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Partial Silver Stranded Secondary Transformers


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Partial Silver Stranded Secondary Transformers

  • Silver transformers without the high cost of solid silver wire
  • Custom built, hand crafted
  • Silver performance with high flux sensitivity
  • Wide bandwidth -1db 20 - 30 Hz to over 20 kHz.

Information needed to order single-ended output transformers:
  1. Impedance of primary
  2. Current through primary
  3. Expected power output
  4. Impedance of secondary

Note: No winding DCR requests.

Different size transformers will have a different bandwidth. All will be within -1db 20 - 30 Hz to over 20 kHz.

Information needed to order push-pull transformers:
  1. Power level
  2. Plate to Plate impedance
  3. Current through each primary
  4. Taps for ultra linear operation (40% to 50%) if needed
  5. Secondary impedances

Different size transformers will have a different bandwidth. All will be within -1db 20 - 30 Hz to over 20 kHz.

Solid silver performance:
Silver wire audio transformers have been considered, for many years, to make an improvement in audio reproduction. Due to silver�s higher sensitivity to flux change (200%) it is able to reproduce lower level information produced by the output stage. This resulted in an audible increase of the low level higher harmonics that do exist from various musical instruments. ElectraPrint Audio has developed a new line of transformers using Partial Silver Stranded Secondary (PSSS).

PSSS transformers are built to order:
To order, indicate the primary impedance, primary current, transformer power level and a choice of one secondary impedance. The secondary impedance can be dual use such as 6 ohms for 4 and 8 ohms or 12 ohms for 8 and 16 ohms, or 4, 8, 16, or other single impedance value. No taps are available with this winding arrangement.

Impedance considerations:
Primary impedance for lower power level types can be higher than 10k ohms. High impedance primaries 10K+ on larger builds can have high frequency roll off within 20 kHz. High ratios (example, 15k ohms to 2 ohms) can be difficult or impossible.

Silver performance and pricing:
Recently the price of silver has increased to a point that not many builders can afford silver transformers as a choice for improvement over standard copper output transformers. We have tested lower priced partial silver wire or silver plated multistrand wire and have found that the results were equally the same as solid silver wire. The amount of silver to copper was measured and it was found to be about 20% silver and 80% copper. The reason this combination worked as good as solid silver wire is that it is plated around the circumference of each copper wire. The flux generated by the primary would excite these surfaces first. The many strands then resulted in a larger silver surface area than one singular silver plated wire.

New winding Design:
ElectraPrint Audio has developed a winding technique that uses PSSS wire effectively with a standard copper primary. Primary windings do not have to be silver. Plus, primaries cannot be wound with the silver plated stranded wire due to the final size being too large in diameter. Finally, a silver primary would not offer a performance improvement anyway as it provides the flux for the secondary.

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