New at runoffgroove.com: Tri-Vibe

[doc_drop]

Just some more info based on what I discovered this weekend.

I plugged my Tri-Verb build into a Thor pedal to hear what it would sound like amped. I noticed a "fitzy" noise, especially in the swirl mode that I couldn't get to go away. I decided to see if changing the 1uF cap to a 220nF per the updated docs would help to filter it out. It did. It sounds much better with the 220nF. I guess there was some high frequency noise that needed to be filtered out.

Like this the Thor/Tri-Vibe combo is a thing of beauty.

[salwa]

Hi!
I've just finished building Tri-Vibe using layout from ROG. It works, but with some issues. First of all, I hear strong LFO ticking when Depth pot is turned to maximum or somewhere nearby. Any idea what may be the cause? Second thing - Swirl and Whirl settings causes circuit to work rather like tremolo than anything else. But it's not that important, I can live with it. But the ticking is ruining this circuit for me. I'm using LM13600N chip, TL062's and TL072.

The LFO in this circuit does not tick if properly built.  A 10n+100k couple around pins 1 and 2 of U3a prevent ticking by reducing the slew rate during transitions.  As you report the circuit is actually ticking and two modes are not working as expected, it is clear that there is something wrong with your build.  I suggest you do a thorough revision (once again) looking for shorts, wrong connections, wrong part values, etc. and post the voltages on every pin.

Thanks for your response. First of all, I forgot to thank you for this great circuit. Even in this half-baked state my Tri-Vibe sounds wonderful and retro - it almost made me cry:).
I've checked my components and wiring. It turned out, that problem with other modes than vibe was in bad cable on output (it distorted sound, so it was little choppy, it wasn't that obvious in vibe mode). Now it's fixed.
But LFO is still ticking. When I turn depth pot above 14 hour, it's noticeable. I've checked components and traces - everything looks OK. I also measured voltages - here they are:
IC1
pin 1 - 4,5v
pin 2 - 4,48v
pin 3 - 4,07v
pin 4 - 0v
pin 5 - 4,46v
pin 6 - 4,39v
pin 7 - 4,13v
pin 8 - 8,94v

IC2
pin 1 - 4,46v
pin 2 - 4,46v
pin 3 - 4,43v
pin 4 - 0v
pin 5 - 4,52v
pin 6 - 4,38v
pin 7 - 3,18v
pin 8 - 8,92v

IC3
pin 1 - 3,44-5.44v (slowly alternates)
pin 2 - 4,39v
pin 3 - 4,12-4,73v (slowly alternates)
pin 4 - 0v
pin 5 - 4,44v
pin 6 - 4,44v
pin 7 - 4,18-4,65v (slowly alternates)
pin 8 - 8,88v

IC4
pin 1 - 1,26v
pin 2 - 5,35v
pin 3 - 4,67v
pin 4 - 4,67v
pin 5 - 5,96v
pin 6 - 0v
pin 7 - 5,97v
pin 8 - 4,88v
pin 9 - 4,38v
pin 10 - 5,49v
pin 11 - 8,86v
pin 12 - 5,52v
pin 13 - 4,67v
pin 14 - 4,67v
pin 15 - 5,34v
pin 16 - 1,24v
The only thing that differs my build from layout is that I didn't have 3,9K resistors, so I used two 3,3K+68ohm pairs instead.

[stm]

salwa, your voltages look OK.  As I mentioned before, the ant-tick components are a 100k/10n pair around pins 1 and 2 of U3a.  Make sure the 100k resistor is actually 100k and not a smaller value (like 100 ohms), also verify that pin 2 is not shorted to Vref by mistake, and also check that the 10n capacitor between pins 1 and 2 is actually 10nF and not 10pF or so.  If in doubt, remove the capacitor and place another one (maybe even larger) and see if it makes a difference.  Same goes with the 100k resistor.  The values of these two parts are not critical, consider +/-50% variations are acceptable.

Also, which type of opamp are you using?

[salwa]

salwa, your voltages look OK.  As I mentioned before, the ant-tick components are a 100k/10n pair around pins 1 and 2 of U3a.  Make sure the 100k resistor is actually 100k and not a smaller value (like 100 ohms), also verify that pin 2 is not shorted to Vref by mistake, and also check that the 10n capacitor between pins 1 and 2 is actually 10nF and not 10pF or so.  If in doubt, remove the capacitor and place another one (maybe even larger) and see if it makes a difference.  Same goes with the 100k resistor.  The values of these two parts are not critical, consider +/-50% variations are acceptable.

