Optimum System Ground Isolation Defined
I’ve made a few significant changes in my system since I last reviewed the Synergistic Research Galileo UEF AC power cables (here). My journey started when evaluated the SR Galileo UEF Ethernet cable against my current reference review. As good as my reference was which consisted of two Ethernet cables separated by a LAN filter was, the single SR Galileo UEF Ethernet was the most relaxed, non-fatiguing, and analog sounding of all Ethernet cables I have ever tested.
I followed that major system upgrade with another major system upgrade which included replacement of my long time reference AZ Crescendo loudspeakers with the Tekton Design Double Impact SE loudspeakers. Believe the reviews, Tekton Design has a SOTA speaker that performs nearly 10X the price of comparable loudspeakers. Another system change consisted of the addition of the NAT Audio Transmitter SET monoblock amplifiers to drive the new Tekton DI SEs which proved to be a match made in heaven.
The addition of the SR Active Grounding Block SE (AGB SE) to my reviewing system occurred about a year ago so I am quite familiar with its application in a high end audio system. I originally reviewed the passive SR GB UEF back in 2015 (here). In that review I found the SR GB UEF to be a must have component in the lowering of the noise floor and on the critical path to creating a high stereo system back then. Ted Denney, president and lead engineer at SR is not the kind of guy that rests on his laurels and with the introduction of the AGB SE as a prime example.
The 3″ tall x 10.75″ wide x 6″ deep AGB SE model takes the original UEF Ground filter to the next level with the addition of an active ULF Field Generator and dedicated Electromagnetic Cell. The larger sized (3 times) UEF Ground Filter found on the SR AGB SE allows for 44 Star Ground Points to reduce component to component ground inductance. The SR AGB SE employs the same Field Generator technology which re-clocks high frequency ground noise to the Earth’s Schumann resonance the as found in the SR PowerCell 12 UEF.
The term “ground” refers to a connection to the Earth, which acts as a reservoir of charge. The high-speed, SR Active Ground Block provides a conductive path for this ground, separate from the normal current-carrying path of your components. The SR AGB SE was designed to provide a ground path with the least resistance.
There are two versions of the SR AGB offered. The Active Ground Block SE which is the subject of this review, replaces the standard model’s passive Quantum Black Power Cord with a specially modified Atmosphere Level 2 Active power cord equipped (coupled with an upgraded SR Blue fuse) with Galileo UEF Quantum Gold and Silver Filters that give you two distinctive sonic options to the overall sound of your system.
In my mind, the addition of the Atmosphere Level 2 power cord alone makes this a high value package and there are advantages to being able to tune the AGB depending on the mix of electronics, tastes, etc.
The list of components that can be connected to the AGB SE include:
• Synergistic Research Galileo UEF and Atmosphere Cables
• Synergistic Research Tranquility Bases
• Synergistic Research Atmospheres
• Turntables – Standard or Small Spade Connect to Ground Post on Turntable
• Phono-stage - Standard or Small Spade Connect to Ground Post
• Digital to Analog Converters (DACs) – Connect to spare Digital Input, Output or Chassis Ground
• Reel to Reel Tape - Connect to spare Analog Input, Output or Chassis Ground
• Pre-Amplifiers – Connect to spare Analog Input, Output or Chassis Ground
• Power Amplifiers – Connect to spare Analog Input, Output or Chassis Ground.
• USB Devices – Connect to spare USB Input, Output or Chassis Ground
• Audio Computers - 3.5mm Headphone Jack
• Any Component with an active circuit inside – Connect to spare Input, Output or Chassis Ground
In my system I positioned the SR AGB SE on top of SR MiG 2.0s in a central location to allow easy access for connection via SR High Definition Grounding cables which are sold in standard lengths of 4 feet.
The chassis of the AGB SE has a “small” front panel blue light that indicates when the unit is energized. If you’re familiar with other SR products, a “small” blue light is an appreciated design feature … lol.
Previously when I swapped out the original passive SR Grounding Block for the SR AGB SE. I remember concurring exactly with the SR website description. Images were more clearly focused, the music was more refined, the image density was enhanced at the sound field extremes, and the image depth was greatly enhanced.
I thought the addition of the SR HDG cables to the passive SR Grounding Block improved the bass extension but the AGB SE took the bass extension to another level. There also was an apparent increase in resolution with the recording space vividly portrayed which I think relates to a much lower noise floor. I’ve made many system improvement over the years and going from the passive SR GB UEF to the AGB SE was one of the most significant improvements. In this review I will totally remove the SR AGB SE and report on the results.
