Build Report: Meatball and CE-2

[lowstar]

hi everybody,

after giving up on the la-light for now, i finally took on two things that have been on my mind for a long time:
1) building a meatball clone
2) starting to etch my own pcb´s

so, first i perfed the meatball, and after some debugging (all in the offboard wiring, the board was perfect right away), the thing worked, and wow, this one´s really useful for me as a bass player, phat biouuuapp (think jestofunk) and myriad ways to tweak. a bitch to box up, though, had to use a 1590D. the pisotones site was helpful, but also misleading, i think there is one mistake in the poti wiring and first i had all the lorlin switches wired the wrong way round, so then i took to looking at the schem rather than looking at the pisotones diagram and i got it right.
one thing i´m not sure about: in lowpass mode, the blend knob has a kind of out-of-phase thin sound in the middle position, it goes from pure fx sig to winy-thin-sound to pure-no-fx-sig. is this normal ? in the other positions (bandpass, highpass) the blend knob works perfectly ok, so i wonder if this is inherent in the design. any other meatball builders who can comment on that ?

second, i bit the apple and tried making pcb´s. i used the photo-optical method. bought a uv-photo-lamp, printed 2 times on transparencies, put 2 transparencies on top of each other, 5min under the lamp. into the developer, and...it took a long time ´til the traces showed up...oh yeah i put double the amount of water into the chemical...stupid me...but amazingly, it still worked. the into the etchant solution (i used a modern one, ammonium persulfate, not the brown soup). and...wow...it worked too. i felt like a little kid at xmas. then onto the drilling, i used a small minidrill with a drillpress, works like a charm. the only thing is, next time i put the solder-spray thingy on the pcb after drilling, cos the dust of the drilling was always sticking to the surface of the pcb.

and then...populating the ce-2 board (tonepad)...i was excited and nervous when i put the mn3007/mn3101 combi in the sockets, fired her up and...worked ! boxing it up, i had some minor ticking issues, but by shortening the rate leads to a minimum, i was able to tame them enough. instead of the 250k revlog, which seems impossible to get here (not even banzai has them), i used a linear one, and it works pretty ok.

so...i´m outrageously happy that i have those two powerful circuits at my hands now to play with. i´d like to thank everybody that developed those pcbs, worked on the schemos, everything. i started out last year in feb/march, and within one year, i´ve come from veroboard (yeah, my frst post..."help, my scrambler does not work !") to pcb´s and have about 40 completed circuits now.

a special thumbs up to tonepad, you rock ! it was nice to think about us bass players too and include the bass mods !
hey, while i´m at it: how about a boss bf-2 layout with mods to turn it into a bf-2b ?

so much for now. when i have more time, i will do a close comparison between my original ce-2b and the corral chorus in bass mode.

cheers,
lowstar

[markusw]

Hi lowstar,

one thing i´m not sure about: in lowpass mode, the blend knob has a kind of out-of-phase thin sound in the middle position, it goes from pure fx sig to winy-thin-sound to pure-no-fx-sig. is this normal ? in the other positions (bandpass, highpass) the blend knob works perfectly ok, so i wonder if this is inherent in the design. any other meatball builders who can comment on that ?

As far as I understood the hp and lp filter are out of phase with the dry signal. Therefore, I added an optional phase inverter for the dry signal. This allows for "in-phase" of lp and hp with dry as well as out-of-phase of bp with dry (with about 50% blend this gives a notch filter, which btw is not that useful). For the hp filter I believe the out-of phase effect is less obvious since the "bottom" is not affected that much.

Just curious: what kind of UV lamp did you use?

Regards,

Markus

[Johan]

hi everybody,

after giving up on the la-light for now, i finally took on two things that have been on my mind for a long time:

lowstar

hello Lowstar..first. congrat's on the two working builds..
..and next, sorry, havnt been around much lately..didnt see this untill now, but..why dont you get the LA-light to work?...it's such simple circuit..can we walk through the problems together?..

johan

[lowstar]

hey johan,

cool you´re checking in again. i really don´t know why i can´t get it to work. i should give it a try later this week. i should try to figure it out how to post the layout, or pm me if it´s ok with you to send you my stripboard layout.
cheers,
lowstar

[Johan]

..check your mailbox 

johan