Also, which type of opamp are you using?

Thanks for fast reply. I've checked my board few times - nothing is shorted, values of components are OK. I substituted 10n with 15n and 100k resistor with 150K, but without luck - LFO is still ticking. I'm using TL062CP for U3. I've tried TL082, but nothing has changed.

[doc_drop]

As I wrote above, the only way I could get the LFO working at all was to try an NE5532 for U3. If you can get your hands on one you might try it. It is a low noise chip so it might help. I didn't have the ticking, so that's the best I can offer...

[stm]

As I wrote above, the only way I could get the LFO working at all was to try an NE5532 for U3. If you can get your hands on one you might try it. It is a low noise chip so it might help. I didn't have the ticking, so that's the best I can offer...

In my breadboard I have a TL062CP by Texas Instruments in place of U2 and U3.  Haven't experienced any problem here.  I don't see why it shouldn't work, since the TL062 is not being used close to or outside its limits in any way I can think.

I'd try replacing the pair of 10uF electros, and also make sure that they are actually with their polarities back-to-back as shown in the schem.

[svstee]

Has anyone verified the Vero layout yet? I got distracted by other projects...

[doc_drop]

I only mentioned the replacement for U3 because that worked for me. My build had no LFO with a TL062 for U3, either on the breadboard or on perf. Pop in a NE5532 and I get LFO.

I unfortunately don't know enough to explain it. But it did happen that way. I used a LM13700, instead of the LM13600, so I don't know if that changed anything.

I wish I did know enough to be more than a hack, but at least I got mine to work. 

[salwa]

I'm using non-polarised 4,7uF electro there. Maybe that's the source of ticking? I'll try to change it to pair of 10uFs.

[stm]

I'm using non-polarised 4,7uF electro there. Maybe that's the source of ticking? I'll try to change it to pair of 10uFs.

I referred to the change of cap mainly as an alternative to fix a non-working LFO.  For instance, a very leaky capacitor might need the additional output current that an NE5532 can provide.  Eventually a faulty cap could increase ticking, but I suspect the real problem lies in wrong connections or in the way the GND and VREF tracks are laid out.

Which layout are you using ?

[salwa]

I'm using layout form runoffgroove.com. I've checked my traces once again, but couldn't find any shorts. Especially I'm sure, that pin 2 is not connected to pin 1 or ground. Maybe I should look into that capacitor.

[John Lyons]

Circuit boards are for sale now via the link at ROG.
http://www.runoffgroove.com/tri-vibe.html

Thanks to Andre for being very generous with his
layout and my redraw of it for the ROG page.
I have to get busy on mine now.

John

[solderman]

Hi
I have just finished a layout for the Tri-Vibe to fit in a 1590A box. It's not the most perfect layout I have done. In fact it's quite a mess with a lot of ugly solutions. But it was not that easy to fit every thing in. The layout is NOT verified yet. Feel free to use it if there is some one out there that is as stupid as I am and tryes to squeeze this one in to an all to small box. I have ordered a couple of LM13600 so I can build the more normal sized version as well as this design really looks like it's going to be one off the classics and a "must build".


http://solderman.fatabur.se/Tri Vibe/Tri Vibe Project file.pdf
http://solderman.fatabur.se/Tri Vibe/Tri Vibe PCB.pdf

[salwa]

I've tried different capacitors, but there was no change - LFO's still ticking.

[alparent]

Just looked at John's layout ......... what's the font of the title?
Look great (the title and the layout) 

[John Lyons]

It's called "Radio Dayz NF "
It's the Collins radio font from the 40's

John

[danielzink]

Quick question - John.

As we're looking at your layout - are we looking at the bottom of the pots - or the top (for numbering purposes).

Thanks !

Dan

[John Lyons]

They are shown from the bottom.
As looking in to the enclosure.
Lugs down left to right: 3,2,1 (CW Wiper CCW)

[TamuT]

Biggest thanks to runoffgroove and André for this nice project. Sounds really awesome...

Actually this was my first pcb & enclosure etch... worked alot better than I expected  

[Andre]

Hi TamuT,

Welcome to the forum and glad you like it.
Love the etched enclosure.

I like my TriVibe a lot too.
Gigged with it last night and it worked great, both as phaser as well as vibrato.
With the Lovepedal Eternity in front of it I made some nice overdriven organ sounds with it.