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Okay, I am willing to gamble a few bucks on an NOS 6K6 tube for my
Fender Reverb tank (I have the high note "tinniness" others have
complained of), but am new to tube amps. Is there anything more to the
swap than simply changing the 6V6 to a 6K6? Are some 6K6 tubes
preferable to others? And is there a difference between a 6K6 and a
6K6 GT?
Please let me know if you've actually done this swap, or if you are
only speakng from hypothetical experience.
Gavin:
IMO, you're not gambling your money - this is a sure thing! I would
do a swap of all the tubes to their NOS counterparts (12AX7, 12AT7,
and 6K6). If you want to reduce the piercing high notes even more,
you can swap a 12AT7 for the 12AX7 (it has less gain).
The difference between a 6K6 and a 6K6 GT? About five bucks!
Hahahaha - sorry, just kidding - couldn't resist the opening!
Electronically, I don't think that there is a difference. The "GT"
suffix refers to the T9 glass bulb tube shape ("globe tubular", I
think, or "GT"), which you can see in the shape of the original
Groove Tube supplied with the unit. Other 6K6's that don't have the
GT suffix might have the "ST" tube shape, which is different . . .
I feel that the swap is worth the money - just make sure that you
swap them all! As always, unplug your tank and lock the reverb pan
before replacing the tubes - and don't forget to unlock the pan after
you're done. That's about it - enjoy!
-Dick
--- In SurfGuitar101@y..., "windanseabeachboy" <gavinehringer@m...>
wrote:
> Okay, I am willing to gamble a few bucks on an NOS 6K6 tube for my
> Fender Reverb tank (I have the high note "tinniness" others have
> complained of), but am new to tube amps. Is there anything more to
the
> swap than simply changing the 6V6 to a 6K6? Are some 6K6 tubes
> preferable to others? And is there a difference between a 6K6 and a
> 6K6 GT?
>
> Please let me know if you've actually done this swap, or if you are
> only speakng from hypothetical experience.
I've got some questions about this stuff too.. Tubes
go for pretty cheap, but what's this about rebiasing?
Does that cost a lot of money and what exactly does
that do? Also where do you recomend purchasing NOS
tubes?
--- windanseabeachboy <> wrote:
> Okay, I am willing to gamble a few bucks on an NOS
> 6K6 tube for my
> Fender Reverb tank (I have the high note "tinniness"
> others have
> complained of), but am new to tube amps. Is there
> anything more to the
> swap than simply changing the 6V6 to a 6K6? Are some
> 6K6 tubes
> preferable to others? And is there a difference
> between a 6K6 and a
> 6K6 GT?
>
> Please let me know if you've actually done this
> swap, or if you are
> only speakng from hypothetical experience.
>
>
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> -----Original Message-----
> From: Fred Pleasant [mailto:]
>
> I've got some questions about this stuff too.. Tubes
> go for pretty cheap, but what's this about rebiasing?
> Does that cost a lot of money and what exactly does
> that do? Also where do you recomend purchasing NOS
> tubes?
>
>
Hi, I am certainly not an expert, perhaps Dick Messick or someone else can
chime in here. Rebiasing, as explained to me, is kind of like setting the
idle on your car. It is only done on power tubes. I think the goal is to get
a set of power tubes to play together nicely. Sometimes you see tubes sold
as a set and if you install them together no rebiasing is needed (because
the manufacturer feels these tubes have "close enough" characteristics). To
confuse you worse, some tubes don't need rebiasing. If the tubes aren't
adjusted right to work as a set, they can draw too much current and burn
out, or even take out your transformer too.
Check this page out. You can buy NOS tubes from them, plus they have lots of
FAQs and links to other tube sites. I've seen these guys recommended on the
Fender Forum. If you poke around on here long enough you may find some
answers.
BN
I don't think I'm the resident expert on biasing, but I'll throw in
my 2 cents. Brian has summarized the issue of biasing quite well -
the setting of a car's idle analogy is a good one. Like any mass-
produced item, power tubes will have slight variances in operating
characteristics from one another. Also, tubes need a brief "burn in"
period so that these characteristics stabilize. Biasing serves to
adjust the amount of current conducted by the tube so that the tube
is operating at it's maximimum potential - and sounds its best.
Without biasing (or with improper biasing), a tube (or tubes) will
just sound plain crappy. It will also shorten tube life and can
cause other components to fail, as Brian mentions. For a good
summary, check out this page from Svetlana:
I guess the good news about biasing in relation to the reverb tank is
that the tank doesn't need to be biased!!! :)
Another good place to buy tubes is Antique Electrical Supply in
Tempe, AZ. Although they primarily cater to the vintage radio crowd,
they also are friendly to musicians. I've never ordered tubes from
them, but have purchased other items - service is fast & friendly.
