Have a Tektron 6J5 preamp, very nice, but gain is a bit too much...Having the
volume pots (100K) at 9:00 position,the unit is too loud with both my amps...I
was advised by Tektron to change pots to 50K each and this would allow me to
have more range...Is this true??? I am unsure if he understood my question...
Thanks...

Rimfire1022 wrote:

Have a Tektron 6J5 preamp, very nice, but gain is a bit too much...Having the
volume pots (100K) at 9:00 position,the unit is too loud with both my amps...I
was advised by Tektron to change pots to 50K each and this would allow me to
have more range...Is this true???

It sounds very unlikely to me. If the pot is in the normal place (at the
input), the value will not matter. The problem is that linestages are
not really needed - in many cases any gain is too much.

If you want to reduce the gain, you could add some resistors at the
inputs (perhaps dividers) to reduce the signal level.

Best regards,

Mikkel C. Simonsen

On 23 Sep 2004 21:25:03 GMT, (Rimfire1022) wrote:

Have a Tektron 6J5 preamp, very nice, but gain is a bit too much...Having the
volume pots (100K) at 9:00 position,the unit is too loud with both my amps...I
was advised by Tektron to change pots to 50K each and this would allow me to
have more range...Is this true??? I am unsure if he understood my question...
Thanks...

Don't think that would do too much, might add distortion...

Do you have a linc to a schematic?

Rimfire1022 wrote:

Have a Tektron 6J5 preamp, very nice, but gain is a bit too much...Having the
volume pots (100K) at 9:00 position,the unit is too loud with both my amps...I
was advised by Tektron to change pots to 50K each and this would allow me to
have more range...Is this true??? I am unsure if he understood my question...
Thanks...

Changing to a 50k pot will only reduce the gain by 1 dB, or next to nothing,
and what you need to cosider is why you have any gain at all.

You would probably find that if you had a 50k pot in a metal box with a couple of
RCA
sockets for the input and wiper output,
that the CD player level is quite adequate when the pot was in the
12 o'clock position, and with the possibility of going deafeningly louder.

But if you insist on gain, then the 6J5 is a great choice of tube, but
for lower gain, a shunt FB network between input and output is needed.

We need to see the schematic before we could advise further.

Patrick Turner.

A 6J5 is a fine tube and should make a great simple pre-amp stage.
However, because of the output level of your source and sensitivity of
amp and speakers, you may not need any gain at all.

You could consider reconfiguring the tube as a cathode follower. Then
your pre-amp becomes a simple buffer with a high source impedence and
low output impedence.