less harmful thread - which bassman circuit for mod?

drew_half_empty

drew_half_empty

Looking for Real Life
well, i got the 100 on the way, and the 50 would be loud enough if i actually USED it for its distortion, which right now sounds like crap, so...help me pick a mod & i'll be your friend forever

what i want is, well, some really tweed/blonde sounding crunch

like if you listen to reverend horton heat, or brian setzer, or the heavy strat demo on proguitar.de well, thats basically the ammount of crunch i want, with the amp like maxed out. If i need something thicker I can just get a tubescreamer.

But i'm also told that i don't wanna blonde or tweed the power section cuz they were...not really all that loud. And as for the RI's well, i dunno how the controlls are set on proguitar.de, but i imagine they weren't maxed out, which is what i want, that light twangy crunch on like "9" or "10"

so, what's the verdict? Some tube reccomendations would work too, though i think my guitar teacher is hookin me up with some NOS stuff
 
Re: less harmful thread - which bassman circuit for mod?

perhaps lew will chime in, he knows plenty of tricks and tweaks such as swapping out certain tone capacitors in the tone stack, reducing the negative feedback loop for earlier more tweedish breakup, etc.

I do know that if you want less harshness in your tone, get NOS mallory tone capacitors, and since it's a silverface, I'm sure it wouldn't hurt it's value to put a presence knob wired to the negative feedback loop so you can have full control of it.
 
Re: less harmful thread - which bassman circuit for mod?

yeah, i was thinking about turning the master volume into either a gain or presence control, but eh...i dunno, it's kind of a nice feature to have when you're playing with pedals, and in the studio if i need pedals i think a 50 watt would work better than a 100, I only planned on modding one of the channels, but, well, maybe i can have jeff wire in a half power switch...or just pull some tubes or something on the 100, I guess that'd be more realistic
 
Re: less harmful thread - which bassman circuit for mod?

I don't know how difficult it would be to convert yours to Blackface specs, but I think it would be worth it.

My Black Face Bassman Export sounds killer when driven.


BTW, I can't speak highly enough about the current Electro harmonic 6L6 tubes.

After playing them back, to back, to back with my NOS RCA blackplates and my buddy's NOS GE 6L's, We both liked the EH's better than ither the RCA's and GE's.
:burnout:
 
Re: less harmful thread - which bassman circuit for mod?

dude, RCA blackplates are the friggin holy grail of power tubes, I feel like i've jsut been shot

anyhoo, which circuit does it sound like i'm after?
 
Re: less harmful thread - which bassman circuit for mod?

AA864 if im not mistaken...the holy grail of BF bassman circuits.....

It seems to me that the pre '65 fender amps that didn't have reverb, or a circuit that was based on one that had reverb had a more tweedish/blonde vibe to their power stage. Mine is an AA763 and its power stage sounds amazing, and I'm using Mesa tubes!!!??? When i throw in some real tubes it will sound even better with a good bias setting.

See if you can make that sucker an AA864, it will surely rip. If I were you, I'd turn the master volume control into a presence control, if you're really serious about being able to dish out more tweedish/blonde tones, and having control of negative feedback.
 
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Re: less harmful thread - which bassman circuit for mod?

The 6G6-B circuit (with the presence knob) Is the holy grail of BF Bassman
IMHO. I sold mine like a Dope :smack:
 
Re: less harmful thread - which bassman circuit for mod?

well, like i said i'm looking for a very light setzerish crunch

and he plays a '61

so i suppose...well, what circuit is that?

Right now, rockabilly tones are most important to me, i can do the blues thing with the other channel some other time, like...when i play more blues, heh
 
Re: less harmful thread - which bassman circuit for mod?

On my Hotrodded '59 Bassman, I have a control added that allows you to vary the amount of negative feedback. It goes a LONG way towards making the sound more complex. As you turn up the control, the amount of negative feedback in the loop decreases. New harmonics creep into the tone while the mids take on a rawer presence. It's awesome for making strats and p-90s sound more badass, especially at low volumes.
 
Re: less harmful thread - which bassman circuit for mod?

...you mean a presence knob?

and can someone explain the difference between 6g6-a & 6g6-b to me?
 
Re: less harmful thread - which bassman circuit for mod?

As far as I know, there is no 6G6-B circuit, only a 6G6 (without letter) and a 6G6-A which is the one I have in my early 1962 blonde tolex Bassman head. The main differences to the earlier 6G6 from 1961 are the solid state rectifier instead of a tube and the changes in the Bass channel concerning the missing 2nd negative feedback loop in the '62 model which makes it sound like a tube limiter when pushed. By the way, you can read up most of this stuff in the "Fender Amps" book by Teagle & Sprung.
 
Re: less harmful thread - which bassman circuit for mod?

yes there is a 6g6-b

but since you have the 6g6-a, can you sort of describe how it sounds? If you wanna compare it to like a ab165 or '59 ri bassman that'd prolly work out the best. How much gain does it get?
 
Re: less harmful thread - which bassman circuit for mod?

Do you have a link with a diagram or other description about the 6G6-B version (difference to 6G6-A for example)? I looked up the Groove Tubes and Fender Amps books, but couldn't find that circuit design.

Concerning the sound I don't know who told you that a blonde tolex Bassman would not be loud enough, especially its power amp stage, because that's actually the most impressing part of its unique sound. Mine is an original export model, and the power transformer, rectifier and capacitors deliver a plate voltage that exceeds +500V when the bias is set up the standard way. I either connect it to one half of my old 4x12 Marshall cab with 2 greenbacks (8 ohms) or 2 G12 H30 (4 ohms) or use all four Celestions which is a total load of ~2,67 ohms then. It's important not to use a 16 ohms Marshall cab when testing, because the output transformer will react to that load, i.e. the sound will be rather compressed and scratchy. But if you use a similar speaker setup, it will sound very huge, stable, with a lot of headroom, actually quite scary for faint-hearted band mates or amp testers. ;)

By the way, the presence knob is the most important control of this amp, so you should definitely add one in your mod. It's actually the only knob I touch on my amp now and then to adjust the overall "bite" to another guitar or the different speakers. At the moment I'm only using the Bass channel for both my Tokai Les Pauls and a Strat, volume at 10, treble and bass at zero (which would be the same when using the Normal channel). That way I have enough gain and mids to play rhythm and lead parts in our ZZ Top cover band, and I turn down the guitar volume knob to change between these parts and/or simply hit the strings a little softer/harder.

Re: the other Bassmans you mentioned I might add that I tested quite a lot of them in the past (and other old amps, too), but usually they didn't have a chance against the 6G6-A (sound- and volume-wise), that's why my guitar buddy also bought one some time ago.
 
Re: less harmful thread - which bassman circuit for mod?

Thanks for the link, I'll have a closer look at it when I have more time. By the way, mine rather looks like the picture of the 6G6 on the previous page, i.e. maroon grille cloth, brown front plate, rough white tolex (before some dumbass painted it black), "dog bone" handle. And I should mention that I changed the bias circuitry to be adjustable.

Concerning available gain the '59 Bassman also has the same four-stages preamp design in the Bright channel, but with an additional middle control which I don't like, because it behaves differently than the simple treble/bass circuit. Like I mentioned before, the missing negative feedback loop in the 6G6-A compared to the 6G6 lets the preamp produce some really sick sounds if you crank the Bass channel too much, e.g. with treble above 5 and volume above 7. So that would be definitely more gain than the '59 Bassman, but not very usable or only for extreme cases. I think Brian Setzer likes to twist his knobs towards that direction once in while, too, but his normal crunch sound isn't a problem for that amp either of course.
 
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