HELP! Can't Find NPN Transistor I Need

[seanthomas46]

I'm looking for one NPN 2n5133 transistor.  I can't seem to find anyone who has one for sale.  It seems that there is only a converted type, NTE 161?

[R.G.]

You need to apply Keen's Second Law: When in doubt, put in a 2N5088.

[johngreene]

and the 1st would be?

Mine is, "NEVER fry bacon when you're naked".

--john

[seanthomas46]

do you suppose that the nte 161 modern replacement be possible and serve just as the original 2n5133. 

[R.G.]

In general, the whole slew of discrete transistor circuits designed into commercial products between about 1968 and today were designed by people who had been taught to design the circuit in such a way that the specific transistor did not matter much. The designs substituted having enough for having the right amount in the transistors by using feedback and other tricks to make the transistor not be a critical part. This is because transistor characteristics vary a lot even within ONE part number and ONE manufacturer, let alone multiple manufacturers.

These efforts were largely successful. It is rare to find a low signal level audio circuit powered by under 24Vdc that cannot be substituted by any number of transistor type numbers. That is what NTE uses to make their living. They buy parts that are "close enough" and then sell them - at a healthy markup - for substituting many part types. Whatever part you get from NTE f or subbing the 2N5133 is likely not to be a 2N5133. It's whatever was cheap enough and close enough to work in most things, and perhaps most importantly, have the same pinout in most cases.

Small signal NPN's are by and large small signal NPNs. When in doubt, use a 2N5088. Or a 2N3904. Or a 2N4124. or a 2N4401. Or a BC549. or...

[RDV]

R.G.'s Laws

RDV

[seanthomas46]

hey R.G.
thanks.  that really helps, so now I know what direction to look and what are good options.
  Do you have any other recommended replacements?  What I want to ask is, what would you use to replace it?

[seanthomas46]

While I'm asking questions.  Are there any other parts not included on the schematic that are required for completion.  Besides, enclosure and board.
Sorry for the acrobaticidiotics.

[spudulike]

SteveD has 'em here

http://www.smallbearelec.com/Updates.htm

[smallbearelec]

Where you can't find the OEM replacement, of course R. G.'s advice holds. But please do check my stock list first; in this case (and many others) I can offer the original part. For others, I offer a "work-alike"--a device that is sorted and tested to match the original factory spec. Prices are usually pretty reasonable, because there are tons of these sitting in warehouses, and I don't take anything like the markup that NTE does.

Does using the original types really make a difference in tone? Many of my customers--worldwide--say that the old Fairchild/Motorola devices in the "dot" package sound slightly different from the modern re-makes in TO-92 black plastic.