Preamp Tube Questions for a Fender Blues Deluxe RI...

[VintageToneGuy]

...Hi, I want to experiment a little with different preamp tubes for my new BDri. I've already done the normal putting in new JJ\Tesla's and they are okay. Can't really tell any improvement. I have a few questions.

1)- Can you recommend a really good NOS preamp tube?

2)- Do I have to put all NOS tubes in (three); or can I just put one NOS tube in the V1 position?

3) - The next logical question is: Which tube is the V1?

Thanks for any help!

vtg

[SatelliteAmps]

1) Mullard. Amperex. Bugle Boy. Telefunken.
2) You can put one in any of the positions. V1 is usually the most noticeable.
3) The preamp tube closest to the inputs. Usually it is the farthest tube to one side of an amplifier.

[Champlifier]

What Sattellite said.
Depending on how bad your current tube is, the differences are usually subtle but worthwhile IMO.

[TweeDLX]

1) Mullard. Amperex. Bugle Boy. Telefunken.
2) You can put one in any of the positions. V1 is usually the most noticeable.
3) The preamp tube closest to the inputs. Usually it is the farthest tube to one side of an amplifier.
I agree. NOS tubes are generally warmer (IMO) and smoother sounding. You may also want to try different types (gain levels) of tubes (12AY7, 5751, etc) in the V1 position and see if you find a combo you like. Sometimes, changing the phase inverter (V3-closest to the power tubes) to a good NOS tube makes a big difference. I put a Mullard CV4024 in my Concert that made a huge difference.

Mike

[VintageToneGuy]

I agree. NOS tubes are generally warmer (IMO) and smoother sounding. You may also want to try different types (gain levels) of tubes (12AY7, 5751, etc) in the V1 position and see if you find a combo you like. Sometimes, changing the phase inverter (V3-closest to the power tubes) to a good NOS tube makes a big difference. I put a Mullard CV4024 in my Concert that made a huge difference.

Mike

That was my next question. I was wondering about putting the different gain levels of tubes in. Should that be done in just V1 socket or all three or what?

Thanks

[rockon1]

That was my next question. I was wondering about putting the different gain levels of tubes in. Should that be done in just V1 socket or all three or what?

Thanks

Placed in the V1 a lower gain tube will affect both channels gain. Placed in the V2 it will not affect the clean channel gain but will affect the dirty channels gain. Placed in the V3 it will affect the signal going to the power tubes and result in reduced output-possibly cleaner(less output tube distortion) I have my doubts that more clean headroon is available this way as some claim.

If you want to try some old stock pre's I suggest going with used old stock tubes. Much cheaper and will yeild the same results. If you dont think the results are worth it your not out that much. Many Fender guys seem to like RCA short plates. Bob

[TweeDLX]

Placed in the V1 a lower gain tube will affect both channels gain. Placed in the V2 it will not affect the clean channel gain but will affect the dirty channels gain. Placed in the V3 it will affect the signal going to the power tubes and result in reduced output-possibly cleaner(less output tube distortion) I have my doubts that more clean headroon is available this way as some claim.

If you want to try some old stock pre's I suggest going with used old stock tubes. Much cheaper and will yeild the same results. If you dont think the results are worth it your not out that much. Many Fender guys seem to like RCA short plates. Bob
You can find cheap USED old stock tubes (as opposed to NOS) in plentiful supply on eBay and elsewhere. I used a lower gain JAN 5751 in my Fender Concert II in V2 to "tame" the highs on the OD channel. Sounded pretty good there, but I didn't care for it in V1. My experience with changing pre tubes to higher/lower gain than spec is that it works well in some amps, not so well in others. depends on lots of factors: placement, circuit, speakers, and the tone your actually "shooting" for. It is fun to experiment with them though...

Mike

[rockon1]

My experience with changing pre tubes to higher/lower gain than spec is that it works well in some amps, not so well in others. depends on lots of factors: placement, circuit, speakers, and the tone your actually "shooting" for. It is fun to experiment with them though...


I have found the same. For instance due to a 12AT7's different plate resistance it offers virtually the same amount of gain when subbed for a 12AX7 even though it is a lower mu tube. It also is usually thinner sounding because of these different design specs too. Bob