Fuzzrite in amps...

[Brinkman]

Nokie may indeed be correct that Red Rhodes designed the Award version but I need a little more verifiable information than that. It's not a strong enough premise for me. Hence, I don't yet consider the schematic for the FuzzRite given in the Award amp as a Red Rhodes design. I don't know that Red Rhodes himself ever took credit for designing that one.

Yeah, I agree something more conclusive would be nice. Though I'm not sure that Red taking credit for creating the fuzz unit is actually any more verifiable than Nokie saying as much. A lot of this stuff is anecdotal, including the rise and fall of Mosrite. I doubt there's even verifiable proof that Sanner even designed the Fuzzrite circuit attributed to him .

The only verifiable thing I've seen along these lines is the Glen Snoddy fuzz patent that became the Gibson/Maestro FZ-1 (filed May 3, 1962, granted Oct. 19, 1965). Beyond that, there's the Tone Bender in the UK which was, according to the internet, more or less a modified version of the FZ-1. At any rate, neither of their respective schematics have much a commonality with the Award fuzz circuit. This seems to have been unexplored territory at the time, as some of the unconventional implementations would suggest. So I suppose the question remains: Whomever engineered the Award amps in 1966, would they even know how to tailor a satisfactory fuzz effect or would they simply copy a proven and desirable (and unpatented) circuit as Nokie has stated? And if it was the Rhodes circuit they were using, was Red even aware of this?

Yeah, it is pretty subjective. But not subjective enough that I would suggest the differences between the Red Rhodes fuzz effect and that of your typical Sanner Fuzzrite are indistinguishable to the ear.

The FuzzRite that appears in the Award Amp sounds to me very much like a pedal FuzzRite though I'll agree that the two are not completely indistinguishable.

Sorry, I wasn't being very clear here. While I completely agree, I was actually referring to all the pre-'66 Ventures' recordings with fuzz and before them, the Ann Margret track "I Just Don't Understand" (1961) featuring Billy Strange equipped with a Red Rhodes fuzz unit.

[Brinkman]

My above speculation aside, I was wondering if any you lucky Mosrite Award amplifiers owners would mind checking on something the next time you look inside one: if you could take a peak at the FUZZrite PCB, could you also check over the two 2N2926 transistors for any sort of colored markings (ie., paint smudges on the top of either brown, red, orange, yellow or green)? You might have to rub off a little grime as it's probably a little dusty in there. If that doesn't work, a dab of rubbing alcohol (lightly) applied with a cotton swab ought to do the trick.

If any of you guys see anything along these lines, it would be really cool if you could let us know!

Thanks.

[Nokie]

My above speculation aside, I was wondering if any you lucky Mosrite Award amplifiers owners would mind checking on something the next time you look inside one: if you could take a peak at the FUZZrite PCB, could you also check over the two 2N2926 transistors for any sort of colored markings (ie., paint smudges on the top of either brown, red, orange, yellow or green)? You might have to rub off a little grime as it's probably a little dusty in there. If that doesn't work, a dab of rubbing alcohol (lightly) applied with a cotton swab ought to do the trick.

If any of you guys see anything along these lines, it would be really cool if you could let us know!

Thanks.

And those smudge marks would be significant becaaaause...?

[Mr. Bill]

The color dots were sometimes used to sort transistors by gain ratings, so that a manufacturer could assume that a yellow dot or a green dot transistor would work in a particular circuit.

[Nokie]

The color dots were sometimes used to sort transistors by gain ratings, so that a manufacturer could assume that a yellow dot or a green dot transistor would work in a particular circuit.

Thanks for the further details, Mr. B. If we suppose that I find a yellow dot on the transistor within the FuzzRite circuit, for example, I'm not clear on how that info is of value to someone other than the original mfg'er. If you're saying it is a standard color code like those we see on resistors, then I see the value. But I think you're saying the amp mfg'ers labeled transistors that way in which case a yellow dot would mean something different depending on who applied it. -Marty

[Mr. Bill]

There is no standard color code for trasistors that I know of. Some of the generic replacement companies will specifically list colors in their substitution guides, but more often than not the same substitute number will cover an assortment of color types.

So yes you are correct in that the color code is probably meaningless in modern times, except as a historical fact.

