Vintage Collector Quality Matched Pair Of General Electric Ge 6550a / Kt88 Tubes

Vintage Collector Quality Matched Pair Of General Electric Ge 6550a / Kt88 Tubes

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Vintage Collector Quality Matched Pair Of General Electric Ge 6550a / Kt88 Tubes:

Vintage Collector's Quality Matched Pair of

GE 6550A / KT88 Tubes

General Electric 6550A / KT-88

Very Strongly Tests and

Appears to be a New Old Stock Tubes by Their Tester Readings

Superb Silk Screening & Crisp Boxes

Although I obviously don't know the history {nobody does really of the tubes they sell} of the tube, these tubes appear to be NOS as they functionally test very strong at a brand new old stock tube level on a professionally calibrated TV-7D/U (illustrated here for easy to understand exact readings), U.S. F.A.A.Hickok 752A and Industrial B+K 747B. These are the only facts we do know and can be sure of. I cannot guarantee that these are brand new old stock tubes and really nobody can, because these tubes have been kicking around for 40-50 years on average.

My TV-7D/U Military Tube Tester used here is not just any old U.S. Military “de-commissioned unit from active service purchased from a war surplus sale” TV-7D/U that may well be out of calibration since it left military service years ago!

The fact is the old TV/Radio repairmen used to repair equipment by many times “TRIAL AND ERROR”. They would take a new boxed tube they had in their shop and plug it into the equipment being repair edto see if it made a difference. If that happened to these tubes, it's not really evident by the crisp silk screen, which rubs off with one's fingers. Does anybody really know what the original owner of these did? . . . You know the old cliche: “if it looks like a duck; quacks like a duck; and walks like a duck; it must be a duck.LOL!

I will call these “new old stock” as that is my best judgment. You can formulate your own opinion with pictures and readings here. Other tube sellers/major dealers would call these PREMIUM “NOS”, but I like to tell it like it is as absolutely nobody knows the “total provenance” of a tube they call “NOS” unless they bought it themselves directly from the retailer decades ago.

FYI regarding readings obtained from a calibrated U.S. Military TV-7D/U or similar class tube testers – as you know NOS tube factory production can vary greatly even with U.S. Made tubes of decades ago, plus there is reading variation even among the same model tube testers of as much as 20% as stated by Mr. Wendall Hall, the unchallenged nationally recognized expert on tube test gear who calibrated Hickok military,government and civilian tube testers for me as well over the years before his untimely passing.

It's been my experience the Russian, Eastern European and Chinese RE-ISSUE copies such as Tung-sol 6550 s , Mullard KT-88, Genalex KT88 are FAR LOWER QUALITY than the original tubes of 40-50 years ago that they are poor copies of. Although they appear the same, the Problem with them is their quality of materials/production is so inferior that they just don't last very long like the "vintage tubes do" as long as your amplifier does not have any problems that will “cook” tubes. A vintage U.S. General Electric 6550 will outlast many of the current import brand name copies by many times. Heck, I've played with people that still have their original 6550's in their Ampeg SVT, Sunn 200S, etc. For example I personally own a late 1960's Sunn 100S ( two 6550), Peavey Roadmaster (four 6550) that still have the original tubes in them still going strong. I've used these amps over the years a lot and have had them serviced, but I'm not a gigging player doing 7 nights a week for 52 weeks continually touring.

My point is simple, buy one set of U.S. Vintage tubes at a premium price or pay for 5-6 or more plus pairs of cheaper imports. Sort of like having vintage Craftsman or Snap-on tool set versus the cheap Chinese import tools that look good, but break far easier. The old cliche fits: "You can pay now or pay later, but you will align="CENTER">PICTURES OF TUBES AND EACH TUBE UNDER ACTUAL TEST FOR TUBE NO. 1 OF MATCHED PAIR (RESPECTIVE READINGS = 70 AND 62-63 for the matched pair with the higher military grade minimum value for a good safe tube ”minimum acceptable service reading" = 44.


Asis the common practice with all vintage/antique electronic equipment,this item is sold as is tested from a calibrated TV-7D/U SHIPPING,packing, handling and insurance TO ANYWHERE IN THE LOWER U.S.CONTINENTAL STATES. Hawaii and Alaska will be more.

If you want signature confirmation of delivery (assuring it gets received by someone at your address rather than being left at the door), please add $2.50 to $12.00 flat rate shipping U.S. Continental States' shipping cost.

If you live outside the continental U.S. 48 states or in a foreign country and want the item, email me before you offer/buy for a quote with adequate time to give you a quote. For your safety and the safety of the item, the higher cost Express Mail International Parcel Post is STRONGLY recommended rather than the less expensive international postal service. The best service, but far more costly would be Fedex International Economy, but few buyers opt for this level of very expensive I email the buyer the total including Packing and Shipping, the Buyer Must Make Payment within 3 Days or Less or please advise me of your legitimate reason for the payment delay, if you can't meet the requirement. I'm willing to work with you, but I got to know as some folks may never pay despite their huge response. It has happened and I wish to prevent that from happening again.

I will accept Paypal from buyers in the U.S.A. As a payment option.


Will accept payment via Paypal as one form of payment. If you choose to use Paypal, a“Confirmed Paypal Account” is recommended to avoid delays.

Paypal IS NOT instant payment, because they hold the money for days, before transferring payment to the seller, although some buyers are in error in believing that money is instantly transferred to me. It is not!

Vintage Collector Quality Matched Pair Of General Electric Ge 6550a / Kt88 Tubes:

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