HifiZine
The enthusiast's audio webzine

Grant Fidelity W-30GT Integrated amplifier

As I have continued my journey though the home audio hobby, my personal preferences have taken an unfortunate fork in the road. Naturally, what I continue to strive for is always better sound quality in my music playback. However, I have also grown tired of many components being connected by many wires in a large jumble in my living room. A minimum number of components has always been required in my system as I run a PC based music server which sounds best with an external digital to analog converter. Having played around with many preamplifier/amplifier combinations in the past, as well as integrated amplifiers coupled with DACs, I still had not found the right combination of form and function. Finding an integrated amplifier with an on-board DAC is easy. However, finding a vacuum tube integrated amplifier with an on-board DAC was like a study in cryptozoology. I found many fantastic vacuum tube integrated amplifiers on the market, but none with an on-board DAC during my product search. Then one day while looking over Grant Fidelity’s site, I noticed a vacuum tube integrated amplifier that had never caught my eye before. The description on the product page was “Grant Fidelity W-30 Integrated All-in-one Tube Amp w/ Phono”, so not being vinyl guy, I did not give it much thought. However, after clicking around to the rest of their integrated amplifiers, I went back to the W-30 to give it a second look. To my amazement, the first words on the page were, “Celebrating Grant Fidelity’s 5th year anniversary, we are pleased to launch our latest offering the W-30 Fully Integrated Modular Digital Analog Tube Amplifier”.

The Grant Fidelity W-30GT vacuum, integrated amplifier arrived on my doorstep shortly after a conversation with Ian and Rachel about the details of their new modular integrated tube amplifier. Having just come off a solid-state kick, I was looking for some tubes to play around with on my horns; a little filament glow to light up my living room. My last integrated tube amplifier (Shuguang Treasure S300MK) was what I would consider a true tube amplifier with tube rectification, high-voltage (650v) output tubes, different input and driver tubes, and a class A sound that lets you know these are the best tubes you’ve ever heard. This new integrated tube amplifier was an interesting hybrid of technology; DAC section, Phono section, headphone output, solid-state rectification. Knowing that I needed a comparison between these two different styles of vacuum tube amplification, I dragged out the 300B integrated amplifier for a head-to-head comparison; but more on that a little later.

I love features in a piece of audio equipment. So when I downloaded the manual for the W-30 while the amplifier was in transit, I quickly found myself in feature heaven. Here is a short list of the features built into the Grant Fidelity W-30GT integrated amplifier: headphone output tapped from the power tubes 30 ohm to 600 ohm, tube phono stage using two 12AX7s with 40 dB of useful gain, 192 kHz/24-bit DAC via coax/pptical inputs, 48 kHz/16-bit DAC via USB input, tape record/line level outputs, pre-out jacks for biamping or a subwoofer, pre in/out jacks for external processing or amplifier, manual power tube bias to tailor the sound to your speakers, clip power indicator, all-aluminum remote control, Jungson HQ pure copper patented output transformers, gold-plated connectors including WBT speaker terminals. With all these features, this amplifier obviously replaces the usual stack of components that sits on your component rack; but how would it compare to all these separates, and would consolidating down to a single component be sonically worth the minimization? I was excited to find out for myself if this integrated amplifier could sound as good as separate components, and whether compressing everything into one box really was a good idea.

Build quality overall is pretty good, but not top notch as I would expect for a component costing twice as much. The chassis and cage is standard stamped steel, with rubber feet for clearance and dampening. Connectors are good quality, with the binding posts on top of the back panel facing up rather than facing back. At first I did not like the look of this design, but once I connected my speaker cables, it made sense to me as bare wire, spade, or pin connectors would connect straight into the amplifier rather than against the back. Luckily for consumers, Grant Fidelity thought ahead and the insulated, 5-way binding posts are also big enough to allow for banana plugs like mine to be inserted straight through the post instead of having to be plugged into the top which would be awkward with short or stiff cables. My only negative comment about build quality seems to be more of a programming issue. The front of the amplifier has two large knobs; the left for selecting input and the right for volume control. The issue is that the input selector knob turns the wrong direction in my opinion. For example, when I turn the knob clockwise, the input below the current one is selected; clockwise for down and counter clockwise for up. It is not an issue that affects the sound quality or my overall opinion of the amplifier, it just took me a little while to get used to as it is not the natural direction in my mind.

