Western Electric 91E Integrated Amplifier and 300B Tube

I must confess that I am biased toward tubes (pun intended). I’ve owned several tube-based amps, preamps, and phonostages. There is something that has always drawn me to their sound. Tubes seem to capture musicality in a way that their solid-state counterparts often don’t quite equal. My favorite amplification tube is the 300B. Though not without limitations, it has a wonderful, lush sound that pulls me into the music. I have monoblock amplifiers for my reference system that are based on this tube. Those familiar with the 300B would probably stereotype it as possessing a full, blooming midrange with an overly polite top end and a lack of control and dynamics in the bottom end. I would have to agree that’s a characteristic description; however, if you’ve ever wanted the benefits of the 300B without its shortcomings, read on.

When Robert Harley initially asked me if I would like to review the 91E, I had to decline, because the 91E was just too good an integrated amplifier to adequately review in what was then my second system, and there was no practical way of using an integrated amp in my main system. Having recently moved to an apartment, my main (and only) system can now accommodate an integrated amplifier and is worthy of this level of hardware. At this point, I happily said yes to Robert and, wow, am I glad I did.

A Bit about 300B Tubes

The first 300B tubes were made by Western Electric (WE) in 1938. The tube was in continuous production for 50 years, but in 1988 that came to a halt. These tubes were highly desired when they were in production, but particularly so after production ceased—some WE NOS 300Bs were fetching thousands of dollars apiece. I have had experience with many 300Bs from Shuguang, Genelex, JJ, and Electro Harmonix, but have not had the pleasure of listening to Western Electrics even though production resumed in 1997. These new tubes are faithful reissues, but built to a much higher standard of manufacturing and performance. While not inexpensive at $1495 a matched pair, they are not stratospherically priced the way many NOS tubes are these days.

I have ample experience with 300Bs in general and love their sound. But I was never willing to pay for an NOS pair of WEs. Most new 300B tubes sell in the neighborhood of $150 to $220 per tube. So, one would immediately wonder why the new WE tubes are so expensive relative to their competition. There was a significant sound quality difference among the previous tubes I tried, but sadly the ones I preferred failed on numerous occasions. (I bought four tubes at one point and had to replace all of them within six months. Two were within their 90-day warranty period; two were not. I no longer buy this brand of tube because it’s just too expensive to replace the tubes so frequently, not to mention the hassle.) This is where WE really sets itself apart by offering a five-year warranty. That’s unheard of for tubes and particularly surprising for a power tube. The CEO of Western Electric, Charles Whitener, told me that he has customers who still have tubes in service from his first production run in 1997. That is over 20 years running!

A Bit about the “New” Western Electric

Charles Whitener had sold a previous company in another industry successfully and was on the hunt for something new. He was passionate about high-end audio and noted the rising prices of 300Bs. He viewed this as an opportunity and looked for a way to faithfully bring back the WE 300B. First, he had to buy the naming and technology rights from AT&T (the last owners of Western Electric). It took a long time and many attempts to finally get AT&T to agree. In 1992, he started the revival. For his staff, he used people who had been with WE previously, working in the original plant. With this expertise and infrastructure, the pathway was clear. But, as any entrepreneur will tell you, there are always unexpected challenges. For the new WE, glass was the issue. Unfortunately, the new company lost a key employee who knew how to make the glass. This delayed the first release until 1997. After that, WE assumed it would be smooth sailing, but that was not the case. AT&T sold its WE plant to an investor, who turned the building into office space. The new WE lost its lease in 2002 and moved to Huntsville, Alabama. A similar issue occurred in this location, and in 2016 WE moved to Roseville, Georgia, and has been there since. (See the Factory Tour sidebar.)

