AGD Productions Alto Stereo Preamplifier Reviewed

It is no secret that we at Future Audiophile are fans of GaN technology and have a great deal of respect for AGD Productions for getting on the bleeding edge of this technology. I was so thrilled by AGD Productions Tempo di GaB Amplifier (editors note: this amp has since been sold as of early 2024), I chose to make it a new reference piece for me, dethroning the Parasound A21 and A21+ amplifiers that formed the heart of my reference system for a decade. That’s a cash vote for the future of how amplifier technology is heading. 

Most good electronics companies like AGD Productions are not a one-trick ponies. In this spirit I requested the AGD Productions Alto preamplifier for evaluation to keep my excitement about AGD Productions in check. I also wanted to make sure that all of their equipment represents the outstanding performance of the Tempo (di GaN) amplifier. As always with today’s preamplifiers, there is a lot to cover, so let’s find out if the AGD Productions Alto stereo preamplifier represents the same value and cutting edge technology as their amps. 

What Makes the AGD Productions Alto Preamplifier So Special?

• The Alto is a fully balanced design with no capacitors in the analog signal path. Fully balanced preamp designs provide less noise, and removing capacitors from the signal path can provide less coloration to the sound. 
• The Alto provides full support of moving magnet (MM) and moving coil (MC) phono cartridges in its high-performance phono stage.
• The passive ladder volume control in the  Alto utilizes precision resistors for superior channel separation, low distortion, and a high level of signal integrity. 
• The  Alto has superior noise performance and extended bandwidth. Total Harmonic Distortion with Noise (THD+N) is a whisper-quiet 0.005 percent, and the bandwidth is 1Hz to 100kHz. 
• The display on the  Alto is large, high resolution, and visible from far away. 

Why Should You Care About the AGD Productions Alto Preamplifier?

The  Alto is a well-engineered, new school audiophile preamp that is all about providing the best and cleanest sound possible at its nearly $5,000 price tag. There are preamps with more features out there to consider at or around the same price. There are more standard-sized products that match well with different brands of audiophile electronics. This isn’t why you’d be interested in the  Alto preamp. What is appealing is its ability to simply switch inputs, boost the volume on vinyl, as well as handle your converted digital sources as analog inputs from your chosen DAC. It is a very good preamp for doing what very good preamps do, and for many audiophiles, that should be appealing. 

Some Things You Might Not Like About the Alto Preamplifier 

• The  Alto is a little light when it comes to features. The phono preamplifier is definitely a plus, and has the sonic chops of an expensive standalone unit; however, where’s the high-performance internal DAC? The room correction? The bass management? The lack thereof definitely takes away from the value proposition. 
• The Alto’s small, non-standard form factor makes it visually not match most other audiophile products other than those from AGD.
• Since its smaller than an average preamplifier, the Alto is limited to one balanced input. It also only has one balanced output, too, so balanced bi-amplification is off the table if that is something that you care about. 
• The review unit that I had was an early production model thus came with a clicking sound when changing volume. We were able to fix the design problem with firmware and did that with excellent results. While this was a small bump in the road for me with an early production unit, I don’t expect this to be a problem on more modern units.
• The plastic remote feels chintzy and had to be synced with the Alto to work. I have never had to sync a remote to a unit before. It was easy to do but still an extra, unexpected step. Normally, there is an original Apple (metal) remote included but my review sample was missing that feature.  

Listening To the AGD Productions Alto Preamplifier…

I had the $3,000 Amped America AAP-1 preamplifier (review pending) on hand at the same time as the  Alto. I also had my reference Bricasti Design M20 preamplifier and Parasound Halo P6, though the latter was not in the same sonic league as the  Alto, and the Bricasti offered superior performance. The  Alto was surrounded by a Bricasti M1 Series II DAC (review pending), the Bricasti Design M30 amplifiers, and the PSB Synchrony T800 floorstanding loudspeakers (read the review). 