The first comparison was of the internal DAC. Previously I had been using the Audio-GD NFB-7 which is 35lbs, three transformers, and separate digital and analog boards worth of DAC. Being the best DAC I’ve heard to date, the internal DAC board in the W-30 was in for a challenge. Connecting the NFB-7 to the analog inputs on the W-30, and feeding both the NFB-7 and W-30 the same digital signal out of my Audio-GD Digital Interface, I was ready to play a few tunes, switch inputs back and forth, and hear how the two DACs compare directly. Playing through Paul McCartney’s “Band on the Run” in 24/96, I started to get a good feeling for the difference between the two units. For starters, the NFB-7 provides a bit more depth and exaggerated detail. The noise level is very low on both, and both provide a very dark background for the music. After listening though the album twice, I can definitively say that the NFB-7 is a better DAC; but not better enough for a separate chassis. As great of a DAC as the NFB-7 is, if you only need the three connections that the W-30 provide, the W-30 has a good enough DAC that you will not give an external DAC a second thought. Ian and Rachel have also assured me that since the DAC section of the W-30 is modular, they may decide to release more/different DAC sections in the future, which would simply be plugged in to replace the current option.

The second comparison I did was between the W-30 and the Shuguang Treasure S300MK. These two amplifiers are both integrated, tube amplifiers, but that is where the similarities end. The W-30 is a class A/B amplifier using your choice of pentode tubes at 40wpc whereas the S300MK is a class A amplifier using 300B triode vacuum tubes at 9wpc. After warming both amplifiers up, and ensuring that both were using stock tubes (Shuguang EL34 and Shuguang 6N1 for the W-30 and Shuguang Treasure 300B, Shuguang Treasure 6CA7, Shuguang 12AX7, and Shuguang 5AR4), I started the comparison using my custom Klispch Forte speakers.  Playing through a number of albums including “Genius Loves Company” by Ray Charles in 24/96 and “Brushfire Fairytails” by Jack Johnson in 16/48, I let the music of both amplifiers soak into me before coming to any conclusions.

When I started penning my thoughts, the differences flowed to paper as cleanly as the music was presented by both amplifiers. Both amplifiers are very musical in their presentation and enveloped me in song playing though the horn speakers. They both have the great musicality and tone that I attribute to good tube amplifiers, and they both present a sense of soul. However, the S300MK does give a warmer presentation that comes across as more musical. Part of this could be attributed to the frequency response of the 300B tube verses the EL34 tube and its mid-range emphasis. The sound difference could also be attributed to the class A amplifier topology verses the class A/B topology. Whatever the cause, the S300MK does sound more musical and presents a fuller sound stage than the W-30. However, similar to the DAC comparison, the difference between the two amplifiers is not huge as far as enjoyment. Yes, both amplifiers present a different listening experience with the W-30 sounding more flat than the S300MK, but both just sound great. Both amplifiers draw you into the musical experience, and make you want to listen to music for hours. The S300MK to my ears is the better amplifier for a listening experience, but the W-30 has a few more options which could give it a leg up.

Having had the W-30 for a while now, I have had the opportunity to put it through the paces and see the different sides of the amplifier. Ian and Rachel from Grant Fidelity were nice enough to ship a quad of Shuguang KT88 tubes with the amplifier as well as the Shuguang EL34, to provide a different sound while testing the amp. The amplifier can accept EL34, KT88, 6L6 or variants as output tubes, as well as 6N1P, 6DJ8, ECC88, 6922, and variants as input and driver tubes. After burning in the amp, the stock Shuguang 6N1 input/driver tubes, and both sets of output tubes, I swapped the KT88s and EL34s back and forth to get a good feeling to their tonal and sound quality difference. Being that the amplifier is manual bias for output tubes, the user does need a voltmeter or multimeter and screwdriver in order to dial in the correct amount of bias to provide the best combination of sound quality and tube life, while also preventing red-plating. Ian provided me with a number of recommended bias points for each tube, which were easy to follow as long as I remembered to turn down the bias when switching tube in order to not overload them on start-up. Having listened to both KT88 and EL34 tubes in the past, the W-30 did a great job at presenting the tone and character of each tube on playback. With the KT88s loaded in, the sound was balanced and even with strong bass. Music was powerful, yet detailed, without being warm or mushy. It truly sounded like the flat response I have come to expect from the king of the pentode tube. On the other hand with the EL34 tubes loaded, the sound was warm and detailed with pleasantly exaggerated mids, and tone that any guitar or horn lover would listen to every day. Being able to retain the tone and character of each output tube rolled is a difficult task, but accomplished wonderful and musically by the Grant Fidelity W-30.

To ensure that I peeled back all the layers of the W-30, I decided to test out its preamp output. Ian told me that it was intended to be used as a second output for bi-amping a pair of speakers along with the W-30, but I decided to try it running the W-30 as a preamp only. The process was fairly simple, although Ian’s recommendation should be taken to heart. “When using the W-30 as a standalone pre-amp and not using the amplifier section, we recommend that the user remove the pre in/out jumpers so that no signal is going to the amplifier section. Then any 4 to 10 ohm (5 watt minimum) resistors can be used as the dummy load across the W-30 binding posts. We further suggest that any expensive tubes be removed from the power section and be replaced with affordable current production stock tubes. Biasing will still need to be checked on at least a monthly schedule.” Once I had the signal cables connected between the W-30 and my Harman/Kardon HK775 monoblocks, I sat back to take a listen; knowing that the output tubes in the W-30 were “on” even though there was no signal being run through them.

