Looking for a Tube preamp with Tube Rectifier stage <= $/£/€ 3000

in addition to what has been mentioned already...

primaluna

modwright

both gz34 rectification

Quicksilver Full Function

Just a FWIW: there is no good argument for a tube rectifier in a home audio preamp. The reason is simple- the only real advantage of tube rectifiers is that they are lower noise than solid state, if the solid state rectifiers are not treated correctly. This noise might be heard as a buzz.

But that really is the only advantage. Otherwise tube rectifiers have a voltage drop, which varies with load (the more current, the more voltage drop). This makes them very desirable in a guitar amp intended to play the blues, due to the additional distortion introduced by the sagging power supplies. But in a preamp there's not that much current, and not really any reason to have a tube. If you use modern rectifiers like HEXFREDs or the like, you get less voltage drop and the power supply voltage stays more constant. Plus you can also handle larger filter capacitance values, as this is a further limitation of tube rectifiers.

@atmasphere

ralph, by your explanation, then why are rectifiers used in some tubed power amps as well? the notion of the undesirable voltage drop would seem to be even more of a negative in higher power applications where distortion is not wanted...

i recall when dan wright (modwright) was starting out, he made quite a splash with a standalone 5ar4 rectified power supply for many of his cd player modifications (which in turn powered his 5687 triode output stages) - these were absolutely some of the loveliest sounding cd players ... so the tube rectification in your view is undesirable and unnecessary?

i thought there was something about the benefits of the tube rectifier being slow and smooth at turn on, and so there was less electrical ’shock’ to the downstream circuits at turn on...

Tradition is the main reason you see tube rectifiers in tube power amps. Quite often when that is the case, you will also see that the amplifier circuit itself is from the 1950s or 1960s.


5AR4s have a controlled warmup characteristic, so they do get used in tube circuits to prevent cathode stripping of the power tubes. There really isn't a reason to use one in a preamp. Dan Wright's circuit probably sounded good due to proper design, not the rectifier, and I agree he's done some nice work with his CD player mods. I liked his Oppo mod quite a lot- we used it at AXPONA a few years ago.