Fender Bassman heads... Do they sound different due to iron used, year to year ?

[Chevy]

I'd like to get a good sounding 50W Bassman head. Can afford a silverface version at the moment. Can do any mods or tweeks necessary on the circuit board end of things fairly inexpensively, but am wondering if perhaps they cheaped out on the transformers or something in later years, and this would affect the tone of the amp negatively. Currently looking at a 1972 head in good original condition.
In other words, would a '72 head sound pretty much the same as a '68 head from the perspective of the transformers used? Or should I wait for a good '68 ?
Thanks much,

[Enzo]

Ask yourself a couple of questions. If we had two identical amps side by side with different Fender transformers, could we hear a difference? Now come back tomorrow and someone picks just one of them, and plays it hidden from you. Do you think you would know which it was?

My own prediction would be in the first question, maybe you could. In the second question, I'd think probably not, it will sound like a Bassman no matter what.

[olddawg]

I would say that if you like the way it sounds and you like the price get it. He old axiom always applies as well. "Tone is in the hands". You will sound like you no matter what you play. Some people think a magical piece of gear will change that.

[bob p]

If you want to know about the different transformers used on different years, compare the transformer numbers on the schematics and look at the transformer numbers in the amps.

Regarding OT:
I don't think you're going to find any huge differences in transformers as you go from BF to SF bassman heads, as most of the time when one model of transformer was replaced by another model, the transformers ended up following the same type of winding recipe -- that is true until you get to the ultralinear bassman transformers. The UL transformers have a different winding recipe, the UL circuits behave differently and they do sound different than their pentode counterparts.

One thing to remember is that most of this "the tone is in the transformer" business is mostly marketing hype from people who sell transformer "upgrades." They can't move enough units selling only replacement transformers, so their business model has evolved into convincing people that to get good tone, they have to rip perfectly good transformers out of their amps and "upgrade" them with expensive replacement parts. When that happens, the smartest guy in the room is the guy who's buying the used take-offs at a bargain price.

Regarding PT:
There may be some significant differences from year to year, specifically in those years when B+ voltages changed. A significant change in B+ voltage will change the tone of the amp.

[Chevy]

OK, thanks guys... spot on, Bob P...
I was assuming there were some model years of some amps that would stick out and perhaps rate poorly or whatever, but that doesn't seem to be the case for this instance. thanks for the input.

[blindboybenton]

My Opinion is that you have 2 amps side by side you will/May hear difference between them, But more likely due to the age and some components aging more in others. This will change the tone i think, more than the transformers. But my hearing is shot.
i don't hear any small tone changes these days.
bbb

[soundmasterg]

With the smaller Fender amps that used tube rectifiers, the power transformers changed when they went from the GZ34 to the 5U4. Since the 5U4 drops more voltage they had to wind the power transformer to supply a higher voltage on the B+. I'd have to check the numbers on the output transformers to see if they changed or not, but you can easily check that yourself too. The bigger Fender amps like the Twin Reverb, the Showman, and the Bassman heads use solid state rectifiers, so as BobP said, unless they changed the voltages, the transformers are probably the same. The circuits did change over the years but that can all be changed pretty easily. Keep in mind that many of the SF Fender amps had poor wiring when they were made so if you change one over to reflect the BF circuitry, you may have to re-do some of the wiring to stop oscillations.

Greg

[J M Fahey]

Thanks God, Fender never ever skimped on transformers, always rated them properly and used the best.
I'm talking classic USA made Fender, of course.

I have rewound some along the years, but the OT because of some gross overload such as driving them full tilt without speaker (the musician strumming *loud*, all knobs on "10", while muttering "what may be happening"?) and the odd PT because something shorted and was "repaired" with a nail/aluminum paper turd/30A car fuse.

Excellent quality all of them, specially the Blackface/Silverface era.

[Joe L]

I have a '64 BF and a '68 SF and I can tell you that both have good iron. Only having a four ohm output tap can be problematic, but they have sounded great with any Fender style circuit I have stuffed in them. I even used the '68 as a donor chassis for a Mesa Mark III as my first build way back in '86.

[wizard333]

5U4 draws more heater current than a GZ34, which is probably the reason behind the size change. They did not try to hold B+ constant with different rectifiers. Also, many Fender models that spec'd both over the years seem to use the same PT with either rectifier specified.