Perfect amp? A 35 watt small 5f6-a?

dreamingtele

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So, I think I want to (with massive help from others) design a 35 watt, either 2x10 or 1x12 tweed Bassman/HP Twin.

I know it won't have the 4x10 spread... But, this is more of a grab and go, or small gigging amp. Something light, relatively compact, but enough juice to get over my saxophone player (We all adjust to his volume). I am contemplating adding bias vary trem... But, not so sure about that just yet. Might keep it simple?

I guess I could go with one of the mid-powered tweeds... I mean, they kinda do what I'm asking about here, but they are different. I haven't really studied the circuits yet, but I do know they are different... And, I love my Bassman (and HP Twin).

Anybody wanna help me find a schematic, or help me design something like this?

But, the other part of this post is to find out what you think YOUR perfect amp would be? Is it small wattage, big wattage? Multiple speakers? Reverb and trem?

There’s an amp builder here in Australia, who does a small Bassman-inspired amp. His name is Darryl Hoy, and his company, Valvetone

It’s just 25 watts, solid state rectified. 1x12AY7, 2x12AX7, 2x6L6GC

I had it for a while and it’s very good. Tweed goodness. I like my Tweeds, its my favorite amp style/tone and this delivers in a small, light package with some punch.

Untitled by D Y, on Flickr

Untitled by D Y, on Flickr

Untitled by D Y, on Flickr

Untitled by D Y, on Flickr

Point to point wiring too. (This is not the bassman amp, but just an example)

images
 

cousinpaul

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My favorite is the 5E6A. I acquired mine in '69 and it was my main gigging amp for 25 years or so. Eventually had to move it on because the kids needed something. I'm currently playing a ProLuxe set up with cathode bias. Nice Amp but not the same.
 

2L man

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Very good looking circuit construction!!!

It has only one input jack but dark and bright potentiometers. Is there channel switch or do both pots effect one input?
 

dreamingtele

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Very good looking circuit construction!!!

It has only one input jack but dark and bright potentiometers. Is there channel switch or do both pots effect one input?

Both pots affect one input. Kinda like the channels are bridged and are always active.

I dial in my preferred sound and volume using the bright preamp volume, and then add the dark for oomph and some more bass.

Then crank the Master for really clean tones. Works great.
 

JohnnyCrash

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The resonance thing I'm suggesting is really just adding some spice, more than anything.

I have an old Marshall 2204'ish build that I've had a sort of love/hate thing with over the years, and I recently reverted the whole thing as close to factory stock as possible, and then did a supposed (but I think unofficial) 'Jake E. Lee' mod to. This particular mod caught my eye because it didn't really look like anyone was trying to add more gain - they were more just sort of moving around what parts of the EQ spectrum each gain stage was pushing or attenuating...

...Long story short is whoever came up with the mod was probably trying to make the amp brighter & less bassy at the first gain stage, and then attempting to bring the lows back in at subsequent stages. This included what's a popular addition for modded Marshall amps - resonance, to accompany presence. It adds the lows back in on the back end, which IMO is probably the smartest place to do it.

I don't run my 2204 really hot or gained up, so to speak, so the 'extra garlic' of the resonance has actually worked out well - puts a little extra thump in there, where a more stock 2204 is just punching in the midbass or lower mids (especially with just a 2X12, as my 4X12 cab days are now done).

The 2204 IMO is kind of a descendant of a 1987, which is kind of a descendant of a JTM45, which is sort of a relative of a 5F6-A, so I have no doubt that this little resonance trick would work in it, as well.

Loosely related - I was looking at a schematic of the Peavey Classic 30 the other day, and lo and behold - it's got hardwired resonance in it! It's C37 and R56 in the schematic, if anyone wants to Google the schem and take a gander. It's VERY easy to add resonance to amps that have presence circuitry in them, especially if it's a non-PCB build.


One of my go to amps is a 2x10” 2204 that I hardwired a resonance cap into the NFB.

That is probably the best mod for that particular circuit (which cuts bass and adds treble peaking caps all over the place to get that gnarly grind, but this means it’s a little bass light at lower volumes).

However, I’d also suggest it for any Marshall-ish or tweed Bassman-ish circuit where you don’t have four speakers or a closed back cab.

