Factory Update Program for SP3 Series Preamplifiers
Audio Research has the reputation for the best product support in the industry, which includes service for products that date back to the beginning of the high-end industry and to the founding of our company over 30 years ago. As further support, we occasionally offer update programs for older products to extend their service life and enhance their sonic performance.
The SP3 was introduced in 1972 and was instrumental in establishing Audio Research's world-wide reputation for sonic excellence. Several thousand were sold during the period of 1972-1976 and most, we believe, are still in service today.
Audio Research continues to provide product support and parts for the SP3 to this day. However, some of the electrolytic capacitors used in the power supply of the original design are no longer available. These parts had about a 25-year service life. Therefore, virtually all SP3s which still have these original parts need to have them replaced in order to provide reliable operation.
Audio Research has made significant advances in sonics and reliability during the 30+ years since the original SP3 was introduced. The SP3C update we are offering contains a completely new power supply circuit board to replace the obsolete power supply and its worn-out parts. Benefits of this new power supply include increased energy storage for improved dynamics, superior regulation of both B+ and tube heater operating voltages for rejection of AC power line interference, a lower noise floor for improved retrieval of micro-dynamic nuances, and it allows operation over AC line voltages from 100 to 130 VAC. We have also added an auto-mute circuit for turn-on, power interruption and turn-off to protect your power amplifier and speakers from transients.
Along with the changes to the power supply, the input and output connectors are replaced with audiophile-grade gold-plated RCAs. Also, coupling and bypass capacitors on the main Printed Wiring Board are changed to brand names such as Infinicap, REL-Cap and WIMA.
The sum of these changes results in a vacuum-tube stereo preamplifier (with RIAA phono) that approaches the performance of our current preamplifier product line. You will find the bass much more well-defined and extended, the mid-range smoother and more accurate, and the high frequency range extended and more accurate. For those of your who like classic tube sound, this modification takes a large step toward accuracy while preserving the things you like about vacuum tubes.
This update applies to all versions of the SP3. Cost is US$1,295.00. It does not include tubes, if needed, or shipping. It is offered on a direct basis only, rather than through our dealer or distributor networks. Updates must be scheduled for timely turnaround. Please do not send in your units without first obtaining a Return Goods Authorization number from our Customer Service Department--(763-577-9700).
If you have premium quality tubes such as NOS Telefunken, or other quality brands, we suggest you remove and keep such tubes at home, not risking the possibility of loss or damage from handling or shipping. Recommended shipping: UPS. Units sent in without tubes will be tested and evaluated sonically with our tubes installed, but will be returned without tubes unless you request otherwise. Highly modified units may be deemed unacceptable for this update.
Sincerely,
Terry Dorn, President