I sit in opposition to most of my generation in regard to the legendary grunge-era band Nirvana. While I do not think they were the bee’s knees, their influence on music was certainly up there with greats like The Beatles, Led Zeppelin, and Pink Floyd. “Oh Me” is off of their MTV Unplugged in New York album and is a nice alternative to the overplayed “Lake of Fire” off the same album that dominated the airwaves. I used my vinyl copy to test out the phono preamplifier, and turned to Qobuz for some digital love. Both were fantastic. The  Alto provided small inner details that yielded a very realistic sense of being in the audience. Kurt Cobain’s droning but sullen voice had palpable texture and was anchored perfectly in the soundstage. I found this performance consistent between vinyl and digital, and for this track the Alto certainly carried the sound as expected for a $4,995 preamplifier.

I am supposed to put some high-rez, audiophile jazz or classical track next to clean up the grunge I just talked about, but I am not going to. The  Alto’s slightly warm sonic signature, while possessing very low noise with strong dynamics, really brought my mainstream music to life. “I Miss You”appears on Blink 182’s self-titled album. The track surprises with instruments like a bass string section, piano, and bells. Also, there is a quiet overlaid background vocal that is out of phase, so it haunts your ears from behind when reproduced properly. The  Alto had no problem recreating the haunting vocals, as well as the driving drum beat, slide guitar, and punky main vocals. There is not a lot missing between the  Alto and the Bricasti Design M20 preamplifier in terms of sound, but at a little more than double the price the Bricasti Design M20 had better dynamics and ultra-fine resolution. In comparison with the Amped America AAP-1 preamplifier, the  Alto was equal, but the Amped America AAP-1 had dead-neutral tonality. 

Does the AGD Productions Alto Preamplifier Have Any Resale Value?

The Alto might suffer a little in the used market compared to some of the big boys. While the AGD Productions brand is becoming better-known, it certainly does not have the weight of established brands. The odd form-factor and lack of features doesn’t help either. This is an excellent sounding preamp from a disruptive company. It might not hold its value like a McIntosh, Audio Research, Anthem, Pass Labs, or other A-list preamp manufacturers. You will note, this same issue didn’t keep me from writing a check for the amp after my review. Sometimes, you need to pave your own road in this hobby, especially in times of change. 

Who Is the Competition for the AGD Productions Alto Preamplifier?

The Anthem STR preamplifier (read the review) is an extremely strong contender weighing in at $4,300. The STR has an extremely capable internal DAC, excellent ARC room correction, bass management, and a flurry of other features that puts a lot of advanced technical control in the user’s hands. The STR has extremely low distortion that betters the  Alto, at least on paper.  

Amped America is, like AGD Productions, sharing their newness to the audiophile scene. The AAP-1 preamplifier (review pending) is a very strong sonic performer at $3,000, which is nearly $2,000 less than the Alto. The Amped America AAP-1 has sonic performance on-par with the  Alto, yet is neutral in tonality instead of warm, and includes a DAC, headphone amplifier, and phono stage. 

Greg Handy recently reviewed the Pass Labs XP-12 stereo preamp (read the review), which at $6,100 is not too far from the  Alto’s price point. Both are very high-end stereo preamps that do just that do what they say on the box. They aren’t AV receivers. They aren’t DACs. They don’t do HDMI. They are very simply focused on the preamp tasks at hand and both do a very, very good job of it. 

Final Thoughts on the AGD Productions Alto Preamplifier…

The $4,995  Alto Preamplifier is a high-performance preamplifier that matches the form of AGD Production’s entry-level, but technologically advanced amplifier offerings. 

AGD Production’s bread-and-butter is still their bleeding-edge amplification, though the Alto preamplifier shows the advanced engineering behind AGD Productions can certainly produce other components with incredible sound. If you have the need for small form factor with very high performance, and integrated features is not a necessity, the Alto can certainly be added to the list of considerations.