formerly 732-278) 1.01 GBP
1 Tyco/­Meggitt LT300016T261K0J 5% +3000 0.17 axial Farnell 732-291 0.92 GBP No longer stocked as of 2008-12.
1 Tyco ? ? +3000 ? axial Henry link 2.50 GBP
1 Akaneohm LT16S102F33 1% +3300 0.167 axial Katayama Technical Service link 40 JPY Email Takuya Katayama at <memorymoog@cabbage.org> (replace the synth by "pata" and the vegetable by "ieee").
1.8 Panasonic-­ECG ERA-S33J182V 5% +3300 0.1 SMD 0805 Digi-Key P1.8KCDCT-ND 0.552 USD
2 ? ? ? ? ? ? The Bridechamber link 2.50 USD
1 Akaneohm LT16S202F33 1% +3300 0.167 axial Katayama Technical Service link 40 JPY Email Takuya Katayama at <memorymoog@cabbage.org> (replace the synth by "pata" and the vegetable by "ieee").
2 ? ? 1% +3500 ? ? Elby Designs link 9.45 AUD Includes a 84.5 Ω resistor to lower the coefficient to +3300 PPM/K if desired.
2 Micro-Ohm ? ? 2% 3500 0.25 ? Magic Smoke link 3.50 USD
2 Precision Resistor PT146 1% +3500 0.25 axial MFOS link 9 USD
2 Tel Labs Q81K 1% +3300 ? axial 0.575"×0.15" Jim Patchell link 10 USD
10 Koa LP1/8W10kF 1% +3300 0.125 axial Katayama Technical Service link 40 JPY Email Takuya Katayama at <memorymoog@cabbage.org> (replace the synth by "pata" and the vegetable by "ieee").

Transformers

Audio transformers. OK, that's for general audio, not synth DIY.

Reverb tanks

Accutronics

Belton

Semiconductors

Oscillators & TOG

M108

M110

Combined keyboard scanner and DCO. Outputs four square waves one octave apart which can be summed to approximate a sawtooth. Used in the Siel Mono and Jen SX1000.

OTA

CA3080

Harris/Intersil stopped making them (see under CA3280 below for details) but Rochester Electronics have taken them up and old stock is not hard to find.

CA3280

LM13600/LM13700

Don Sauer tells The LM13600/LM13700 story.

NE5517

The Philips fab in Caen where they were made burned down in December 2003. ON Semiconductor (Motorola) make an equivalent but, reportedly, it's not as good.

VCA

BA6110

BA662

RIP

SSM2164/V2164

A nice, cheap, temperature-compensated quad VCA. Analog Devices, in their long term crusade against the SSM line, have obsoleted the SSM2164 in 2010 or early 2011. Coolaudio have a clone, the V2164 which is reportedly just as good. It is available from Small Bear Electronics. The SSM2164/V2164 will go up in smoke if it loses the negative supply. Oscar Salas and Neil Johnson have found a simple and effective protection scheme (a Schottky diode from V- to ground).

THAT 2162

THAT 2162 dual Blackmer VCA (QSOP only)

Profusion PLC and Mouser sell them.

THAT 2150A/2151/2155

Discontinued, replaced by THAT 218x.

THAT 2180/2181

Profusion PLC and Mouser sell them.

Voltage references

FIXME Don't trust the grades in this table, they don't carry across manufacturers !

Chip/Grade Max
voltage
(V)
Reverse
breakdown
voltage
(V)
RBV
tolerance
(%)
RBV
temperature
coefficient
typ/max
(PPM/K)
Max
fwd
cur
(mA)
Max
rev
cur
(mA)
Through
-hole
packages
LM329
LM336-2.5 2.5 10 15 TO-92(ADJ,C,A)
LM336-5.0 4 ~ 6 10 15 TO-92(FB,C,A)
LM4041-1.2 E 15 1.225 2.0 150 10 20 TO-92(NC,C,A)
D 1.0 150
C 0.5 100
B 0.2 100
A 0.1 100
LM4041-ADJ 15 1.24 ~ 10 0.1 (-A)
0.2 (-B)
0.5 (-C)
1.0 (-D)
2.0 (-E)
100 (-A)
100 (-B)
100 (-C)
150 (-D)
150 (-E)
10 20 TO-92(FB,C,A)
LM431/
TL431
37 150 100 TO-92(R,A,C)
DIP-8
(C,NC,NC,NC,
NC,A,NC,R)
REF01 12 ~ 40 9.7 ~ 10.3 20/65 (-C)
10/25 (-H)
3/8.5 (-A/-E)
DIP-8
REF02 7 ~ 40 4.7 ~ 5.3 ±100 (-D)
±50 (-C)
±25 (-/-H)
±15 (-A/-E)
[mV @25°C]
70/250 (-D)
20/65 (-C)
10/25 (-/-H)
3/8.5 (-A/-E)
DIP-8

