I have for sale a complete Audio Research SP-3 tubes set. As can be seen in the pictures, these are very rare Audio Research labeled 12AX7 tubes. The tubes are new old stock and have never been installed or used in equipment.
The tubes were manufactured by EI for Audio Research corporation back in the 1980's. The tubes were made on original Telefunken machinery and are basically an exact copy of a Telefunken 12AX7 tube using high quality parts and manufacturing not available in current production tubes. Do the research on these (Prewar) EI 12AX7 tubes and you'll find they are excellent sounding long lasting tubes.
You get eight (8) tubes for my listed price. These tubes are from the estate of an Audio Research employee and now have very limited quantities left...once I sell out they will be extremely hard to find.
I tested and listened to the tubes on a reference quality Amplitrex AT-1000 tube tester and got the following test results E (emission). 100/85, 108/100, 98/100, 100/85, 100/100, 100/108, 105/80, 108/114. The GM or (Transconductance) for all the tubes in both sections tested above 100 for all the tubes.
The tubes will be shipped via USPS in the generic white tubes boxes as shown in the pictures. Continental USA sales only. No International sales
Please Note: It's really hard to get a good picture of vacuum tubes with all the reflective and shiny surfaces...there are many reflections in the pictures.
If you have any questions about the tubes, please email me before buying them. Thanks.