Description

Tube Summary These are the legendary "medical tubes" made by Amperex Holland for Hewlett-Packard's medical devices distributed around the world. Each tube had to go through rigorous test and selection processes designed, implemented and monitored by HP. What you get is the best from the best candidates in build quality and low noise. Sound Qualities Despite the HP label, you get the "textbook" Amperex Holland midrange presentation that is transparent, natural and expansive, with a slight touch of warmth that illuminates your musical world. The top end is super airy, smooth and nicely extended like one would expect from the best Siemens tubes. Vocals are intimate, sweet and forward (but not right in your face) and that always reminds me how the vocals sound on the best Mullard tubes. Bass is deep and well controlled and the accuracy feels very similar to the high end German ECC88's (Siemens, Telefunken.) To see how these sound differently from their German counterparts, please feel free to take at a look a wonderful pair of Siemens 6DJ8's we recently sold here: https://www.ebay.com/itm/266137613847 Professional Sound Evaluation The pair worked wonderfully and sounded terrific in our professional studio setup for monitoring. - Input: Cambridge Audio CXC V2 dedicated CD transport + Schiit Audio Bifrost 2 Multibit DAC - Amplification: Liquid Platinum Tube Amplifier by Alex Cavalli - Output: Focal Clear MG Pro open-back headphones Our full tube sound review was written 100% based on the actual listening experience while this pair of tubes were running in the system described above. Professional Tube Testing NO short, leakage or gas. NO noise or microphonics. Both tubes tested Strong NOS (110%+ nominal mutual conductance) on a reliable and regularly calibrated Mercury 2000 tube tester with the following result (mutual conductance in both uMhos and percentage of nominal value ): Tube 1: 14,500/14,000 (116%/112%) Tube 2: 14,200/14,000 (113%/112%) Good tubes start at 7000 and new tubes (incl. NOS/NIB) 12,500 - 13,000 , and the Mercury 2000's rated mutual conductance (nominal) for new tubes is 12,500 . Test result can also be seen in the pictures. In case you wonder what all these numbers mean to your sound experience, it's actually quite straightforward: mutual conductance directly translates to a tube's ability to amplify sound , so the higher the numbers the stronger. Appearance & cosmetic condition Besides its remarkable sound characteristics, we also treasure this pair for its near pristine cosmetic condition given the tubes' age - at least 90% of the paint is still intact on both tubes, and the very close (practically identical) acid-etched date codes of the Heerlen factory are perfectly visible on both tubes: delta 1F2 (delta = Heerlen, 1 = 1961, F = June, 2 = Week 2 of the production month) delta 1E5 (delta = Heerlen, 1 = 1961 , E = May, 5 = Week 5 of the production month ) Shipping Policy - US Shipping : Flat-rate USPS Ground Advantage - International Shipping : (Please read carefully) USPS First Class International is used for all countries EXCEPT: Armenia, Chile, China, India, Latvia, Mauritius, Serbia, Slovenia, Tuvalu, and Vietnam. If you prefer to use a different carrier or shipping service, please contact us first so we can establish shipping rates before you make payment. If you are a buyer in one of the excluded countries, you must contact us prior to purchase to arrange shipping. Soundlumia-sponsored 3-day guaranteed worldwide delivery program ($35 flat rate for ALL destinations in the world) via DHL Express is highly recommended to serious and committed buyers. - Same day shipping: Orders placed by 2:00PM US Pacific Time on weekdays are posted on the same day, otherwise the next business day. - Combined shipping available - request invoice for total before making payment or receive shipping credit after order ships. Return Policy - Please READ carefully Returns are acceptable if we made a mistake by delivering you wrong or defective products. Tubes we sell are guaranteed to work because we run professional tests and sound evaluation TWICE: before they are approved for listing AND before we ship them to customers. So the "defective item" case doesn't exist and please do not bother trying - this type of returns will NOT be accepted without proof that tubes are faulty and we will open disputes with eBay. Sound experience is very subjective and we do NOT accept returns because you do not like the tube's sound signature or because you changed your mind about your purchase. Please contact us to work things out before submitting return requests claiming "item is defective" or "item not as described" or "just didn't like it." Tube rollers abusing the return system will be reported to eBay immediately and negative feedback will be left to your account - that's guaranteed. We have already opened several dispute cases to report abusive buyers and eBay has always ruled in our favor. International buyers who request return or refund claiming your country's import duties or sales taxes/VAT/GST are too high will be reported to eBay immediately for dishonesty and will be permanently blacklisted from purchasing from Soundlumia. We are committed to working closely with eBay to help rid the marketplace of dishonest, unjust, unreasonable, abusive buyers that are detrimental to the vintage tubes market and the audiophile community.