Vibes, voltage, and the continental divide

[Mark Hammer]

A friend and neighbour mentioned something to me today that I was previously unaware of.  That may be because I know too much, or because I don't know enough, but I'm in no position to judge, so I turn it over to you.

What he told me was that on Hendrix recordings made in Europe, the Univibe sounds more "intense" than it does on American recordings.  As he understands it, this is attributable to the difference between the line voltages on the two continents.

What I'd like to know is:
a) Do any of you who listen as intently to Hendrix recordings corroborate or agree with his observations?
b) If so, is it a consistent audible difference, or only on something that crops up here and there? (for example, depending on country)
c) Is there any theoretical basis to suggest there ought to be a difference?
d) If there is a consistently heard difference, that is not attributable to possibly different units being played on American vs European recordings, and if there is a theoretical basis for it, is it possible to modify the conventional circuit such that people can attain "European" vs "American" sounding tones?

I'm not disputing my friend, since, as I say, I have not the familiarity with the breadth of recordings that he does., so I can't judge one way or the other.  I understand fully how it might be possible for one's hearing to be biased or misdirected, but the notion that a line-powered effect might behave differently with a different line voltage is not so farfetched either.

So, mystery, masterable, or myth?

[R.G.]

While the critical listening tests are going on, I would wonder if he was provided a different unit when he was in Europe. Then I'd wonder what else was different with his rig. And when all that curiousity was satisfied, I'd start on the voltage tests.

[John Lyons]

I would wonder if he was provided a different unit when he was in Europe.
I'd imagine that this is the difference more than the voltage. Photocells, bulbs and the
parts tolerances etc. 

[Jaicen_solo]

I can say with some level of certainty that he had at least two different units with slightly different bulb biases, because the sweep of the woodstock recordings is quite different from the sweep produced on recordings like the Isle of Wight (1970). Also, the new years Filmore unit sounds different again.
Now, some of it may be to do with the other gear he was using, such as the Sunn amps etc. I couldn't say for certain what to attribute the different tones to, it still sounds like Hendrix after all  

EDIT: Compare and contrast;

http://www.youtube.com/watch?v=jAzabcgEvyY

http://www.youtube.com/watch?v=6SG5fiSkcfA

[Mark Hammer]

The potential difference in the units being played was my first instinct as well.  At that point in time, of course, the Uni-Vibe would not have been something that had settled to the degree of uniformity and standardization as, say, a Boss DS-1.  Moreover, there is that lamp/photocell interface.  As I found out, in the process of repairing someone's older Morley Wah years back, a little bend here or there in the photocell, or a couple millimeters closer or farther back, and things work differently.  So the design, and possibly even the unit itself, could have been identical on each side of the Atlantic, but jostling in transit might have modified the behaviour of the light transmission/sensing.

At the same time, I think it is still worth considering the potential role that AC line differences could play in the behaviour of that little lamp, until such time as we can say "Naw, culdn't possibly be that, for this that, and this reason".  Jaicen Solo's comments about the bulb biases used for Woodstock and Isle of Wight has some serious substance to it, though.

I don't consider this to be one of life's great mysteries, but my buddy Norm is a serious Hendrix-o-phile, so I told him I'd try and learn more on his behalf if I could.  And if his assumptions about line power differences being the basis for what he hears is incorrect, then it would be good to....ahem....rectify that (  ).  This is, after all, how rumours start on the net, right?

[Jaicen_solo]

I can understand that the line voltage may have an effect, because the Univibe originally had half wave rectified PSU's, and the LFO is driven off whatever that comes to if the same transformer is used. However, wouldn't the UK spec units have appropriate step down transformers to output 24v anyway?
At the time, continental europe was using 220v, and the UK 240v, so there is a potential difference there of 28v on the secondary assuming the same transformer is used.

[Earthscum]

But what about the line frequencies? Even if you cut your line in half, the ripple is still going to appear at a different frequency in Europe than in the U.S. That might play into this.

[R.G.]

Having watched people build Neovibes for - what? over a decade now? - with all kinds of light bulbs, all kinds of LDRs, all kinds of power supplies, weird parts substitutions, whatever; and having fixed a number of real, made-in-the-factory Univibes, which varied a lot, I personally think that squinting fine differences in Univibe tone from recordings and whatever else is a losing proposition. Univibes vary. A lot. Attributing a specific 'vibe sound to the prevailing line voltage or frequency is a real stretch, I think. I could be wrong, but I believe there are many other things that make a lot of difference.

Like especially those 5% or 10% mixing resistors in the mixer, the tolerances of the series 4.7K resistors between stages, the LDR responses, tolerances of the phasing caps, and several others.

The Univibe was current at a time before we had evolved several more generations of ever-more-sensitive rumor mills and cork-sniffing equipment.

There are real differences in sound. It's just that people want to attribute them to things that they personally know about, just like people used to think that the alignment of the various planets and stars affected whether they'd get hangovers or should invade the neighbor. People find patterns in everything. Even the best randomness we can find or make up.

There *are* differences. But how would you ever really be able to tell if it was the line voltage or instead an odd run of resistors in the factory that week?

[Mark Hammer]

I'm with you on that.  Just figured I had to ask, and will pass this on to my buddy.  If he comes back with anything that suggests it deserves closer scrutiny, I'll surely raise the matter again, but I'm inclined to think that, even if we do have habeus corpus (i.e., clearly audible differences from recordings), the crime will not be solved.  So as far as I'm concerned, the file is closed.  This cop is going to bed.

[petemoore]

  Univibe has a mix knob.
   The next time 'a Hendrix like Jimi' comes along, we should provide free of charge a knob settings recorder, shows where the knobs on all the equipments were set at any time.

[Johan]

the line voltage used to vary quite a bit through out Europe. from 220volts here in Sweden to allmost 250 in other parts ( as I understand it). if the powersupply was unregulated, the bias for bulbs and transistors would vary throughout a European tour. if it was audible I am not qualified to speculate on since I never built, played or even looked inside one
Sweden raised the line voltage  to 230volts mid-90's to comply with EU directives...Europe is also 50Hz, wich played cruel tricks one some northamerican bands bringing their Hammond's and leslie's over on tour..
J

[Meanderthal]

 I think Pete's got a good point. Who can tell where the knobs were set? Or how intense of an effect the producer(Jimi? Chas Chandler? I dunno who) wanted at the moment.