Audio by Van Alstine FET Valve CF Vacuum Tube Preamplifier Review Highlights
The FET Valve CF Vacuum Tube Preamp is a highly flexible little component. The base unit has six analog inputs, a tape loop, two line outs and a nice headphone amplifier. Possible upgrades include a remote volume control, a phono stage, a buffered tape out and a theater bypass switch. The preamp can also be ordered in either black or silver. So you can see that it is the type of component that will grow with your system
The only transistors in the box are used for power regulation. There are no transistors in the signal path. It is an all-tube design with a lot of line gain and an unwavering ability to feed just about any amplifier I can imagine. The sound is grain-free and detailed with just a touch of tube sweetness. The build quality is above what one would expect at this price point and the bench test results are quite strong for a tube component.
Audio by Van Alstine FET Valve CF Vacuum Tube Preamplifier Highlights Summary
- Solid build quality
- Plenty of inputs (6)
- High gain design
- Smooth, grain-free sound
- Excellent bass response
- Very good channel separation
- Lots of customization options
Introduction to the Audio by Van Alstine FET Valve CF Vacuum Tube Preamplifier Review
Audio by Van Alstine has been making high quality audio equipment for the better part of 40 years! They have a reputation for building solid, affordable amplification components. They have not expanded too much over the years and this means their customers enjoy a personal touch in dealing with the company. Odds are pretty good that Frank Van Alstine himself may well answer your emails or your phone call. I love this type of company because it means that the owners have a direct and personal commitment to their customers in terms of product quality and long term support.
AUDIO BY VAN ALSTINE FET VALVE CF VACUUM TUBE PREAMPLIFIER REVIEW SPECIFICATIONS
- Design: Vacuum Tube Stereo Preamplifier
- Inputs: 5 Unbalanced RCA, 1 Phono and 1 Tape Loop
- Outputs: 2 Pair Unbalanced RCA, 1 Pair Record Out RCA and ¼” Headphone (Front Panel)
- Tube Complement: One Pair 12AT7 (Gain Stage) and One Pair 12AU7 (Cathode Follower)
- Input Impedance: 47k Ohms
- Output Impedance: 560 Ohms
- MC Input Impedance: 30 Ohms to 1 kOhm (Adjustable)
- Line Gain: 20 dB
- Phono Gain: 60 dB (MC) and 40 dB (MM)
- Dimensions: 3.5” H x 17” W x 12” D
- Weight: 15 Pounds
- Available Colors: Silver and Black
- MSRP: $2,099 (Silver); $1,899 (Black) USD
- Options: Remote Control/Motorized Volume Control $299, Phono Stage $329, Buffered Tape Out $199 and HT Bypass $50
- Audio by Van Alstine
- SECRETS Tags: Vacuum Tube Stereo Preamplifier, Audio by Van Alstine, preamplifier reviews 2014, Vacuum Tube, tube component
Even though the company has been in business a long time, the following review of the FET Valve CF Vacuum Tube preamp represents my first opportunity for a long-term involvement with any Audio by Van Alstine product. I was quite excited the day the review unit showed up and my excitement didn’t waver one bit during the review as the preamp performed flawlessly during the evaluation period. Briefly, the line stage section is an all-tube design predicated on a cathode follower architecture. This means it is tolerant of difficult loads, has wide bandwidth and high gain. My review unit was packed with almost every available upgrade including the silver faceplate.
Design and Setup of the Audio by Van Alstine FET Valve CF Vacuum Tube Preamplifier
The Audio by Van Alstine FET Valve CF preamp is the next evolution of their highly regarded and award-winning FET Valve Hybrid Preamp. The biggest advancement is that the new FET Valve CF unit has an all-tube signal path where the prior model was a hybrid design.
Audio by Van Alstine claims that the updated preamp uses premium parts throughout to include precision volume and balance controls, a precision source selector, polypropylene capacitors in the signal path and multiple MOSFET-regulated power supplies.
The included tubes are a pair of 12AT7’s used for gain and a pair of 12AU7’s which serve as the cathode followers (CF). CF designs are said to be particularly tolerant of demanding loads. Additionally, well-executed CF designs offer low distortion and wide bandwidth with particular improvements in the bass.
My review unit had the silver faceplate and was packed with several of the available upgrades. Let me give a broader overview of the preamp before going into my description of the optional upgrades.
The sturdy front panel is machined from ¼” anodized aluminum. The clean look is dominated by three large knobs on the left. These are the input selector, the volume control and the channel balance knobs. Each of these controls has a tight and confident action.
There are two clusters of two pushbuttons above the main control knobs. These buttons are the Tape Monitor Selector, a Stereo/Mono Selector (nice), a “Low Gain” Toggle and a “Filter” button. The Low Gain switch reduces the gain when depressed and is used if the source doesn’t need a lot of gain and/or to allow greater selectivity of the volume control. I used the Low Gain setting a lot, especially with my Oppo BDP-105D which has a high output level. The Filter switch engages a filter that subtly reduces the low bass and the very high frequencies. I used this to tame the screechy highs on some older vinyl and also to reduce the bloat on some modern recordings. It can also be used as a rumble filter for your vinyl sources. The effect was subtle but useful and it is good to know that Van Alstine can tailor the frequency and slope of the filters on request.
On the right side of the faceplate are the power indicator, remote IR pickup, the ¼” headphone jack and the On/Standby switch.
In the back you will find a ground lift switch, 6 pairs of RCA inputs, a stereo tape in and out along with two sets of unbalanced outputs. Again, the parts quality and workmanship are of a very high order particularly when you take into account the reasonable price. This little preamp represents a no-nonsense design and execution in just about every respect.
Let’s talk about the included upgrades that came with my review unit. The “biggest” upgrade would be the optional remote control. For an extra $299, Van Alstine will include what is in essence a remote volume control with a motorized volume pot. Take a look at the image of the remote. This is my kind of remote! (Although it may be the most intuitive remote ever invented, you would be surprised how many of my friends studied this clicker very closely before adjusting the volume. I was flummoxed, what else could this remote possibly do?)
The next upgrade is a $249 phono stage that Van Alstine describes as an “outstanding brand new split passive EQ optional phono section with its own isolated regulated power supplies.” This add-on has flexible loading options (factory-set) and takes up Input 1 when installed. My reference cartridge is the Sumiko Blackbird which is a high output MC design that uses similar loading as an MM cart. This phono stage proved to be way better than I expected and I have a lot to say about it in the “In Use” section to follow.
Here is how Van Alstine describes the included power supply – “The power supply consists of a multi-tapped shielded toroid power transformer, a high voltage diode bridge and six isolated high voltage active regulators, one for each half of each tube section (the cathode followers run both halves in parallel). There is a separate regulated power supply for each channel’s tube heaters. If any solid state option is ordered (phono, tape buffers, or inverters) two additional low voltage regulated power supplies are installed. An additional regulated power supply drives the remote control board, and there is one more for the mute circuits.”
One last point is that the FET Valve CF Preamplifier has a built-in speaker protection network that provides a 30 second time delay at turn-on and an instant disconnect at turnoff to suppress switching transients.
The Audio by Van Alstine FET Valve CF Vacuum Tube Preamplifier In Use
From an operability standpoint, the AVA FET Valve CF preamplifier was about as simple as could be. It is a straight forward design with many useful features. I used many of the features on a regular basis.
Of the included features, I used the Low Gain switch most often. This was due to a number of reasons. First off, some of my sources have pretty high level outputs like the aforementioned Oppo BDP-105D. Secondly, the FET Valve CF preamp has gobs and gobs of gain. It is nice to have this much gain. It means that your preamp circuitry is operating well within its design envelope. Lots of gain is also useful in the event you need it for weak source components or poorly mastered material. But I found most of my sources did not need all the available gain so the Low Gain switch remained engaged a majority of the time.
Another point on this topic – AVA claims that the circuit design of the FET Valve CF Pre is so pure that you will find yourself playing back your music at lower volume levels due to the increased clarity. They are definitely right about that. I wound up keeping the volume lower than usual while still hearing all the intricacies in my music. The Low Gain mode allowed for a wider range of volume selectivity at these low levels.
I also used the Filter Circuit once in a while. In so doing I was typically trying to take some of the sizzle out of period recordings or trying to reduce the bloat on some more recent recordings. I also used it as a rumble filter on warped records.
One little problem I had with this preamp was with the Mute function. There is no mute switch on the chassis so the remote is the only way to mute the output. Since there is also no visible indication that the mute is engaged, there were times when we would check the input, the source, the amp, pretty much everything else until someone remembered that we had pressed the mute button on the remote. It’s OK for you to laugh at this, but it happened more times than I would like to admit.
I started my listening evaluation by testing the headphone amplifier over a pair of Onkyo ES-HF300 headphones. These phones are a relatively easy load and the AVA didn’t miss a beat. I particularly loved the sound I got listening to a high resolution download of Beck’s “Morning Phase” album through my Oppo player. The AVA and Onkyo combo brought forth the bass in a strong supporting role and with more nuance than I have heard before. I also tried the headphone amp with some Paradigm Shift E3m ear buds and enjoyed the AVA’s smooth, extended presentation. The only thing I didn’t like about the headphone amp is that using it didn’t automatically mute the line level output. You must remember to turn off your power amp.
I will lead off the discussion of the preamp as a linestage by evaluating Allison Krauss and Union Station’s most recent album “Paper Airplane”. I bought this album on heavy vinyl when it first came out. Frankly, I haven’t liked what I’ve heard from this record audio-wise. The fidelity has been something of a letdown. So I was most pleased with what I heard when I listened to it through the included RIAA input in the FET Valve CF preamp.
