H.H. Scott, Inc. was an American company that manufactured and marketed audio components and stereo equipment in the 1950s and 1960s, best known for their high-quality tube amplifiers. The company was founded by Howard H. Scott in 1946. Scott was a talented electronics engineer, and his brand soon became synonymous with high fidelity and audio performance.
H.H. Scott products were renowned for their solid construction and sound quality. Their tube amplifiers were particularly appreciated by audiophiles of the era. The company produced a series of popular models, including the Scott 299, Scott 222, and Scott 299B. These amplifiers delivered clean power and accurate audio reproduction, and many are still sought after by vintage audio enthusiasts.
In the 1960s, the company also began producing stereo receivers, preamplifiers, turntables, and loudspeakers. H.H. Scott continued to build a reputation for excellence in the audio industry until the mid-1970s.
However, starting in the 1970s, the audio industry transitioned from vacuum tubes to transistors, and many companies, including H.H. Scott, had to adapt to this new technology. The audio quality of transistor devices improved considerably, but this led to the end of tube devices. In 1978, H.H. Scott, Inc. declared bankruptcy and was acquired by Emerson Electric Company, which later ceased production of audio components under the H.H. Scott brand.
Although the company no longer exists, H.H. Scott products from the 1950s and 1960s remain highly appreciated by vintage audio enthusiasts, and many still seek their amplifiers, receivers, and other devices on the used market to enjoy the authentic sound experience of those years.
A Journey Back to Vintage Audio: Restoring the Legendary H.H. Scott Stereomaster 222C
In today’s digital era, where technology advances at an unrelenting pace, there is timeless charm in repairing and restoring vintage audio gear that embodies the warmth and nostalgia of the past. In this article, we embark on a fascinating journey into the world of period sound, focusing on two gems from yesteryear’s audio: the prestigious H.H. Scott Stereomaster 222C units.
Born in the golden age of tube audio, H.H. Scott amplifiers captured the imagination of enthusiasts and audiophiles with their extraordinary sound quality and artisanal construction. However, time can test even the sturdiest creations, and these two specimens needed some loving care to be brought back to life.
Our journey begins with replacing the burnt power transformer on one of the 222Cs—an engineering work of art requiring skill and attention to detail. Next, we take on the challenge of fully repairing a burnt output transformer, opening the door to reverse engineering and the craft of rewinding. The perseverance and dedication this undertaking requires are a tribute to the passion for vintage audio.
But the adventure doesn’t end there. As we restore these unique pieces, we also explore the subtle differences between the EL84 tubes and the lesser-known 7189s, which were installed in the H.H. Scott Stereomaster 222C. Understanding the differences between these tubes is essential to getting the most from these wonderful audio units.
In the end, what emerges from this journey is admiration for the past and the desire to preserve the richness of vintage audio. Our goal is to bring these H.H. Scott Stereomaster 222Cs back to life so they can continue to deliver joy and wonder with their extraordinary sound, just as they did decades ago. Get ready for a deep dive into the art of audio restoration and the appreciation of period sound. Welcome to the world of classics restored with passion and mastery.
This amplifier was brought to me after a service, but unfortunately the transformer was damaged. I proceeded to create a new transformer (for anyone wishing to purchase it separately, code 21S4665) and then installed it.
Subsequently, I was entrusted with a second unit that suffered from a damaged output transformer. This device had clearly been affected by moisture, which inevitably compromised the transformer’s material quality. To tackle this challenge, I disassembled the transformer and obtained a detailed diagram of the internal winding. This preliminary step allowed me to start creating two new transformers, reusing the original laminations and transformer covers from the damaged units.
In the photo below, you can see a distinct greenish oxide trace left by the copper wire that had lost its enamel due to contact with damp paper. During the unwinding process, I noticed numerous such traces. In some spots, the wire would break on its own as I unrolled it.
In this other image, a black groove is evident in the insulating paper, the result of an electrical discharge between adjacent wires. This discharge pierced the insulating paper and caused burning that propagated to the point of breaking the copper wire itself.
After completing the unwinding process, I decided to add a touch of modernity to the remake. I made two bobbins using a technical resin similar to nylon…
I then proceeded to rewind the transformers, using materials that preserved the authenticity of the era, combined with modern insulators at those critical points where safe, advanced insulation capability was required…
And so I did for both transformers; I fully rewound the one that was still working as well. But before proceeding with the article on the amplifier repair, I want to focus on the tubes. I invite you to read this article where I clarify the differences between EL84 tubes and 7189s, highlighting why they should not be interchanged to avoid potentially disastrous situations, as illustrated in this specific case.
