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
- US Shipping: Flat-rate ($5.50) USPS Ground Advantage for ALL states.
- International Shipping: Flat-rate ($35.00) DHL Express Worldwide for ALL countries.
