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Impressions:  The ModWright Analog Bridge...a Rave!

05-08-2023 | By David W. Robinson | Issue 127

Robinson with cigar. Munich, 2018 (photograph by Bill Parish; ink outline image processing by Robinson)

Last summer at the first Pacific Audio Fest, I heard a product that I really liked, first take and all. While in the ModWright/Seattle HiFi/Cardas Audio/Revel/SME/Ortofon/Solidsteel room, I got to hear Dan Wright's newest design. This was his new ModWright Analog Bridge.

Dan Wright with an audio rack full of ModWright gear, except the turntable. The Analog Bridge is the larger unit on the second shelf up.

Specs! Got to have specs.

Technical Specs

  • Inputs: (2) pair RCA – Optional (1) pair XLR (add cost) balanced option.
  • Outputs: (2) pair RCA – Optional (1) pair XLR (add cost) balanced option.
  • Gain: Unity
  • Noise: -105dB (unweighted)
  • Frequency Response: (20Hz – 150Khz(-1dB))THD:
  • < .005%
  • Output Impedance:* < 20 ohm.
  • Dimensions: 10.5"W x 3.5"H x 14.5"D. (RCA length included)
  • Product Weight: 18 lbs
  • Shipping Weight: 23 lbs

Damnation! While listening in Dan's PAF 2022 room, the sound was smooth, clean, and really organic. I was fascinated by the Analog Bridge, and its effect(s) on the music.

But I wondered:  What is an Analog Bridge, anyway, and what is it supposed to do?

According to the ModWright Web site:

"The Analog Bridge was designed to fill a niche left by our custom tube modifications for digital source equipment. Due to the rapidly changing world of modern digital, we wanted a product that could be used with a variety of digital and analog SS (solid-state) sources. The Analog Bridge will not be replaced as digital technology progresses and system components change. It is an accessory that will be a constant and improvement in your system.

The purpose of the Analog Bridge, is to add the strengths and positive attributes of tubes to any system, without the bandwidth limitation, noise and added distortion that many associate with tube electronics."

So, the Analog Bridge is a tube-based analog device that is intended to ameliorate some of the edginess and glare that both some solid-state and many digital devices (DACs, preeminently) can lend to the sound of a system. As digital/solid-state technologies change, it can migrate. It has two different tube complements, so that you can explore the nuances between them.

You can source the Analog Bridge in either its basic configuration, with unbalanced RCA, or add the balanced XLR option for an additional $1000.

I just had to try the Analog Bridge in one of my systems here at Positive Feedback, so that I could hear it with equipment I was very well familiar with. Dan Wright and I talked after PAF 2022, and he promised to send me a review sample as soon as possible, once main production had begun. This turned out to be in February of 2023. He sent an Analog Bridge with the balanced option, for maximum flexibility.

Rear view of the Analog Bridge (photograph courtesy of ModWright Instruments)

As I've mentioned, the Analog Bridge is around a complement of 2×6SN7s, 2×6922s, which are switchable on the fly…very important that…and 5AR4 rectification. It looked like a very fine audio component for addressing possible problems in system sound. (It's heavy, built like a tank with potent power supplies, and yet attractive to the eye in a practical way.)

A closer look at the tube complement of the Analog Bridge:  the 5AR4 rectifier up front and center, with the 6922 pair next layer back, and the 6SN7 pair in the back. Tube rollers are welcome!

The Analog Bridge in its place on one of our Stillpoints ESS Rack

Since I was having just such an issue…a DAC that was sounding a bit forward and edgy at that point in its break-in…I gave it a run. Frankly, even with the advanced experience of PAF 2022, I wasn't sure what I would hear. Subtle? Obvious? Would it take countless hours to break in?

Talk about a pleasant surprise! In the default 6SN7 position, using Synergistic Research RCA for the input side from the Aavik D-580 DAC output, and Cardas Clear Beyond RCA cabling on the output side to the Vinnie Rossi L2i SE Integrated Amplifier, and thence via the TARA Labs Omega Concerto speaker cables…plus AC Power via RSX Technologies Benchmark and Kubala-Sosna Elation!…truly reference grade all the way…the touch of break-in stridency that I had been hearing simply went away. From the first hour, and without any doubt in my mind at all.

It was truly amazing.

Note that the feed I was using to the Aavik D-580 came from JRiver's Media Center, with sources that ranged from our QNAP 1273U NAS-based server to Qobuz and TIDAL via their applications on my Dell T7920 Precision Workstation. Regardless of what type of music I was in the mood for, from all sorts of genres, and in both DSD and PCM, the benefits of the Analog Bridge came through every time.

Rear view of the cabling on the ModWright Analog Bridge in use here at PF

To say that I was impressed would be an understatement. In fact, I now consider the ModWright Analog Bridge to be an essential tool here for my listening and evaluations, and I am convinced that many audiophiles would come to the same conclusion in their own systems.

Whence this magic? I invited Dan Wright to provide a few notes about his Analog Bridge. He was courteous enough to send the following comments for our readers:

"The Analog Bridge was designed as the answer to our tube modifications that we have offered over the years for a variety of different digital sources. The Analog Bridge is an outboard product that can be used with a variety of sources, and, being analog, will not become obsolete.

From a design standpoint, I wanted to incorporate the following features and benefits.

1) Three variables to allow changing the sound and tonality of the system, by changing between 6922 and 6SN7 family of tubes, and tube rectification, that allows for further tube rolling with different rectifier tubes, each with their own sound and tonal characteristics.

2) 'Do No Harm': As an 'accessory' circuit, it could not add noise, distortion or limit frequency response. Additionally, by its very nature, it has a very high input impedance and very low output impedance. It should only IMPROVE the sound of the system, not penalize it. It has an exceptionally low noise floor and low THD (<.006%).

3) 6SN7 and 6922 are very different tube families, with unique sonics and operating characteristics. The 6SN7 has a characteristic 'Fat Tone', while the 6922 is more transparent and resolving. This allows for different tonality that may suit different genres of music.

[I will add that, regardless of the genre of digital music, or its format, Dan's observations about the sound of these two tube complements parallel my own experience over many hours.]

4) Separate circuits for each tube type. Rather than one tube circuit that could allow the use of either tube, but not truly be optimized for either, I chose separate and parallel operating circuits for 6922 and 6SN7 playback. The same basic circuit topology is used, but each circuit is optimized specifically for the tube that is used.

5) Lastly, and this was a bit tricky, but I did it, was to allow on-the-fly switching between the two tube types, without any thumps or bumps due to DC shift. A momentary mute is engaged when switching between the two tube types to prevent any problems.

The Analog Bridge can be used between source and preamp, preamp and amp, source and amp (provided source has a volume control) and it will allow for the proper impedance ratio between all, not add noise or distortion, and bring an additional level of control over the tonality and voice of your system."

There you have it, from the designer himself.

The Analog Bridge in a ModWright system being fed by Mytek's newest streamer/DAC (photograph courtesy of ModWright Instruments)

There's no reason to prattle on. In sum:  There's no doubt about it in my mind. The ModWright Analog Bridge is outstanding…a real winner! My review sample is remaining here…it's too bloody useful, and too cost-effective for its benefits, for me to come to any other decision.

Yes, that is a rave. Take it to the bank.

It has therefore received one of my Brutus Awards in 2023. (Note that I had come to this conclusion back at the end of March.)

For more information, see https://www.modwright.com/products/analog-bridge.php.

Price: $2900 for unbalanced only model; $3900 for unbalanced plus balanced option

ModWright Instruments, Inc.

21919 NE 399th Street

Amboy, WA  98601