2SC1849 in TonePad Ross circuit (cough)

[markm]

I think I can safely say, now that the smoke has cleared that the
layout for the Dyna/Ross comp at TonePad will NOT accept the 2SC1849 tranny.
I've burned up a few tonight
Seems that Q5 in the schematic just up an goes to component hell for some reason.
I thought the first few times that perhaps it was an error on my part however, after
seeing the 3rd 2SC1849 go down in a literal blaze of glory, I decided to swap 'em all out
for the old relaiable 5088 (unwritten rule #2 folks!) and sure enough, fired.....well....
worked with out a problem.
I searched the forum here and found some other posts with this same concern but, no wrap up so
I am kind of left in a cliff-hanger here as to whether someone ever managed to get a set of 2SC1849 trannies
to function in this circuit.
Any thoughts
    MarkM

[cd]

Just out of curiosity, where did you get the 2SC1849s?  And did you verify the EBC pinout with a meter?  I wonder if transistor faking has made its way down to lowly TO92 devices!

[Dan N]

I don't know if I ever ran across a 2SC transistor without the collector in the middle position.

ECB or sometimes BCE.

[markm]

I researched some data sheets from the web showing the 2SC1849 having an identical pinout to the 2n5088.
So I figured, what da heck.
It didn't work.
Lots of smoking.....cool effect but, not practical 

[Dan N]

Come to think of it, the 2SC's in metal cans might have normal pinouts.

Glad to see you have kept your sense of humor over this.

I may have to build that circuit just to fry any transistors that piss me off...

[MartyMart]

Either I'm very "lucky" or this place is even better than I thought .... but I have not
fried one transistor  .... yet  !!
( smoked a couple of opamps and my skin though ! )

I guess that just reversing "C" and "E" isn't harmful enough ...

MM

[Unbeliever]

I think I can safely say, now that the smoke has cleared that the
layout for the Dyna/Ross comp at TonePad will NOT accept the 2SC1849 tranny.

Obviously you've inserted it with the wrong orientation - and not just once, three times. It's a bit rough blaming the layout for that!

[markm]

I think I can safely say, now that the smoke has cleared that the
layout for the Dyna/Ross comp at TonePad will NOT accept the 2SC1849 tranny.

Obviously you've inserted it with the wrong orientation - and not just once, three times. It's a bit rough blaming the layout for that!

Ummm...... the pinout, according to the data sheets, is the same as a 2N5088 which is why I inserted them with the same orientation
as shown in the layout.
3 times?
Well, yeah your right but, I originally had thought it was an error on my part {solder bridge- wiring issue etc}
There was no problem with such.
I did do a search last night and found posts covering the same topic but, with no resolve. 
Please don't misunderstand me, I don't blame the layout, I love tonepad!!!!
I blame the stinkin' transistor manufacturer!!! (*){joke----ha ha}
I guess I'm warning others of the outcome of using these trannies. If I can get a good closeup, I'll get a pic up
of a couple of these......it's scary!
  MarkM

[Unbeliever]

Fair enough ... I was trying to hint that maybe the datasheet isn't right. Whenever I get in a new 'batch' of transistors I always check the pinout of a few just to make sure things are as I think they are.

[markm]

Whenever I get in a new 'batch' of transistors I always check the pinout of a few just to make sure things are as I think they are.

I think that sounds like a good idea......especially now

[Mark Hammer]

Just note that only Q1 and Q2 are in the audio path.  The other three transistors are for the sidechain.  Of those, Q3 and Q4 should be matched, if possible, to help minimize envelope ripple.

The key message here, though, is that the transistors in the circuit perform different functions, hence have different requirements.  I mention this not so that you *will* drive yourself nuts about it, but that so you *won't*.  Q1 should probably be selected for low noise characteristics.  Q2 should be selected for more gain since it is your output stage.  Q3 and Q4, as noted don't really seem to have any specific requirements other than that they should match.  And Q5 doesn't strike me as having any requirements other than being able to run off a 9v battery.

[markm]

Intersting.....I think you have posted that info before Mark but, this time I'm going to past
your response into notepad for a possible future use.
Thanks again for your help kind sir
  MarkM

[phillip]

The 2SC1849 that was originally used in the Ross Compressor circuit had a BCE pinout.  The pinout will vary from manufacturer to manufacturer, but I've never seen a 2SC1849 with the US semi-standard CBE pinout.  The 2SC transistors were manufactured almost exclusively in Japan, where the BCE pinout is still very common.

The Tonepad layout has transistor pads that only work with the CBE pinout, which is why the 2N5088 transistors work perfectly.  I've used a variety of CBE transistors in the Ross Comp circuit (both stock and highly modified) and I've found that the 2N5088 works as well as any other transistor.  The 2N4401 is pretty good too, but I like the 2N5088.

Phillip