I have recently upgraded my AVA FET Valve Hybrid Preamp to the new FET Valve CF version and have spent a little more than a month listening and evaluating it. The purpose of this post is to share my experience and initial thoughts on its performance. I will cut to the chase and “bottom line” it right now by saying - this new “CF” preamp is a
very nice improvement over its highly regarded predecessor.
Frank Customer Service:First a quick note about AVA’s customer service. I sent my, less than 2 year old, FET Valve Hybrid Preamp back to Frank and he happened to received it on a Friday. The following Monday morning I received an email from Mary with a tracking number for the new “CF” preamp return shipment. I found this hard to believe so I called AVA and Mary answered the phone and sure enough she confirmed saying: “Yes, Frank was all prepared to receive your preamp, he spent Saturday performing the upgrade, then spent Sunday listening to it most of the day, and we shipped it out to you this morning”. Talk about customer service, Frank & Company’s service is a dream come true, what more can be said?
Evaluation:
This review presents an evaluation of the new “CF” preamp in the following tube configurations:
Genalex Tube Selection:The reason I selected the Cryoset Genalex ECC82 & ECC81 tubes as my first choice to evaluate in the new “CF” was due to my previous experience with the same Cryoset ECC81/12AT7 tube performance in the FET Valve Hybrid 600R amp. Needless to say in the 600R amp this ECC81/12AT7 tube was a fantastic performer so this was a natural “best first guess” for a tube to try with the new “CF” preamp.
Evaluation System Description (2 Channel):The main system used for this review is comprised of the following components: AVA - FET Valve Hybrid DAC, FET Valve CF preamp, FET Valve Hybrid 600R amplifier, a pair of Salk Sound HT-3 speakers, and a listening room with good acoustic dampening. A full and complete system detailed description and listening room details are presented at the end of this review.
Evaluation Test Conditions, Method, and Process:For evaluation purposes all critical listening was conducted in the most disciplined and consistent method as possible. Tubes all had a QTY of one Herbies Audio Lab, Ultra Sonic RX-9, tube dampener mount on them during evaluation sessions. All tube sets were broke in for a minimum of 36 hours prior to any critical evaluation sessions. When preamp tubes were exchanged a minimum of 45 minutes of warm up time was achieved prior to evaluation listening. For comparison of preamp configurations (A thru D) the same music track selections were used as reference points for the purpose of comparison evaluation. Critical listening evaluations were conducted over several days. Listening session for each different preamp configuration (A thru D) were initiated with a baseline music track playlist to re-establish listening reference points. A full list of musical tracks (baseline tracks & evaluation tracks) used in this evaluation are presented at the end of this review. Evaluations were performed with the “CF” preamp High/Low filter pushbutton in the ON position and again in the OFF for all tube configurations (A thru D).
Evaluation Configuration A (“as delivered” CF: JJ - ECC82 / Gain Stage: JJ - ECC81):My very first impression with the “CF” was how deep, dark, and black the background noise was (or more correctly “wasn’t”). No noise at all, none, anechoic, as I would imagine an “outer space” vacuum type of quite. Words are hard to find that describe it but once you experience it you will “get it”. Next I discovered that this deep dark background goes hand in hand with a new level of dynamic range, a more refined liquidity of resolution and image, and clarity of source material that is presented in a truly lifelike coherence. From the highest of highs, the lowest of the lows, and everything in-between this preamp reveals new levels of details from the same old source material. Compared to the FEV Valve Hybrid preamp predecessor the new “CF” has a “just rightness” about it in all the right places. The ever so slight harshness and shrill that I could sometimes hear on certain source tracks with predecessor preamp was gone with the “CF”. All-in-all the new “CF” preamp is truly awesome, definitely a better sounding preamp than the predecessor, and takes the listening experience into a new domain.
Synergy with the FET Value Hybrid 600R amp? Maybe the “CF” incredible performance is due to its synergy with the 600R amp because of the amps ability to handle dynamic range so well. It would be very interesting to evaluate a different amp with to get a different perspective. At this time I have no other amp available to use as a comparison for testing this hypothesis.
Evaluation Configuration B (CF: Genalex - ECC82 / Gain Stage: JJ - ECC81):For this “B” configuration the original cathode follower JJ tube was swapped out with the Genalex counterpart. This Genalex tube provided a subtle (not immediately noticeable) improvement in sound quality. After close evaluation of many different tracks and swapping back and forth to and from the original JJ tube, a slight smoothness was discernable in both ON and OFF positions of the High/Low filter. The subtle smoothness was noticed on the decay of the cymbal that is struck in the beginning of the Lynyrd Skynyrd track “Tuesday’s Gone”.
Evaluation Configuration C (CF: JJ - ECC82 / Gain Stage: Genalex - ECC81):For this “C” configuration the original gain stage JJ tube was swapped out with the Genalex counterpart. This time a nice level of sound quality was noticed across all tracks and genre. The best way I can explain this improvement is an overall “just rightness” through out throughout all source music. The music just sounds better, more believable, and more real/lifelike. The undertones and overtones of voice and instrument harmonics are revealed more precisely.
