RM22 preamp tubes!

[Anomaly]

V1: Input

V2: Efx Loop

V4: Phase Splitter

V3 & V5: Output Tubes


Which one is V1, V2 & V4? there not labeled?
I'd like to replace those stock (ruby's?) preamps
what's a good combination?

 

[JKMV12]

V1: Input

V2: Efx Loop

V4: Phase Splitter

V3 & V5: Output Tubes


Which one is V1, V2 & V4? there not labeled?
I'd like to replace those stock (ruby's?) preamps
what's a good combination?

well the one closest to the input jack is the V1 (first two gain stages).

The larger tubes are the output/power tubes.

The preamp tube closest to the power tubes is the phase inverter.

the remaining tube (most likely in close proximity to the FX loops) is the loop buffer.

you should put a 5751 in the phase inverter spot. it cleaned up the noise in my amp. i haven't messed with the loop buffer (i don't use the loop). i have a Tungsol 12AX7 in the V1 but that is just me. Penta Labs has some good tubes. you can also try a 5751 in the V1 if you want similar tone to the 12AX7 with less gain. personally i would keep this one a 12AX7 and make the changes in the modules themselves.

hope this helps...

 

[Anomaly]

well the one closest to the input jack is the V1 (first two gain stages).

The larger tubes are the output/power tubes.

The preamp tube closest to the power tubes is the phase inverter.

the remaining tube (most likely in close proximity to the FX loops) is the loop buffer.

you should put a 5751 in the phase inverter spot. it cleaned up the noise in my amp. i haven't messed with the loop buffer (i don't use the loop). i have a Tungsol 12AX7 in the V1 but that is just me. Penta Labs has some good tubes. you can also try a 5751 in the V1 if you want similar tone to the 12AX7 with less gain. personally i would keep this one a 12AX7 and make the changes in the modules themselves.

hope this helps...

Thanks!

5751 in phase inverter will it affect the total gain of the amp?

 

[eyeball987]

Dropping a 5751 into the PI is a very standard mod that many of us do simply to increase clarity and reduce some noise. I don't notice any reduction in gain but I do hear a more balanced tone.

Maybe I am in the minority but I like the stock Ruby's. My modules and RM100 have all kinds of pre's loaded in them but for the most part, I have tried to stay away from fooling around with them too much. I split hairs for years with my rig and the only two things that really made a huge difference for me was making sure I didn't have too many JJ pre's in there and putting a Jan GE 5751 in the PI. Power tubes are another story.

 

[Anomaly]

Dropping a 5751 into the PI is a very standard mod that many of us do simply to increase clarity and reduce some noise. I don't notice any reduction in gain but I do hear a more balanced tone.

Thanks! I guess I'll have to start with 5751's in PI and work my way from there :lol:

 

[Daryl]

I hear a lot about people putting a 5751 in P1. I have some NOS ones, but I am a little concerned about the longevity of the tubes in P1. That's the hardest working spot for a preamp tube, if I'm not mistaken. Would it be more appropriate to leave the NOS for the module preamp tubes or should I go ahead and throw a '63 Jan/GE in there? I don't want to needlessly sacrifice a NOS tube. Any thoughts on the matter?

 

[KillTone]

That is a good question Daryl. My thought is that the PI tube is not really part of the signal path and should not color the tone too much if at all.
Some people put a 12at7 in the PI for the same reasons you would use a 5751 - a lower gain/cleaner signal driving the power tubes.

A lot of people who sell vintage and NOS tubes will admit that a good vintage tube in V1 is where you will hear most of the "goodness" of a vintage tube. Using them anywhere else is overkill and probably a waste of a great tube.

Having said that, I use as much vintage glass as possible. I like overkill :twisted: