Re: 6SC7 -> 6SL7? Any reasons why not?

[John Byrns]

In article >, "Shiva"
> wrote:

> I got a tiny RCA mic /phono (yeah) preamp, and it uses a single toob - 6SC7.
> I've got a couple, but I have a weird aversion to metal toobs. Any reason
> why I shouldn't go with a 6SL7? i know the pinout's *slightly* different,
> but only one grid. Anyone done this? The specs look close enough...

Don't forget to add a shield.


Regards,

John Byrns


Surf my web pages at, http://users.rcn.com/jbyrns/

[Shiva]

"John Byrns" > wrote in message
...
> In article >, "Shiva"
> > wrote:
>
> > I got a tiny RCA mic /phono (yeah) preamp, and it uses a single toob -
6SC7.
> > I've got a couple, but I have a weird aversion to metal toobs. Any
reason
> > why I shouldn't go with a 6SL7? i know the pinout's *slightly*
different,
> > but only one grid. Anyone done this? The specs look close enough...
>
> Don't forget to add a shield.
>
>
> Regards,
>
> John Byrns
>

Because the metal toob has a shield pin? I've never really seen shields on
6sl7's (i 'm sure they exist), the only time a shield made a diff. is when I
stuck the first gain stage too close to the output toobs (trying to squeeze
in too much on too small a chassis)...
-dim
>
> Surf my web pages at, http://users.rcn.com/jbyrns/

[Phil]

Shiva wrote:

> "John Byrns" > wrote in message
> ...
> > In article >, "Shiva"
> > > wrote:
> >
> > > I got a tiny RCA mic /phono (yeah) preamp, and it uses a single toob -
> 6SC7.
> > > I've got a couple, but I have a weird aversion to metal toobs. Any
> reason
> > > why I shouldn't go with a 6SL7? i know the pinout's *slightly*
> different,
> > > but only one grid. Anyone done this? The specs look close enough...
> >
> > Don't forget to add a shield.
> >
> >
> > Regards,
> >
> > John Byrns
> >
>
> Because the metal toob has a shield pin? I've never really seen shields on
> 6sl7's (i 'm sure they exist), the only time a shield made a diff. is when I
> stuck the first gain stage too close to the output toobs (trying to squeeze
> in too much on too small a chassis)...
> -dim

I'm sure the shield pin on the metal tube is for the metal enclosure itself. I
think those were put on all metal tubes so that if an element shorted to the
metal enclosure, it wouldn't wind up killing someone who touched the enclosure.

Phil

[t.hoehler]

>
> I'm sure the shield pin on the metal tube is for the metal enclosure
itself. I
> think those were put on all metal tubes so that if an element shorted to
the
> metal enclosure, it wouldn't wind up killing someone who touched the
enclosure.
>
> Phil
>
I remember opening up a bad 6F6 metal tube a long time ago, and IIRC, there
was a thin glass envelope inside the metal can. Strange consruction, but
that is the way that one was made. I'm not sure any electrode could ever
contact the outer metal can, but maybe they are all not made that way. The
outer can was connected to a ground point as you referred to as the shield
pin.
Regards,
Tom
Regards,
Tom
>

[Fred Nachbaur]

t.hoehler wrote:
>>I'm sure the shield pin on the metal tube is for the metal enclosure
>
> itself. I
>
>>think those were put on all metal tubes so that if an element shorted to
>
> the
>
>>metal enclosure, it wouldn't wind up killing someone who touched the
>
> enclosure.
>
>>Phil
>>
>
> I remember opening up a bad 6F6 metal tube a long time ago, and IIRC, there
> was a thin glass envelope inside the metal can. Strange consruction, but
> that is the way that one was made. I'm not sure any electrode could ever
> contact the outer metal can, but maybe they are all not made that way. The
> outer can was connected to a ground point as you referred to as the shield
> pin.

I never took apart a 6F6, but the couple small-signal tubes I did take
apart did *not* have an inner glass envelope.

Don't want to sacrifice a metal tube to science? Here's a dissection
story, with photos:
http://www.r-type.org/static/6j5.htm

Cheers,
Fred
--
+--------------------------------------------+
| Music: http://www3.telus.net/dogstarmusic/ |
| Projects: http://dogstar.dantimax.dk |
+--------------------------------------------+

[Carroll Conklin]

Dim,

The only reason to keep the original is for resale value. If you are just
going to experiment, have at it!

For the responders who don't think the outside metal case is connected to
anything --BEWARE--.

I got one of the worst shocks of my life from a metal 6L6. It was a beater,
I was using to troubleshoot an amp. I brushed my hand against it and it had
the full B+ on the can! It is common practice for un-used pins on tube
sockets to be used as tie points. Just my luck that this amp tied the shield
pin to B+.

Carroll
"Shiva" > wrote in message
...
> I got a tiny RCA mic /phono (yeah) preamp, and it uses a single toob -
6SC7.
> I've got a couple, but I have a weird aversion to metal toobs. Any reason
> why I shouldn't go with a 6SL7? i know the pinout's *slightly* different,
> but only one grid. Anyone done this? The specs look close enough...
> -dim
>
>