In a chat with Charles, he described the design goals of the 91E very clearly. He wanted the lush sound that is so characteristic of the 300B but without the shortcomings. His desire was for it to sound good from top to bottom, with low hysteresis. He described the challenges in achieving this goal with single-ended topology, which generally needs massive transformers that by their very nature are going to have significant hysteresis. Additionally, Charles wanted an ultra-low noise floor, which is a challenge for single-ended tubes and particularly for a 300B, which has a directly heated filament.

As you might expect, Charles would not have told me about his goals had he not already achieved them, so I’ll spare you the suspense. The question remains, how is it possible? There are some unique parts of the design that made Charles’ goals attainable. One was running the tubes in Class A2. The A2 design is essentially Class A that drives the grid of the tubes a little higher, delivering greater output. This gain strategy is actually not new at all; in fact, the basic circuit design is quite old. But, to my knowledge there isn’t any other 300B amplifier using it. The second and patented portion of the design is the Steered Constant Current Source or SCCS. The basic idea of this patent is to increase the current on the basis of the load at the output terminal. Thus, if the load increases so does the current, and if the load decreases so does the current. A third interesting design parameter is the transformer itself. The A2 and SCCS allow for a smaller and lighter transformer, which helped meet Charles’ design goal of reduced hysteresis. The transformer is also unique in that it lacks the usual multiple taps for various impedance loads. There is just one set of binding posts; to change the nominal impedance the transformer needs to be swapped out. This is actually very easy to do because of the way the 91E is designed. Though it ships with whatever nominal impedance the original buyer specifies, it’s nice to know that if you switch speakers and need to make this change, the swap is relatively straightforward and reasonably priced at $999 for a second transformer. (According to Charles extra taps on the transformer degrade sonics, so he opted for perhaps a simpler, albeit more expensive approach to favor the best possible sound.)

The result is a reliable single-ended 300B integrated amplifier with double the output power (around 18–20 watts) that what one would normally expect. Yes, Charles achieved his technical goals, but the real proof is just how good this integrated sounds.

Initial Setup

The 91E has six single-ended analog inputs, including a phono input that can be changed from mm to mc via a switch on the back panel. I currently do not have a phono system set up, so I was not able to test the phonostage. There is also a Bluetooth antenna and connection. This was a little surprising to me, as Bluetooth audio quality is limited and certainly not up to the sonics of the rest of this product. Nevertheless, I wound up really liking the feature because I was able to connect my TV to the 91E via Bluetooth. No surprise that it was infinitely better than the integrated TV speakers. There are three outputs: the standard speaker binding posts, a line-level output, and a preamp output.

Installing the 300Bs is a little tricky in that you must open the “chimney” that houses the tubes. A ring that can be rotated holds down a glass cylinder and grate. The ring is rotated slightly counterclockwise using a red-colored spanner tool included in the accessories. The instructions could be a little clearer in this area. There is more than one spanner tool, so a drawing that shows which spanner and just how the “chimney” is opened would have helped. Each of the tubes was labeled, one for the right channel and one for the left channel. While the tubes are matched, they have slightly different gains. Each amplifier is calibrated for the tubes that will be used in it. The preamp section’s ECC81 tubes are installed at the factory.

The unit had been broken in for a day at the factory, but I felt it probably needed additional time. I expected I would need to bias the tubes as well over the first few days, but I was pleased to discover the 91E is auto biasing. The tubes are biased each time the amplifier is turned on. It takes about 30 seconds to warm up, then 30 seconds to monitor and bias the tubes. The microcontroller in the 91E uses an analog-to-digital converter to sample the plate voltage and current and then adjust the grid voltage to the correct value. Tubes will drift over time, so this is a great feature. I would have liked to know what kind of drift was occurring, particularly in the first week or so, but there is no feedback to the user as to what the bias settings are. I expect that the WEs drift less than some other makes of 300B, but I have no way of knowing for certain.

Initial Listening

At first listen, I could tell there was need for some break-in. There was a little harshness and imbalance, which I expected. I figured it would take a couple of weeks to get the best sound from the 91E. To my surprise, the break-in seemed to be complete in a matter of hours, rather than days or weeks.

Being very familiar with the 300B sound, I had to start with a series of vocals. Roon was kind enough to mix a Holly Cole playlist for me, which also included Jane Monheit and Melody Gardot, among many more of my favorites. This was a perfect starting point and, wow, did the amp sound good without any substantial break-in. I was cooking dinner while casually listening and was already impressed. My wife even commented on how good it sounded. She would not call herself an audiophile, but she has gotten a little spoiled by good sound. It was immediately obvious to her, as it was to me, that this was, indeed, a very special piece of audio gear.

Curiosity

Having owned many tube amps and preamps I’ve learned how much sonic change can occur by changing tubes. It’s usually fun, but sometimes it can be frustrating. I have a nice collection of 300Bs, though they are in storage. I did think about digging them out and seeing just how much of the sound quality I was enjoying was a result of the WE tubes and how much was owed to the 91E. But in the manual, there is a clear warning: “The 91E was designed for operation with Western Electric manufactured 300B electron tubes. The application of non-original or replica-type 300B tubes may result in weakened performance, distorted sound, or unexpected behavior, potentially harming both the amplifier and said replica tubes.”

As a reviewer, I felt it necessary to heed this warning. I’m sure the sound is a combination of both an outstanding tube and a circuit that seems to be purpose-built for the WE glass. Although I’ll likely never really know the answer to the question I posed, I won’t lose any sleep over it. The 91E sounds so incredibly good, who cares?

Serious Listening

When you hear a system come together and really gel, it no longer sounds like a combination of various pieces of audio equipment attempting to faithfully reproduce music; it sounds like the real thing. The equipment gets out of the way, and it becomes all about the music. How the textures of a saxophone that resonate all the way from the reed to the horn take on the three-dimensional quality of the real instrument, or how a vocal feels as if the singer were leaning over and whispering in your ear, like he or she were actually present in the room. I was already experiencing this with the 91E, and I was just getting started.

The WE’s output power of around 20 watts is well suited for my very efficient (94dB) speakers, which also present an easy load to drive. Nominal impedance is 4 ohms. The actual impedance across the audible frequencies varies from 2 ohms to 14 ohms. This is a tube-friendly pair of speakers. (This is not true for all speakers, so keep in mind that difficult-to-drive loads may not fare as well.)

I continued with more female vocals and jazz, which is mostly what I listen to anyway. Every track I played just made me want to play more. I could listen to this amp for hours, and on the first day of installation I did. And while vocals and jazz sounded the best I had heard on my system, I wanted to see how other musical genres performed. A system that can only play one type of music well is far too limited for my musical tastes.

Starting off easy but still providing slightly more of a challenge, I wanted to see how the drum solo in Dave Brubeck’s Take 5 fared. The drums are dynamic but also have a great deal of subtle texture to them (the weight of the drum strokes vary, and the drumheads’ tone is well pronounced). The 91E captured this as well as I’d ever heard it. So, that just naturally led me to see how well the 91E could handle John Bonham on the drums. I personally like the older Led Zeppelin; I and II are my go-to albums. Christopher Huston, who I worked with at Rives Audio for many years, recorded Led Zeppelin II and was often asked how he got the sound of those drums, as it really is spectacular. Chris is incredibly humble and would frequently respond: “I didn’t. John Bonham did. I just documented it.” He later told me he recorded the drums with only three microphones. Three microphones? Now, that is truly amazing! It is safe to say the WE 91E reproduced everything Chris Huston “documented,” and it was magical. It captured the speed and pure raw dynamics of that unique sound John Bonham was famous for!