Transistor arrays

NPN PNP Part Package Availability Comments
Met.
can
DIP SOIC
8 14 16 8 14 16
2 - LM394 N A - - - - - DIP-8 version discontinued in 1998. Futurlec used to have some (out of stock as of 2009-10). Bridechamber are out of stock.
TO-99 version marked "Lifetime buy 2010-07-30"
LS318 L M A - - A - - In production
MAT01 M - - - - - - In production
MAT02 M - - - - - - Discontinued by AD in 2009, replaced by MAT12.
MAT12 M - - - - - - Introduced by AD in 2010 in replacement of MAT02.
SSM2210 - A - - A - - AD discontinued them in 2009.
SSM2212 - - - - A - - Introduced by AD in 2010 in replacement of SSM2210. Only available in SOIC-8 !
- 2 LS358 O P B - - B - - In production
MAT03 P - - - - - - In production
SSM2220 - B - - B - - In production
4 - MAT04 - - C - - - - Discontinued.
THAT100 - - D - - D - Discontinued.
THAT300 - - C - - C - In production
2 2 THAT140 - - F - - F - Discontinued. Jim Patchell has some for sale.
THAT340 - - E - - E - In production
- 4 THAT120 - - H - - H - Discontinued. Jim Patchell has some for sale.
THAT320 - - G - - G - In production
5 - CA3046 - - I - - I - Discontinued by Intersil circa 2005. Same die as CA3086 but differential pair tested for matching. National still make the LM3046 but in SOIC only.
Ian Fritz 2008-12-12 : I've used the CA3083 in many projects. The log conformance is *way* better than for the 3046, namely Re = 1.3 Ohm vs. 5.0 Ohms. The 3046 is pretty far down on the list for expo converters.
CA3146 - - I - - I - Discontinued. Futurlec, Nikko and a few other stockists have some. High voltage version of CA3046. Intersil used to make them but now deny they ever did.
CA3083 - - - J - - J In production Ian Fritz uses this device in his triangle core VCO : I chose the CA3083 array for the converter transistors. My measurements indicate that these have much better characteristics than their specs indicate, with matching better than 0.2 mV and betas above 200. Although general-purpose arrays like this have a bit more emitter series resistance than expensive, special purpose pairs, the the D1-R14 feedback path provides highly effective compensation for the effects of this resistance.
CA3183 - - - J - - J Discontinued. High voltage version of CA3083. Intersil (and apparently Philips) used to make them but now deny they ever did.
CA3086 - - I - - I - Discontinued by Intersil. Same die as CA3046 but differential pair not tested for matching.
3 2 CA3096 - - - K - - K Discontinued. Replaced by Intersil HFA3096 (same pinout, I think), which Digi-Key, Newark and others stock but is only available in SOIC.

Pinout codes :

A
DIP-8, 2 × NPN : N1C N1B N1E nc nc N2E N2B N2C
B
DIP-8, 2 × PNP : P1C P1B P1E nc nc P2E P2B P2C
C
DIP-14/SOIC-14, 4 × NPN : N1C N1B N1E SUB N2E N2B N2C N3C N3B N3E SUB N4E N4B N4C
D
DIP-14/SOIC-14, 4 × NPN : N1C N1B N1E N2C N2B N2E SUB nc N3E N3B N3C N4E N4B N4C
E
DIP-14/SOIC-14, 2 × NPN, 2 × PNP : N1C N1B N1E SUB P1E P1B P1C P2C P2B P2E SUB N2E N2B N2C
F
DIP-14/SOIC-14, 2 × NPN, 2 × PNP : N1C N1B N1E P1E P1B P1C SUB P2C P2B P2E nc N2E N2B N2C
G
DIP-14/SOIC-14 : 4 × PNP : P1C P1B P1E SUB P2E P2B P2C P3C P3B P3E SUB P4E P4B P4C
H
DIP-14/SOIC-14 , 4 × PNP : nc P1E P1B P1C P2E P2B P2C P3C P3B P3E P4C P4B P4E SUB
I
DIP-14/SOIC-14, 5 × NPN : N1C N1B N1E/N2E N2B N2C N3B N3E N3C N4B N4E N4C N5B N5E/SUB N5C
J
DIP-16/SOIC-16 : 5 × NPN : N1C N2C N2B N2E SUB N3B N3C N3E N4C N4B N4E N5E N5B N5C N1E N1B
K
DIP-16/SOIC-16 : 3 × NPN, 2 × PNP : N1B N1E N1C N2E N2B N2C N3E N3B N3C P1E P1B P1C P2E P2B P2C SUB
L
6-lead TO-71, 2 × NPN : 1=Q1C 2=Q1B 3=Q1E 5=Q2E 6=Q2B 7=Q2C
M
6-lead TO-78, 2 × NPN : pinout same as L
N
6-lead TO-99, 2 × NPN : pinout same as L
O
6-lead TO-71, 2 × PNP : pinout same as L
P
6-lead TO-78, 2 × PNP : pinout same as L

