It’s funny how the introduction of a new component to your system can highlight an issue elsewhere that you didn’t even know you had!
I have had and enjoyed my Aqua La Scala DAC for a few years now and for most of that time it has been fed by a Metrum Ambre streamer with the output of the DAC connected to the CD line input of my Marantz KI-Ruby integrated amplifier with RCA cables.
A week or so ago I upgraded the Metrum to a Lumin U2 Mini. The Lumin was simply inserted in place of the Metrum, connected to the Aqua using the same AES/ EBU cable and was configured as a Roon end point to minimise any user differences between the streamers. Over this short period the Lumin has shown itself to be a worthy replacement and I was looking forward to trying some of the alternative configurations it offers.
Last night my brother in law visited and we figured out that to use the Lumin’s Leedh digital volume control to best effect the output of the DAC should be fed into my amplifiers “PWR AMP” input bypassing its preamplifier section. This was a bit intense as I anticipated an error on my behalf with the Leedh volume control could explode my speakers!
All went well and when I played some music it sounded great, but there was a noise I hadn’t noticed before. Further investigation found that it was louder in the left channel than the right so everything was powered down and the channel inputs swapped over on the amplifier. The noise followed the swap so the culprit had to be my beloved DAC, this was most distressing.
This is where my brother in law earned his cup of tea and a cookie. He has the same DAC, actually I copied him, and he is more familiar with it than I am, not to mention he is a more “hands on” type whereas I am a manual muppet!
Now that I have finally got there this is the point where any Aqua La Scala users may care to take note.
This DAC has two valves but they are not used one per channel. They are twin triodes and one is used for its single ended output and the other for the balanced. My brother in law suggested swapping them over rather than assume my DAC was faulty so I left him to it. Turned out he was correct and with them swapped over the noise was gone and the sound was quite different. He suggested this was only exposed by the noisy output being fed into the unattenuated input. I generally listen at quite low levels so the noise never showed itself when fed through the attenuated CD line input of my amplifier. There is no telling if this valve was always noisy or it had deteriorated with use but I would suggest that anyone with this DAC and it is around 3-4 years old should try swapping the valves over, there may be a benefit.
I have had and enjoyed my Aqua La Scala DAC for a few years now and for most of that time it has been fed by a Metrum Ambre streamer with the output of the DAC connected to the CD line input of my Marantz KI-Ruby integrated amplifier with RCA cables.
A week or so ago I upgraded the Metrum to a Lumin U2 Mini. The Lumin was simply inserted in place of the Metrum, connected to the Aqua using the same AES/ EBU cable and was configured as a Roon end point to minimise any user differences between the streamers. Over this short period the Lumin has shown itself to be a worthy replacement and I was looking forward to trying some of the alternative configurations it offers.
Last night my brother in law visited and we figured out that to use the Lumin’s Leedh digital volume control to best effect the output of the DAC should be fed into my amplifiers “PWR AMP” input bypassing its preamplifier section. This was a bit intense as I anticipated an error on my behalf with the Leedh volume control could explode my speakers!
All went well and when I played some music it sounded great, but there was a noise I hadn’t noticed before. Further investigation found that it was louder in the left channel than the right so everything was powered down and the channel inputs swapped over on the amplifier. The noise followed the swap so the culprit had to be my beloved DAC, this was most distressing.
This is where my brother in law earned his cup of tea and a cookie. He has the same DAC, actually I copied him, and he is more familiar with it than I am, not to mention he is a more “hands on” type whereas I am a manual muppet!
Now that I have finally got there this is the point where any Aqua La Scala users may care to take note.
This DAC has two valves but they are not used one per channel. They are twin triodes and one is used for its single ended output and the other for the balanced. My brother in law suggested swapping them over rather than assume my DAC was faulty so I left him to it. Turned out he was correct and with them swapped over the noise was gone and the sound was quite different. He suggested this was only exposed by the noisy output being fed into the unattenuated input. I generally listen at quite low levels so the noise never showed itself when fed through the attenuated CD line input of my amplifier. There is no telling if this valve was always noisy or it had deteriorated with use but I would suggest that anyone with this DAC and it is around 3-4 years old should try swapping the valves over, there may be a benefit.
, but I'll certainly get back to you about those Valvos as and when 
