I'd been using a Rega Apollo R for a fair few years as a transport and tried various flavours of DAC before settling on a lightly modded Xiang Sheng DAC-O1A for streaming music and as a DAC for the Apollo (which it easily) bettered having given up on serious DACs and streamers mostly due to the lack of control on download quality in terms of mastering....how many know the origins of their streamed files or who mastered or produced them? Music quality was just too variable for me.
Then I rediscovered what Red Book done really well could offer me again, albeit using a high quality CDP. I sold the Rega, put the DAC into storage (where it remains) and bought an Acoustic Research CD7 Reference (strictly speaking a so called CD7.5 Reference, the name given to the factory upgraded original with improvements to the valve regulation circuit). I've been in love with this player since it first came out, partly due to it using the entire gain stage lifted out of the AR Ref3 pre-amp, a multi-award winnng design which still sounds fabulous to this day, if a little spendy new.
The one I bought had a few issues so was sent to Absolute sounds for a full overhaul including new NOS transport including laser assembly, a full compliment of new valves and a few tweaks. It uses a Crystal 24 bit oversampling DAC and for a diehard fan of well implemented 1541 chipsets, this was an unknown but hearing one left me in no doubt it ranked up there with the best digital sounds I'd ever heard at any price.
I've since spent many happy hours rediscovering my entire CD collection and it's an understatement to suggest this is an end game player for me. The most analogue sounding player I've ever come across, which unlike most, doesn't tend to compress the soundstage depth. It delivers effortless scale with real bass heft and is sublimely smooth without losing anything in resolution or frequency response, unlike some NOS 1541 players I've had. I think that the output stage is crucially important in CDPs and the twin 6H30 triodes per channel using that CD Ref 3 circuit are no doubt part of that magic delivering ultra low distortion across the whole bandwidth.
However, whilst it gives my TT systems a real run for their money and even excels with full dynamic range CD's (including the superb Hans Zimmer Interstellar sound track which thrashes the vinyl version), it still cannot compete with the Acoustic Signature Turntable/Convergence Signature phonostage unless CD's are low in audio compression. Thankfully this covers many of my classical CDs but more modern vinyl releases are still better spun up on the TT. Physically, it's a bit of a beast and weighs a proverbial ton.
A few gratuitous pictures:
