Can I replace the 12AT7 tube in the bassman with a 12AX7?

[titser_marco]

well...it's just like those food commercials wherein they exaggerate the picture...hehe

Hmm. How about this pic?



Are these tubes glowing properly? They're from a bassman as well, but the blackface version.

[stratman1]

Another question: Can I just frop in the new tubes on the bassman (2x6L6, 2x12AX7, 1X12AT7) when I get it and start using it? Or do I have to have it rebiased before I can fully use it? Thanks

OK with replacing the preamp toobs in no time.  But with the power tubes, you have to bring your amp for rebiasing.  That way you can optimizeyour new tubes by making them run not too hot or too cold.   Now if you're really excited, try replacing the 6L6s and play with your amp for the whole day while observing the tubes.  They must NOT have any glow in the plates.  Should that be the case, have it rebiased so that they won't run too hot.  On the contrary, if the plates aren't running red but the tone is too bland, chances are your tubes are running too cold.  Again you have to bring it for rebiasing.

korek except that whole glow thing. output tubes do glow but...if skunky means that cherry red almost gonna explode type of glow, yea, that's a bad thing...heheh...

if you're replacing it with the same type of output tubes (same make and model eg Sovtek WXT to Sovtek WXT) it shouldn't be a problem

the bias is basically like the car's idle...it's exactly like that. i mean, your amp will work and all but to rebias it would be like setting the correct idle, like skunky said, for optimization purposes...

Thanks for clarifying that Mark.  Yes, I meant the red glow in the plates as if you were seeing those heaters in a bread toaster.  That is the BAD type of glow.  But under normal circumstances it should be blue, purple or sometimes even very dark.  But what makes it better is the smell of burning paint on the tubes.

So you mean to say those tube amp ads are baloney because they feature tubes that have an orangey glow? Do you have some pics of a properly glowing tube? Thanks

Yeah, the glowing orangey light emminating through the front panel, like the Crate Blue Voodoo, is just a marketing plow. They actually have a 4 small light bulbs and a mirror panel behind the tubes and light bulbs to give it the nice glowing effect. Kinda like the preamp tubes you see in one of those guitar multi effect preamps. Those tubes don't glow that well. If they do then they have some problems in them. You know how it is, shiney things attarcts people, hehe.

[stratman1]

Another question: Can I just frop in the new tubes on the bassman (2x6L6, 2x12AX7, 1X12AT7) when I get it and start using it? Or do I have to have it rebiased before I can fully use it? Thanks

OK with replacing the preamp toobs in no time.  But with the power tubes, you have to bring your amp for rebiasing.  That way you can optimizeyour new tubes by making them run not too hot or too cold.   Now if you're really excited, try replacing the 6L6s and play with your amp for the whole day while observing the tubes.  They must NOT have any glow in the plates.  Should that be the case, have it rebiased so that they won't run too hot.  On the contrary, if the plates aren't running red but the tone is too bland, chances are your tubes are running too cold.  Again you have to bring it for rebiasing.

korek except that whole glow thing. output tubes do glow but...if skunky means that cherry red almost gonna explode type of glow, yea, that's a bad thing...heheh...

if you're replacing it with the same type of output tubes (same make and model eg Sovtek WXT to Sovtek WXT) it shouldn't be a problem

the bias is basically like the car's idle...it's exactly like that. i mean, your amp will work and all but to rebias it would be like setting the correct idle, like skunky said, for optimization purposes...

It's been a while since I re-biased any amps. Can any of you guys please refresh my memory as to the the safe tube parameter reading for 6L6'S and EL34'S. Can't remmeber if it's either 32-48ma, 36-38ma, or something else.  

[skunkyfunk]

So you mean to say those tube amp ads are baloney because they feature tubes that have an orangey glow? Do you have some pics of a properly glowing tube? Thanks

Dude, if you see the PLATES turning red then that's bad.  But if you're talking about the thin filaments turning red then that's ok.

