Parts and where to get them

[Techknowman]

The one thing I realize now that I'm my own "boss" is buying and finding parts.
Sometimes I spend more time just trying to find a part than it takes to do the repair.
So when I find said parts, even if i only need 1 or two I buy 5 or 10, so I'm slowly building up a stock of parts.
I don't know if they can be called "common" parts but I always feel that if I need 1 today I will probably need one tomorrow or the day after! of course my garage is full of stuff I keep for the same reasons. I'll probably be featured in "Hoarders buried alive" one day!
I buy from the usuals, Mouser, Allied, Digikey and Audiolabs in Georgia.
Audiolabs seems to be the only descent place to get Jap transistors (2SA, 2SC etc)
Anyway I digress.
Has any of you guys ever compiled a hot 100 list or something like that of parts you would definitely stock and in modest quantity's?

Any other places you would recommend for hard to gets?

I don't mess with tube amps so I don't need those parts much.

[bkahuna]

Besides the ones you mentioned:
Newark
B&D Enterprises (Japanese xistors here, too)
MCM
Jameco
Small Bear


Thanks for mentioning Audiolab. I've never used them before. Good idea for a thread. It would be nice if someone could compile a list into a stickie.

[Enzo]

Mouser et al have an ever increasing selection of Asian transistor types. MCM has most of them. B&D has a (so far) safe selection of Sankens and all the other Asian types. I don't know what you consider hard to find parts.

There are industry suppliers like Antique Electronic Supply (CE Dist) and Parts is PArts (Marshallparts.com)

You will find that transistors are extremely non-critical about substitutions.. A few of various ratings can cover many needs. Larger types all pinout the same, but the small TO92s come in various flavors. The USA types like the 2Nxxxx and the MPSxxxx are EBC across the front. while Asian types like 2SC1815 or 2SA1015 will be ECB across the front. And for the life of me, no matter how many times I look it up, I can never remember the lead order on the BCxxx series. Those two Asian ones are great general purpose audio transistors, by the way. USA types 2N3904/3906 are generally useful, though I more often rely on 2N4401/4403 or the various MPS types.

The problem us that there are common parts for just about any type, but there are thousands of types too. If I work on a lot of PV SS stuff, I will stock a lot of the Moto MJ series of TO3s. On the other hand if I service a lot of Crate and Fender SS amps, I can expect to use a bunch of TIP142 and TIP 147 types. The 2SC5200/2SA1943 pair of TO247s is a great all purpose pair for that shape, Samson loves them, but then you may never see them.

Building a parts collection is an art. You order extra when you buy them, but temper that with the possibility you will never use them again. Is this the Only Ashdown amp you have ever seen? Do they sell them near you anywhere? Then maybe you don;t stock the parts they use. It is a tube amp, but there is no strong outlet for Mesa amps in my area, I see very few of them. SOmeone across the state from me might se them every day. As a result I don;t stock any Mesa specific stuff.

Tube amps use certain resistors a lot: 100k, 220k, 1.5k, 470 2-5watt, 1k 5w, 68k, some others. Solid state stuff will use many more values. Just having a good overall selection is a good idea in my mind. Little 1/4 or 1/2w film resistors might cost 15 cents each, but often as not if you buy 100 of them it drops to 2 cents. SO two bucks will get you a dozen or a hundred, take your pick. I work on a lot of specific things. I know those Mackie SWA1501 powered subs will need a supply of 330, 56, 2.2 and some other resistors. But that PV powr amp is going to want that 180 ohm guy and the Samsons will burn up a lot of 4.7 and 100 ohm resistors.

Most powr amps will have ballast resistors, often 5 watters. 0.33 ohm is common, but so are 0.22, 0.1, and 0.47 ohm. You might replace one, but when an amp blows you could also need 10 of them - I just rebuilt a Samson power module that needed 10 0.47/5w. The Peavey PV1.3k I recently rebuilt needed a whole pile of 1 ohm 5w resistors. Don;t see those much elsewhere.

Caps? Geez, there are thousands. Power filters can be all over the map. Look at them as you service things. The low voltage supplies will all be similar, I mean everything has +/-15v suplies, so 25 or 35v caps are common, 2200 3300 3900uf will cover many things. SMaller ones like 100,220,470uf are common. And even what I consider more signal caps like 1uf, 4.7 or 10uf. Those are just the e-caps. Tube amps like the 600v film caps, but those won;t appear in a 15v op amp circuit. Having said that, those caps in tube amps get leaky, but generally the film caps in a SS amp don;t

I always keep a bunch of 4558 around, though the more modern 4560 or 4580 drop in their place in almost all cases. I leave the fancy Burr Brown op amps to the amp fans. Worry about those if it ever comes up, it won;t during regular repair work. You should also have some TL072 and a few TL074 in stock. Most of the dual op amps can be subbed for each other with no penalty. SOme are low noise, like the 5532, which usually only matters in a high gain input stage like for a mic mixer.

And before you get the idea of replacing all the common 4558 op amps in a large mixer with low noise 5532, they draw twice the current of a 4558. One or two won;t matter, but a mixer full may overtax your power supply.

A box of 1N4007 will get you through a lot of things, and a box of 1N4148 for small signal diodes. Probably the most common zeners are the 15v 1N4744. I buy each of those 100 at a time. I work on switchers a lot, so I also stock a number of fast and ultrafast diodes, but basic amps don't need them. A selection of bridges couldn;t hurt, but I don't need them as often. A couple 35A bridges is a good idea.

Fuses? 20mm and 1-1/4", fast blow and slow blow. I have hundreds. Jacks, lots of them too, though mainly I find myself replacing the CLiff style most of the time. I don;t remotely try to keep up on pots, there are way too many.

[tedmich]

for true lowball and chance stock the surplus dealers are a good resource:
www.allelectronics.com
www.goldmine-elec.com
www.alltronics.com
www.excesssolutions.com
www.MPJA.com
www.meci.com
www.apexjr.com
www.westfloridacomponents.com
www.midwestsurplus.net
www.surplussales.com
www.electronicsurplus.com

[Techknowman]

I have complete kits of 1/8 and 1/4w carbon film resistors.
And I have a lot of caps I bought from goldmine-elec.
I buy a lot of goldmines gold packs with all kind of good stuff in them.

Its the transistors that I find the hardest to get and needed the most and I will not use ECG parts for anything. I've been burned way to often.
When I was an apprentice, many many years ago, I was told to only sub transistors, only when you have too and even then its touch and go, especially in the driver and power output sections of amps.
Sub transistors only as long as the HFE is equal or slightly greater
The Emitter to base voltage is equal or greater
The base to collector voltage is equal or greater
And the emitter to collector current is equal to or greater.
A good list of subs would be especially helpful.

[tedmich]

for transistors:
Audio Transistors OnLine - AmpsLab
TRANSISTORS - FOR SALE

NTE supposedly has workable substitute for millions of transistors...

and of course everything is available on ebay from asia, even ones discontinued decades ago....in shiny new packages!

[Ronsonic]

Handy website for parts searching: Octopart - Electronic Parts, Electronic Components, Datasheets Automated search of all the usual suspects.

[Techknowman]

of course everything is available on ebay from asia

Yea I just bought a load of MJ15024 and 25. just have to be carefull of forgeries, Especially on rare parts.
I only deal with high rated ebay dealers but its still a cross your fingers kind of deal.
Thanks Ronsonic, I'll check out the site.
I find a lot of surplus parts at a place in Carrolton Tx called Tanner electronics, has just about everything.