The Mazda Ediswan 6P25 are among the best pentode for audio sound. Semi coated to avoid radio frequencies they are very silent tubes! Best performance. They are equivalent of KT61 and EL33 therefore can be used on any Leak TL10 amplifier or any amplifier using KT61 or EL33Excellent sound by Mazda 6P25This quartet of Mazda 6P25 has been fully tested with AVO 1631) Mazda Ediswan 6P25 coated tested 40mA 2) Mazda Ediswan 6P25 coated tested 41mA 3) Mazda Ediswan 6P25 coated tested 40mA 4) Mazda Ediswan 6P25 coated tested 40mAGood value from 38mA Happy bidding Immediate payment required for this item! This is due to time-wasters who refuse to pay. If payment is not received within 24 hours I will sell it to second highest bidder without any further warning! Thanks I ship worldwide.UK GBP 8; Europe GBP 16; Asia: Hong Kong Taiwan China South Korea Japan GBP 20 USA GBP 20

KT61 Vacuum Tube. Has ‘Made and Patented in England’ written on the front. I am not sure of the manufacturer. The tube seems to be in good condition, no rattle or loose parts. I am unable to test this item and it is sold as seen. For exact international shipping costs please message me with your location.

KT61 GEC PAIR NOS VALVES/ TUBES AVO tested

Still thinning out my valve collection and offering a MARCONI OSRAM KT61 TUBE. A superb working example that tests over 90% emission. These are commanding some high prices now but this one is priced to sell. Please see my 100% positive feedback and bid with confidence. Will be well packaged for shipping. Happy to post worldwide via the Ebay Global Shipping Programme or direct international mail. Thanks for looking.

Quad set Philips Radiotron KT61 Power Tetrodes USED test strong Click images to enlarge Description QUAD SET RADIOTRON Made in England, KT61 Power tetrodes-USED A Quad set of early 1950s Phillips Radiotron, Made in England, KT61 Power Tetrodes in Used, closely matched and test strong condition. Made probably at Phillips Mullard Blackburn plant these highly sought-after tetrodes are surplus to my needs and would make a great set of output tubes for such amplifiers as the LEAK TL 10 or similar. Have been tested on my AVO for leakage, Emission and Mutual Conductance with the following results. Va=250V, VS=250V, Vg=-4.4, Vf-6.3V Tube 1) Ip= 44mA, Gm=10.5, Tube 2) Ip=40mA, Gm= 8.2mA/V, Tube 3) Ip==37mA, Gm= 7.5mA/V and Ip= 34mA, gm=8.5mA/V.A new tube should indicate Ip=40mA, gm=10.5mA. Will ship anywhere in the world at buyers expense. Please check out my other Auctions for rare vintage valves. Pictures sell! Auctiva offers Free Image Hosting and Editing.300+ Listing Templates! Auctiva gets you noticed! The complete eBay Selling Solution. Track Page Views WithAuctivas Counter

Pair Radiotron and Osram Made in England KT61 Tetrodes test strong Click images to enlarge Description   OSRAM and Radiotron KT61 tetrodes as used in the Leak TL10 valve amplifier A pair of early 1950s Made in England Osram x 1, and Radiotron,  KT61 Power Tetrodes in Used, closely matched and test strong condition. Made probably at Phillips Mullard Blackburn plant these highly sought-after tetrodes are surplus to my needs and would make a great set of output tubes for such amplifiers as the LEAK TL 10 or similar. Have been tested on my AVO Mutual Conductance and Emission Tester for leakage, Emission and Mutual Conductance with the following results. Va=250V, VS=250V, Vg=-4.4, Vf-6.3V Tube 1) Ip= 47mA, gm=10.5mA/V, Tube 2) Ip= 44mA, gm= 8.7mA/V, A new tube should indicate Ip=40mA, gm=10.5mA. Will ship anywhere in the world at buyers expense. Please check out my other auctions for rare vintage valves Images sell! Get Supersized Images & Free Image HostingCreate your brand with Auctivas Customizable Templates. Attention Sellers - Get Templates Image Hosting, Scheduling at Auctiva.com. Track Page Views WithAuctivas Counter

Still thinning out my valve collection and offering a MARCONI OSRAM KT61 TUBE. A superb working example that tests over 90% emission. These are commanding some high prices now but this one is priced to sell. Please see my 100% positive feedback and bid with confidence. Will be well packaged for shipping. Happy to post worldwide via the Ebay Global Shipping Programme or direct international mail. Thanks for looking.

Still thinning out my valve collection and offering a MARCONI OSRAM KT61 TUBE. A superb working example that tests over 90% emission. These are commanding some high prices now but this one is priced to sell. Please see my 100% positive feedback and bid with confidence. Will be well packaged for shipping. Happy to post worldwide via the Ebay Global Shipping Programme or direct international mail. Thanks for looking.

KT61 GEC PAIR NOS VALVES/ TUBES

Mullard EL33 , KT61 Grey Valves x1Black base, Tested workingThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Marconi KT61 , 25A6G Black, Grey Valves x2Black base, Tested workingThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Brimar Military BVA 6V6GT CV509 , (KT61) Black Valves x2Tested workingThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Military BVA 6V6G CV509 & KT61) Black Valves x4Tested workingThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Brimar Military BVA 6V6GT CV509 , (KT61) Black Valves x2Tested workingThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Marconi KT61 , 25A6G Black, Grey Valves x2Black base, Tested workingThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Army BVA 6V6G CV509 , KT61 Valves x2 Black base, Tested working, used conditionThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Mullard EL33 , KT61 Grey Valves x1Black base, Tested workingThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Army BVA 6V6G CV509 , KT61 Valves x2 Black base, Tested working, used conditionThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Brimar Military BVA 6V6GT CV509 , (KT61) Black Valves x2Tested workingThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Mullard EL33 , KT61 Grey Valves x1Black base, Tested workingThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Marconi KT61 , 25A6G Black, Grey Valves x2Black base, Tested workingThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you

Military BVA 6V6G CV509 & KT61) Black Valves x4Tested workingThese items will be well packed for UK, Worldwide ShippingPlease do not hesitate to ask any questions. Thank you