Arenith, I have an extremely complex digital 3-way active system. I started on the IfI bandwagon when I bought just one AC Purifier. The first track I played identified a quiet background cowbell that I’d never heard before. I was stunned. I then added two more AC Purifiers, a couple of DC purifiers and one USB Purifier. The final result produces a very detailed sound which is mainly improved in the higher frequencies and the tone (not a word I like) just seems better than without any of the purifiers.
I have a dedicated 240v ring circuit and attach three powerplants (each with a nearby IfI AC Purifier).
A Stellar P3 handles a Melco music server, which outputs USB (the source material is mainly CD rips, i.e. 16/44.1). The USB through a W4S Recovery USB reclocker (fed by a W4S LPS plus an Ifi DC Purifier). This then goes to a Chord M-Scaler (attached to the SP3). The M-Scaler upscales 44.1/16 to 88.2/24 and outputs coax S/PDIF. This then goes to a W4S Remedy reclocker which converts to 96/24, the reclocker is fed from the W4S LPS plus an iFi DC Purifier.
The 96/24 then goes to the DEQX digital crossover. The Crossover works internally at 96/24 (so feeding it with 96/24 avoids internal upsampling). The crossover outputs three coax 96/24 S/PDIF streams.
The DEQX digital crossover is attached to a P10 (for convenience and load spreading the P10 also drives the two 2 channel bass amps (each speaker has a pair of 15" bass drivers directly connected to the amp channels).
The above kit also has a total of five Sunyata Delta NR power cables with their RFI filtering.
The final P10 has three Direcstream dacs connected and a pair of BHK250s connected. All the power cables to and from this P10 are PS Audio AC5s (remember I’m in a 240v country). My aim was to clean up the digital input to the crossover as much as possible but to leave the final dacs and power amps connected without any filtering. You can see that there’s a huge amount of digital processing before hitting a dac and each unit will have added power noise and without excellent reclocking may have added additional jitter.
The above explains the main paths for listening to CD rips. I mentioned using a converter to convert USB output from my computer when using Spotify Free (which sounds crude unless it gets improved).
My Computer uses two USB outputs. One is connected to the DEQX crossover purely for management purposes (e.g. setting of parametric equalisers) and I add an IfI USB Purifier to clean up USB from the computer. The other USB output of Spotify goes to a USB reclocker - it’s a Mutec MC 1.2 (this is powered from the USB and won’t switch do anything until it gets USB power) which purely converts USB to S/PDIF which is fed to the Chord M-Scaler.
To summarise, I’m afraid it’s difficult to say which purifiers provided the most benefit. I think the reclockers (all of which have very fast clocks) all help greatly (IfI make S/PDIF cleaners but I’ve not tried them, as I already had W4S reclockers - I might try the IfI gear when DEQX bring out their new digital crossover at the end of the year).
One final note. The IfI purifiers are not expensive and the cost of them pales into insignificance compared with the cost of the rest of the system.
Dan.