Hendrix "trick" with boosted VIBE (free preset)

musicman0001

musicman0001

Experienced
I tried the UNI VIBE boost trick and expiriment with VOLUME KNOB and I get it now

The last few day's I've been trying again as the latest iterations have changed some stuff that seem to work for my set-up. I was never a volume rolldown kind of guy as I never had one sound as I started quickly with the purple digitech 2120 artist. And I just set the preset in the 2120 in the ballpark and all was great.

But to really get the feel and the sound of a vibed dimed fuzzed amp and see some vids on hendrix with the vibe and fuzz and that he roll's down his volume etc.. I started some day's ago with several amps. I got it working with the JM 45 and tried also the 1987X and wondered about the JCM800. This latest preset also includes the 75% variac and SAG tweaking. Of course I have tuned and setup my guitar and pickup to match my IR so this preset would not work for you. For machinegun: also try the VIBE with modulation and have a fuzz after it. Play around with rate, feedback and the tone knob in right corner of the vibe.
When you set VAR back to 100% -> Make sure you also play with the SAG as the SAG is tweaked in this preset!

The sounds that you can get with this preset if you play around with SAG, volume knob (on your guitar) and even toneknob are plenty!!
(at least I did on my adams, even with low volume -> axe fx at +4 db and out 1 at around 6 or maxed at 10) .

Question:
As many VIBES have a ON/OF for modulation I tried to mimic that, BUT would be nice to have a toggle for this in some way.
So what's best setting to have same boosted sound, but stop the modulation (with the use of the pedal in the axe fx, as I'm not sure I can get the modulation really gone and what the effect is on the sound)?

See presets below (as examples with different marshalls)
 
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Man I’m so confused... Lol

You are saying you are using the univibe as a boost?

If you want a boosted sound without modulation, use a boost?

I’m clearly missing something.
 
cole lewis said:
Man I’m so confused... Lol

You are saying you are using the univibe as a boost?

If you want a boosted sound without modulation, use a boost?

I’m clearly missing something.
Click to expand...
Thats what Hendrix did 😉
Besides vibe modulation its used as a boost. Many vibe pedals have a cancel button for modulation.
 
Maybe explain what the “Uni-Vibe boost trick” is because to me, pitting a vibe in front of an amp isn’t a “trick” that’s how you use a pedal. Every pedal...
 
I looked this up out of curiosity. The “trick” you seem to mentioning. Is the tone suck from non true bypass. Treble getting cut off from the pedal making the amp sound fatter. At least that what it seems to be to me.
 
cole lewis said:
Maybe explain what the “Uni-Vibe boost trick” is because to me, pitting a vibe in front of an amp isn’t a “trick” that’s how you use a pedal. Every pedal...
Click to expand...
I call it a trick, as it part of getting certain tones that hendrix applied. Without its really hard to get. Whatzinaname 😉
 
There’s like 1000 ways to boost your sound in the Axe. I’m pretty sure one of them will work better as a boost than a pedal not designed as a boost. It’s not that special trust me.
 
cole lewis said:
There’s like 1000 ways to boost your sound in the Axe. I’m pretty sure one of them will work better as a boost than a pedal not designed as a boost. It’s not that special trust me.
Click to expand...
That is ok. Every one has different ideas and knowledge. It was for me and maybe others that would like some hendrix tone and feel.
 
(The stock 'vibe has a slight signal drop from input to output when the volume control is at full volume. This is the bane of simple "true bypass" modifications to the 'vibe. The "cancel"function does not have this problem since the signal still goes through the same gain/losses that the effected signal does, and gets unity gain by default.

The key to making the 'vibe be unity gain is there in the preamp. The gain overall is controlled by the split emitter resistor on the third transistor, and is the reciprocal of the resistor divider ratio. To get a bit more signal through the signal chain to match the dry signal level in bypass, change the value of the lower resistor down slightly and the upper resistor up slightly. The only kicker is that once you have the gain level matched, you must make the collector resistor in the third transistor in the preamp be the same as the sum of the two emitter resistors to keep the phase inverted signal on the collector at the same magnitude as the signal on the emitter so the first phase stage operates correctly.

Update March 2010: The preamp of the vibe already has about 12db gain. What's killing gain is the input mixer. By simply changing the input 47K resistor to ground up to 2.2M or bigger, you add in a lot more signal level by NOT dividing down the input. Give it a try. Simpler than dinking with the dividers.

Most 'vibe afficianados don't think of it this way, but the stock 'vibe suffers from some of the same problems that the unmodified crybaby does. The input resistance to either input is only 69K (22K plus 47K). This is low enough to significantly load the output of a guitar and dull the sound. In the stock vibe, you pay this price to a degree even when "bypassed", as the "cancel" switch is not a bypass, it merely turns off the lamp, and the signal still goes through the phase stages with the LDR's at very high resistance.

Update March 2010: I've found that the preamp of the univibe itself has a fairly high input impedance all on its own. What's poisoning things is the 22K/47K input divider. Those are there to mix two inputs (I think), but hardly anyone ever uses two inputs there today. To clean things up a lot, change the 47K to well over 1M, preferably something like 4.7M. This kicks the input impedance up to about 430k ohms, and there's then almost no treble loss. This pretty well makes input buffers unnecessary. So try the one-resistor change first.

