Description: Here, a pair of double silver matched Tung-Sol 6550 branded DYNA Corp.ST envelope "coke bottle" shape, triple getter, gray plate 6 hole. Matched by production number: 3227425, 1974 and by test results.Matched by tests within 9% of each other (interestingly the accepted error from Hickok machine to machine is known to be 10%.) Marker from old tests on a calibrated recapped B&K 707 at 102 and 110% Gm.Recent testing on AT1000 factory re-calibrated/upgraded tester at fixed bias and 250V plate yields 87 and 96% GmEmission on the AT1000 rated them at 78 and 85% or 110 and 120mA current, strong and close.low gas rating at 2.7 and 3.0 mATubes test lower on AT1000 than Hickok and B&K, more stringent test parameters with higher plate V of 250 and 1% error. Tested and sounded great in MK3 amps.You will absolutely enjoy this USA vintage strong matched pair.12% price drop 5-22-24. I will insure these tubes at no charge and pack carefully.
Price: 240 USD
Location: Bradenton, Florida
End Time: 2024-09-12T13:24:21.000Z
Shipping Cost: N/A USD
Product Images
Item Specifics
All returns accepted: ReturnsNotAccepted
Brand: Tung-Sol
Type: Vacuum Tube
Model: 6550
MPN: 6550
Country/Region of Manufacture: United States
