Encounters are very mysterious, and by a chance event, we were given the opportunity to handle Q-tron Audio, a high-end amplifier brand from Sweden. Embarrassingly, until I got acquainted with this brand, I was unaware of the existence of OTL (Output Transformerless) amplifiers that do not use output transformers.
However!
Upon a bit of research, I was amazed by the brilliance and fine line of danger of this OTL amplifier, and was impressed by Q-tron's technical skill in flawlessly overcoming all of it and even enhancing it further. If we compare it to cars, it's like Mazda, which overcame the high performance and low production efficiency of the rotary engine. Speaking of which, the supercar manufacturer Koenigsegg, loved worldwide by VIPs for its ingenious design and top speed, is also from Sweden. Similarly, Q-tron's intense sound and design, which breaks the established notions of veteran audio journalists, might be a testament to the greatness of Nordic Sweden.
OTL amplifiers bring a new dimension to traditional vacuum tube amplifiers through their unique technology and design. In a conventional vacuum tube amplifier, an output transformer is used to convert the speaker's low impedance into a suitable load impedance, but the transformer limits sound quality, causing distortion and frequency response limitations. OTL amplifiers, abbreviated as 'Output Transformer Less,' completely eliminate the output transformer, allowing smooth and clear sound. This achieves a much more transparent sound compared to traditional amplifiers.
Here is the product page for Q-tron's OTL amplifiers.
https://exclusive-audio.jp/collections/qtron
Q-tron's OTL amplifiers are particularly high in resolution for both low and high frequencies, faithfully reproducing even the subtle nuances of music. While maintaining the warmth of single-ended tube amplifiers (SET), they feature an expansive sound that is less fatiguing for listening. Additionally, with excellent transient response, the dynamics of music can be expressed more richly, allowing even clearer sound quality than conventional push-pull amplifiers.
Furthermore, Q-tron adopts an improved Futterman circuit, which has a lower output impedance compared to the Circlotron circuit, making it compatible even with 4Ω speakers. It achieves high output with a small number of vacuum tubes, preventing thermal runaway and tube deterioration, thereby enhancing reliability and stability. In terms of sound quality, it realizes over tenfold distortion reduction through a unique driver stage, achieving astonishingly low distortion in the 25W output model (PA12) with less than 0.01% at 1W and less than 0.1% at 10W. Moreover, this performance is achieved without using excessive feedback.
Additionally, it boasts an industry-leading noise level of less than 100dBA, maintaining high reliability even with long-term use. The use of high-quality components designed and manufactured in Sweden, with no reported failures over more than seven years of production, is a testament to Q-tron's reliability.
Q-tron Audio's OTL amplifier sets a new standard for vacuum tube amplifiers, combining transparent, clear sound with excellent durability and safety. Please experience the highest quality sound.
Q-tron Audio amplifiers pay meticulous attention not only to their outstanding sound quality but also to preamplifiers and safety.
First, Q-tron's preamplifier is designed to bring out the best performance when paired with the power amplifier. It achieves extremely low noise levels and distortion, providing very clear and transparent sound quality throughout the entire amplifier. Additionally, it features a high-precision volume control that allows volume adjustment using 64 discrete resistors. This volume is switched by relays, and the contacts are gold-plated, ensuring durability and signal purity.
Q-tron Audio also gives thorough consideration to safety. Some OTL amplifiers have a design that poses risks to speakers and listeners, but with Q-tron amplifiers you don't need to worry about that. Especially when using expensive speakers, you don't want to risk damaging them due to an accident. Q-tron's amplifiers include protection circuitry that instantly shuts down the amplifier in the event of harmful DC voltages on the output, and an ultra-fast fuse is also added. This double protection mechanism provides peace of mind while protecting your speakers.High-FidelityYou can enjoy.
Q-tron Audio uses an improved Futterman circuit of two typical OTL circuits: the Futterman circuit and the Circlotron circuit. The Futterman circuit features a simple power supply design and low output impedance, making it compatible with 4Ω speakers. Compared to the Circlotron circuit, it can achieve high output with fewer vacuum tubes, and since the output is connected to ground, it provides reliable and stable performance. The Circlotron circuit, on the other hand, works on a symmetrical design and is particularly tonal balanced, but it is more complex than the Futterman circuit, requiring more vacuum tubes and a special power supply.
Q-tron's improved Futterman circuit further reduces output impedance, achieving stable high output and clear sound quality with fewer vacuum tubes. This also improves the lifespan and reliability of the vacuum tubes. This improved Futterman circuit also completely eliminates the risk of electric shock. For this reason, Q-tron's OTL amplifiers can also be safely used with headphones. Ensuring electrical safety, especially when using headphones, has been a difficult challenge with traditional OTL amplifiers, but the Q-tron design overcomes this issue.
Q-tron Audio not only delivers the ultimate sound of tube amplifiers but also achieves a design that is unparalleled in terms of reliability and safety. All components, designed and manufactured in Sweden, use the highest quality parts from world-leading manufacturers, such as Nichicon, Kemet, Panasonic, KOA, and Vishay Vithrom, ensuring consistent high performance over the long term.
Q-tron Audio's OTL amplifiers are the ultimate amplifiers, combining clear, high-resolution sound, durable design, and top-level safety. From preamplifiers to power amplifiers and speaker protection, you can experience a design that allows no compromises.
Loan Program for Listening Devices (Japan only)
Would you like to experience the charm of Q-tron Audio's OTL amplifiers in your own audio setup?
Our store offers a loan service for customers considering a purchase.
The loan period is one week, and you only need to cover the shipping costs.
