tube change in my 59 bassman ri?

[stonabus]

what can i mod in my bassman?
i was thinking about seeing what else i can get out of this awesome amp. i dont think im going to take the ss rect. out. i like how it distorts at high volumes.

i searched here and fenders forum but didnt come up with much..... all i have done is the channel jumper thing.

im just curious as to what kind of a tone change i can do.

is there such a thing as a tube swap without re-biasing?
:dunno:

sorry for the dumb ?'s

 

[the guy who invented fire]

Re: tube change in my 59 bassman ri?

What do you want to make different?

What tubes are you running in the preamp right now?

 

[stonabus]

Re: tube change in my 59 bassman ri?

What do you want to make different?

well, thats where im going to reveal my amp modding noobness, i dont know what tubes do what.... so i guess i need to know what tubes i can swap without rebiasing (something that i dont know anything about)

What tubes are you running in the preamp right now?

stock.... lemme look.....
SAR4
6L6GC
6L6GC
12AX7
12AX7
12AX7


thanks

 

[stonabus]

Re: tube change in my 59 bassman ri?

they are stock.... the 6L6GC's are groove tubes.... the 12AX7's are blank...
thanks

 

[the guy who invented fire]

Re: tube change in my 59 bassman ri?

Ok, the 5AR4 is the rectifier tube which does not need to be biased but you said you are using the SS plug in right?? The 6L6GC's are the power tubes and have to be biased, the 12AX7's are the pre amp tubes and do not need to be biased.

You can change the voice of the amp a good bit just by playing around with the preamp tubes. The original 59 Bassman amps came with 12AY7's in the preamp which will give you a lot less gain than the 12AX7 you are using now. Just so you know you can swap a 12AX7, 12AT7, 12AU7, 12AY7, and a 12AZ7 all for each other without any mods at all. All of those tubes I mentioned have different amounts of gain, a 12AX7 is the highest but different brands and makers of tubes have different 12AX7's some with higher gain that others. I would get all new tubes and have the bias set. Without modding the amp you cal also use 5881 power tubes which will give you a little more breakup and a tad less power, the 6L6's like you are using now generally have more clean headroom and make a little tiny bit more power.

Now that your mind is trying to catch up to all that junk, what do you want out of the amp...more headroom, more sag/sing, more gain, less gain???

 

[stonabus]

Re: tube change in my 59 bassman ri?

wow, thanks for that! gimme a sec....

edit: long story short... tighter low end and warmer top end. big and fat.. is milky a tone term?

p.s.

whats this? does it require a re-bias?

 

[the guy who invented fire]

Re: tube change in my 59 bassman ri?

That is a set of JJ Tubes and the power tubes woudl require setting/changing the bias. You could go with the JJ's if you want but I liek to mix and match brands to get the tone I want out of an amp...

If you want to keep a tight bottom end stay with 6L6's and for suggestions I really like the Svetlana's, the Sovtek 6L6WXT's and the tall botle TAD 6L6's are great too, for preamp tubes I can't say enough good things about the new Tung-Sol 12AX7's, great/solid lows and smooth highs as well as a good bit of gain and they are pretty low noise too. Another good 12AX7 is the Electro Harmonix, I also like the Sovtek 12AX7LPS and the JJ's get rave reviews but I have never tried them.

Have a blast, and good luck!

 

[stonabus]

Re: tube change in my 59 bassman ri?

...low noise...

thats a concern for sure.

thanks for the info!

 

[Gearjoneser]

Re: tube change in my 59 bassman ri?

I'd probably buy another set of GT 6L6GE's. Then buy one good pre tube for the 1st position. If you want to add reverb, bridge the 2 channels with an EH Holy Grail, so you're mixing in bass and reverb with the normal channel volume.
Get something like the Fulltone 10th Anniversary Mosfet Fulldrive II.
You'll be suprised at how awesome it all becomes.

 

[stonabus]

Re: tube change in my 59 bassman ri?

I'd probably buy another set of GT 6L6GE's. Then buy one good pre tube for the 1st position.

cool. where can i get some 6L6GE's?

i just ordered some of these. i cant wait. i heard good things about them.

gearjoneser, if i order some 6L6GE's can i just drop them in? the sticker on the inside of my amp says that they are GT6L6GE. but i pulled them out and they are GT6L6B
thanks.

If you want to add reverb, bridge the 2 channels with an EH Holy Grail, so you're mixing in bass and reverb with the normal channel volume.
Get something like the Fulltone 10th Anniversary Mosfet Fulldrive II.
You'll be suprised at how awesome it all becomes.

i like this idea. bridge both #2's with the pedal? or one channels 1 and 2?

 

[baritone]

Re: tube change in my 59 bassman ri?

TheTubeStore.com has a lot of cool information, also. I like Electro-Harmonix tubes for my amp.

 

[jeremy]

Re: tube change in my 59 bassman ri?

plug the guitar into bright 1, run a jumper into the reverb then out to normal 1. as you bring up the normal volume youll get a fatter tone with reverb. i do this trick with a fender reverb unit and it works great.
i use the small bottle tad 6l6's which are fairly similar to the gt6l6ge which are some very nice new production tubes.
i used to have one of these amps and i put a nos mullard in v1 and a very hot balanced gt12ax7m in v3. i biased the amp by ear and then tested it, 44 ma was the sweet spot for me.

when you run the volume high (i liked both channels at about 9) make sure to roll the bass way down to keep the bottom end tight. even with the bass control on 1 youd be supprised how fat the tone is in front of the stage