Swapping out 12ax7 with 5751 preamp tube in Rebel 30?

[gregrjones]

Can I swap out the 12ax7's with 5751 preamp tube in Rebel 30?

If so, is it possible to just swap out the v1 preamp tube or would I need to swap out the whole set?

 

[bbrodie]

I use a NOS JAN Phillips 5751 in my Rebel 20 in V1 and like it a lot. It seems to have reduced the gain a little to where it suits my playing style a little better. You don't need to do the whole set.

 

[Steedee]

Can I swap out the 12ax7's with 5751 preamp tube in Rebel 30?

If so, is it possible to just swap out the v1 preamp tube or would I need to swap out the whole set?

Mixing and matching with different types of tubes is fun and rewarding. And time consuming....

 

[gregrjones]

I just ordered a 5751. I'll post the results here. I'm hoping that reduced gain will mean that I can crank the master volume more and get more power tube saturation.

I've not noticed this on other amps, but with the Rebel 30, I've noticed that the gain actually affects the volume. As I clean up the dirt channel, I can crank the master volume more to get the same level of dBs.

I thought that was kind of strange.

I'd like to get power tube saturation which was one draw to getting a low wattage amp with the variable watts feature. But it is hard for me to get that if I only need about 85 dBs from this amp for gigs.

Why 85 dBs you might ask?

For metal music, such a band would probably push above 100 dBs but for the rest of us, a comfortable volume level for your average audience is somewhere in the 90's. If the band I'm playing in is pushing 95 dBs in the house, studies show that you need at least 10 dBs less with the monitor and amp mix if you want the FOH speakers to mask the stage volume. In other words, this 10 dB difference will ensure that the audience is not hearing sound coming from the monitors.

Even at 1W, this amp is loud!

 

[Steedee]

I just ordered a 5751. I'll post the results here. I'm hoping that reduced gain will mean that I can crank the master volume more and get more power tube saturation.

I've not noticed this on other amps, but with the Rebel 30, I've noticed that the gain actually affects the volume. As I clean up the dirt channel, I can crank the master volume more to get the same level of dBs.

I thought that was kind of strange.

I'd like to get power tube saturation which was one draw to getting a low wattage amp with the variable watts feature. But it is hard for me to get that if I only need about 85 dBs from this amp for gigs.

Why 85 dBs you might ask?

For metal music, such a band would probably push above 100 dBs but for the rest of us, a comfortable volume level for your average audience is somewhere in the 90's. If the band I'm playing in is pushing 95 dBs in the house, studies show that you need at least 10 dBs less with the monitor and amp mix if you want the FOH speakers to mask the stage volume. In other words, this 10 dB difference will ensure that the audience is not hearing sound coming from the monitors.

Even at 1W, this amp is loud!

Greg r u using the Rebel 30 for metal?

 

[gregrjones]

I installed the 5751 last night. The primary difference I noticed was about 10% - 20% less volume and maybe 10% less distortion.

I haven't gotten the amp up beyond bedroom volumes yet to judge tone better, but so far I'm not really hearing a tonal difference between the 5751 and the 12AX7.

I'll know better how I like it by the end of this weekend.

And to answer the latest question, no I'm not using this amp for metal. It is really not a metal amp short of running a high gain pedal in front of it. I go for classic and blues type tones.

I'm running an overdrive and compressor in front of the amp with a Stratocaster.