Monoblock CMA15 Kitset

The Radford MA15 series of amplifiers was a well-regarded line of vacuum tube audio amplifiers produced in the 1960s.

There were four versions:

1. MA15 Mk1: This was the original version of the amplifier.
2. MA15 Mk2 Early: An updated version of the original design.
3. MA15 Mk2 Late: A further refinement of the Mk2 design.
4. CMA15: This was a kit version of the MA15 amplifier.

CMA15 (Kit Version)

• Kit version of the MA15 likely based on the Mk2 Late design
• Available for DIY enthusiasts to build themselves
• Priced at approximately 60% of the fully assembled versions
• Included detailed construction articles in Hi-Fi News (June to September 1962)

Radford CMA15  Output Transformer (T2063G)

• Resonance Frequency: The CMA15, the same as the Mk2 late output transformer was significantly improved, pushing its first resonance to approximately 150kHz.
• Performance: This allowed for reduced phase shifts, better high-frequency stability, and lower distortion across the frequency range. It also enabled the amplifier to deliver its rated power up to 20kHz.
• Design Complexity: The improved design contributed to a more refined sound and greater technical performance, addressing the limitations of the Mk1.

These enhancements in the Mk2's & CMA15 output transformer were a critical factor in its superior performance compared to the Mk1.

The kitset was priced at £17/15/- in August 1963.

In questo link sono elencati 32 modelli, di cui 25 con immagini e 10 con schemi.
Elenco delle radio e altri apparecchi della Radford Electronics Ltd.; Bristol