The first thing to strike me was that it sounded much cleaner and better balanced than what I have heard in the past. Krauss’ voice was as pure as I imagined it should be. And on the tracks that call for it, the bass thundered without obfuscating the upper registers.
Then I noticed that there was a seamless spread across the front that was much wider than the speakers’ separation. Though it was wide, the stage did not lose any of its placement specificity and this was heard clearly on “On the Outside Looking In” where Dan Tyminski’s voice emanated from a black space, floating in the middle of the room.
After this, my notes just say that the AVA RIAA EQ “respects your music”. I then sat back and just listened.
Next up was The Who’s great classic “Tommy” which was recently reissued by Quality Record Pressings. Thankfully, this new record is not gratuitously compressed like so many other iconic rock albums.
There were two aspects of the sound that were about the best I have heard from my Blackbird cartridge – the channel separation and the bass extension. The Van Alastine preamp really let my vinyl front end shine in these areas. But that was not all. The overall sound was at once smooth and dynamic. And Daltry’s voice had a fleshy presence like hearing him in person. The phono stage in the AVA preamp is among the best affordable phono preamps I have heard.
Now I wanted to listen to some more digital fare so I fired up my Blu-ray player and inserted my Phantom of the Opera 25th Anniversary at Royal Albert Hall disc. This disc’s audio and video are both reflective of a very high production standard. One reason it sounds so great is that all the singers are mic’d, including the chorus.
The FET Valve CF’s strongest quality on this disc revolved around the high gain which led to unrestricted dynamics. (The gain can get away from you on louder passages sort of in the way a sports car’s tires might break up if you aren’t paying attention.) You need to find the right set point so the loud passages stay within the capability of your amp and speakers. When the volume control was set to an optimum level, the AVA preamp really let the lively dynamics flow on this disc.
The staging was a highlight once again with the soloists’ front and center while the orchestra painted the edges. The stage depth was still better than average if not the best I’ve heard. With the dynamics, the staging and the smooth accuracy of the FET Valve CF, “Music of the Night” gave me goose bumps despite that I have heard it a thousand times before.
It all snapped into focus on the “Jack Ryan: Shadow Recruit” Blu-ray. As with the Phantom disc above, I needed to play with the gain a little to find the “right” volume level. And once I found it, then the whole of the presentation came to offer a deep audible experience. Not just in the extremes, as it is, but also in a sense of spatial reality. There was bass extension that went on forever with a warm yet fresh sound up top. The mids were simply golden and eerily lifelike. It’s at times like this where adding surround would be a purely frivolous effort.
The Audio by Van Alstine FET Valve CF Vacuum Tube Preamplifier On The Bench
The first test I ran was a 1 kHz sine wave at 2V RMS. THD+N measured just 0.00381% with the first harmonic being 90 dB below the test tone.
Still tested at 1 kHz, but bumping the output to a blazing 5 Volts (14 dBV) RMS, the FET Valve CF’s THD+N rose to 0.00862% and the first harmonic was 83 dB below the fundamental.
This is the Intermodulation Distortion Test with signals at 60 Hz and 7 kHz. The measured IMD at 6 dBV (2 Volts) came to just 0.0028%.
This is the other IMD Test we run with signals at 19 kHz and 20 kHz. The B-A peak is 90 dB below the signal at 2 Volts output.
This plot shows the frequency response of the FET Valve CF at 2 Volts output. Notice the scale of the vertical axis is highly exaggerated in order to make the response curve easier to see. The response is within 0.25 dB of flat from DC to 20 kHz. It continues to roll off from 20 kHz to 90 kHz at which point the response is 1.4 dB below the 1 kHz level.
Conclusions about the Audio by Van Alstine FET Valve CF Vacuum Tube Preamplifier
I highly recommend the Audio by Van Alstine FET Valve CF Preamp. It is an all-tube design that isn’t crazy expensive like so many competing products on the market. It has been designed with care to perform in just about any system I can imagine. And the sound is not overly mellifluous as one may wrongly expect based on the tube design. Instead, you get a sound that is accurate, extended, clean and with lifelike transient response. Sure the tubes add a touch of the golden hues tube lovers crave, but that doesn’t define or dominate the sound you hear. It’s simply a natural smoothing of the rough edges adding a nice bloom to what you hear. The FET Valve CF Preamp is also capable of excellent staging in both width and depth.
Another strong point is the flexibility of the unit. Six inputs, two outputs and a tape loop. Plus you can customize the unit with so many available options. You could start with the base unit and then upgrade later if you have real-world budget problems like the majority of the population. But I would strongly advise those with turntables to order the phono stage with their FET Valve CF Preamp. This phono stage in and of itself may be the best value in audio that I’ve heard this year.