Description
Perfect matched pair of vintage Mullard E188CC audio tubes - Made in Holland - 1961 - Identical Date Code - Extremely Rare Tube Summary The "textbook Heerlen sound" has been referenced in several Soundlumia listings of Amperex Holland/Philips E88CC/6922 tubes, and many tube enthusiasts asked what that all means. So this is the answer: the late 1950s and very early 1960s tone, the beginning of over a decade's excellence in sound, the classic tonal template for all the great (and greater) Amperex/Philips/Valvo/Miniwatt tubes to be made in the years to come, the timeless Philips radio tone that many of us grew up listening to. And this super rare E188CC pair is the "further amplification" of all that. Sound Characteristics Be assured - you will not miss one single bit of the legendary Heerlen sound just because the tubes are labeled Valvo. The proud delta symbol in the date code tells you this is 100% "textbook" natural sound from Heerlen: warm and lively tone with infinitely expansive midrange and nice extension on both top and low ends. The technical advantages of the E188CC/7308 design on these tubes have taken sound to the next level: you get more forward vocals and a wonderful airy top end, super large imaging and incredibly spacious sound stage. Like any other E188CC/7308 tubes, they have low noise to the vanishing point, and that makes these tubes the top choice if you look for the finest sound details and ultra clarity. 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 Both tubes tested Strong NOS (100% - 110%+ mutual conductance) on a Mercury 2000 tube tester with the following result (mutual conductance both in uMhos and in percentage of nominal ): Tube 1: 14,000/13,900(112%/111%) Tube 2: 14,100/14,200(113%/114%) 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 better. Appearance & cosmetic condition We treasure this pair also because of the pristine condition of both tubes (clear inscription and clear date codes), which is amazing given the tubes' age. What makes this pair even more rare is the identical date code on both tubes: delta 1B3 ( delta = Heerlen, 1 = 1961, B = Feburary, 3 = the 3rd week of the month ) Shipping Policy - Ship worldwide! Flat-rate expedited shipping (USPS Priority) within the US. - One business day handling. 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. - Customers outside the US please pay extra attention: International shipping is through USPS Ground Advantage International by default. It's the least expensive option and customs declaration is automated but it may take longer than other carriers. If you prefer to use a different carrier please contact us first so we can get you the correct shipping rates before you make payment. Return Policy - Please READ carefully First of all, returns are acceptable as long as you are reasonable . Soundlumia sets extremely high quality standard for the products we deliver. Tubes we sell are guaranteed to work because we run professional tests and sound evaluation 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 do not work and we will open a dispute with eBay. Sound experience is a very subjective thing, and let's be real it's not that easy to run into compatibility issues between amps and tubes (so that one won't fly, either.) Please contact us to work things out before submitting return requests claiming "item is defective" or "item not as described." We would really appreciate your respect to the professional work we have done (sourcing, testing & matching tubes, evaluating tube sound, sharing our sound experience with you, packing and shipping) to make these wonderful vintage tubes available to you at reasonable prices. Secondly, if you are a tube roller looking to game the return system, Number One STOP. We have seen it all and we know what you're up to. No tricks here please. Abusive behaviors will be reported to eBay immediately and negative feedback will be left to your account - that's guaranteed. We have already reported several abusers and eBay has ruled in our favor the dispute cases. We are more determined than ever to continue working with eBay to help rid of these unprofessional, unjustified, unkind, unfair and unacceptable abuses that are detrimental to the eBay marketplace, the vintage tubes market and the audiophile community.