Siemens CCa vs. Amperex PW 6922

9999999,

Sam has a pair of CCa 50's dull sheild with readings of 86/83 82/67

He said the CCa 50's tubes can read out like this and is not uncommon.

What think you?

Gary

Mr G- Just in case you're looking at the CCa's on eBay: There are some tubes listed there that the seller claims are 60's vintage. They aren't! They've got the shiny plates and internal date code that indicate the very bright(strident) version.

I'm usually at Deland Airport Thanksgiving week for the Skydiving party they host every year. I was in Perry for a few months last year(whatta hole!). If you're into the music and not the tube- the CCa's for you. The pre-70's vintage just gets out of the way of the music. I had the Siemens E188CC's in a modded SP-14 a few years back, and they were very lucid(and quiet) too- (http://www.upscaleaudio.com/product.asp?itemid=611&catid=42). Kevin has the CCa's also, but I don't know if they are the early ones.

99,

I am in Sunny Destin, FL. one block from the Gulf of Mexico.

Check pics on my system.

You are welcome to come down when it is -10* or 30*. I have access to my client's beach homes in Seaside FL. Jim Carry did the Truman Show there.

Clean, liquid mids for me.

Glory- Where are you located? I've got a spare pair of NOS Siemens CCa's and E188CC's we could try in your rig, if you're somewhere in Indiana. Not German- But I've bought a bunch of tubes from there over the years. The Internet makes it easy to do your homework, before spending a lot of money. Do you enjoy a very clean, liquid midrange, or a warmer(some people call it, "tubier") presentation?

999999999999999999999,

Kool info you have there. Are you German by any chance?

Why don't you sell me two of the six you have and I will be done with it. =8^)

I bet you even have six more in your stash.

CCa: What is It?
German Description:
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Die folgende Valvo-CCa ist keine der "Gelben Serie" zugehörende, sie ist auch nicht tailliert.
Es ist eine weiss gestempelte CCa die für die Post bestimmt war und auch entsprechend bezeichnet wurde.
(Die Namensgebung CCa impliziert schon die Post-Zugehörigkeit, aber nur bei dieser wurde es zusätzlich auf der Röhre angegeben.)
Sie besitzt den eingeätzten Code 7LH, darunter (Delta) 4D5.

Die CCa ist eine Poströhre. Also eine speziell für die Post selektierte.
(Besonders Rauscharm, Klingarm, besonders Langlebig.)

"Klingarm" is the term for low microphonics.
You often see Telefunken EF12K or AC701K, the K means Klingarm

English Description:
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CCa was an E88CC specially selected for "Post Germany"; special low noise, low microphonic, long-life 6922.
Philips had similar selections for the "Dutch Post", some tubes are selected had "PTT" etched.

The "German and Dutch Post" = telephone, telegraphie, telex, and the postal system.
Much of the telephone centrals used tube equipment and for telephone equipment you want a "noise-free" enviroment.
The letters "CC" probabably equates to "double triode", and/or a for special design. I've been using the Siemens (pre-70's) CCa's for years in my equipment because I hate microphonics, and they are the least microphonic tube in the 6922 family that I could find(I tried a bunch of the high dollar ones). I've got six in my BAT VK-D5 right now. Microphonics are a noise generated by vibrations in(or around) the tube, and these were specially designed to have much less than ordinary 6922's(as stated in the above definition). If you go the CCa route, be certain to find the pre-70's vintage(dull grey plate below the getter support and no internal date code plate). The later ones are very strident. Given the Siemens CCa's excellent transparency, clarity, timbre, imaging, sound staging and frequency extention(in both directions)- it's 10,000 hour life expectancy makes the seemingly high price of NOS ones actually a bargain. Given that you are planning to use them in a pre-amp: I WOULD try to find some that were tested for noise, and pre-amp "graded" (as with any tube intended for that circuit).