In my current system I have three Tranquility UEF Bases, Atmosphere XL4, FEQ, all Galileo UEF signal cables, and all components (QNAP NAS drive, Ayon Audio S-5 Network Player/DAC/Preamp, and NAT Audio Transmitter monoblocks) plugged into the AGB SE. I started the review by playing various cuts from the jazzy blues album “Everybody Has a Plan Until They Get Punched in the Mouth” [GroundUP Music] by Charlie Hunter. In this recording, Charlie Hunter leads a quartet featuring three highly individualistic players-drummer Bobby Previte and trombonist Curtis Fowlkes, both of whom have collaborated with Hunter previously, and newcomer Kirk Knuffke on cornet. After extended play time, I shut my system down and totally removed the SR AGB SE. Where possible, I plugged the existing grounding cables into an isolated outlet strip on my second 20 amp dedicated line to maintain active grounding in the SR Galileo UEF signal cables. I quickly came to the conclusion that my system was unlistenable without the SR AGB SE. There was such an edge to the music that I hadn’t ever heard before or know ever existed. I never expected the technology employed in the SR AGB would have this large of an impact.
This alone demonstrated to me that the quality of the grounding in a high end system is required to lower the noise floor and reduce signal compression. I also believe the connection of the SR AGB SE to the cable internal ground plane found in the Galileo UEF cables is necessary for the Galileo UEF cables to achieve the highest level of performance possible. This would also apply to any SR cables with an internal ground plane such as the new Atmosphere X cable series. It wasn’t long after removing the SR AGB SE, I was reinstalling the SR AGB SE. With the SR AGB SE reinstalled, I immediately heard an effortless organic presentation with more depth, a neutral tonal balance, and music with a more intimate realistic quality. The realistic portrayal of the soundstage at the boundary edges and sense of space had the effect of detaching the music from the speakers. To put things in perspective, the improvement brought by the SR AGB SE was greater than going from the SR Atmosphere Level 4 signal cables to the Galileo UEF signal cables.
The albums “Koln Concert” [EMC] and “Tokyo 96” [EMC] by the Keith Jarrett has been receiving a lot of play time lately since upgrading many components in my system. It’s been almost a rediscovery of a hidden treasure. On the “Tokyo 96” album, the magic comes through in the strength of the mutual connections between Jarrett on the piano, Peacock on the bass, and DeJohnette on the drums in perfect balance. “By focusing on standards, with their familiar, formal blocks of four and eight measures and balanced harmonic progressions, Jarrett and friends open wide the windows on their inventions, making it easier to hear the way they extend the musical field of view, without significant creative restraint”. On each cut, Jarrett’s piano technique remains remarkable, with a subtle touch that supports liquid phrasing and a conception that reaches far out across bar lines and other conventions. With the SR AGB SE engaged, there was an added wholeness and realness to the music you aren’t able achieve with any other component change that I’ve experienced. The background washes of sound that inspire further investigation now take on a scale, texture and clarity that had previously been completely masked sans the SR AGB SE. Switching off the internal active EM cell alone (back chassis rocker switch), resulted in a compressed soundstage that was merely located between the speakers and a reduction of the microdynamic gradients. Another favorite album of mine, Autumn Leaves: The Songs of Johnny Mercer [Groove Note] by Jacintha was chosen to demonstrate the effectiveness of the SR AGB SE on my system’s reproduction of female vocals. For her sixth album, Jacintha pays homage to songwriter Johnny Mercer. A small ensemble culled from L.A.’s finest jazz accompanists backs her and lends authenticity to the history behind each song. Jacintha’s warm, clear, delicate approach to storytelling enables the vocalist to deliver each song in a comfortable manner with intimacy and charm. Jacintha is at her best when incorporating her impeccable enunciation on "I Remember You" (my favorite cut). The effects of the lower noise floor and reduced signal compression imparted by the SR AGB SE was clearly heard in the vocals of each cut. There was a whole new level of shading, nuance, breath work, and subtly inflections present with the SR AGB SE installed. I also found it was easy to develop an emotional connection to the music. I came to the conclusion once again that I would never consider removing the SR AGB SE from my system.
One of the most significant effect results of reducing the noise floor and signal compression via the SR AGB SE allowed me to listen to music at much lower volumes without any loss of detail, silence between notes, and dynamics. Component changes alone have never resulted in the type of improvement the SR AGB SE brings to the table. With the SR AGB SE installed I was more engaged with the music and not left searching for it. The SR AGB SE is an integral part of my reviewing system. Highly recommended.