David G. Dixon 2009-12-05 : [...] the Linear Integrated Systems LS358 log conformance matched pnp [is] an excellent candidate for expo converter applications [...] Linear has two distributors: Trendsetter in Texas and Nacsemi in Florida. Canadians can also obtain Linear parts from and Eli Manis in Quebec. Linear also ships direct. As far as I can tell, none of these suppliers have minimum order policies. Trendsetter likes to see orders of at least $50, and Linear of at least $100 (which shouldn't be hard). Eli Manis didn't mention any minimums, and seemed genuinely eager to help, as did they all.

Bulk resistance (rBE) comparison by René Schmitz.

Parts to look into : Philips BC847BS and BC857BS, Zetex ZTX795A and ZTX1151A, 2SA798, 2SC1583, 2SC3381, 2SA1349, CA3045/LM3045, HFA3128.

Logic

Logic Threshold Voltage Levels explains the difference between 4000-series or 74C and 74HCT.

Vactrols a.k.a. optoisolators

An LED and a photoresistor in the same package, forming a voltage controlled resistor. Useful for adding voltage control to a circuit.

Some (most ? all ?) types of photoresistors contain cadmium sulphide (CdS). Cadmium is one of the substances banned in the EU under RoHS. There used to be an exemption for "cadmium in photoresistors for optocouplers applied in professional audio equipment" but it has run out on 2010-01-01.

A. Documentation

B. Manufacturers and resellers

Specialised stores : The Bride Chamber, Electronic Schematics for Hobbyists, Kevin "Synthfool" Lightner, Pedal Parts Plus, Doug Terrebonne at synthparts.com, TubeAmpDoctor and Senso at Vintage Planet.

Cross-vendor search :

General electronic components resellers : E44 (mail order + stores in Nantes, Poitiers, La Roche-sur-Yon and Vannes), ECE espace composants électroniques (mail order + store at 66 rue de Montreuil 75011 Paris), RAM/Verdier SA/Zeus (mail order + stores in Paris) and RS Components (known as Radiospares in France, formerly Verospeed). ESR Electronic Components Ltd near Newcastle.

Allied Electronics

Their web site lists a number of shipping methods :

UPS Next Day
UPS 2nd Day
DHL Next Day Noon
DHL Next 10:30 AM
DHL Saver - Next 3 PM
DHL 2nd Day
Fedex Standard
Fedex Priority 1
Fedex 2nd Day
U.S. Express Mail

The cheapest is Express Mail. There is no ground delivery.

If you choose Express Mail as I did, the delivery guy will collect the VAT and handling charge. Have some change ready.

Farnell

Until a couple years ago, Farnell France would only deal with businesses. They will now sell to individuals. There is a minimum order and you will pay shipping but it's very reasonable.

Futurlec

There are sometimes delays but the goods usually do arrive.

Mouser

A few things you might want to know before ordering from them :

Rapid

Rapid are funny. They ship orders in reused cardboard boxes. They seem to try to carry as few items as possible and be cheaper than everybody else. They are the anti-RS. If their headquarters came in contact with those of RS, they would probably annihilate each other, converting all their matter to energy.

They used to have a very stiff minimum order of 500 UKP for people outside of the UK. As of 2008-01, that is a thing of the past : their web site says Export orders to countries outside the EU have a minimum order value of £25. No minimum order value within the EU..

They do have a maximum order of sorts, however. If your order exceeds 500 GBP, you cannot pay by credit/debit card. "For security reasons", you must pay via bank transfer. This means a 12 GBP bank fee and a delay, hence items going out of stock in the meantime and complications with any "end column day" deals. The 500 GBP limit includes shipping and 20% VAT ; the "basket total" limit is closer to 370 GBP. Smile : back in 2009, it was 250 GBP and their online ordering system didn't know about the limit so you learned about it the next day.

RS Components / Radiospares

Formerly known as Verospeed.

Beware of order codes beginning with 25 or marked as "Newark InOne". There is an additional charge of 15 to 25 EUR on those.

Historically, Radiospares would sell to individuals with a small (or no) minimum order. Sometime in 2005 or 2006, they started enforcing a 150 EUR minimum order for individuals. So not content with being more expensive than Farnell, they are now also harder to deal with.

Update : in 2009, their terms have changed again. There is no minimum now but

At least this is the case for their French branch.

C. Acknowledgements

Most of the information on this page comes from synth-diy subscribers. Archives : http://dropmix.xs4all.nl/pipermail/synth-diy/ (from 2007-03 on), http://search.retrosynth.com/synth-diy/ (from 1995 on).


This is http://www.teaser.fr/~amajorel/sourcing/, last modified 2012-09-03.