The sound of the W-30 as a preamp was just as delightful as what I had come to expect from the Grant Fidelity W-30 as an integrated amplifier. The music was detailed with a slight tube warmth that was very enjoyable, and the W-30 truely imparted its flavor on the solid-state monoblocks making the sum of their sound better than other preamps I had heard with those amplifiers. I very much enjoyed listening to music using the W-30 as a preamp, but it does seem like a bit of a waste of equipment using it in that way. “We provided the pre-out jacks for bi-amping etc and our thoughts on the pre-in/out jacks was more for jumper cable tweaks or processors, or HT integration. Of course using it as a stand alone pre-amp is always an option at the expense of maybe $80 worth of tubes doing nothing every 3000 hours or so.” Ian put words to my thoughts exactly. Besides all the above mentioned hassle involved with setting up an integrated amp as a preamp, the W-30 has a great output section that should not be ignored.

Listening to the W-30 concluded with headphones as I plugged my Klipsch X10i into the ¼” jack on the front of the amplifier. One very unique aspect of this amplifier is that it drives your headphones by tapping off of the output tubes, whereas most tube integrated amplifiers simply use a separate opamp to drive the headphones, thus losing the sound characteristics of the amp. The listening experience though headphones was very similar to speakers as the Grant Fidelity W-30 provides very low noise with excellent dynamics. I have always thought tubes and headphones paired well, but I had never listened to headphones driven off output tubes – and it was a new and delightful experience. Clearly because of all the other features, the W-30 was not designed to be used as a primary headphone rig, but it does the job just as well as it drives speakers. For the casual or late-night headphone user like myself who wants tubes but does not want to invest it a separate rig, this is the perfect solution for that quick but infrequent on/in-ear fix.

The only part of the amplifier that I did not get to test was the onboard MM/MC, 12AX7 tubed phono section. Not being a vinyl guy myself, I have in the past taken a road trip with test equipment to a friend’s house who does have a turntable and the full set-up. Unfortunately this time, we were not able to hook up because of schedules. Upon asking Ian about the phono input, he claims it is very quiet like the rest of the amplifier, and also allows the tube rolling and space-saving benefits I have come to know and expect from the W-30. I’m personally not interested in adding a turntable to my set-up as I’m continually improving and pushing my music-server based source, but having the phono section in the amplifier does give me peace of mind knowing that I always have the option to go that direction.

I have heard it said that variety is the spice of life. If you believe that to be true, the Grant Fidelity W-30 tube, integrated amplifier could be for you. Being able to roll variant tubes is one of the things that makes tube amps great. Being able to roll two different kinds of input tubes including variants, two different kinds of driver tubes including variants, and three different kinds of output tubes including variants is what makes the W-30 greater. Add in a DAC, a tubed phono section, remote control, and every input and output option available, and the W-30 is a mighty package at a more than reasonable price. As much as I enjoy the stock sound of the W-30, I really enjoy the ability to roll a majority of the popular output tubes on the market and have a new amplifier in the process every time. This is by far the most quiet tube amplifier I’ve ever heard, and even when turned up, is completely silent through my 98 dB horn speakers. Has Grant Fidelity created the perfect amplifier? Not quite, as every piece of equipment on the market has flaws. More importantly, Grant Fidelity has created an amplifier that I could enjoy listening to every day for the rest of my life; and that’s better than perfection.

Specifications

• Power output: 2×40W (RMS, Class AB, KT88)
• Output impedance: 4Ω, 8Ω
• Frequency Response: 10 Hz-30 kHz±0.5db, KT88
• THD: ≤ 1% at 1kHz
• S/N: ≥ 90% dB
• Input Sensitivity: 420mV (combined input)
• Input impedance: 100kΩ
• Tubes: KT88x 4 pcs, 6N1x 4 pcs, 12AX7x 2 pcs
• Power consumption: 240W
• Size: 17″ L x 16″ W x 8″ H
• Weight: 57lbs
• MSRP: $2100 with stock tubes

Associated equipment used for review

• Vortexbox Server
• Squeezebox Touch
• KingRex UD384 + UPower USB Transport
• DH Labs D-75 Digital Coax
• Luminous Audio Custom Silver ICs
• Custom Harman/Kardon 775 Monoblock Amplifiers
• Shuguang Treasure S300MK Amplifier
• DH Labs Q-10 Signature Speaker Cable
• Custom Klipsch Forte speakers with Jantzen Crossover and Crites Tweeters
• Tripp-Lite LCR2400 Power Center