If you own an Audionote M1 preamplifier and are experiencing issues with its power transformer, the 23S2 model is the ideal solution. Designed as a fully compatible replacement for the M1, this transformer was developed through reverse engineering of the original Audionote component. While the original transformer performs well, it is prone to occasional failure. One of its main weaknesses is the lack of insulation between the secondary sections, with the three windings stacked directly on top of each other without proper separation.

Click here to see how I restored and repaired an M1 unit…

The original M1 transformer

The 23S2 transformer installed in place

The new 23S2 transformer is built with a slightly larger core to ensure improved reliability and mechanical strength. Furthermore, each secondary winding is now properly insulated, providing a significant upgrade in safety and long-term durability. With identical voltage and current ratings to the original model, the 23S2 serves as a perfect drop-in replacement, preserving the original specifications of your Audionote M1 preamplifier.

By choosing the 23S2 transformer, you’ll not only restore your Audionote M1’s full performance but also gain greater reliability and extended service life. If you’re interested in purchasing the replacement unit or having your M1 repaired, click here to contact me.

We are pleased to introduce our replacement power transformer, model 24S95, specifically designed for the vintage VERDIK QUALITY TEN tube amplifier. This transformer is an essential component for audio enthusiasts looking to maintain or restore their valuable classic amplifiers.

The VERDIK QUALITY TEN is a push-pull tube amplifier based on EL84 valves, renowned for its outstanding sound quality and beloved by audiophiles worldwide. This amplifier is a faithful clone of the famous Mullard 510, a legendary model whose excellence has been recognized for decades.

Our power transformer has been meticulously built to match the original technical specifications, ensuring optimal performance and long service life. Whether you’re restoring a VERDIK QUALITY TEN or building a Mullard 510 clone from scratch, this transformer is the ideal choice.

Thanks to the Mullard 510 schematic, publicly available for over 50 years, faithful reproductions of this legendary amplifier can still be made today. Our power transformer provides all the reliability and quality needed to achieve excellent sonic results.

Here’s a customer testimonial:

Good evening Stefano, I’ve completed the restoration of my Verdik Quality Ten and everything works beautifully!

Thank you very much for your top-quality service. I’m attaching a couple of photos of the finished amplifier (I deliberately left the transformer cover off so your work would be visible…). Kind regards, Antonio.

For vintage sound lovers and DIY builders, our transformer is an indispensable component to achieve authentic and uncompromising sonic performance. Don’t let a faulty transformer affect the quality of your audio system — choose our power transformer to ensure maximum performance and faithful sound reproduction.

If you’re interested in purchasing, feel free to contact me directly.

The 24S83 power transformer is the ideal solution to replace the original 4090-1575-0003 transformer used in the Harman Kardon HK990 amplifier. This critical component is well known as the weak point of the unit, often prone to overheating and long-term failure.

The original 4090-1575-0003 transformer frequently fails due to its undersized capacity compared to the amplifier’s 32-watt power requirement. Overheating is a common issue, and finding an original replacement today is nearly impossible.

The Solution:

The 24S83 transformer has been designed to be electrically compatible with the original unit but built with greater robustness. Despite slightly different dimensions, it can be installed in the amplifier without drilling new holes. Simply raise the control board by 5 millimeters using four spacers before reattaching it for a perfect fit.

Contact Us: Don’t let a faulty transformer limit your Harman Kardon HK990’s performance. Contact us today to purchase the 24S83 power transformer and restore your amplifier to full efficiency.