EF91/CV138/6AM6 Mullard/Valvo/Philips NOS, D-getter, milspec, matched pair, for Little Dot

Description

One premium matched pair/2 pieces Valvo/Philips/Mullard EF91/CV138/6AM6 with big blue shield and D-getter for Little Dot headphone amps tube rolling. 

These tubes are made by Mullard, all have a Mullard code etched in the glass. They are branded either Valvo or Philips. No matter what label, they are all the same. I reserve the right to deliver either Valvo or Philips branded pairs (you may tell me of course your preference if you like). Some tubes may carry values written on them by the army personal. This does of course not affect the proper operation.

This is the early big blue shield Mullard EF91 with D-getter. These tubes came in bulk from Swiss army surplus. All tubes are tested and burned-in/pre-aged (hence the colors on the tubes). The burn-in was done to secure stabilized operations in highly sensitive measurement instruments. 

You will receive a tightly matched, noise and distortion free pair! Guaranteed!

Matching is done on a milspec Neuberger RPM375, still one of the best tube testers out there… 

EF 91 and EF92 tubes can be noisy at times in the Little Dots amps. While some noise during heat up is normal with these tubes it should disappear after 60 seconds latest. To guarantee that you will receive a pair that is noise free after warm-up, we will listen to each pair ourselfs on our LD MK2 with super neutral and noise free Neumann studio headphones.

We do have plenty of different versions of the EF91 and EF92, please drop us a line, if you would prefer another brand or just check our other offers. All are from the same provenance and most are burned in. We also do have many other kinds of 7-pin tubes, which you may want to try. We will be happy to check our stock for you!

Using EF91/EF92 instead of EF95: You may use this kind of tubes in your Little Dot headphone amp after changing the settings on your amp. This is a less than 5 minutes job and can be done by really everyone. No expert know-how necessary! Please consult your user manual how to do this prior to using these tubes in your particular amp!

From own experience we can tell you, it is more than worth it!