New at runoffgroove.com: Tri-Vibe

[solderman]

Interesting discussions.....

In light of Solderman's comments I tried an experiment......

Since mine has been built it has always resided at the beginning of the pedal chain - and yes - it is a bit less than unity gain and pretty subtle - I just figured I'd let it all shake out here and a fix would be posted at some time. I mean it works and all.......


After Soldermans comments - I hooked the pedal up directly to the amp - guitar/cord/trivibe/cord/amp.
Using a Pedal Power II for a power supply.........

it sounds like wind is blowing throughout my music room !!!!!

a very pronounced whoosh-whoosh-whoosh in time with the LFO pulse......

I'm going to try and remove the LED that pulses with the LFO and see if that helps....also - when connected directly as described - I get a hellacious on/off pop....that isn't evident when the pedal is in the lineup.....

Odd things today.....

Dan

Hi Dan
I have already tryed that and it makes no change to the volume issue. This is logical since this is on the LFO side. When I made the layout i invoked a  pad for a flashing LED. I built it with one but when i boxed it i decided not to use it and removed it. I tested both with and without the flashing LED and it has no difference for the sound.
About the pop. I invoked a 1M to GND before the 10nf (R1 on my layout ) to kill possible pop:s

[danielzink]

Interesting discussions.....

In light of Solderman's comments I tried an experiment......

Since mine has been built it has always resided at the beginning of the pedal chain - and yes - it is a bit less than unity gain and pretty subtle - I just figured I'd let it all shake out here and a fix would be posted at some time. I mean it works and all.......


After Soldermans comments - I hooked the pedal up directly to the amp - guitar/cord/trivibe/cord/amp.
Using a Pedal Power II for a power supply.........

it sounds like wind is blowing throughout my music room !!!!!

a very pronounced whoosh-whoosh-whoosh in time with the LFO pulse......

I'm going to try and remove the LED that pulses with the LFO and see if that helps....also - when connected directly as described - I get a hellacious on/off pop....that isn't evident when the pedal is in the lineup.....

Odd things today.....

Dan

Hi Dan
I have already tryed that and it makes no change to the volume issue. This is logical since this is on the LFO side.  When I made the layout i invoced a  pad for a flashing LED. I built it with one but when i boxed it i decided not to use it and removed it. I tested both with and without the flashing LED and it has no difference for the sound.

Volume issue aside - I'm wondering if the audible whooshing (would this be the infamous "ticking" that people talk about ?) - has anything to do with the LED connected to the LFO ?

Does yours make (white) noise as well ?

[solderman]

Hi,
I've built this pedal, I'm using André's layout modified by Lyons.
I've had some trouble debugging this effect. This is what's happening:

When I turn on the pedal it doesn't nothing, the led I'm using for the LFO speed doesn't go off, it stays on. When I move the depth pot and change between the modes the sound gets affected for the filters but there's no oscillation or pitch change going on there.

The fact is that my LFO isn't working at all. I'm using a TL064CN for the LFO Opamp, a NE5532 at the buffer and a LM13700N from RS. I have triple checked all my build, my solderings are fine, no shorts, everything is fine there.  I have checked the voltages and they seem to be fine but doesn't oscillate where they should oscillate. I've changed the TL064 and the LM13700N for another one that was left from an older proyect that didn't work either (Rick Holtz's Multimode Envelope Filter). My guess at this moment is that the LM13700N could be damaged, but I'm not pretty sure if this have something to see with the LFO oscillation. I'm not using any other replacement than that.

Could you give me some tips of where should I check?

I'm a little frustrated with this building at this moment...

EDIT: Here are my readings:

Battery: 8.9v - It drops to 8.4v when connected to the pedal.

TL064CN:

1- 4v
2- 4v
3- 3.9v
4- 8.2v
5- 4.4v
6- 4.4v
7- 5.7v
8- 7.3v
9- 0v
10- 3.9v
11- 0v
12- 7.3v
13- 3.9v
14- 7.45v

LM13700N:


1- 1.2v
2- 4.8v
3- 4.15v
4- 4.1v
5- 5.1v
6- 0v
7- 5.1v
8- 3.9v
9- 4.25v
10- 5.45v
11- 8v
12- 5.4v
13- 4.1v
14- 4.1v
15- 4.8v
16- 1.2v

Well #9 shold defenetly not be 0V. have you turned the IC the wrong way around by mistake?

