An Orange Tiny Terror preamp in a (stomp)box

[The Bathroom]

And here I thought I would be the one to breadboard this high gain machine...guess not! LOL. But dude, Savvas, seriously you are really awesome for doing this! I had no idea that this project would be taking off so fast, and here you are posting vero layouts already! Hahaha. I say we name it the Savvas Terror after this guy, or maybe even Nano Terror! I'm really stoked! I can't wait to see this put up on the blog and build it.

Cheers Savvas! You rock.

P.s. What software are you using for the vero layouts? I'd like to get it.

[Frank_NH]

Yes, excellent work Savvas!  You probably don't need 100K pots for your trimmers.  For a 1.5K source resistor, my JFET calculator says that your drain will be about 20K for J201s, so 50K should work fine and will be easier to dial in the bias.  Note that if you used 2N5457s, your drain goes down to 7.5K - 10K, so a 20K trimmer would work.

I would build this but I have too many builds that need to be boxed!  

[ξεναγος νεκροπολης]

thanks Frank!
i've used 20k trimmers and j201.
i just have this low output problem to deal with as i said.
i think  i'll add an LBP1 as Ciaran suggested and see what happens.

and "the Bathroom" (what's your name anyway?) i use diylc for these layouts (diy layout creator), and Mirosol's library for them to look nice!

have in mind everybody, that the layout i've posted works, but has some low output issues.
i'll try in the next days to fix it and when i'll do it i'll post a new layout here and in the contribution section

[The Bathroom]

Savvas, Thank you. I'm gonna download my own. Do you know where I can download mirosol's library from?

It's Pat by the way.

[Frank_NH]

Hey Savvas.  Try reducing your Volume pot to 100K log.  1M is much too large, and your output impedance is probably way high for your amp.  See if that fixes your volume issue.

[ξεναγος νεκροπολης]

yeah!!!!!!!!!!!!!!
done it Frank!
100k pot solved the problem.i think we could go even at 50k. i've also added the cap at the first stage

updated!!!

the previous layout had the correction on the layout without the gate caps(first one that i posted).
this one must be ok.

[squirrels]

You could also make this into a #4 Terror emulator by swapping out the following:

-lower the 47k resistor to 39k
-raise 2.2nf cap to 4.7nf
-raise both 470pf caps to 1nf

[Frank_NH]

Yeah!  Way cool Savas.  We need sound samples now...

[Ciaran Haslett]

Thats class man!  Top job.

And....yep!  We need some sound samples now.  Congrats again

[ξεναγος νεκροπολης]

i've build the board. it's verified.
but...


it reaches unity when level is maxed, but it needs treble maxed too. as you turn treble down it still acts like a treble as for the tone, but it lowers the total volume too.also bass has a small affect to the tone with my strat like guitar, and a slightly bigger affect with my les paul like guitar. middle works perfect.

any ideas?i think it still needs more output after all...

[Frank_NH]

The tone stack is definitely lossy so a gain stage after the tone stack may be warranted here.  Also, if you've played around the Duncan Tone Stack calculator, you'll find that it is very hard to get a good compromise for a tone stack that includes a Mid control.  That is, you can get the bass and treble to have good variation but then the mid doesn't change much.  Or the mid changes a lot but the bass doesn't do anything.   It doesn't surprise me that that when you turn down the treble the volume decreases since you're likely cutting the audio output over a large range of upper frequencies.  

One thing you can do is to put a simple JFET buffer in front of the tone stack.  That will probably improve the behavior of the tone stack itself by presenting it with a low impedance input.   Obviously you can also place a JFET gain stage at the end to bump up the output.  Let us know if you experiment with this.

[ξεναγος νεκροπολης]

i've boxed it a couple of days ago but forgot to post it. i've used an LPB-1 in the end and all problems solved.here it is. 6 pots (2 gains) in a 1590b...tight, but i could have made it easier if i was more careful in measuring the holes distances...
enjoy.





thanks again guys for all your help on this one!

[Ciaran Haslett]

Dynamite job lad!

Also nice to see I'm not the only one who solders one transistor leg to a socket when I'm happy with the component.

You know what's coming......sound samples?

And again....fantastic work!

[tabbycat]

you've totally owned this one, savvas. now you've got to name it. orange pre amp 15 emulator blah blah, not good enough. that's a description not a name.
what's greek for orange? or as pat (the bathroom) said, 'the savvas terror'. or ‘the pompom terror’ after those shoes the greek guards wear, with knives in the pompoms. they look cute but kill.




how did you go about biasing? did you do it by ear or did you use a meter? that's the thing i think i'd get stuck on.

and do you think it would be worth taking any of those trimmers out and having them as pots? if some severely change the tone.

congrats on your success. i would definitely like to hear it.