Perfect matched pair of vintage Valvo Heerlen CCa 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 Valvo CCa yellow print pair is the "crown jewlrey" 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 CCa design on these tubes have taken the Heerlen 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 CCa 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: 13,900/13,600(111%/109%) 
Tube 2: 14,000/12,500(112%/100%)

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 1L2 (delta = Heerlen, 1 = 1961, L = December, 2 = the 2nd week of the 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. 
 - 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.