One way to brighten things up some is to buffer the input. I've shown two ways to do that; one with a high gain transistor buffer, similar to the input buffer on the Ibanez series of pedals, and another with a JFET source follower. The JFET is a higher input impedance and a simpler circuit, but a lower allowable input voltage. The bipolar buffer is a lower input impedance (but probably good enough) and a slightly more complicated circuit.

I've recently messed with some simulation of the stock 'vibe circuit and come up with some interesting results.)

Okay so from this from what I can tell. The preamp is there only to have the pedal be at unity volume/gain and not have signal drop. I'm pretty sure the only thing "special" about this, is again, the fact it's not true bypass and you are getting tone suck. Jimi could've liked the tone suck as less treble perhaps for him was beneficial.

When you use the Fuzz Face emulation in the Axe for the most accurate results if you don't know, you want to set your input impedance to 90k
 
cole lewis said:
(The stock 'vibe has a slight signal drop from input to output when the volume control is at full volume. This is the bane of simple "true bypass" modifications to the 'vibe. The "cancel"function does not have this problem since the signal still goes through the same gain/losses that the effected signal does, and gets unity gain by default.

The key to making the 'vibe be unity gain is there in the preamp. The gain overall is controlled by the split emitter resistor on the third transistor, and is the reciprocal of the resistor divider ratio. To get a bit more signal through the signal chain to match the dry signal level in bypass, change the value of the lower resistor down slightly and the upper resistor up slightly. The only kicker is that once you have the gain level matched, you must make the collector resistor in the third transistor in the preamp be the same as the sum of the two emitter resistors to keep the phase inverted signal on the collector at the same magnitude as the signal on the emitter so the first phase stage operates correctly.

Update March 2010: The preamp of the vibe already has about 12db gain. What's killing gain is the input mixer. By simply changing the input 47K resistor to ground up to 2.2M or bigger, you add in a lot more signal level by NOT dividing down the input. Give it a try. Simpler than dinking with the dividers.

Most 'vibe afficianados don't think of it this way, but the stock 'vibe suffers from some of the same problems that the unmodified crybaby does. The input resistance to either input is only 69K (22K plus 47K). This is low enough to significantly load the output of a guitar and dull the sound. In the stock vibe, you pay this price to a degree even when "bypassed", as the "cancel" switch is not a bypass, it merely turns off the lamp, and the signal still goes through the phase stages with the LDR's at very high resistance.

Update March 2010: I've found that the preamp of the univibe itself has a fairly high input impedance all on its own. What's poisoning things is the 22K/47K input divider. Those are there to mix two inputs (I think), but hardly anyone ever uses two inputs there today. To clean things up a lot, change the 47K to well over 1M, preferably something like 4.7M. This kicks the input impedance up to about 430k ohms, and there's then almost no treble loss. This pretty well makes input buffers unnecessary. So try the one-resistor change first.

One way to brighten things up some is to buffer the input. I've shown two ways to do that; one with a high gain transistor buffer, similar to the input buffer on the Ibanez series of pedals, and another with a JFET source follower. The JFET is a higher input impedance and a simpler circuit, but a lower allowable input voltage. The bipolar buffer is a lower input impedance (but probably good enough) and a slightly more complicated circuit.

I've recently messed with some simulation of the stock 'vibe circuit and come up with some interesting results.)

Okay so from this from what I can tell. The preamp is there only to have the pedal be at unity volume/gain and not have signal drop. I'm pretty sure the only thing "special" about this, is again, the fact it's not true bypass and you are getting tone suck. Jimi could've liked the tone suck as less treble perhaps for him was beneficial.

When you use the Fuzz Face emulation in the Axe for the most accurate results if you don't know, you want to set your input impedance to 90k
Click to expand...

Interesting, what's the source?

another thing Hendrix did is different strings (non standard) this also impacted his sound
 
cole lewis said:
I watched almost the whole thing I was waiting for an answer to my question but this video is just people talking about liking the uni-vibe modulation sound and getting Jimi tones without the trick you refer to.
Click to expand...

Should have given TITLES ;)

First VID = it's not trying to emulate a rotary, but radio sound from mosco

The SECOND video is about a guys showing the VIBE & boost stuff
 
PS: all presets are for FUN only, I'm NOT trying to replicate ANY specific sound. You can easily do that with your VOLUME knob on guitar and even the TONE.

@FractalAudio -> maybe I missed it, but is there "trick" to use the UniVibe only as a "booster"? Or any thoughs of implementing this in some way like a toggle switch on the pedals?
 

Attachments

  • Jimmy Fuzz & VIBE JM45.syx
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  • Play VolumeKnob 1987X Treble.syx
    48.2 KB · Views: 9
  • FUZZ & VIBED SLP.syx
    48.2 KB · Views: 10
  • Stereo JCM 800 DIMED with VIBE.syx
    48.2 KB · Views: 12
cole lewis said:
The trick is to turn it off and use a booster pedal.....
Click to expand...
Yep, I get your point. Your talking about the real pedal and the Univibe. I'm talking about getting more quick into Hendrix his sound and his usage of the Univibe pedal (together with a fuzz).

It's also that this vibe is part of many presets for me and is placed before the compressor and drives. And with only one press of the cancelbutton the sound remains the same but the modulation is gone. Like the real pedal. Should not be very difficult. Or I can assign a controlswitch. Axe can do so much. Especially with FW 20.X it's real easy.

Can we stop this discussion about boosting. Yes I get close with the Bussom Booster. This thread is about a vibe and about hendrix together with volumeknob and fuzz to more easly get hos sound.
Thanks!
 
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