Castledine Electronics - The Wizard

[Dex3887]

Yeah I tried a me4003, 2n3904, bc109c and a bc548b and they all technically worked. It just made the base gain/treble level higher with the higher beta ones. Anything with a hfe around 200ish sounds okay. Ac181vii sounds KILLER in this. So did ac176 and mp38a

[traktop]

nocentelli wrote

...The Ge input stage (rangemaster boost) might well need a tweak to the bias depending on the transistor used...

You mean the collector resistor, right?
What colector voltage should I look for?

Dex3887 wrote

...Anything with a hfe around 200ish sounds okay...

You mean when using a silicon transistor, right?

Dex3887 wrote

 Ac181vii sounds KILLER in this. So did ac176 and mp38a

I´ve got mp38´s. What gain should I look for those?

I noticed that the gain pot almost just affected the volume level, (and maybe the character), but barely affected the gain. Anyone noticed something like that?

Cheers, Gilberto

[Dex3887]

Transistor wise: just Try using whatever you have on hand. And I'll revise my earlier post and say that using anything in the Q1( the only bipolar transistor) works as long as its npn. That said I gotta admit I settled on a mp38a with a gain of around 90 and its perfect. The 470k on the volume control got knocked back to 100k and output is loud enough to slam my peavey ranger (super reverb with mods) into valve saturation on the clean channel. Its a weird circuit in that the 1st stage(ge treble boost) seems like it was set up for tight spec mil type 2n1308. But after playing and plugging many dozens of transistors in it seems to want something lower than 200 beta. Otherwise it just craps out from too much gain slamming the mu-amps which overdrive and go into turnoff type noise.

But this is my best advice get some sockets and plug in a suitable transistor , play your guitar and fiddle with the controls on the pedal and amp. Repeat until you find tonal nirvana or at least something close to what you wanna hear.

The gain control is the common amp/big muff/ jfet emus type where it is basically a volume control on the input. It limits signal to lower gain. Its interactive with the output to a small degree. But I'd go back with a knife between the tracks on the veroboard bc I can't count how many times its been a microscopic bridge or piece of copper from a cut messing everything up. Also check connections etc.....

[traktop]

Thanks for the elaborated answer  
I´ve just tried like 10 mpa38a´s in there and to me all sounded the same, (just great).
Will take a look to the gain pot, but I´m 99% sure it´s fine.
Just tried with a strat, and while I get a very nice and dinamic low gain crunch, I miss a little bit of gain, (sure that my les paul will push this thing further), so may be I should look for a higher gain mp38a, (germanium transistor tester is on the way).
I tried to play the smart guy and put a switch that allowed me to bypass the treble booster, (the 10n out which goes to the first fet stage), to see what I find soundwise. The thing is that I got a very nice tone but never achieved any kind of saturation, so the fet circuit seemed to be tuned for receiving a big blast from the input stage.

[Dex3887]

Do you have any plain silicon transistors? Like 2n3904 or bc549? I'd try plugging them in and seeing if that helps you get closer.
Also what type jfets are you using? They can make a big difference in the output and gain of This. I have about 500 2n5485 that I have paired up a few decent sets and the 2n5458 I have work good too but I found the 1st set of jfets as j201 and the second as 2n5458 round it off pretty well.
 This pedal is similar to the catalinbread sabbra cadabbra, and it uses a silicon Q1. Its a lot louder on the output but this is closer to Tony's work up to Vol 4. Around never say die he went balls out and had that Rat thru a dimed Marshall type tone. If I may ask what type amp are you using?

The more I mess with it I find  this pedal is more part specific than originally had assumed. But with every jfet pedal comes this same headache til I find some that work how I want it.

[traktop]

Didn't try with sillicon yet. Maybe I could try some nice me4003 I've got around and see what I get.
I'm using smd J201s for the jfets, (got 5457s as well). Just put first five I got and throwed them in there, so maybe I could try more. I think to remember having some average 2n5458s, but I practically have discarded any non sms jfet. I Will take a look too.
I'm playing a hiwatt dr-103 with a strat and a p90 les paul.

[traktop]

Well, finally the part of the circuit involving the second pair of j201s was a mess on my board. They basically weren´t sounding, but the signal found a way to get last buffer fet,  so basically what I was hearing was just the rangemaster booster, (perfect for finding the right transistor there indeed )

Now, the switch which isolated the fet build from the treble booster just worked, kind of having the chance to enjoy the "amp" with no treble booster. It worked very nice as a very dinamic od, with a great clean up, (highly recommended mod).

Tried some low gain silicon transistors for the booster part; not bad, but I find myself liking the warmth of  any of my mp38a with gains between 29/35...  Anyway, I´m trying to minimize the gritty shrillness of this effect, cause my amp already has plenty of it... (in fact, I find that my amp cranked with a rangemaster pushing the preamp, sounded very similar to Iommi´s tone...).

I don´t know if it does exists a "darker" fet than "the other", cause I think it´s here where I must experiment for the general body of the effect. SMD j201´s gave me more gain than 5457, but quite similar tone. Have some SMD 5484s, (yet to solder on its boards), but never heard them in action.
I guess It´s all about  trial and error as you said...
Cheers, Gilberto.

[HamishR]

I haven't designed a stripboard layout before so thought I'd tackle this one.  Sorry if I am breaking some protocol or anything but can someone have a look and see if it would work?

[anders]

For a first layout, that looks really good, nice and tidy! Great work! Can't spot any errors either so it should be good to go but a another set of fresh eyes could chime in since mine is quite puzzled after a day of soldering...

[HamishR]

Thanks Anders - that is high praise coming from you!

I will build this in the next few days and let you know how it goes.  I quite enjoyed making this layout - it's not easy though, is it?  It's fun seeing how small you can get it.

[Dex3887]

Great job man. Looks Hella good and tidy too. Ill build it up today. There is some room to experiment with that 470k before the output pot as it severely attenuated the output. Go too low and it affects the filtering a bit. I think I went with a 120k there. Or one could put like a 62k and a 470k on a switch and make it have another option. I really love this circuit. It was well worth the wait.

Also I went with a c100k for gain, b50k for tone and a b100k for volume because I like to fool with tapers and stuff. It works for me

[HamishR]

Well I built my layout and it works, but man is it high gain!  I went back and listened to some clips and mine sounds pretty much like them.   It's insanely gainy.  Not really very useful to me so I'll use the box for something else!  Oh, and mine is plenty loud too.  The tone control works but gets a bit nasty past halfway.

Interesting sound but too heavy for me.

[traktop]

I finally didn´t boxed my build.
It was too thin for my amp, but really loved that so dinamic amp in a box pushed by a germanium transistor thing.