|
|
|
|
NOS SIEMENS CCA (E88CC 6922) GRAY-SHIELD 1962 HOLY-GRAIL MATCHED PLATINUM LOW-NOISE PAIR - RATED "BEST SOUNDING" # 1 CCa EVER MADE
1962 Vintage.
NOS comes with Authentic Siemens Blue & Yellow original boxes, the same identical tubes with gray-plates in the pictures.
ACTUAL PICTURES OF 1960's low-noise 1960's ACID CODES ERA: THE ACID-CODES ARE IN THE GLASS in THESE EARLY VERSIONS ( and of course NOT stamped on metal tags which you want to stay-away from).
From the Tubemuseum Vaults - A REAL Archeological find … 1962 Siemens Halske with VERY RARE "O" Getters with Gray Electro-Static Shield-Plates CCa. "Rarest and most sought after CCa, has "gray shield" between plates, Most realistic sounding holographic soundstage, pure seductive sonic joy, complex symphonic images emerge effortlessly" - quote from the tubemuseum review.
Audiophiles vote these as the best-sounding * Frame-Grid Construction 6922 - even better sounding than Telefunken! These tubes are known for excellent performance, smooth highs, inner detail and overall resolution and balanced sound.
Revered by many as one of the MOST DESIRABLE CCa / 6922 - the HOLY-GRAIL of the E88CC family and the MOST DESIRABLE 6922.
CERTIFIED ULTRA-LOW-NOISE PHONO-GRADE SPECIMENS - Manufactured in Munich Germany almost half a century ago! Low Noise early
1960 Siemens & Halske CCa = 6922 - THE BEST!
Price is for a Balanced Matched Platinum low-noise pair.
15,600/14,200 mA/V (124%/113%) & 14,200/13,200 mA/V (113%/105%) WOW!!!
32.155 & 32.155 MATCHING run codes
AФ2 ≠ 2A and AФ2 ≠ 2A MATCHING ACID CODES
MATCHING Numbers "8" and "8" molded in the glass bottoms between the gold pins. Matching 32 155 and 32 155 on glass tubes!
No leaks, zero (0) uA heater-to Cathode (H-to-K) zero leaks
Fixed Bias Readings tested @ 90 eP % of the Balanced Matched, Platinum Low Noise "Best Quality" Siemens CCa = E88CC/6922
This tube is known for excellent performance, smooth highs, outstanding 3-D holographic soundstage, lots of open-air, inner detail, and overall perfect resolution and balanced sound. Improved dynamics, frequency extension accross the spectrum are immediately obvious, making the music sound much more accurate and real. A major improvement over other E88CC / 6922's
Make sure you are buying Real Siemens Halske CCa = E88CC / 6922 tubes - They have the double-stage getter frame-grid construction, Gray separator or Gray Electro-static shield, 4 seams on top and numbers in the glass between the pins and the Siemens & Halske S+H logo on the front of the tube.
"...If you haven't yet experienced EARLY 1960's Siemens Halske CCa = 6922'S you don't know what you have been missing. Instruments seem to come out of the wood-work, you hear harmonies, musical energy & subtle Nuances which you haven't heard before, and without these you may never hear them ..."
CCa = LOW-NOISE E88CC "6922" = PREMIUM QUALITY GOLD PIN E88CC:
The "CCa" is an E88CC specially selected for "Post Germany" in the 1950's -60's, they were a special low noise, low microphonic, long-life E88CC / 6922. Philips had similar "designations" for the "Dutch Post", some tubes that were selected had "PTT" * and "BP" lettering or etched designations, but they were the same as a top specification E88CC. The "German and Dutch Post" consisted of telephone, telegraph, telex, and the postal system "tube" technologies which required LOW-NOISE E88CC / 6922. A CCa is the same as a 6922 but was tested and certified with high mA, RP, and Mu and lowest-noise audio threshold - the same proceedure the Tube Museum New York certifies tubes by today. Much of the telephone centrals used vacuum tube technology equipment for telephone equipment requiring a "noise-free" enviroment. The letters "CC" probabably equates to "double triode", and for a special low-noise design - the * "frame-grid" inner construction, which was actually invented by Amperex USA, and became ubiquitous - Present, appearing, or found everywhere in the 6922/E88CC design of the day, including Siemens Halske, Telefunken, Amperex, Philips, and many others. Internally the inner construction of the CCa is identical to Siemens Halske E88CC - why? Because the only difference is the cosmetic-lettering and ofcourse the "special selection" of the best and quietist specimens. In addition, the suppliers of the day, wanted a sure method of identifing the tubes they provided, as the very tubes sold to these companies. It could have been very easy to swap with a current different E88CC in the day, if it wasn't uniquily labeled, simply by walking down to the local radio shop and purchasing a different tube. The CCa factory markings identified the original supplied tubes as the ones guaranteed by the Siemens "Klingarm" Division ( "Klingarm" is the term for low microphonics. You often see Telefunken EF12K or AC701K, the K means Klingarm) whom charged a premium for selected low-noise high mA specimens for industrial customers.
* The sturdy construction provided by the grid frames allows the control grid to be made of wire only five microns in diameter?about half the thickness of the finest grid wire normally used. This allows more turns to be wound per inch while it minimizes grid current.
The gray-plate is a special electrostatic-shield, also known as a gray-shield to prevent unwanted bombardment of excessive electrons, which results in an improved tube life.
With both control and screen grids using frame-grid construction, the frame-grid pentode boasts performance features that far surpass those available in conventional pentodes. Compared with some of the better pentodes using conventional construction, the gray-plate frame-grid tube type, is said to offer a better gain-bandwidth figure, a higher transconductance (stronger tube)and an equivalent noise resistance of 100 ohms (vs. 200 to 300), and a much higher plate-to-screen-current ratio.
The frame grids have generally better parameter stability, lower noise and lower hum. These are the later technology, and also a technology only very few could make. Frame grid wires can be as thin as 10um, which is technologically speaking a masterpiece of fine mechanics. The frame grid wire is so thin, when you open up a defective tube, you can not see it with the bare eye. To give you an idea, the size of a large bacteria is 5um.
Another clarification is the meaning of frame-grid. The frame grid has its wires wrapped around a rectangular frame for good control of tension, as opposed to being wrapped around two posts supported by mica discs, like a ladder.
Frame grid tubes are better quality engineering, and cost more to produce than conventional single-post on halo tubes.
* *Pneumatic tubes controlled by vacuum tube amplifiers (or capsule pipelines or Lamson tubes; also known as Pneumatic Tube Transport or" PTT" in the 1950's-60's PPT systems were vacuum tube controlled) In the 1960s, Lockheed and MIT with the United States Department of Commerce conducted feasibility studies on a vactrain tube powered by ambient atmospheric pressure and "gravitational pendulum assist" to connect cities on the East Coast of the US.
NOS Siemens Halske CCa = E88CC / 6922 Grey-Shield HOLY GRAILS
|
|
|
|
|
|
|
|
|