It adds some body and kaboom.
 

Gris

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I think you are on to something. I have had or still have all the amps you could ever want. And the one I like most? My 5F6A with multi tap OT. It’s set up 2x12 but I use spade clips so it’s easy to just switch to one spkr & plug in to 8 ohms instead of 4…
 

63 vibroverb

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How about fitting a JTM45 into a 1x12 combo? KT66 tubes and radiospares-style trannies for the beautiful cleans, change any resistor/cap values if needed for more "5F6A"-ness. Choosing the right speaker for that setup would be fun....

At 30 watts, really no need to create another circuit.
 
Last edited:

PCollen

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So, I think I want to (with massive help from others) design a 35 watt, either 2x10 or 1x12 tweed Bassman/HP Twin.

I know it won't have the 4x10 spread... But, this is more of a grab and go, or small gigging amp. Something light, relatively compact, but enough juice to get over my saxophone player (We all adjust to his volume). I am contemplating adding bias vary trem... But, not so sure about that just yet. Might keep it simple?

I guess I could go with one of the mid-powered tweeds... I mean, they kinda do what I'm asking about here, but they are different. I haven't really studied the circuits yet, but I do know they are different... And, I love my Bassman (and HP Twin).

Anybody wanna help me find a schematic, or help me design something like this?

But, the other part of this post is to find out what you think YOUR perfect amp would be? Is it small wattage, big wattage? Multiple speakers? Reverb and trem?
... if you go the 2 x 10 route, why not the 5F4 Super ? You can find 5F6-A schematics all over the internet. Google : 5F6-A schematic.
 

Axis29

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... if you go the 2 x 10 route, why not the 5F4 Super ? You can find 5F6-A schematics all over the internet. Google : 5F6-A schematic.

I've contemplated building a Super/Bandmaster/Pro for years.

But, they are different. I spent a short amount of time with one of Fender's 57 Twin reissues (which is the next step up in that particular circuit lineage). I liked it... But, not sure why, just not as much as my Bassman. It was a feel and tone thing. Close, but just not the same feel.

It might be that a lower wattage version of that sound might be a better fit? Dunno.... Always wanted to spend some real time with one.
 

Gris

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Dunno what the circuit difference is, but I like the brown Vibroverb better than the brown Super.
 

King Fan

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I love my 5G9, and the tone and trem are to die for, but if I wanted to gig against a sax or a loud drummer, I doubt it would work. Hard to find a lot of good sound samples, but I've seen others comment it's a great amp for a small blues club, not the loud gig scene you describe.

Now, sorry, I may have missed it. If you really want a smaller 5F6a, what about one built to run 6V6s? Say 2x10 or even 4x8 Neos? Rob has info on his 5F6a mods page, and some smart folks chimed in on this TGP thread (tho I can't vouch for any of it myself).

https://www.thegearpage.net/board/index.php?threads/5f6a-with-6v6s-and-deluxe-reverb-ot.1598934/
 

Wally

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I've contemplated building a Super/Bandmaster/Pro for years.

But, they are different. I spent a short amount of time with one of Fender's 57 Twin reissues (which is the next step up in that particular circuit lineage). I liked it... But, not sure why, just not as much as my Bassman. It was a feel and tone thing. Close, but just not the same feel.

It might be that a lower wattage version of that sound might be a better fit? Dunno.... Always wanted to spend some real time with one.

There are differences in the circuit that affect things. The phase inverters are different. The 5E8A has a local feedback as do the 5E5A Pro, 5F4 Super, and the 5E7 Bandmaster. The output transformers are different. The voltages are different.…higher in the 5F6A Bassman.
 

kLyon

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Perfect amp? I don't know if that unicorn exists.
But I'll say this:
A hand-wired AC15 (not the point to point one they make that has no reverb and tremolo, dumb idea...) made out of pine - or something else light so it isn't a boat anchor - would go a long way toward getting there...
 

63 vibroverb

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Just another thought, but how about building a 5F6A 1x12 combo with a switch to go between fixed bias (stock) and cathode bias? Running it in cathode bias mode would knock it down to 28-30 watts and you get the increased touch sensitivity, softness, and lively mids. Switch it back to fixed bias when you need more firmness and headroom.
 




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