Sovtek 12AX7LPS


Silver Supporting Member
Are these tubes really as good as I read about?

Any experiences?

Do they really smooth out the Overdrive channel of an Amp?

I have a Bogner Shiva EL34...I have noticed that at times the overdrive tends to be a bit to buzzy for my taste so I called Bogner and they told me to try these tubes! I guess the correct slot would be in V2!



A Tribe of One
Staff member
I think it depends on the application. Lord Valve recommended that I not use 'em in a modern high gain amp 'cause the LPS can be a bit microphonic in those amps.


Gold Supporting Member
I highly recomend the LPS's, They came stock with an SLO I recently had, I didn't care much for the Sovtek 5881's that also came stock with the amp, so I swapped them out, and in the process tried a bunch of different preamp tubes but just kept coming back to the LPS's, Very natural and musical. I didn't experience any microphonic problems at all. I'm not much of a Sovtek lover but boy they got this one right!;)
However if you want to calm down a buzzy high end, I strongly suggest trying the JJ ECC83S's. V1 & V2.


Many of the older 12AX7LPS's were prone to be microphonic. The newer ones seem to be much better. If you get a bad one from a reputable dealer, send it back! NO big problem.......

I've had good luck with them in the Deluxe Reverb, only one bad one in four years. Haven't trrried them in the Rivera yet.

As Braciola noted, JJ is making some excellent preamp tubes now too.

Hammer on.......Blair


Gold Supporting Member
Platinum Supporting Member
When I first got my Fuchs modded DRRI, I ordered a bunch of NOS tubes from Mike at KCA, and some LPSs. I found most of the NOS tubes to be microphonic and no better sounding than the Sovteks. I ended up using them and have had no trouble. They sound great. Surprise, huh:rolleyes:



I tend to use NOS stuff just because I've got a large stash around. I have some LPS, have tried them and generally like them. Keep in mind that changes in preamp tubes will make a difference in how an amp sounds. But the changes can be pretty subtle. Often you need to have a discriminate ear to tell the difference and form a preference. In my experience, it's not really going to change the overall tonal complexion of an amp. If it sound's buzzy to you now, I doub't that a preamp tube swap is really going to help you.


Another thought. If you are really trying to change the amp's overdrive behavior, try using some lower gain preamp tubes in V1 and V2 - maybe subing in one or two 12AT7s or a 12AY7 for the current 12AX7s. It can hurt anything and it can really change how the preamp behaves.

Blue Strat

I just tested 200 LPSs and found about 10% too high in microphonics to risk selling to my customers.

In general, any long plate tube is more prone to microphonics than short plate tubes. The LPS are quite good however and have a strong following.

Also consider the EH 12AX7s which are extremely quiet and low in microphonics.

ALL tubes are microphonic to some degree and this is not necessarily a bad thing. Microphonics can actually enhance tone especially in lower gain (like vintage Fender) amps. High gain monsters are the amps that have the most problems with microphonic tubes.
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