Ross Phaser - Doesn't work the first time...go figure?

[modsquad]

Okay I just completed the Ross Phaser with Univibe modes switchable with another 3pdt to switch between caps.  Added a switch for the vibrato and a volume pot in place of the 150k resistor on the output.  Oh and a sweep control per Mr. Hammond. 

Okay so the leds work with the switching and bypass works.  Unfortunately switch it on and nothing.  Could someone help me with the voltages I should be seeing across the ICs?  Or any other pearls of wisdom...I hope I didn't add to much "stuff" to figure it out.

Thanks,

Stan

[modsquad]

Sorry Mark, I know its Hammer.  I have Hammond on the brain as I work on the enclosure.

[Mark Hammer]

Doug just breathed a sigh of relief!

What I wanna know is "Why the hell am I the only person who ever gets called 'Mr' around here?"  I certainly don't mind being called Mr, but being singled out for it is a little creepy. Particularly when there are so many others here who are also old enough to have watched Elvis and the Beatles on Ed Sullivan.  I realize part of it is because I can't seem to shake my professorial-like ways, but heck, even when I was teaching univerisyt I insisted on being called Mark.  Ah well.

Yeah, I guess that it's a generally good practice to do mods AFTER one has the basic circuit working.  Makes it a whole lot easier to troubleshoot and second guess.

You *should* get at least something in effect mode, as long as you don't have it in vibrato (i.e., no straight signal).  For my part, the Tonepad layout is so tight,and the cost of the overall circuit so modest, that I think it is just simpler to make a dual board, with one optimized for Uni-Vibe functioning, and the other optimized for phaser functioning.  That has a few advantages.  First, it drastically reduces the amount of switching and wiring needed and you bypass the "cramped board" thing.  Second, phasers want a different range of speeds than Univibes do, so building in the right "diability" to serve each need can get tricky.  Third, incorporating cap switching for modding to uni-vibe function AND phase-filter function (worth doing) can get nuts.  Fourth, Regeneration on a Uni-vibe does diddly-squat at best, and ruins it at worst, so you'll want one version of the board without Regen.

So, bottom line: Feel free to make an OTA-based Univibe with the Tonepad Ropez board/layout.  I can confirm that it sounds real nice, but it is best and least problematic to have it as a dedicated Univibe, and make a second board for phasing and phasefiltering.

[modsquad]

I am in your camp as I sit down and try to figure out where to start debugging.  I actually created a seperate board with the .0033 caps and the subs with wiring to the second switch.  The switch and the board then wires to the main board.

I will try to see if I can tack it down.  If not I have another board already drilled with the IC sockets soldered in.  I was hoping to do another one when I got this one done.

Thanks for your advice MARK.

Stan

[Arn C.]

Mark,

    I guess you have to be over 50 to be called Mr.   

By the way, I will be 50 next month, so I guess in another year and a bit I may also be called Mr.   

Merry Christmas, Happy Holidays, Happy Hannakah,  Happy Kwanza! 

Peace!
Arn C.

[Eb7+9]

What I wanna know is "Why the hell am I the only person who ever gets called 'Mr' around here?" 

... dunno, you're the psychiatrix Mark - maybe it's that authoritarian Dad archetype you created for yourself

[Mark Hammer]

Say, you kids, get outa my yard....and STAY OUT!!   There.  Proof postive I'm over 50.  Now I have to figure out how to shake this "Mr.' thing.  Let's see if this works..

Chicks, man.   Um.....DUDE that rocks!  Hmmmmm...Whoa, I remember when my dad played me his Kiss records for the first time!   Er, say Guitar Centre dude, what's the pointiest guitar you have?  No, WAIT!  Um, what will make me sound like Stevie Ray Vaughan...no WAIT, maybe hold off on that, my stupid girlfriend wants me to spring for a...a...a....dining room set.  Jeez.  How I'm gonna pay for that AND tuition without selling my Valvestate, I dunno.

... dunno, you're the psychiatrix Mark - maybe it's that authoritarian Dad archetype you created for yourself

Busted!

Modsquad,
I doubt whether there is any particular source of difficulty or nonfunctionality that is unique to this circuit.  My recommendations were primarily to help simplify the challenge.  Not being able to hear anything in effect mode indicates one of two things: either you don't have power when you thought you did, or there is a discontinuity in the signal path.  One of the things I am confronting more and more these days is my own cheapness with respect to the sockets I buy, and the opportunities they create for poor pin to socket contact.  If you are using sockets, I might also suggest verifying that none of the pins has gotten bent underneath the chip (but above the socket).  That can be hard to spot sometimes when a board is fairly compact....especially if it doesn't occur to you to look for it.  Just a thought.

Hey you kids!  I thought I told you to stay outa my yard!!  That's it.  I'm calling your parents!!

[modsquad]

Know what you mean about the bent pins under the socket.  I bent one on this circuit because it is so compact and had to replace.  Today I am going to start the routine of checking the voltages on the pins of the ICs and trace it from there.

Stan