[Brinkman]

And those smudge marks would be significant becaaaause...?

The color dots were sometimes used to sort transistors by gain ratings, so that a manufacturer could assume that a yellow dot or a green dot transistor would work in a particular circuit.

Thanks for the further details, Mr. B. If we suppose that I find a yellow dot on the transistor within the FuzzRite circuit, for example, I'm not clear on how that info is of value to someone other than the original mfg'er. If you're saying it is a standard color code like those we see on resistors, then I see the value. But I think you're saying the amp mfg'ers labeled transistors that way in which case a yellow dot would mean something different depending on who applied it. -Marty

The colors, while having no fixed nominal value, do follow resistor color band order with respect to representing increasing values. Just to be clear, it was transistor manufacturers, not amplifier manufacturers, who categorized betas within a specific transistor model.


It's too small to read, I know. Here's the pertinent info:
2N2926 transistor, hFE 35-470
BROWN - hfe 50
RED - hfe 74
ORANGE - hfe 135
YELLOW - hfe 225
GREEN - hfe 350

I've corroborated this with multiple datasheets from the datasheet archive (were color-codes are specified). One datasheet describes the 2N2926 transistor as such: "Five distinctly color coded AC Beta (hfe) groups, each with 2 to 1 spread, non-epitaxial."

I had initially included this info in my last post but figured I was probably belaboring the point if it turned out no one was compelled enough to look inside their amp in the first place. Regardless, I was aiming for a comparatively less-intrusive method of ballparking hfe than pulling the transistors and measuring them out-of-circuit.

[MWaldorf]

Well, I can't follow all of what's being said, and I don't have an Award amp, but I think this is cool as all get out.

[Mr. Bill]

Great bit if information there, the gain figures increase like the standard colors. I never looked into that before. I can't read anything on the chart, but is this true of all manufacturers? Was this an industry standard? What company's chart are you showing there?

I don't think that color coded transistors were all that common in guitar amps. The only ones that I'm sure had them were the Thomas Organ Vox amps.

[Brinkman]

Well, I can't follow all of what's being said, and I don't have an Award amp, but I think this is cool as all get out.

Mel, "Beta" (aka hfe) is simply the typical gain factor of a transistor, either listed as a range or minimum. In the case of the transistor under consideration, that range is pretty big (35-470). So big that if one of them had to be replaced you could not be certain the replacement would not alter the behavior of the circuit audibly. What we are discussing is evidence that this transistor (well, some of them at least) was actually pre-sorted and marked according to it's measured gain before being distributed and sold.

Great bit if information there, the gain figures increase like the standard colors. I never looked into that before. I can't read anything on the chart, but is this true of all manufacturers? Was this an industry standard? What company's chart are you showing there?

All my info is from the 2N2926 page at the datasheet archive.

The "Five distinctly colored..." quote was off a GE datasheet from 1971.

Sprague gives a better range in their Semiconductor Data Book from 1977 (second page of the pdf). Notice the overlap in gain "ranges":

hfe color code:
Brown 35-70 Red 55-110 Orange 90-180 Yellow 150-300 Green 235-470

Note that the numbers used in my last post were the median values for each range.

The ZaeriX (UK) catalog page below that repeats the same ranges. Dates from 71/72.

According to this page, Motorola had their own color and letter code to indicate Beta (hfe). However, the Motorola datasheet I've seen for the 2N2926 doesn't specify any subcategories.

And yet another vintage datasheet (manufacturer unknown) not only lists the 2N2926 with letter suffixes indicating color (eg 2N2926-R), but also five respective numerical suffixes (eg, 2N2926-2). In each case the hfe divisions are consistent with those above, though the colors are listed in terms of their hfe range minimums.

To complicate matters, we have no way of knowing how many 2N2926s were distributed without any markings at all. If unmarked 2N2926s comprised the bulk of those distributed at the time, I wouldn't be surprised if the internals of the Award amps reflected this as well.

Not sure what to make of all this. Perhaps this was a convention that was introduced for transistors with extra-wide-ranging Betas that never caught on? Was this a failed attempt to market the 2N2926 as a sort of "universal substitution"?

Whatever the reason, I suppose the failure of the convention to become widespread doesn't make it any less true for our purposes.

Sooooooo......... who's gonna go look inside their amp?