Counterpoint SA 5.1 upgrade.
Well, the preamplifier Counterpoint SA 5.1 due to his age, urgently needs a total renovation and also a change in the high voltage regulation.
The sonic benefits we get only updating the preamp part are formidable. First of all, the cleaning is fantastic, voices have no graininess, everything flows more naturally, more open, more rhythmic.
After the upgrade we have made an improvement of two levels in supply.
The first level involves puting special fast diodes, aeronautical level, to give the speed that lacks music in this design, to clean even more the frequency eléctricos reproduced. With this, the level of silence we get now is extraordinary, the image is automatically expanded. The instruments control is much better, it has nothing to do with the original, in a good way. It is a change worth, since the original rectifier tube is too slow and it consumes too much current from the power transformer, and in this model, the transformers tend to fail because they are not properly sized, whereby the rectification change now makes less noise from the transformer to be freer, and also consumption is lower.
The second level consists of modifying the high-voltage regulator. Why? Because it is too complex, has many feedbacks and also tubes consume too much power. They also have the problem that a complex regulation does not sound good, it is naturalness and slow, and in generall it is worse.
With the new design of regulation, simple but effective, now the music is very natural, musical, with a very realistic scenic opening, with a depth of sound levels that facilitate the location of the instruments, the bass is well controlled, it does not scatters, voices are realistic and do not bother, and the upper part of the spectrum is just perfect, without adding or subtracting anything. When the soundtrack of "Pirates of the Caribbean" is played, for example, it does not smudge anything, because everything is very clean and it has fast enough response to smoothly drive the great orchestral masses, of course, if the power amplifier and associated speakers are able to follow this excellent new preamp.