Check them out at
My favorite "secret" source of tubes is the "hamfest" - a flea market
for the amateur radio crowd. Although tube prices have skyrocketed
in recent years, you can still find some bargains there on NOS stuff.
I've seen some junk radios with pre-amp and power tubes in them that
are worth multiples of the asking price! They have these all over
the country, and are interesting to electronics buffs, if nothing
else. If anyone wants more info, I can look through my "favorites"
to see if I can find the Internet link that will tell you where these
events occur - Summer/Fall is prime time!
For those with good luck/timing, don't forget the garage sale/tag
sale/rummage sale (whatever they're called in your part of the
country if you're in the US). Sometimes there's gold in that old
crap! If you're a scavenger, be on the lookout for old (I mean
early '70's and before) TVs - those had pre-amp tubes and sometimes
power tubes that can be used in guitar amp applications. Of course,
these are becoming more rare these days.
Those aren't the quick & easy ways to get NOS tubes, but they are fun
sometimes (especially if it gets you out of doing yardwork in the
Fall!)
-Dick
--- In SurfGuitar101@y..., "Brian Neal" <bneal@z...> wrote:
> > -----Original Message-----
> > From: Fred Pleasant [mailto:fredpleasant@y...]
> >
> > I've got some questions about this stuff too.. Tubes
> > go for pretty cheap, but what's this about rebiasing?
> > Does that cost a lot of money and what exactly does
> > that do? Also where do you recomend purchasing NOS
> > tubes?
> >
> >
>
> Hi, I am certainly not an expert, perhaps Dick Messick or someone
else can
> chime in here. Rebiasing, as explained to me, is kind of like
setting the
> idle on your car. It is only done on power tubes. I think the goal
is to get
> a set of power tubes to play together nicely. Sometimes you see
tubes sold
> as a set and if you install them together no rebiasing is needed
(because
> the manufacturer feels these tubes have "close enough"
characteristics). To
> confuse you worse, some tubes don't need rebiasing. If the tubes
aren't
> adjusted right to work as a set, they can draw too much current and
burn
> out, or even take out your transformer too.
>
> Check this page out. You can buy NOS tubes from them, plus they
have lots of
> FAQs and links to other tube sites. I've seen these guys
recommended on the
> Fender Forum. If you poke around on here long enough you may find
some
> answers.
>
>
>
> BN
> -----Original Message-----
> From: flatwound01 [mailto:]
>
> I don't think I'm the resident expert on biasing, but I'll throw in
> my 2 cents.
[...]
Cool, thanks Dick.
I found this link, it talks about the history of tubes, how they work, and
their applications today. Very interesting if you are a techie type person:
BN
Thanks, Brian - that is a very cool link, and not too technical.
Interesting stuff . . . and amazing that tubes can do what they do!
I especially liked the description/photos of the tube assembly line -
can you imagine a bunch of white lab coat clad people with tweezers
and tiny spot welders making each tube individually? Wow!
-Dick
--- In SurfGuitar101@y..., "Brian Neal" <bneal@z...> wrote:
> > -----Original Message-----
> > From: flatwound01 [mailto:rmessick2@a...]
> >
> > I don't think I'm the resident expert on biasing, but I'll throw
in
> > my 2 cents.
> [...]
>
> Cool, thanks Dick.
>
> I found this link, it talks about the history of tubes, how they
work, and
> their applications today. Very interesting if you are a techie type
person:
>
>
>
> BN
Any advice on getting the 6V6 out of my reverb unit? I feel dumb, but I'm
having a really difficult time and don't want to break anything. I've never
had this problem with my Twin.
thanks,
Erik
-----Original Message-----
From: Brian Neal [mailto:]
Sent: Saturday, June 22, 2002 7:47 AM
To:
Subject: RE: [SurfGuitar101] 6K6 verus 6V6 in Fender Reverb reissue
> -----Original Message-----
> From: Fred Pleasant [mailto:]
>
> I've got some questions about this stuff too.. Tubes
> go for pretty cheap, but what's this about rebiasing?
> Does that cost a lot of money and what exactly does
> that do? Also where do you recomend purchasing NOS
> tubes?
>
>
Hi, I am certainly not an expert, perhaps Dick Messick or someone else can
chime in here. Rebiasing, as explained to me, is kind of like setting the
idle on your car. It is only done on power tubes. I think the goal is to get
a set of power tubes to play together nicely. Sometimes you see tubes sold
as a set and if you install them together no rebiasing is needed (because
the manufacturer feels these tubes have "close enough" characteristics). To
confuse you worse, some tubes don't need rebiasing. If the tubes aren't
adjusted right to work as a set, they can draw too much current and burn
out, or even take out your transformer too.
Check this page out. You can buy NOS tubes from them, plus they have lots of
FAQs and links to other tube sites. I've seen these guys recommended on the
Fender Forum. If you poke around on here long enough you may find some
answers.
BN
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