What components do you keep in inventory?

[z-adamson]

If you work on vintage receivers, amps, preamps etc. fairly regularly for a hobby what should be kept on hand at all times in the ways of caps, variable resistors, diodes, relays etc.?

Clearly one will make a special order for each project, but an inventory of "spare parts" so to speak would be a good thing to have.

For example 16v 47uf and 50v 1uf are very common for the projects I do. As is the 1000ohm variable resistor with the wiper lead in the middle and offset from the others. Other things too......

Maybe you screw up trimming leads, bending leads. Maybe the order comes up one short. It really sucks having to wait a week because you came up short on components.

So, if you were to make a list of things to keep in inventory to prevent unforeseen component shortages while in the middle of a restoration, what would be on your list?

 

[Hyperion]

Personally I try not to maintain a stock of electrolytic capacitors as I like these to be as fresh as possible. Because of 'per unit' cost I try to keep stock of trimmers low too, but resistors and film capacitors - - no holds barred.

When placing an order I will always try to take advantage of quantity discount if available, and also avoid shipping charges too, consistent with the points already mentioned above.

My work volume is very low, so my answer above is heavily influenced by this.

 

[z-adamson]

You never really know how long a cap has been sitting in various warehouses before it gets to you and the difference in per unit cost between buying one and ten is huge....usually about 30% with smaller caps.

 

[century tek]

As a kid, I would tear apart everything I got my hands on.......and I got my hands on a lot of stuff I wish I hadn't torn apart.

I have bins of junk (parts) from all kinds of stuff under the sun like speaker jacks from all different manufacturers, transformers from old receivers, spare tubes, fuses, resistors, you get the idea!

 

[ChrisMarantz]

It really depends on the age of the equipment you regularly work on and how many units per month move across your bench.

For capacitors, you need either Radial or Axial - or both if the age of the equipment ranges between the 1960's through 2018
I keep both types on hand - Radials between 0.1 - 1000 mfd in voltages between 10 - 50, plus some special values for some models that I know I will need them for. I keep axial capacitors between 1 - 1500 mfd in similar voltage ranges plus specialty values. I typically only order in 100 quantities unless the need for a value is limited and those typically have much higher prices.

Resistors are much more difficult - there are just so many values, so a good place to start is often resistor kits which have the most commonly needed values. This is especially true if you're working on tube equipment. I do stock some specific types of resistors - which are for models i work on regularly.

I keep a large selection of LVR's in different values, so I always have what I need.

In my shop we work on between 25-30 units per month, per person. We work through lots of parts and we place parts orders every week - so our on-hand supply is large, but if we need something special, it's only 3-4 days wait time.

Over time, you will learn what you should have and build up extra parts - Chris

 

[z-adamson]

When it comes to spare caps to keep on hand, it makes sense to keep the voltage on the high side.

You can replace a low voltage cap with high, but not the other way around.

How high to go though...

Keep them all at 50v?

 

[Grenadeslio]

Oh hell, when I saw the title I thought "what don't I keep in inventory?" "I have stacks of amps, tuners, tape decks, turntables....preamps I don't have any spare preamps" lol.

I open the thread and, caps, resistors, etc etc. lol, it's in the DIY section.

 

[z-adamson]

Oh hell, when I saw the title I thought "what don't I keep in inventory?" "I have stacks of amps, tuners, tape decks, turntables....preamps I don't have any spare preamps" lol.

Those are devices.

This is about components to keep in inventory.

 

[Grenadeslio]

Those are devices.

This is about components to keep in inventory.

I'm an electrician, devices has a totally different meaning to me lol.

 

[gslikker]

If my NOS electronic components would be "audio components", I would need a big building

 

[gadget73]

loads of film caps from .001 to .22 uf 630v, electrolytics 1-47 uf 50v and 10-47uf 450v, lots of 1/2w resistors from 10-1M. I usually order at least 10 of an item, resistors are usually by the 100, same with film caps. If its something odd, which for me is SS gear, I might order exact quantity with one or two extra for screwups.

 

[elnaldo]

I've found useful to have a little stock of 0.1 and 0.22 uF X2/Y2 rated capacitors.

Fuses too.

Diodes at least in 2 sizes.

And I have a box with electrolytic caps from 1 to 2200 uF, 50V. Some in 25 or 35V (specially from 220uF when size starts to matter) .

What I use more are 10uF and 1000uF. I don't know why but those stocks go faster.

Resistors, a box full of spares, but half of the times you need a value or size you don't have.

For tube amps, I usually buy the electrolytics when I need them. They are more expensive and I can buy just a few at a time. The same with large electrolytics at 50V, since they are more expensive I prefer to buy as I need them. Anyway a pair of 4700/50V 6800/50 and 10000/50 are useful to have if you plan to do some recaps in the near future.

