The Skull Tone:booster and p.u. simulator

artyone · Post by **artyone** » Tue May 31, 2005 8:16 pm

Its on trade me right now and I hope it sells so I can keep into doing a run of knobs and enclosures.I think its nice and cheap,okay the buy now option is kinda mad,and hope it finds its way to a good home.

philipnz · Post by **philipnz** » Tue May 31, 2005 8:35 pm

So how do you turn it on and off?

Tehhaxorr · Post by **Tehhaxorr** » Tue May 31, 2005 8:47 pm

maybe you press down on the head.

artyone · Post by **artyone** » Tue May 31, 2005 11:08 pm

You don't turn it on and off...you wouldn't want to!,but you get a very fair approximation of it not even being there with the guitar volume right down and the filter set the same as your own.

ant · Post by **ant** » Tue May 31, 2005 11:30 pm

I think adding a true bypass (only $5 more) would be a 'value added' feature

philipnz · Post by **philipnz** » Tue May 31, 2005 11:31 pm

I doubt anyone is going to buy a pedal they cant turn off. Most pedal geeks won't buy a pedal without true bypass.

I guess you could always run it with a loooper.

Post by Bg » Wed Jun 01, 2005 1:11 am

agreed - its got to have true bypass

stark · Post by **stark** » Wed Jun 01, 2005 10:45 am

wouldn't worry me at all if it doesn't turn off, i already have a fuzzbox that won't turn off. i can kinda turn it off anyway by reducing my pick attack.

Sean, i'm intrigued by what this pedal sounds like, anyone who says "AlNiCo at both ends" is on the right track IMO.

Are these available as just the guts, switches, pots, sockets? Sorry, and no offence intended, but i really dislike the casing and knobs.

artyone · Post by **artyone** » Wed Jun 01, 2005 10:20 pm

No offence taken Mr Stark,Looper the next build actually,tomorrow and its an 8 bit offense to hi fidelity,or did you mean a parallel fx loop type mixer thingy.That really is a tiny box and the thing is basically an offboard...onboard preamp and I don't think you'd ever see anyone with an onboard preamp using a bypass so whats the difference.Umm,you can have the schematic if you like,or schematics,they're both on the net.But if you want a PCB and parts list I can do that too or anything inbetween.You could even have true bypass.
This is the boost schematic

http://www.diystompboxes.com/analogalch ... drive.html

and this is the LRC filter

http://www.muzique.com/lab/pickups.htm

The only imported parts are the small transformer and the 2N5089 which are both from smallbear.BC type transistors can be subbed if the hfe is in the late 500's and the transformer can be any interstage or in/output with a 10k winding with CT and about 600 ohms actual resistance.These mini ones are about 250mW rated so I'm sure some of the saturation I'm getting is from overdriving the winding and creating leakage.Who knows?
But I'm doing another PCB for this tomorrow so I'll do an extra one for you while I'm at it.$10.00 alright by you?

stark · Post by **stark** » Thu Jun 02, 2005 1:49 pm

I saw the update on your TradeMe ad that said it was really a distortion unit?

Maybe it's not what I'm looking for, I'm more interested in clean boost, pickup simulation, and goosing certain frequencies. hey, i know, I'll wait to hear the sound clips.

artyone · Post by **artyone** » Thu Jun 02, 2005 9:09 pm

Its kinda funny this thing,You try the amp straight ,with full volume on the guitar,and then you plug in the pedal with the guitar volume right down and bring it up slowly and at about 1/6 rotation your back at where you started from without the pedal.From 1/6th to 1/3rd is clean boost and just gets louder,then from 1/3rd to about 5/6th its into overdrive territory and just starting to crunch on hard hits and chords but still kinda clean on soft and single but then you hit the final sixth and its just insane crunch distortion but I've only tried it on my tryout transistor amp and haven't taken it upstairs and put it through the tubes and quad.I was supposed to be into that tonight but I'll definitely do it tomorrow.The LRC on the end is very subtle,less than I'd hoped it would be but it is working in that it provides a slight peak at different frequencies but nowhere near what a row of active parametrics will do for you.If you want a clean boost you need,well don't absolutely need but its easier,to use an opamp on a 18-24V supply and something like the 5532,which is a really low noise type opamp normally used in mic preamps as the first thing the signal sees,and do a set of active tone controls followed by a volume control,but call it clean boost and then have the p.u.simulator stuck on the end.Clean boost seems to be a bit in fashion these days,which is a good thing,so you can get the signal going into a clean channel at its optimum levels to get your initial preamp tube voltage swing just at clipping.I don't need to worry about this because my tube amps are all really small outputs so its never a problem getting the power tubes working hard.My favourite which is Simcha Delfts moonlight has even got a tube recto which is on the edge of max and a power transformer that gets kinda hot so the whole thing is kinda designed to clip and sag like crazy but I must admit clean boosters and buffers also help,in my case, to get that intial signal strong so as to counteract the heaters omnipresent hum if only a guitar is driving it.Maybe I can do something like that for you...basically a preamp optimised for guitar?
This might also be what your after
http://www.muzique.com/amz/mini.htm
this type of arrangement using j-fets is quite popular these days for boosts and with active tone in front you'd be away.The picture is my favourite active tone so far and can be done with one TL072 instead of two LF351's as on the picture.

tasty · Post by **tasty** » Thu Jun 02, 2005 10:32 pm

hey i might be interested in your pedal casings
how much u selling em for?

tasty · Post by **tasty** » Thu Jun 02, 2005 10:37 pm

juz the plain casing with holes drilled without the knobs and stuff

artyone · Post by **artyone** » Fri Jun 03, 2005 6:14 pm

Those squary cases I'm using for these are from Jaycars in Khyber Pass in Auckland and the little one is about 11.00.Theres a slightly bigger one for about 14.00
I wouldn't want to drill holes without having the stuff you want to put in there because....well,simply because.So you send or bring over the stuff and I'll measure it all up and figure out where all the holes should go while also hearing where you want them to go.Maybe take two hours so it'd be 60.00 plus the box.