Relive the Golden Age of Audio with the Impedance Step-Up Transformer: Your Key to the Exceptional Sound of 800-Ohm Philips Speakers

If you are a true audio enthusiast, you have probably heard of the legendary sound quality of the rare 800-ohm Philips loudspeakers of the 1950s and 1960s. These sonic gems captured the hearts of audiophiles worldwide thanks to their ability to create a natural, enveloping sound, loved for its purity and musical detail.

However, these loudspeakers were designed to work best with the OTL (Output Transformerless) tube amplifiers of their time, which had a high output impedance. This often created a dilemma for modern audiophiles eager to enjoy the unique sound of Philips speakers with their newer amplifiers, which usually have low-impedance outputs.

Here is where today’s revolutionary solution comes into play: our Impedance Step-Up Transformer. With this device, you can finally connect beloved 800-ohm Philips speakers to any standard amplifier with an 8-ohm output, whether tube or solid state.

The Magical Bridge between Past and Present

Our impedance step-up transformer has been meticulously designed to ensure that you can experience the vintage magic of Philips speakers without compromise. Its high-quality features and clever design allow you to:

1. Preserve Sound Quality: The transformer is engineered to maintain the natural, warm character of 800-ohm Philips loudspeakers. Every note and musical nuance is delivered with precision and clarity.
2. Ease of Use: Installation is effortless. Simply connect the transformer between your amplifier and speakers, and you are ready for an extraordinary listening experience.
3. Versatility: Now you can enjoy the vintage sound of Philips speakers with any standard amplifier. The transformer works equally well with tube and solid-state amps, offering maximum flexibility.

Your Passport to a Unique Sonic Experience

The 800-ohm Philips speakers hold a special place in audio history, and now, thanks to our impedance step-up transformer, you can bring that magic back to life and enjoy their unique sound with the convenience of modern amplifiers. Don’t miss the chance to own a piece of audio history and experience a sound cherished for generations. Get your impedance step-up transformer today and begin your journey toward an unparalleled listening experience. Rediscover the beauty of music with your new ally in sonic fidelity!

The Prototype

I was commissioned to create an audio impedance step-up transformer capable of raising an amplifier’s standard 8-ohm output to 800 ohms, making it possible to use high-impedance Philips loudspeakers.

The transformer had to guarantee a solid low-frequency response, while no extreme extension was required in the high frequencies, considering that the wide-band speakers it was meant to drive are not particularly extended in that area. Despite an initial failed attempt, I succeeded in producing a perfectly functional sample, as shown in the photo above. Measurements were taken using an 800-ohm resistive load and this measuring setup.

I present two sets of bandwidth measurements: in the first case, the transformer was connected directly to a solid-state amplifier with a high damping factor of about 200; in the second case, I tested it with a series resistor on the primary side, simulating a low damping factor of 2, comparable to that of a typical tube amplifier without feedback.

Direct to Solid-State Power Stage

Simulating Drive from a Low-Damping Tube Amplifier

These measurement results highlight the excellent behavior of the transformer. When connected to a solid-state amplifier with high damping, the frequency response is impressively flat, with only about –1 dB attenuation at roughly 15 kHz, already at the upper limit of the speaker’s range. When used with a tube amplifier—the transformer’s real target—the attenuation is even less significant, about –0.2 dB at 10 Hz and –1 dB around 30 kHz.

These instrumental data confirm the neutrality of our transformer and its ability to deliver an unaltered audio signal to high-impedance speakers. Note that measurements were performed at 15 W RMS, which is well above the power handling of most of these speakers. As a result, our transformer can be used universally with a wide range of Philips 800-ohm speaker models.