Univibe suggestions

[Robert]

Expression jack option too?

You could certainly add one. You'll probably need a taller 1590BB enclosure (1590BBS / BBM) so the added jack clears the PCB.

Keep in mind though, 'Vibe circuits require a dual-ganged expression pedal.

 

[Bricksnbeatles]

You could certainly add one. You'll probably need a taller 1590BB enclosure (1590BBS / BBM) so the added jack clears the PCB.

Keep in mind though, 'Vibe circuits require a dual-ganged expression pedal.

It’s a dual gang 100k pot with each gang simply wired as a variable resistor and not a voltage divider, right? I guess that would be simple enough to do offboard with a pair of photoresistors, and the expression pedal just varying the brightness of the LED that controls the two of them (or just using vactrols, but I think the photoresistors would work fine in this application and be a bit cheaper) so you only need a standard expression pedal

 

[music6000]

View attachment 11997

So, something like this :

 

[music6000]

So, something like this :

View attachment 12038

This might surpass the Low Tide as the Latest Greatest PedalPCB pedal!

 

[Robert]

I guess that would be simple enough to do offboard with a pair of photoresistors,

Yep, that will work, it's been done before.

I considered building that circuit into this PCB but decided against it... I have another plan for expression control (and a few other features) that will be part of a future version. That one will require a larger enclosure though.

 

[ADAOCE]

Oh wow this is just excellent. I was going to stop building for a bit but I can probably squeeze one more build in before my next kid is born and I disappear for 6 months... lol

 

[orangetones]

Photon Vibe is great, especially with a few mods. The bulb vs. LED makes a difference. The filter knobs on the Photon are useless IMHO.

I agree the filter knobs are useless. The low one is somewhat useful.

What mods are you talking about though here? What mods would you make to the circuit?

 

[Chuck D. Bones]

Take a look in Chucks Boneyard for mods.

 

[jeffwhitfield]

Got a Photon Vibe and EQD Depths clone. Both are good but differ a bit. Good for different things really.

I debated on doing a Uni-Vibe clone but decided against it. EQD Depths can get really damn close.

I might be persuaded to do a JHS Unicorn clone. That one is likely to be much, much easier to dick with than a Uni-Vibe clone.

 

[Robert]

I might be persuaded to do a JHS Unicorn clone. That one is likely to be much, much easier to dick with than a Uni-Vibe clone.

From a building perspective the only real difference is that the Unicorn has a digital LFO driven by a microcontroller instead of an analog LFO.

We'll have a project that is similar at some point in the future. that was one of the reasons the ElectroVibe Mini was designed with stacked (modular) PCBs.... the lower LFO PCB can be replaced with a digital LFO without making any changes to the audio PCB.

 

[Chuck D. Bones]

The Electric Druid STOMPLFO would make a good digital LFO for any UniVibe-type circuit. As much as I like the sound of my Photon Vibe, I do not like the charge-pump noise. It would be great if an LED-based Vibe could mimic the sweep of a lamp-based Vibe because with LED's no charge-pump is required.

 

[Robert]

I'll most likely do a custom LFO controller because there are a few functions I want that are probably not a part of the STOMPLFO... also, considering all the fun we've had sourcing FV-1 IC's lately, I'd really like to avoid depending on a 3rd party whenever possible.

I don't see any reason we couldn't capture/simulate the lamp response curve, the sinewave values are pulled from a lookup table so those values could be manipulated as needed.

 

[orangetones]

Take a look in Chucks Boneyard for mods.

Thanks. I had a look. Wondering if I can ask a couple questions here.

I'm finding that this circuit has some treble loss when compared to the stock univibe audio path. I find that even when the Hi knob is turned all the way up to the brightest setting, there is still a rounder sound than my univibe clone. Would eliminating the Hi pot, R25 and C18 solve this? Or would changing the value of C18 affect the maximum treble/brightness that can be achieved?