Evaluation Configuration D (CF: Genalex - ECC82 / Gain Stage: Genalex - ECC81):For this “D” configuration both JJ cathode follower and gain stage original tubes were replaced with the Genalex counterparts. The results of this configuration was subtle, even more so than what was observed in configuration “B”. Since the Genalex gain stage tube was established to be a good improvement in sound quality this “D” configuration was all about the Genalex cathode follower tube performance. After multiple days of evaluation and swapping out the cathode follower tube from Genalex to JJ tube 3 different times finally a real, but subtle, difference was revealed. This improvement was demonstrated on two specific music tracks: The first track (1) was with the Pretenders, Greatest Hits album, the track titled: I’ll Stand by You. Deep in this track there is a high pitched electric acoustic guitar segment that produces a slight but noticeable shrill (I can best describe it as a high pitched dirty scrubbing sound). The Genalex cathode follower tube sweetened this shrill and made it sound more natural and lifelike. The second track (2) was Lynyrd Skynyrd, Pronounced album, the track titled: Tuesday’s Gone. At the beginning of this track there is a cymbal strike. The decay on this cymbal strike is smoother, more lifelike and real sounding with the Genalex cathode follower tube. Later, in this same track the lead electrical guitar solo produces a hint of high end shrill which the Genalex tube smoothed out and produced a more lifelike and real sound. Both tracks were evaluated thoroughly with the High/Low filter switched to the ON and again in the OFF positions with the same results. These two tracks demonstrated and confirmed the performance advantage of the Genalex cathode follower tube.
Evaluation Summary:Please note that even though there is an improvement with the Cryoset tubes all tube configurations (A thru D) represent a superb, high quality, listening experience that is much better than what was produce by the FET Valve Hybrid predecessor preamp.
The configuration matrix table below provides a results column with the best performing configuration being “D” with its 1st ranking. There were subtle performance gains between configuration “A” & “B” with “B” being the better performer. There were subtle performance gains between configurations “C” & “D” with “D” being the better performer. There was good performance gains between configurations “A” & “D” with configuration “D” being the best performer of all 4 configurations tested. The biggest improvement was attributed to the Cryoset Genalex, ECC81 gain stage tube. This same tube also provided big performance gains in sound quality in the 600R amp. Perhaps there is some unique synergy going on between the new “CF and the 600R. I would like to test this hypothesis sometime in the future.
Music Tracks used for Reference & Evaluations:
Test System Detailed Description:The picture below of the system is about a year old but is still an accurate representation of the system as of the date of this review.
System Components (2 channel system):Speakers: Salk Signature Sound, Veracity HT3, floor standing, full range
DAC: AVA, FET Valve Hybrid
Preamp: AVA, FET Valve CF Preamp
Amp: AVA, FET Valve Hybrid 600R
Universal Player: OPPO Digital, BDP-103
Digital Media Server: Windows media player, source music compiled in lossless digital format
Component Vacuum Tubes (matched pairs):DAC: QTY 2, Cyroset-Genelex, Gold Lion 6CG7/6FQ7
Amp: QTY 2, Cyroset-Genelex, Gold Lion, ECC81/12AT7
Preamp:
Original “As Delivered”– Gain Stage: QTY 2, JJ, 12AT7/ECC81
Original “As Delivered” – Cathode Follower: QTY 2, JJ, 12AU7/ECC82
Evaluated – Gain Stage: QTY 2, Cyroset-Genelex, Gold Lion ECC81/B739
Evaluated – Cathode Follower: QTY 2, Cyroset-Genelex, Gold Lion ECC82/B749
Interconnects: Media Server to DAC: Toslink Digital Fiber Optic
Universal Player to DAC: Digital Coax
Digital Cable Box to DAC: Toslink Digital Fiber Optic
DAC to Preamp: Cryoset Analog, 4.0V (1.3m), cryogenically treated
Preamp to Amp: Cryoset Analog, 4.0V (1.3m), cryogenically treated
Amp to Speakers: Reality Cables, cryogenically treated, 8 ft.
Other System Components:Tube Dampeners: Herbies Audio Lab, Ultra Sonic RX-9, on each tube
Component Dampeners: Herbies Audio Lab, Tenderfoots, under each foot of component
Component Stabilizers: Herbies Audio Lab, Supersonic stabilizer, on top of each component
Power Conditioning: Balance Power Conditioner, Model BP1, used for powering DAC, Preamp, and Universal Player
Power Isolator: Balance Power Isolator, Model CPC, 20 amps, used for powering amplifier.
Media Room:Shape and Size: Rectangular, 13.5’ wide, 16.5’ long, 9’ high
Walls constructed with wood frame and drywall, floor is padded carpet over concrete.
Acoustic Treatments: QTY 18, 2’ by 4’ wall & ceiling panels. QTY 9, 18” by 18” by 4’ solid bass corner traps.
Relevant Website Links:http://www.avahifi.com/http://cryoset.com/All comments and questions are welcomed
Kyle
