Screamer Transistor

[rasco22862]

Hi, i could get a pari of 2SC1815 that are in  the original tube screamer(GGG source). I did this because i supposed that the original sounds better than the generic 2n3904, but the 2sc1815 has ECB and the 2n3904 has EBC, is this correct??

And should i use the 2sc1815¡?

And finally, the ggg layout is for the 2n3904 transistors or the 2sc1815?

[jlullo]

rascco,
check the pinout on alldatasheet.com to figure out which lead is which.  You should also experiment with a bunch of transistors to see what you like best, don't just go by the "mojo hype machine"

the ggg layout will work for any tranny as long as you orient them correctly.  just check out the data sheets and you should be all set.

[jlullo]

also, make sure that if you do decide to go with the 2SC1815, not to spend an arm and a leg for them from some dude on ebay.  Smallbear and Futurlec carry them for way cheaper than you could get on the 'bay.

[axeman010]

Hi

I built the GGG Screamer and found that the layout was wrong for the 2SC1815  that I bought. I used 2N3904 in the end and it sounds great. So good that I haven't modded it in anyway!

The one thing that I would say is that it sounds much much better driving a Tube amp than a tranny.

Axeman.

[Ben N]

They're BUFFERS. How much can it matter?

Ben

[rasco22862]

olk, thanks waht about the rc4558 ic?

[petemoore]

  Those are nice chips mahnn.

[shadowmaster]

olk, thanks waht about the rc4558 ic?

Use sockets. Do yourself some testing. In the end, it's your ears that determine what sounds good and what's not.

Peace.

[Paul Marossy]

olk, thanks waht about the rc4558 ic?

"Purists" would tell you that it has to be a JRC4558D from the 70s or else. Any BJT opamp will pretty much sound the same. An FET opamp like a TL072 might sound slightly smoother. But, we talking subtleties of subtleties.

[jlullo]

rasco,
i think basically what we're all telling you is to try the 2SC1815, try the rc4558 and the jrc4558d, but ultimately use your ears and decide for yourself what you like

[rasco22862]

ok, thanks to all!:D
Should i go fot eh GGG mods(clipper switch, and AMZ Fat)?

[jlullo]

sure, why not? my first one is stock and it sounds so so good.  i'm building another right now with said mods

[rasco22862]

a quick question : a ceramic capacitor that says 500, is a 50pF capacitor right?

[R.G.]

a ceramic capacitor that says 500, is a 50pF capacitor right?

Sadly, there is no way to tell except to measure it some way or look up the maker's info on the datasheet.

The most common code for capacitor value, two numbers for value followed by the number of 0s and the whole thing reading in pF is followed by ... most... makers. It gets ambiguous when you're dealing with values in the pf and 10s of pf range.

Some makers mark one hundred pf as "100" some as "101" It's pretty sure that a "101" is 100pF, but a "100" could be either 10pf (standard marking) or 100pF (I just wrote the value on the part).

I've seen them both ways.

[rasco22862]

the capacitor says:

500
AEC

[rasco22862]

is this mean anything? i mean:
1) there is two posibbilities, one is 50 pF that sounds true,and the other is that is 500pF, is this possible??? isn`t the size too small to be a 500 pF

2)can i use a 56 pF ceramic cap instead of the 51pF (or 47 pF) from GGG?

[rasco22862]

and 3)the Clipper switch doesnt seem to work, i dont hear any difference , also in this diagram:


i think that both positions are the same, there is no diferrene between one position and the other.

[slacker]

is this mean anything? i mean:
1) there is two posibbilities, one is 50 pF that sounds true,and the other is that is 500pF, is this possible??? isn`t the size too small to be a 500 pF

Like R.G said, there's no way to tell except by measuring the capacitor.

2)can i use a 56 pF ceramic cap instead of the 51pF (or 47 pF) from GGG?

Yes that would work fine, you won't be able to hear any difference.

and 3)the Clipper switch doesnt seem to work, i dont hear any difference ,

It's hard to tell from the picture but I think you are supposed to use different sorts of diodes on either side of the swtich. If you used all the same sort then it won't sound different.

[rasco22862]

ok, i want the swith to switch between the symmetric and asimmetric clipping. What should the layout look like for this?

[slacker]

look at the modifications pdf at ggg. Put the diodes in like on the Asymetric Clipping Modification, then wire a SPST switch across the red diode, when the switch is open you get asymmetric clipping, when the switch is closed it shorts out the red diode and you get normal clipping.