Duelund CAST PIO Hybrid Copper-Silver (Cu/Ag) Capacitor Review

I currently own two pre-amps.  K&K Audio's Mir Line Stage Pre-amplifier, which is a recent addition and I intend to write about it in the near future.  And Audio Note Kits (now ANK Audito Kits) L3-Pre.  with Audio Note UK HiB C-core output transformers.  I have been using the L3 for almost 9 years and I have made many upgrades.  Almost all electrolytic capacitors are Blackgates, resistors are AN-UK and Tantalum resistors,  stepped shunt attenuator etc.  As to the coupling film capacitors, I have tried, Audio Note UK Silver Foil, VH  Audio CuFT then Duelund CAST PIO Copper (Cu).  The most recent upgrade was to change this coupling film capacitors to  Duelund CAST PIO Hybrid Copper-Silver (Cu/Ag).

I presume most of you found this page would already know but this so call hybrid capacitor is internally constructed with  two capacitors: a main copper foil capacitor that is bypassed by a small silver capacitor potted together. As my impression of Cu/Ag would build upon my impression of Cu, let me first quote what I wrote about it in my website a few years ago (full text here).

" Immediately after the installation, those capacitors sounded a bit-off but never too harsh or too bright.  It had a strange tonal balance as if one has gone creative using an equalizer.  After a few days of breaking in, the sound truly blossomed.  What struck me first was the sound texture of music instruments.  I was listening to drum solo in the Tommy Flanagan’s “Overseas” CD and the tum tums sounded incredibly real.  I was able to clearly hear the resonating sound of the body of the string instruments, especially cellos and acoustic guitars.   Saxophones and trumpets sounded warm and brassy.  Human voices are very real with warmth and sounded holographic for those CD that are exceptionally well recorded.  Classical and many genre of Jazz recordings sounded closer to the way I am used to hearing them in live performances than I have ever heard from my system.  Highs are smooth and extended and lows are weighty, deep and tuneful."  

What I notice improvements with Cu/Ag over PIO Cu in my system was the increase in the level of details retrieved from recordings.  In addition, it improved PRaT (Pace, Rhythm and Timing) factor. As a result, I felt the overall reproduced illusion of presence and reality of singers and musical instrument have improved. I also noticed, slight improvement in high frequency extension which added to the sense of space.   The overall tendencies and characteristics of the sound of Cu/Ag are on the same direction with the Cu adding incremental but notable improvements.

If you are considering using Duelund capacitors and do have the budget and space in your equipment to install, I would whole wholeheartedly recommend to consider Duelund CAST PIO Hybrid Copper-Silver.

Well reputed review of capacitors : http://www.humblehomemadehifi.com/Cap.

Duelund Website : http://duelundaudio.com/cast/