BF Super Reverb aa763 Normal Channel -- how to increase headroom?

[pdf64]

Robrob's site explain's it https://robrobinette.com/5F6A_Modifi...eedback_Switch to quote
When changing the feedback source from one output transformer secondary to another you change the feedback resistance by a factor of 1.41 for one step change ( for example going from a 2ohm speaker tap to 4 ohm)

[Dave H]

All this faffing around... THERE'S your problem, unless your 2x12 is a pair of 4 ohm speakers in parallel.

It won't make any difference will it? As long as the speaker impedance is matched to the OT tap to give the same load to the 6L6s as the Super Reverb does then the clean output power should be the same.

[Jazz P Bass]

I don't get it.

It's a 50 watt amp.

Even if you sqeek a few more volts out of the output before breakup, will it make a discernable difference?

[Dave H]

I don't get it.

It's a 50 watt amp.

I don't get it either It will produce the same power (50W?) using either the 2 ohm tap or 4 ohm tap even if the feedback resistor isn't changed.

[gui_tarzan]

I get the speaker recommendations, what about trying some other output tube types or different models of 6L6?

[mort]

This thread has gotten all wackered out of shape. I thought "headroom" was tweakable and was just asking how to do it and got bombarded with semantics about the term "headroom".

I'm beginning to wonder if the word "headroom" also has some sort of anatomical meaning as well.

[Jazz P Bass]

I played bass guitar in a small room gig the other night through a Fender Bassman head.

I could not get above 3-4 on the volume knob without it breaking up.
(tones at the middle)

And, you guessed it, it was putting out 50 watts.
(I measured it at break)

[mort]

I've learned some things in this thread, so it's not a total farce. A big part of electronics, as with any field I suppose, is learning what's possible and what's not possible. Up until recently I had really only done paint by numbers style of amp building with some debugging and general troubleshooting. I haven't done much experimenting or modding. In a big way I'm at the bottom of another curve. Joy.

[Dave H]

This thread has gotten all wackered out of shape. I thought "headroom" was tweakable and was just asking how to do it and got bombarded with semantics about the term "headroom".

Yeah, that's unfortunate. We should all agree not to use 'headroom' ever again on the forum It only causes confusion but what do we replace it with? I like loudthud's “I want it to be louder before it breaks up” because it has no mention of “volume” which could be taken to mean the vol pot setting. Unfortunately “I want it to be louder before it breaks up” is not easily tweakable on your amp.

[mort]

"I want it to be louder before it breaks up" certainly captures the intention. But it doesn't roll off the tongue well, so to speak: it doesn't type well. Maybe there should be a code word that condenses the writing a bit. Like maybe... clean balls. Amp needs more clean balls. Kinda works

[Dave H]

"More clean balls" it is then. It's more rock and roll

[J M Fahey]

Short answer is that you have what you have and to go significantly higher you must drop it and start again on a clean sheet of paper which of course is completely out of the way.

That said, take what your customer asked with a grain of salt.

As in: I'm *certain* that when playing live the amp will be too loud, besides any slight crunch will be absolutely lost in the big furry ball of sound, meaning everybody else sharing the stage with you, plus audience noise, sound bouncing all over the place, etc.

Give the customer his cool amp, loved the project, and tell him to *use* it and if any, comment in a Month.

Not earlier, because he will be in the middle of *his* learning curve.

And in 10 years he'll swear by it, annoy others singing praises and telling everybody you da'best !!!!!!

Trust me

[pdf64]

Has the amp's output been measured and scoped?
It sounds great but it can be very beneficial to verify these things.
If you're scopeless, Juan has a great trick to turn any pc with soundcard into one.

[überfuzz]

This thread has gotten all wackered out of shape. I thought "headroom" was tweakable and was just asking how to do it and got bombarded with semantics about the term "headroom".

I'm beginning to wonder if the word "headroom" also has some sort of anatomical meaning as well.

It was the costumer asking for more 'headroom', right. I guess you just have to put up a sign: Don't use the term headroom, the proper term is Clean Balls.

[ThermionicScott]

"More clean balls" it is then. It's more rock and roll

There ya go. Amps need a "Balls" knob that ranges from "Clean" to "Dirty".