[Slade]

Well #9 shold defenetly not be 0V. have you turned the IC the wrong way around by mistake?

Thanks for answering, solderman, in a rigorous reading I realized the voltage was actually 5mV, still too low.

I don't have turned the IC to the other way, it's exactly like in André's layout. Maybe the 10uF could be damaged? I'll try changing it.

Anyway, lug 9 of the TL064 corresponds to lug 6 of IC3 in the schematic, what voltage should I get here?

EDIT: Changing the 10uF capacitors didn't change anything.

[solderman]

Well #9 shold defenetly not be 0V. have you turned the IC the wrong way around by mistake?

Thanks for answering, solderman, in a rigorous reading I realized the voltage was actually 5mV, still too low.

I don't have turned the IC to the other way, it's exactly like in André's layout. Maybe the 10uF could be damaged? I'll try changing it.

Anyway, lug 9 of the TL064 corresponds to lug 6 of IC3 in the schematic, what voltage should I get here?

EDIT: Changing the 10uF capacitors didn't change anything.

I dont think any of your components are damaged. I have not yet after ~80 builds managed to blow mor than a filter E-lyt that I mistakingly turned the wrong way. Those components withstand more than you think. Caps and resistrors almost never fail. I think you have a solderbridge or som mixed up connections.

The volateg on #9 vill depend on the potition on the of the rate pot.

[Slade]

Thanks, solderman, I have re-checked all the connections and they seem to be fine again, so I can't solve this yet... Once again, does the LM13700N has relation with the LFO oscillation? Because I'm thinking all the problem is coming from the LFO part and opamps, is it so?

[solderman]

Hi
You are probably correct about the LFO being the ghost here. There is no "connection" (besides the LFO) between the LFO part and the Audio part so if you have audio coming trough that part is probably OK. Focus on finding the error in the LFO part.
You can check this by being your "manual LFO"
Just lift the LFO connection from your board (the end not facing the IC of the 2x100K at #1&16) and give them a "simultaneously rhythmic pop" of Vref. This will sound like crap but you will know if your audio part works. After this you will never again apply for the job as LFO

[solderman]

Interesting discussions.....

In light of Solderman's comments I tried an experiment......

Since mine has been built it has always resided at the beginning of the pedal chain - and yes - it is a bit less than unity gain and pretty subtle - I just figured I'd let it all shake out here and a fix would be posted at some time. I mean it works and all.......


After Soldermans comments - I hooked the pedal up directly to the amp - guitar/cord/trivibe/cord/amp.
Using a Pedal Power II for a power supply.........

it sounds like wind is blowing throughout my music room !!!!!

a very pronounced whoosh-whoosh-whoosh in time with the LFO pulse......

I'm going to try and remove the LED that pulses with the LFO and see if that helps....also - when connected directly as described - I get a hellacious on/off pop....that isn't evident when the pedal is in the lineup.....

Odd things today.....

Dan

Hi Dan
I have already tryed that and it makes no change to the volume issue. This is logical since this is on the LFO side.  When I made the layout i invoced a  pad for a flashing LED. I built it with one but when i boxed it i decided not to use it and removed it. I tested both with and without the flashing LED and it has no difference for the sound.

Volume issue aside - I'm wondering if the audible whooshing (would this be the infamous "ticking" that people talk about ?) - has anything to do with the LED connected to the LFO ?

Does yours make (white) noise as well ?

