09-06-2022, 08:20 PM
Hi poprock,
The gain structure of the Dionysos and Libra could not be more different.
The Libra uses a differential gain stage directly coupled to the input, so whatever you connect to it first gets amplified, then we decide what portion of the signal goes where. This way the attenuator is after the tubes and the attenuator also attenuates the noise. The second very important feature is that you always have the full signal entering the tubes, so no matter your volume setting the tonal character of the amplification stage does not change. Noise floor follows the attenuation. In realty the signal to noise of the Libra is lower than the one on the Dionysos but you always get all of it!!
The Dionysos uses what we see as the best possible attenuator, a TVC (transformer Volume control)
In essence the Dionysos is a passive preamplifier until you reach step 10 in the volume setting. Up to that point you have the input connected to the output via a variable ratio transformer. Once you reach step 10 the control logic sends the signal to the tube amplification stage and returns a number of steps back to compensate the amplification gain, so you just see a normal 2db step instead of 14db. The output now is taken from the output transformer. We switch transformer windings in parallel or series to further extend the number of steps while keeping a reasonable output impedance. All of this "gear shifting" is done under the supervision of a microprocessor.
Difference is that now above step 10 you have the tube gain stage constantly engaged and with its own noise floor. This noise foor is super low but is there no matter the level. At optimum levels the signal to noise will be over 112db but attenuation will lower that figure. Dionysos is still quieter and with higher dynamic range than all tube preamplifier we have tested. Also the fact that the gain stage is single ended triode it will exhibit a fair bit of second harmonic distortion.
It is a bit more info than needed but now you know why our preamplifiers are so different to the mainstream.
The gain structure of the Dionysos and Libra could not be more different.
The Libra uses a differential gain stage directly coupled to the input, so whatever you connect to it first gets amplified, then we decide what portion of the signal goes where. This way the attenuator is after the tubes and the attenuator also attenuates the noise. The second very important feature is that you always have the full signal entering the tubes, so no matter your volume setting the tonal character of the amplification stage does not change. Noise floor follows the attenuation. In realty the signal to noise of the Libra is lower than the one on the Dionysos but you always get all of it!!
The Dionysos uses what we see as the best possible attenuator, a TVC (transformer Volume control)
In essence the Dionysos is a passive preamplifier until you reach step 10 in the volume setting. Up to that point you have the input connected to the output via a variable ratio transformer. Once you reach step 10 the control logic sends the signal to the tube amplification stage and returns a number of steps back to compensate the amplification gain, so you just see a normal 2db step instead of 14db. The output now is taken from the output transformer. We switch transformer windings in parallel or series to further extend the number of steps while keeping a reasonable output impedance. All of this "gear shifting" is done under the supervision of a microprocessor.
Difference is that now above step 10 you have the tube gain stage constantly engaged and with its own noise floor. This noise foor is super low but is there no matter the level. At optimum levels the signal to noise will be over 112db but attenuation will lower that figure. Dionysos is still quieter and with higher dynamic range than all tube preamplifier we have tested. Also the fact that the gain stage is single ended triode it will exhibit a fair bit of second harmonic distortion.
It is a bit more info than needed but now you know why our preamplifiers are so different to the mainstream.