Mullard 5AR4 vs. Sovtek 5AR4

[ajcllc]

Will I notice a difference in sonics by replacing my Sovtek 5AR4 rectifier tube with a Mullard 5AR4 in my Dynaco ST-70?

[The Voodoo Doctor]

Check the post below for a little more information on how a rectifier could effect your sound. But since these are the same tube types, I wouldn't expect any sonic differences.

http://forums.klipsch.com/forums/thread/962954.aspx

The Dynaco ST-70 also uses a inductive input filter after the rectifier. This inductor will try to keep the current flowing through it as constant as possible. This will even further decrease the sonic differences between different rectifier tubes by 1) helping regulate current flow through the power supply and 2) decrease the rectifier tube's effect on the overall power supply impedance.

Unless you are noticing a difference in performance, there is probably no need to replace the current rectifier.

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[Daddy Dee]

In my very lay understanding of rectifier tube duty, it wouldn't impact the sound.

The Mullard rectifier tube, though, has a rep for being more durable.

It's also a clear winner in cool factor. Vintage amps need to have such a tube just to admire it... the audio equivalent of three guys standing in front of a car, hood up, staring at the engine. It helps to have an occasional buddy over to appreciate an amp that age sounding so good.

[The Voodoo Doctor]

You may also want to be careful when buying Mullard branded tubes, unless you know exactly what you're buying. The Mullard brand was recently purchased by New Sensor (Sovtek). So a "new" Mullard may be made on the same assembly line as that Sovtek you are replacing. Sorta takes the cool factor out of the Mullard brand. But I think they are only currently manufacturing EL34's, EL84's, and 12AX7's.

So if you are buying Mullards, buy from a well respected vendor.

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