Secondly, what is the purpose of R28 and R30? I noticed that you eliminated R28 and jumpered R30. What affect does this have one the overall circuit/sound?

Lastly, is it safe to assume that the Low pot and cap only affects how much bass is let in to the signal and does not affect the treble in any way?

Thanks for the help here. I really like the sound of this pedal, but just want some of that treble back. Even with my telecaster or strat, it is so rounded/muffled compared to my univibe clone.

 

[orangetones]

Thanks. I had a look. Wondering if I can ask a couple questions here.

I'm finding that this circuit has some treble loss when compared to the stock univibe audio path. I find that even when the Hi knob is turned all the way up to the brightest setting, there is still a rounder sound than my univibe clone. Would eliminating the Hi pot, R25 and C18 solve this? Or would changing the value of C18 affect the maximum treble/brightness that can be achieved?

Secondly, what is the purpose of R28 and R30? I noticed that you eliminated R28 and jumpered R30. What affect does this have one the overall circuit/sound?

Lastly, is it safe to assume that the Low pot and cap only affects how much bass is let in to the signal and does not affect the treble in any way?

Thanks for the help here. I really like the sound of this pedal, but just want some of that treble back. Even with my telecaster or strat, it is so rounded/muffled compared to my univibe clone.

Any thoughts or info you can provide on the above, Chuck?

 

[Chuck D. Bones]

The Photon's HI control is cut only. Even turned all the way up, it still cuts a little treble off. If you don't want that, then try removing the HI pot or C18. I don't see anything else in the audio path that cuts treble. C5, C18 & C12 cut off at 34KHz, you're not gonna hear that.

Got a schematic of your UniVibe clone?

R28 and R30 raise the gain by almost 20dB, then the LEVEL control knocks it down again. I don't want my Vibe to add gain, so I set the gain of the last stage to 0dB and deleted the LEVEL control.

C1 & R4 will cut off the bass below 1.5KHz if LOW is turned down. So you could say it's kinda like a treble boost.

I ditched the LEVEL, LOW & HI controls because it didn't want or need their function.

 

[orangetones]

The Photon's HI control is cut only. Even turned all the way up, it still cuts a little treble off. If you don't want that, then try removing the HI pot or C18. I don't see anything else in the audio path that cuts treble. C5, C18 & C12 cut off at 34KHz, you're not gonna hear that.

Got a schematic of your UniVibe clone?

R28 and R30 raise the gain by almost 20dB, then the LEVEL control knocks it down again. I don't want my Vibe to add gain, so I set the gain of the last stage to 0dB and deleted the LEVEL control.

C1 & R4 will cut off the bass below 1.5KHz if LOW is turned down. So you could say it's kinda like a treble boost.

I ditched the LEVEL, LOW & HI controls because it didn't want or need their function.

Thanks for the reply! The Vibe clone I have is the Neo Vibe from GGG, built to spec as in this schematic.

http://www.generalguitargadgets.com/pdf/univibeschm.pdf

 

[Chuck D. Bones]

No component values on that schematic, Dude.

If the GGG is the same as the stock UniVibe, then there should not be any treble boost to it. There are bound to be some subtle difference between the original transistor-based UniVibe circuit and the opamp-based Vibes like the Lovepedal Vibronaut and the EQD The Depths, to name a few.

 

[orangetones]

No component values on that schematic, Dude.

Sorry... They are in this file

http://www.geofex.com/Article_Folders/univibe/vibeupdate.pdf

I will see if I can find one with the values written on the schematic.

 

[orangetones]

Sorry... They are in this file

http://www.geofex.com/Article_Folders/univibe/vibeupdate.pdf

I will see if I can find one with the values written on the schematic.

Should be the same as this (even though this is from the Forum Vibe):

http://4.bp.blogspot.com/-5J3L9R1_Chk/T_WXTQl5NqI/AAAAAAAABo0/K70MXGGHHVE/s1600/fv_sch_vint.gif