H&K Red Box Classic

[rudeez]

Sup peeps!
I've been looking into the H&K Red Box Classic, differs a bit from the MKII version around.
Thought i was gonna do a layout myself but heard that you Mark were on it some time ago, maybe you have finished it already?
I would really like to keep all the jacks like thru, input and xlr etc.
Schematic is found here, no idea if it's verified.
http://reaperpedals.com/schematics/redboxclassic.pdf
Guess groundswitch etc can be useful to!
Have a great summer all of you!

[johnk]

I drew a vero up for that one today. I haven't verified it since I haven't built it yet, but I think that it's correct to the schematic that you posted.

[rudeez]

mind sharing it John? :)

[johnk]

here it is, but like I said, it's not verified yet.

[alltrax74]

Sabro has a verified layout
http://www.sabrotone.com/wp-content/uploads/2011/04/RedBox.gif

[rudeez]

I know, but thats the MKII, not the classic :)

[rudeez]

just built the vero john! it seems to be working in a way but still it sounds pretty much like using a pedal without a cabsim, its really fizzy. cab switch changed the contour in a way, adding more fizz in the other state. have no idea where to start looking for errors reall, all parts are in place atleast and as it seems no bridges. mind having a second look at it? thanks for sharing :)

[johnk]

well, I never got around to building it yet so I don't know if there's an error in my layout, but I think that it's correct.

[johnk]

I just quickly looked it over and immediately found a missing cut. i'll have to check the rest of it but try adding that cut for now and let me know if it works properly.

[rudeez]

Thanks! Just cut it and no change, still veeeeery fizzy :p
I know for sure that it's not how it's meant to sound really as i have a Palmer cabsim to compare to haha.
Sound is coming through at least and thats a good start... And something happens when flipping the cab switch in the contour. It's probably a easy fix once its spotted :)

[johnk]

okay, i'll check it to see if I missed something else.

[johnk]

I think I just found the (hopefully) only other error. on the 22K resistor that's just to the right of the TL064, try moving its upper leg 4 rows down so it connects to the other side of the 22K resistor next to it, like this:

[johnk]

BTW, thanks for being the guinea pig on the vero!
let me know if that last correction made it work properly.

[rudeez]

Just tried it without luck :/ I'm sorry!
Could try to have a look at the schematic to but im not very good at reading schems just yet :/

[johnk]

I went over it pretty darn carefully and those are the only two things that looked incorrect to me.

[johnk]

not sure if it'll make diffence but I found another one. try moving the lower 12K resistor 5 rows to the left and add the extra link as shown.

[johnk]

did you try the last correction?

[rudeez]

Just tried it but no luck this time either :/ Is it possi ble that  the schematic is faulty?

[johnk]

it could be, but just make sure that you don't have any tiny solder bridges or misplaced components. looking at the schematic, it appears that it should work, since it's just four amplifier stages with filters.
and you might want to check the voltages on your TL064.