Back to the amplifier…
In the video below, the amplifier is operating, but the original audio has been overdubbed for copyright reasons.
Now let’s move on to some instrument measurements. The unit can deliver between 22 and 25 watts (depending on tube efficiency) with a damping factor of 18. Below you will find two graphs related to total harmonic distortion (THD) and bandwidth obtained from the “green” amplifier mentioned at the beginning of the article, which retained its original output transformers. In the bandwidth graph, disturbances are evident, largely attributable to less-than-optimal circuit stability that relies on notably high amounts of negative feedback.
THD 1 watt
Bandwidth 1 watt on resistive load
Here instead is the bandwidth graph obtained with the transformers I rewound, after slightly reducing the amount of negative feedback. This adjustment led to a change from a damping factor of 18 to a factor of 12. It is important to note that this modification had no negative impact on the sound, but significantly improved circuit stability. It was a long fine-tuning process.
In conclusion, the restoration of these H.H. Scott Stereomaster 222C amplifiers has been a fascinating journey through the world of vintage audio. From the art of repairing burnt transformers to the reverse engineering of the original circuits, every step of this process was undertaken with care, dedication, and respect for the authenticity of the era. The result? Bringing two classics back to life, capable of reproducing the warm, enveloping sound that made them famous.
H.H. Scott Stereomaster 222D: a chapter of its own
The H.H. Scott 222D model, introduced shortly after the 222C, represents the latest evolution of the “222” series. Aesthetically, it features slightly different controls, but the real differences are hidden under the chassis: the schematic was changed in several places, feedback was reduced, and consequently the damping factor is lower than the 222C. This design choice made the sound slightly more “open” and less controlled in the bass, yet more musical and enjoyable for many listeners.
Recently I received a 222D with a completely dead channel. I was told the classic nightmare story: the customer had already turned to a so-called technician who was supposed to “service” it. In reality—unfortunately as often happens—the job had been done in a thoroughly botched way.
After a quick analysis, I discovered the amplifier still had its original Telefunken tubes, a complete period set, barely used—a real treasure. But—believe it or not—the previous “technician” (I’d rather call him an unscrupulous crook) had made off with the original quartet of Telefunken 7189, which in good condition can be worth €500, shamelessly replacing them with a quartet of Chinese EL84, bargain-bin stuff.
The theft is disgraceful in itself, but worse still, he also showed abysmal technical ignorance: EL84s are not drop-in replacements for 7189s, as I explain in detail in this dedicated article.
Not only did he steal valuable tubes, but he also ignored the customer’s requests, who had explicitly said not to change the tubes or, if so, to return them. As if that weren’t enough, this “expert” didn’t even bother to replace three dried-out electrolytics in the circuit, nor to check and set the bias. In short, he took the money, did nothing useful, and ruined a historic unit. A behavior both incompetent and dishonest that deserves to be called out in no uncertain terms.
When the unit arrived to me, the first priority was to check the state of the output transformers, which often end up burnt precisely because of these reckless EL84 substitutions. Fortunately, they were fine. I then advised the customer to buy a quartet of 7189 Tung-Sol from a reliable dealer and had them shipped to me.
I then checked the other tubes: the ECC83 were all in great shape, as was the GZ34. The pentode section of the 6U8 / ECF82, however, was about 50% worn. Here I show two comparative graphs of the curves, acquired with the uTracer curve tracer, comparing the pentode of the tubes installed with that of a new ECF82.
| ECF82 (P) Worn | ECF82 (P) New |
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I should note that, although worn, the 6U8s still allowed the amplifier to operate, albeit with a higher level of distortion.
I finally replaced the three small faulty electrolytics, checked the can caps which were still good, installed the new 7189s, performed the first controlled power-up with a variac, and set bias and balance.
At the end of the work, the amplifier was back in full shape: 20–22 watts RMS per channel, with a damping of about 5, consistent with the original design and ready to revive the sonic magic of the 1960s—this time without tube thieves lurking around.
These two articles have thus shed light on a common source of confusion regarding tubes, particularly between the EL84 and the 7189. The importance of understanding the differences and correctly adapting the circuit was emphasized to ensure proper amplifier operation and longevity. I also suggest reading an article dedicated to tube replacement in audio equipment and beyond.