Yes, it whoosches along with the LFO speed. No ticking but the background hum from pickups etc is also pronounced it the sound. This is normal as I see it. It's just background sound going thru the effect and the effect effects the sound like it suppose to do

[Slade]

Hi
You are probably correct about the LFO being the ghost here. There is no "connection" (besides the LFO) between the LFO part and the Audio part so if you have audio coming trough that part is probably OK. Focus on finding the error in the LFO part.
You can check this by being your "manual LFO"
Just lift the LFO connection from your board (the end not facing the IC of the 2x100K at #1&16) and give them a "simultaneously rhythmic pop" of Vref. This will sound like crap but you will know if your audio part works. After this you will never again apply for the job as LFO

Ha! Thanks, I'll try that

[stm]

Regarding the volume drop mentioned in the previous page:

1) Neither Brian nor I have noticed a volume drop on our builds, so if it is there, it is likely something related to that particular build, wiring, or external cabling.

2) The output opamp U1b can be considered a buffer (even though it serves as a mixer too), so adding another buffer after it won't help with the underlying condition. An TL072 can drive easily a 10k impedance; your pedals and amp should be well above 100k.

3) Notice that U1a and U1b have a 47k, 15k and 4n7.  These elements form a pre and de-emphasis network to help reducing noise.  If for some reason these parts have wide tolerance (10% or more) volume change might be noticeable.  If volume change is subtle, I'd suspect the 4n7 capacitors being different. Consider one of these components may not be correct in value, so it would help to read it with a meter.  When I was starting in electronics I got a hard time from an 1N4007 diode.  In the end the band that marks the cathode was printed at the anode...

4) I think the most logical test is to use this simple chain: Guitar -> Tri-vibe -> Amp  with nothing else connected.  Make sure this works OK before adding more pedals.

[Slade]

Okay, my problem is solved, it was a bad speed potentiometer
This pedal is killer, really good Vibe sound.

In my build I've noted both of the mentioned problems: Volume loss and Switch Pop, so I changed the TL072 at the buffer for a NE5532 just for testing purposes and both of the problems were solved, no switch pop and no volume loss, now it's a complete build.

Thanks for this awesome project guys, I'm really happy with the results, and thanks to solderman for giving me a hand debugging it, we were right about the problem was in "that part" of the LFO

Soon I'll be uploading a video demo of the finished build and I'll be posting it here.

Regards,
Fernando.-

[solderman]

Regarding the volume drop mentioned in the previous page:

1) Neither Brian nor I have noticed a volume drop on our builds, so if it is there, it is likely something related to that particular build, wiring, or external cabling.

2) The output opamp U1b can be considered a buffer (even though it serves as a mixer too), so adding another buffer after it won't help with the underlying condition. An TL072 can drive easily a 10k impedance; your pedals and amp should be well above 100k.

3) Notice that U1a and U1b have a 47k, 15k and 4n7.  These elements form a pre and de-emphasis network to help reducing noise.  If for some reason these parts have wide tolerance (10% or more) volume change might be noticeable.  If volume change is subtle, I'd suspect the 4n7 capacitors being different. Consider one of these components may not be correct in value, so it would help to read it with a meter.  When I was starting in electronics I got a hard time from an 1N4007 diode.  In the end the band that marks the cathode was printed at the anode...

4) I think the most logical test is to use this simple chain: Guitar -> Tri-vibe -> Amp  with nothing else connected.  Make sure this works OK before adding more pedals.

Sebastian
Regarding the volume drop. I have tested exactly the way you describe. And I have found some very interesting results. I found the same thing as Dan did. When connected

Guitar>cable>Tri Vibe>Amp there is no problem. But when I put it first in my pedal chain
(Guitar >cable>Tri Vibe>13 boxes all true bypass and all switched in bypass mode connected with cheap cables>Amp) there is a considerable volume loss and a loud pop when switched.

This amount of true bypass boxes will result in a tone loss. That's the reason I have a switchbox first that also contains a line buffer that is wired with a true by pass on/off switch. The guitar is normally connected directly to this switch box. In this case the Tri Vibe is in between the guitar and the switch box. As soon as I switch in the line buffer the volume loss is gone and the pop at switching stops. My theory is that the capacitance of the pedal chain rocks the balance of the output buffer some how. I am not that skilled in electronics to say how but that's my guess.