[skunkyfunk]

It's been a while since I re-biased any amps. Can any of you guys please refresh my memory as to the the safe tube parameter reading for 6L6'S and EL34'S. Can't remmeber if it's either 32-48ma, 36-38ma, or something else.  

http://www.tubedepot.com/whisbipo.html

[skunkyfunk]

well...it's just like those food commercials wherein they exaggerate the picture...hehe

Hmm. How about this pic?



Are these tubes glowing properly? They're from a bassman as well, but the blackface version.

Based from the pic I do not see the plates glowing orange so I assume that they're ok.

[titser_marco]

Thanks thanks talaga. Balitaan ko kayo when I get the amp after Easter

[titser_marco]

Hello boys and girls, I finally got the bassman!  I had it repaired though, after it borke down after half an hour of testing. Mr. Raul Quesada finished the job in 2 hours and set the amp to work with the new Sovteks I put in. Now it's nice. And dirty. Well, sure not as dirty as high gain amps but I know you get my point.

Thanks to deltaslim, BAMF, tele-tubby and all the other guys in the forum that I've bothered because of my ignorance regarding tubes. While I still consider myself a tube noob (hmm, great name for a band...), the information that the guys gave me was more than helpful.

Now regarding the preamp tubes, I just discovered that it had these:

1 Sovtek 12AX7WA
1 China made 12AX7
1 China made 12AT7

And the power tubes, originally were:

1 Sovtek 5881/6L6GC
1 USA made 6L6GC

Yes, boys and girls. the power tubes were completely different! I replaced them with the Sovteks at Audiophile that cost 790 a piece and they're pretty decent (although I know I haven't heard a lot of tube amps and tubes to really determine what is more popularly known as "decent").

Another thing is that one of the speakers seem to have a problem with the voice coil, because I hear buzzing that comes from it. Also, when I push the speaker cone slightly, it creates a noise that comes from friction - which never comes out of the other speakers when I push them back. Do you suggest I have the defective speaker rewound?

Thanks again guys.

[markflo]

change 'em to jensens, or jbl...ayos yan...

[markflo]

check this paragraph out, got it from one of those resource websites...

For instance, many consider the original '59 Bassman Reissue speakers to sound closer to the original Jensen speakers than the Jensen reissues! For reference, this speaker was the Eminence 8 ohm Legend 102 with paper bobbin, which has now been replaced by the Jensen P10R reissue. Eminence also manufactures many other company's speakers like Mojo, Magic Parts, and New Sensor. Still, some owners feel the Hot Rod Deluxe's stock speaker leaves something to be desired

[oasgomez-is-banned]

I believe tama si Mark Flo.  Palitan mo na ng speaker.  Rewinds here ... well if you have money to spend, just change it.  I just wanted to add Weber VST to the list of speakers you should consider.

[markflo]

webers are a really good value too...nice replacement speakers...

[buliwyf]

see the 4th tube (counting from left)? thats a BAD tube hehe:

[BALDO]

mga pards
saan pala makakabili ng NOS na 6L6 GC na RCA o GE ?? at magkano ito? me nagsabi kasi sa akin na sa raon DAW meron pero wala ako makita noon

[titser_marco]

mark and oas:

thanks for the tips. Next question: where do I find em? In Manila, that is.

[skunkyfunk]

Try Watson Electronics along Rizal Ave. Cor Ronquillo in Raon.  Scored some cool NOS GE EL84 tubes there in the past.  I understand they still have some Sylvania 6L6GCs there...

[titser_marco]

Try Watson Electronics along Rizal Ave. Cor Ronquillo in Raon.  Scored some cool NOS GE EL84 tubes there in the past.  I understand they still have some Sylvania 6L6GCs there...

Are they matched? How much are they? Would you know if they also have AT7's?

[skunkyfunk]

Try Watson Electronics along Rizal Ave. Cor Ronquillo in Raon.  Scored some cool NOS GE EL84 tubes there in the past.  I understand they still have some Sylvania 6L6GCs there...

Are they matched? How much are they? Would you know if they also have AT7's?

No matched tubes here.  There was no such thing as tube matching way back then.  Matching tubes makes it easy to set the biasing though.

Mas maraming 12AT7s and ECC82s I know.