Just sold the 10th pair. Last 7 pairs sold for $660 or more per pair. Excellent feedback both here and on our other site!! This is the 11th EXCELLENT NOS PAIR of 6900 Gold Pin made in USA by Tung Sol and retested, rebranded by MU . Bendix also purchased the vast majority of its 2nd generation 6900 stock from Tung Sol. These are NOT MU manufactured and in fact I've never seen a true MU manufactured 6900. They bought all the surplus stock of 6900's and tooling to make them from Tung Sol and have never produced any themselves. Each tube was retested by MU and then labeled MU and sold to the military.
Extremely rare and the best you will ever own. These are conservatively rated at 10,000hours in a pulse application. Audio circuits will see longer life.This is an excellent testing matched pair. Current matched internally and externally as well, for excellent push pull circuits such as drivers or as stereo triodes. This means BETTER sound than a standard unmatched pair or a pair matched only for transconductance.
Truly the very best sounding all all the twin triodes we've ever auditioned. They best the ECC32,34, all the 5687 and 7119 (7044) types, as well as any 6SN7 we've heard, 437A's etc. Ceramic insulators, heavy Nomex glass, gold grid wire, tungsten pins with gold plating, microphonic reducing springs, etc. These are tested at 500G's and rated at 300G's / 300 degrees C. Heater to cathode rating is a whopping 450v. Excellent as an output tube as well as a driver or line stage tube. Soundstage is breathtaking. Very low tight deep bass, tons of micro detail and subtle shadings flow from the stage with sweet smooth highs that seem to extend higher, effortless dynamics , these tubes do everything correctly. As for measurements>> We compared them to 6SN7 's without feedback , or 12AX7's without feedback >> 12AX7 frequency response is flat to only 11,000hz or so. The 6SN7 typically will do 25 to 30,000hz. The 6900's are flat without feedback to nearly 100,000 hz!. Tested on Tek scope with Tek frequency generator.
Great tubes!!! We have singles for sale as well. We also have a NON gold pin pair listed and we also have quads or octets of these. A total of 10 pcs will be sold from our collection.Tested on a Hickok 15750 tester as well as a TV10 and an A-118 , these tubes all test in the 10,000 to 11,000 umho range and we have matched internal and matching pairs as well. These are from our personal collection. Zero gas or grid current. Perfect tubes.
We also sell vintage amplifier tubes in quantity to dealers and musicians.
These are rare tubes and getting rarer by the day, because we USE them , unlike most antiques that just collect dust. NOS , PAIR but shipping will be combined if you purchase other items.
Call if you need more info on this or other tubes or would like us to list something that you are searching for with a Buy it Now. Thank you for looking! .Items will be packed extra well so that they do not incur damage and will be sent Priority US Mail. Buyer may choose Parcel Post or other shipping as well. Ask if buying requires another method than the one shown. Please note that we have been selling tubes on Ebay for over 8 years under several user-names during that time period. We are now separating our 2 Ebay businesses to enable us to serve our boat racing & vacuum tube customers better. Our most recent user-name is princess-audio and we have excellent feedback for both our tube sales and other items under that user-name as well.