I have also checked the 4n7 and they are correct. If they were not I assume the problem would occur all the time regardless of routing.

Any thoughts ??

[solderman]

Okay, my problem is solved, it was a bad speed potentiometer
This pedal is killer, really good Vibe sound.

In my build I've noted both of the mentioned problems: Volume loss and Switch Pop, so I changed the TL072 at the buffer for a NE5532 just for testing purposes and both of the problems were solved, no switch pop and no volume loss, now it's a complete build.

Thanks for this awesome project guys, I'm really happy with the results, and thanks to solderman for giving me a hand debugging it, we were right about the problem was in "that part" of the LFO

Soon I'll be uploading a video demo of the finished build and I'll be posting it here.

Regards,
Fernando.-

Hi
Glad to hear that your dessert walk is over

Interesting thing about the NE5532   

[stm]

Sebastian
Regarding the volume drop. I have tested exactly the way you describe. And I have found some very interesting results. I found the same thing as Dan did. When connected

Guitar>cable>Tri Vibe>Amp there is no problem. But when I put it first in my pedal chain
(Guitar >cable>Tri Vibe>13 boxes all true bypass and all switched in bypass mode connected with cheap cables>Amp) there is a considerable volume loss and a loud pop when switched.

This amount of true bypass boxes will result in a tone loss. That's the reason I have a switchbox first that also contains a line buffer that is wired with a true by pass on/off switch. The guitar is normally connected directly to this switch box. In this case the Tri Vibe is in between the guitar and the switch box. As soon as I switch in the line buffer the volume loss is gone and the pop at switching stops. My theory is that the capacitance of the pedal chain rocks the balance of the output buffer some how. I am not that skilled in electronics to say how but that's my guess.

I have also checked the 4n7 and they are correct. If they were not I assume the problem would occur all the time regardless of routing.

Any thoughts ??

Maybe there is something odd going on with the 1uF capacitor at the end.  I'd check polarity and perhaps replace it with a larger value, like 10uF and see if there is a change.  The output buffer is pretty standard, so I can't imagine why it shouldn't work properly, unless there is something odd with the cabling or loading of other components.

[danielzink]

So in a whim today - as noted several times above.......

I decided to give it a shot........I popped an NE5532 in the '072 slot.....

And life is good !

Maybe I had a bad night last night - maybe my amp was mad at me - maybe my pedals decided to stage a revolt......

whatever......the NE5532 has silenced the "white noise"

I have achieved unity gain.......

I can sleep restfully again..................




Dan

[solderman]

So in a whim today - as noted several times above.......

I decided to give it a shot........I popped an NE5532 in the '072 slot.....

And life is good !

Maybe I had a bad night last night - maybe my amp was mad at me - maybe my pedals decided to stage a revolt......

whatever......the NE5532 has silenced the "white noise"

I have achieved unity gain.......

I can sleep restfully again..................




Dan

All work and no play makes Jack a dull boy............

My TL072 is soldered directly to the board so I have to be haunted by the volume loss & pop ghost OR desolder resolder an 8 lug IC.
The devils choice 

But then I put it last in my pedal change and the sky has opened itself to me

There it will rest in Peace with the the rest of my equipment.

[doc_drop]

I did wind up replacing the TL072 with an NE5532. I don't know why, but making that change has made both this circuit and a Nurse Quacky I built last week work much better.

That was my experience as far back as page 6 of this thread.

[stm]

Well, it seems there are at least a couple of reports that support the usage of NE5532 in place of a TL072 for U1.  Apart from being lower noise, it has greater drive capabilities, which seems to be a plus in this particular circuit.  In summary, if you have an NE5532 available, use it for U1 as your first choice.  In my case I have a TL072 working in my build, so I haven't had the need to switch to an NE5532.

[Slade]

Here's a video I've made of the pedal. Hope it serves to you: http://www.youtube.com/watch?v=jdEsIIPE1Sw

Regards,
Fernando.-

[roseblood11]

wow, this is the best sounding demo for the tri-vibe up to now. And the etched enclosure is amazing, as always!