 

[gadget73]

yeah, fuses, fuse holders, safety caps, and UF4007 are also on hand. I've got some 10k trimmers hanging around too, they're cheap and any time I add bias controls to stuff it uses 4 at a go.

 

[ChrisMarantz]

When it comes to spare caps to keep on hand, it makes sense to keep the voltage on the high side. You can replace a low voltage cap with high, but not the other way around.
How high to go though... Keep them all at 50v?

I work on a lot of equipment that has been worked on before - when I see all 50 volts caps - the first thing I think of is " amateurish "

If you're only working on 1-3 units per year - face the fact that you should be ordering parts on a per project basis. If you're working on 1-3 units per month, make the investment and have the correct selection of parts on hand.

I have a sign up in my shop - "Fix it Right - Fix it Once" - Chris

 

[gslikker]

Being one of those doing maybe 1 to 5 restorations a year apart from a few repairs, it definately does not justify the amount of NOS parts I hoarded.

 

[s-petersen]

Fuses holders, film caps .001 - 2mfd 630v a resistor assortment +multiples of the common sizes, a mica cap assortment 12pf - 820pf an assortment of elecrtolytics 16v - 500:v, many tubes, uf4007 diodes

 

[OMGCat!]

I keep minimal e-caps on hand and will usually make an order when I'm looking at starting a project. I do have a crap load of resistors, diodes, transistors and other stuff just because buying in bulk keeps the price low and there's no reason they won't keep forever.

 

[Bratwurst7s]

A growing collection of metal film resistors (mostly Vishay-Dale) and MOX resistors, lots of film caps, MLCC-C0G ceramic caps, a selection of diodes & zener diodes, a few bridge rectifiers, dip-8 sockets for op-amps, op-amp adapters, a small but growing selection of op-amps, a selection of small heat sinks (especially for TO-220 form), a selection of electrolytic caps, a selection of transistors, a selection of relays, some speaker binding posts, odds & ends of wire from 0.4mm on up, a selection of shrink-wrap, lots & lots of esoteric odds & ends that are seldom used but darn am I glad when I find something useful in the pile when nedded.

As OMGCat! said, buying in bulk is often cheaper so the collection grows. And having extras also lets me cherry pick the good stuff for the special stuff.

Lately it's occurred to me that I'm 61 now and won't be living forever. None of my kids will ever use this stuff so I'm going to add a line in my will that all of my test equipment and supplies will be left to a young fellow at work that will make good use of it. Rather than have it all tossed in the dump when I'm gone.

Cheers,
James

 

[dondoucette]

Resistors, common transistors, voltage regulators, at least one set of output transistors for each model amp I own, fuses, fuse holders, capacitors (few electrolytics), tube sockets, barrier strips, IEC power cords, diodes, bridge rectifiers, bulbs, LEDs, selection of PEC pots that I bought when they were cheap...

 

[z-adamson]

I work on a lot of equipment that has been worked on before - when I see all 50 volts caps - the first thing I think of is " amateurish "

If you're only working on 1-3 units per year - face the fact that you should be ordering parts on a per project basis. If you're working on 1-3 units per month, make the investment and have the correct selection of parts on hand.

I have a sign up in my shop - "Fix it Right - Fix it Once" - Chris

I am talking about spares, not replace everything with 50volt caps. Yes I do an order for each project, but sometimes things go wrong there and I need something that was not in my order.

If I need a 33uf 25volt cap and all I have is a 33uf 16volt cap in inventory, I am screwed.

BUT, if I have a 33uf 50volt cap in inventory, then I am good to go. This is the go-to stash for when I am in a pinch.

This is what echowars had to say about recapping. Most here seem to think he was at least a little more than "amateurish".....his rebuilds seem "fixed once and right"....but here are his words...

Nichicons are fine but overpriced and overhyped. Use them if you like. I still swear by Panasonic FC caps from Digikey.

A higher voltage rating is fine (and of course, lower voltage rating is not). Just watch the size. When I'm recapping an amp, I usually just go with all 50V or all 63V caps. Too much trouble to mix up the voltage ratings, so I use one or the other. A few places in a lot of amps require 100V or better caps, and I do have a small selection just for these times. Replace them one at a time, paying attention to polarity of the one you remove...don't rely on the board marking for polarity...I've seen them wrong many many times.

Do NOT replace a film cap with an electrolytic, or replace a ceramic cap with an electrolytic. But you knew that...

Bi-Polar and non-polar are used interchangeably. 6 of one, half-dozen of the other (I use Panasonic SU caps). You are probably looking at the DC offset circuit...not too many places in an amp where bipolar caps are used.