BC184L transistor component

Hi guys.

Thank you all for your help, and comments. I've checked the schematic and that says that the 3 trannies in the circuit are BC169C, BC184C & BC109. However, I'm also working from an original photograph of the circuit and the trannies are ALL BC184L so I'll be going with that. The pin outs are the same on all those transistors I believe so i'll use the 109 from the library and rename it... Simples!! :-)

For your interest, I'm recreating a Colorsound Power Boost version 2. The board will be the same, with board mounted pots, I just need to lay the circuit out in eagle and get the design as close to the trace as possible. I could manually trace the layout from the photo below, but it's a bit messy, and using Eagle to re-draw the circuit and create the board will ensure I don't make any ***-ups along the way as regards the circuit. I'm also sourcing (where practical) original components, so I've just received a delivery of NOS Mullard tropical fish caps the same as in the photo. all resistors are the same, I have however had to compromise with the axial electrolytic caps... I've gone with Vishay caps, a good brand and the same as what's used in the current power boost reissues.

The photos below show a version 1 power boost, which had an extra 10k resistor which the version 2 didn't have. Apart from that they were identical.

.

Groovy! Boost that power, man!

Made in London, too.

What does it do to the sound? It looks like it's a just preamp and a tone control. Do the bass and treble cut as well, or is it just boost? Nice colour and love the graphics.

[In the time I took to write this you've added the schematic and answered my question.]

The BC184L has the base at one end, the BC109 in the middle. I vaguely seem to remember that there was a non-L version with a different pinout (it's the kind of thing that causes no end of confusion because it's inevitable that eventually somebody doing the buying will get offered a great deal on the wrong part).

Also, the pins of the BC184 are in-line, whereas those of the BC109 were in a triangular shape. It was quite normal to bend the centre pin out to form the triangle shape when you had an in-line part. We were producing industrial equipment, so we used small plastic formers that the parts sat on and that guided and supported the legs, but this is the cheap and cheerful end of the market and you can see they've just stuffed the transistors in any old how.

Do the BC184s have a letter at the end? Either BC184LB or BC184LC? The manufacturers grade transistors and offer them in a narrower range of gains than you'd get if you just had them from the end of the production line. If it has C parts, you probably want to match it - that was the higher gain bucket and they wouldn't have paid the extra if they didn't need them for the circuit operation.

The guy that owns that particular power boost has told me that ALL the transistors are BC184L's.

Also the axial caps are 22uf (The big ones), however the actual powerboost has different smaller axial caps than the schematic... the owner has listed the caps as follows:

"the small blue caps are 6.4µF, the small green one is probably a 4.7µF and the large green one is a 22µF." However the schematic lists them as 220pf & 10uf......

As regards the sound. it is a pre-amp, with a treble and bass boost... It's only when you get to about 3/4 on the volume knob does it start to break up into an overdrive. Used extensively by David Gilmour throughout the 70's with a fuzz box, he used the power boost and a big muff fuzz for the classic comfortably numb solo. he also used it on the Animals album and on the solos in Shine on.

Any help with identifying caps and stuff would be greatly appreciated.

here's more pics

Am 30.07.2016 um 14:31 schrieb Andy Betts:

Do I detect an essence of sarcasm??

 

I'm qualified in using AutoCAD, have been using it for years... And I have to say that designing in Eagle is "clunky" to say the least and not at all intuitive. I will design my own devices if I have to.. but if there's something already there that just needs a tweak I'll do that. why try and reinvent the wheel when somebody has already done it. As a CAD program eagle is not a good program, and designing simple things takes thought... I'm used to using absolute coordinates.. Eagle doesn't appear to use that.

 

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To view any images and attachments in this post, visit:

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Do I detect someone comparing apples with pears?

Eagle is a layout program autocad is not, so your argumentation is for

the birds.

Imho this thread is by far too long just for modifying a lousy transistor.

And I see your qualification: This little work took you a week...

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Mit freundlichen Grüßen / With best regards

Joern Paschedag

Andy Betts wrote on Sat, 30 July 2016 08:31

why try and reinvent the wheel when somebody has already done it.

In the case of ECAD library parts, that's already been answered.

Quote:

designing simple things takes thought

OMG!  You mean in engineering I have to use my brain!!?  I just wanted to

plug dis inta dat.  Now I have to add things and think and stuff?  Let me

outta here!!

Quote:

I'm used to using absolute coordinates.. Eagle doesn't appear to use

that.

This shows you haven't even tried to learn, let a alone experiment with

Eagle.  Just about everything in Eagle uses absolute coordinates.  One of

the first things I do when designing a footprint is to pick a origin and

determine the absolute coordinates of things to that origin.

Oh, right, that requires adding things and thinking, and a even more

advanced concept called subtraction.  Nevermind.

You're right. Eagle and any kind of engineering isn't for you.  Perhaps you

can go into politics, or practise really hard and get good as asking "Do

you want fries with that?".

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

Andy Betts wrote on Sat, 30 July 2016 08:31

why try and reinvent the wheel when somebody has already done it.

In the case of ECAD library parts, that's already been answered.

Quote:

designing simple things takes thought

OMG!  You mean in engineering I have to use my brain!!?  I just wanted to

plug dis inta dat.  Now I have to add things and think and stuff?  Let me

outta here!!

Quote:

I'm used to using absolute coordinates.. Eagle doesn't appear to use

that.

This shows you haven't even tried to learn, let a alone experiment with

Eagle.  Just about everything in Eagle uses absolute coordinates.  One of

the first things I do when designing a footprint is to pick a origin and

determine the absolute coordinates of things to that origin.

Oh, right, that requires adding things and thinking, and a even more

advanced concept called subtraction.  Nevermind.

You're right. Eagle and any kind of engineering isn't for you.  Perhaps you

can go into politics, or practise really hard and get good as asking "Do

you want fries with that?".

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.