I wanted to continue to steer toward more and more difficult types of music to challenge this amplifier. Dead Can Dance’s “Yugula” is an excellently recorded piece from the band’s Into the Labyrinth. It runs the full tonal range, from very low bass to more subtle vocals, keyboards, chimes, and sounds that give a sense of space to the composition. All these subtle tones can be lost, and in some cases the depth of the lowest frequencies is often rolled off, reducing the breadth of the soundstage. With the 91E, I was pleased with everything I heard. It felt like the low frequencies were all there, while the subtle overlays almost floated in space, with more dimensionality than I was accustomed to. Everything I was throwing at this integrated amp was seemingly too easy for it.

Several days later I decided to see if I could find the limits of the amp with Foo Fighters’ Medicine at Midnight. Here, the amp sounded a bit strained and compressed, and the bottom end thinned out. I then played Eiji Oui Mephisto and Co., a superb Reference Recording. On really large, dynamic passages, of which there are many, I heard the same thing—a bit of strain and compression and a thinning of the bottom octaves. Because these pieces were so much more challenging from a scale and dynamics standpoint, I thought that the 20 watts of these 300Bs had finally found their limits. But I was wrong.

A few days passed, and I continued to be impressed with this integrated. I found myself scratching my head about what I had heard earlier. There was just no strain or compression on what I was listening to at this point, and I couldn’t believe that those two albums I tested sounded the way they did. So, I went back to both, and (now) they sounded fantastic. There was no strain, no compression, and a full bottom end. Not only was the bottom end full, but it was also well controlled and far better than I’ve ever heard from a 300B amplifier. Additionally, all the mid and upper-end frequencies remained intact throughout these challenging passages. I suspect this has a lot to do with the SCCS technology, since the wide voltage swings that often occur for lower frequencies can create havoc with the current being delivered. After a bit more experimenting, it became clear that this amp needs more warming up for each listening session than I had originally allowed. Sufficient warmup—around 45 minutes—results in a much bigger sonic difference than I’ve heard with most amps. It’s almost like a switch, where the amp locks in and decides it’s game time. Since I generally let the equipment warm up without listening seriously for a while, I did not really appreciate just how important this warm-up period was with the 91E. Now that I know this, it’s really not an issue to me. But if you are auditioning this integrated, be sure to let it warm up amply before passing judgment.

One portion of my listening was with a few Edgar Meyer albums. These included Edgar Meyer and Chris Thile Uncommon Ritual, Appalachian Waltz, and Short Trip Home. Edgar Meyer’s bass playing is wonderful, and many of these albums are just plain fun. The contrast of sounds, particularly with Chris Thile’s mandolin, was superbly reproduced—a delight to listen to. Both instruments were absolutely true to their character. This may not have been one of the most demanding tests, but it was enjoyable.

Conclusion

The 91E is a very special product. It has real innovation in design that is not hype. It is delivering sound quality beyond what I’ve previously heard from any 300B amplifier. The areas that it excels in redefined for me just how great some of the recordings I listened to are. The best sound I’ve achieved on this system was listening to jazz and vocals. The presentation was so organic and fluid that I just wanted to melt into the listening chair and listen for hours. The only time I was not impressed was when the amp wasn’t adequately warmed up, and that was my fault, not that of the equipment.

If you are in the market for an integrated tube amplifier and have ever been exposed to the beautiful sound that 300Bs can offer, the 91E is a must audition. And while not inexpensive at $15k, I find it to be an extremely high value for what it delivers. I’m very happy WE is back and looking forward to more innovations. Very highly recommended! 

Specs & Pricing

Power output: 20Wpc into 8 or 4 ohms
Inputs: Six line, one phono (all RCA), Bluetooth v4.2
Outputs: Speaker level on binding posts, preamplifier out, line out (all RCA)
Tube complement: ECC81 (preamplifier), one pair Western Electric 300B (output)
Dimensions: 18.9″ x 15″ x 11.1″
Weight: 49 lbs. (shipping weight 94 lbs.)
Price: $14,999 (black or champagne), $15,999 (nickel)

WESTERN ELECTRIC
201 West Gordon Ave
Rossville, GA 30741
(404) 352-2000
westernelectric.com