Passive Preamp with Transformer Volume Control

[cma29]

Thanks, Ken. I'm very pleased with it.

Next stop: migrating from XA100.5s to the point 8s

[cmarin]

Originally Posted by PlanarSpeakerFan

Great review Carlos and a beautiful preamp. I'm so glad it worked out for you. Ken

+1

Carlos (Tocayo),

You mentioned the "Bent Audio AVC-1 has done a superb job helping to bring out the secondary harmonic nuances that make acoustic music come alive. Brass, woodwinds and strings timbers just sound real. The brass has that special “blatt” rough sound that is so authentic. Transparency is superb allowing me to follow complex melodies and counterpoint easily. Listening fatigue is non-existent and dynamics are tremendous."

Were these sound quality improvements referenced specifically relative to the K03 going direct to your monos at low volumes or in general?

I'm assuming that in your current setup your K-03 is set at full volume. Did the relative SQ improvements of the AVC-1 relative to the K-03/direct change as the volume increased?

Thanks again for presenting an interesting alternative to going straight from a DAC. Great job in articulating your path.

[cma29]

Originally Posted by cmarin

+1

Carlos (Tocayo),

You mentioned the "Bent Audio AVC-1 has done a superb job helping to bring out the secondary harmonic nuances that make acoustic music come alive. Brass, woodwinds and strings timbers just sound real. The brass has that special “blatt” rough sound that is so authentic. Transparency is superb allowing me to follow complex melodies and counterpoint easily. Listening fatigue is non-existent and dynamics are tremendous."

Were these sound quality improvements referenced specifically relative to the K03 going direct to your monos at low volumes or in general?

I'm assuming that in your current setup your K-03 is set at full volume. Did the relative SQ improvements of the AVC-1 relative to the K-03/direct change as the volume increased?

Thanks again for presenting an interesting alternative to going straight from a DAC. Great job in articulating your path.

Hi, Carlos.

I would say the sound qualities I described are inherent to the K-03 source, but the passive preamp was able to unlock them.

Yes, now I'm running the K-03 DAC at full output (using the +6dB option on the K-03's XLR output) so there is no attenuation by bit-dropping as before and I think this is a big reason that the system is sounding its best: the full signal, robust from the DAC is reaching the amps with very little degradation (yes, there will always be some).

Also, the most dramatic improvements were at low levels when the signal is attenuated by 30dBs or more. Good dynamics and low level detail.

So, in summary I think a passive preamp such as this one will work well in systems with a source that can put out a high voltage signal with respect to what the amps require to reach full power. For my system, the voltage output-to-input voltage required to reach full power is about 3 to 1. An "autoformer" preamp will also help to drive amps with a lower input impedance.

By the way you have a great system and its sound in the specially designed listening room must be impressive. Very nice!

[cmarin]

Thank you Tocayo for the informative reply and kind words. Currently looking at various system changes/comparisons but have defined a path forward that will hopefully lead to even more musical enjoyment. Look forward to hearing about your system progress. Thanks again and good luck.

[bart]

Carlos, I just discovered this thread.
Congrats on finding out a very original way of improving your system without spending megabucks.

[Car commander]

Originally Posted by cma29

Thanks, Julian. I was hoping for something a little heftier, but this will do for now.

Can I see a picture of the rack you are putting it on?

[cma29]

Originally Posted by bart

Carlos, I just discovered this thread. Congrats on finding out a very original way of improving your system without spending megabucks.

Thanks, Bart.

It's the only component I have that I felt like I could get away with spending less while still getting great sound. I'm very happy with the "autoformer."