2SC1849 Transistors with correct pinout

[Bob M.]

I'm rebuilding an effects pedal and have found the 2SC1849 transistor to be a good update for what came originally in this effects pedal. The problem is that this 2SC1849 transistor is apparently available in two different pinouts!! The one I need is (with leads facing down, flat side facing you) pinout: E B C. I bought a dozen from a well-known pedal parts supplier and his came in pinout: E C B. As I'm replacing transistors in a previously existing circuitboard, these won't work for me. Does anyone know where I can get 2SC1849 transistors with a pinout: E B C. It's really strange (and confusing) that the same part number can have 2 different pinouts!?!

Thanks in adv.,

Bob M.

[Mark Hammer]

Don't mean to be impudent, but does the component layout prohibit you from simply twisting the transistor a bit and swapping the B and C leads? I realize there is some legitimate concern about leads shorting but that should be easily solvable with a small bit of stripped insulation or heat shrink tubing over the leads, right?

[Enzo]

I agree with Mark, it wouldn't be the first time I installed an Asian xstr in place of a US type and did the leg twist. Turn the xstr sideways and arange the lefs in a row front to back insteasd of side to side.

US xstrs in a TO92 have the EBC arrangement

Asian numbers like 2SCxxxx should have the ECB arrangement.

SInce you say the 2SC1849 is a good "upgrade" for the original, what was the original? Was it a US type?

[Bob M.]

Thanks for explaining!

I guess to me it looks like a tight fit and I might not be able to 'bend over' the transistors to lie flat on their face if the leads are swapped around (and get the thing's cover back on again). It wouldn't be the 'elegant' solution but..... Thanks for the explanation of why 1 part number can have 2 pinouts, although it still sounds odd to me.

Bob M.

[Enzo]

You didn't clear up my confusion. Was the original factory part the 2SC1849? Your term upgrade has me curious. No part number should have two pinouts. And a 2SC number means it is from the Japanese number series where ECB is standard for all the little ones.

As to laying the part on its face for clearance, is there room on the solder side of the board for it?

[Bob M.]

Upgrade demystified!

Enzo,

The orginal transistor in the circuit was unmarked. From some downloads on the 'net, I think I might guess it be a 2N3904 or a 2N5088 or a 2N4124. I think it was most probably a 2N3904. Some guy sold me an upgrade kit with the exact pinout 2SC1849 transistors, which I installed and was happy with the improved sound (probably helped by other kit parts as well). I decided to try to do another of the same effect pedal so I bought some more 2SC1849 transistors from a well-known parts supplier to DIY pedal guys/experimenters. Only these transistors had different pinouts than that first batch I had. I didn't know that American and Asian transistors had different pinouts (I would've thought they would have a slightly different number or prefix, or something). Live and learn!!

The circuit board is a tight fit. I was able to re-adapt about half of the transistors, using heat shrink and the leg-over method. The others I had the leads trimmed too short for that because of lack of space. Now that I know the answer to my problem I'll be able to make it work. What's a good source for the American made 2SC1849 with the E B C pinout?

Thanks for contributing,

Bob M.

[Mark Black]

I have run into the different pin-out with same part number thing too. Don't remember the exact part number (hey maybe it was 2SC1849...) but they were definitely Japanese transistor types.

The one I ran into was stuffed in a piece of gear, apparently by the factory (didn't work from new). THAT was a head-scratcher for a while. If I remember correctly there was a very slight difference in the logo/lettering between the two types.

Crazy stuff...