Tech 21 XXL built and working... with a few quirks

Started by madboy, December 21, 2006, 01:30:09 PM

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madboy

Hey all.  Just boxed it up and as stated, it does work... but there a few things I would like to pick your brains about. Here's the layout

http://aronnelson.com/gallery/Martys-layouts-and-photos/Tech21_XXLV2

First and most important... this thing is ungodly loud. Unbelievably. Freakin'. Loud.  It seems about the same volume when bypassed when the volume pot is at about 2 ( scale of 1 to 10 ).  From there it gets into the "Oh, crap, I think I hurt my amp" loud.

Next, there is squealing when the drive is maxxed. I've kept the leads as short as possible, and I can actually dial out the squeal with the tone control. I was just wondering as drive lugs 1 and 2 are jumpered ( I know that's not a real word ) to tone lug 3, is there something I haven't done correctly?

Also, the drive knob starts at pretty distorted ( at minimum ) to more distorted to squealey.  Every other pedal I've played with cleans up and will usually cut out with the drive all the way down. Not this one.  What should the lugs be connected to that is not stated in the layout?

On the upside, because this thing is so loud, I can actually hear the difference in the warp control, whereas I have read that some people didn't notice a difference. It's subtle, but it's there.

Any comments or suggestions are greatly appreciated.
Incidentally, there seem to be a lot of fun sounds in this little box. It's a pretty gnarly, obnoxious distortion ( in a good way ), and can almost be tamed down to a fuzz.  I'd like to get this thing ironed out so I can gig with it.  Thanks for all your help, and for all the people that post layouts that drive us crazy until we get them working.

MartyMart

Thanks for the build report madboy and glad that you like it !
First, the volume issue, could just be that I elected to use an MPSA18, though this
is an emitter/follower setup, so should have a gain of 1 X you could try a 5088 to see
if it makes a difference, the original is LOUD ! ... turn down that volume control ...

Gain : The XXL is a "full on" pedal and doesn't really have  a clean sound at all, that's
not a  mistake  !

One end of the tone pot and the drive pot do connect to VB ( 4.5v ) but I dont have a
squeal problem on mine ... could just be a tiny bit of sloppy wiring/solder somewhere ?

MM
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

madboy

Thanks for the quick reply.  As for the sloppy wiring... yeah, probably. I'm still getting the hang of this pedal making stuff. I'll have another look after I've let it sit for a bit... thanks a lot for the help and the layout. It was my first vero project, and I'm glad I got it to work.  I'll probably look through your layout album again for inspiration for my next project, whatever it may be.

madboy