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E188CC identification

190.101.24.52

Posted on December 25, 2020 at 06:56:00
beto1
Audiophile

Posts: 637
Joined: March 12, 2005
Hi everyone,
I just bought a pair of E188CC (gold pin). Usually when I buy NOS tubes locally, I do some research until I find the manufacturer, year of production, etc., based on the inscriptions on the glass. Having exhausted my typical sources of information, I still cannot determine.
The inscriptions (see photographs) are:






Upper rectangle:
Arrow
7501
Lower rectangle:
CV5354
E188CC
Opposite side, with not very legible letters:
GTI (I think)
R2F1
As I understand it, the information enclosed in the upper rectangle means:
Arrow : Government
7501: First week of 1975
Lower rectangle: Type of tube CV5354/E188CC, with military nomenclature.
The information on the opposite side possibly of the factory, but I cannot identify it, for example with the code list of Which Those CV Valves?
by Chris Cooper, nor by looking at hundreds and hundreds of photos on the internet.
Can anyone help?
Thanks in advance.

 

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RE: E188CC identification, posted on December 25, 2020 at 07:40:16
mingus
Audiophile

Posts: 348
Location: mid-atlantic
Joined: July 19, 2001
Mullard - you can tell by the dimpled disc getter/no shield... Good tube, nice stage, wet... depending on the circuit used will determine the sound. but in preamps and the gain/driver stage of amps used here - I like them... palpable "in the room" soundstages, not the best at hall info *you are there" ... but enough of that to be a good all arounder... loved those in a Blue Circle BC 3.1, on the gain stage (followed by a Siemens A Frame! in the cathode follower stage). BIG Sound. also good as a driver tube in the Blue Circle hybrid amps (but just behind the single post Saucer getter Voskshod 6n23 types for me)

 

RE: E188CC identification, posted on December 25, 2020 at 08:05:46
Nunki
Audiophile

Posts: 544
Joined: November 27, 2010
"R" for mulard plant in mitcham (or withleafe? will have to look...). "B" for blackburn plant.

N.


 

RE: E188CC identification, posted on December 25, 2020 at 08:15:04
beto1
Audiophile

Posts: 637
Joined: March 12, 2005
Thank you Mingus.
how you can tell by the dimpled disc getter/no shield is a Mullard tube? I mean, there are other dimpled disc getter, for exapmple from Philips.
On the other hand, I have continued my search and although the way to write the manufacturing code is different from my other tubes, I found tube offers in an online store that referred to "Date Code VRI R0xx, R1xx or R2xx from Mitcham Plant. Made in Gt. Britain. Well known for the rich Mullard Midrange." (https://www.tubemonger.com/Mullard_MPs_MINT_NOS_1970_80_E188CC_7308_RTC_GTBri_p/1111.htm)
Mine are R2F1. Probably the number after R is related to the year or to the batch, so I would have to determine what F1 means in addition.
Best,
B.

 

RE: E188CC identification, posted on December 25, 2020 at 08:18:50
beto1
Audiophile

Posts: 637
Joined: March 12, 2005
That's right Nunki and thanks for comment.
According to "Which Those CV Valves? by Chris Cooper", it is right, but the way of entering the code is different to my previous experiences.

 

RE: E188CC identification, posted on December 25, 2020 at 08:45:43
beto1
Audiophile

Posts: 637
Joined: March 12, 2005
OK, find more information specific to Mullard here: https://mullard.org/blogs/news/mullard-valve-etched-codes-how-to-interpret-them
So, R2F1 must be:
R= Mullard, Mitcham
2=1952 or 1962 or 1972 (The second character gives the year of manufacture with decade differentiation being by number of characters and logo shape. and If its a 4 character code, the valve was produced post 1960, so reduced to 1962 or 1972, no logo)
F=June
1=week 1
but this would contradict what is written in the first rectangle, 7501, which according to other publications, such as the one I quoted in the first post, would mean, January 1975

 

RE: E188CC identification, posted on December 25, 2020 at 11:22:18
Jonesy
Audiophile

Posts: 2387
Location: Winnipeg, Manitoba
Joined: September 1, 2005
Contributor
  Since:
March 1, 2018






The place of manufacture is very important when selecting small signal tubes.

Different brands were often manufactured in each others plants.

Amperex tubes were often made in Mullard plants and vice-versa. So if you are looking for a Mullard sound, you have to make sure it wasn't manufactured in Holland.

Brent Jesse's website (link) is very good for tube information.

Cheers!

Jonesy



"I know just enough to get into trouble. But not enough to get out of it."




 

RE: E188CC identification, posted on December 25, 2020 at 12:07:58
beto1
Audiophile

Posts: 637
Joined: March 12, 2005
Thank you Jonesy for your input.
I knew that page. My regret is that they are mostly written descriptions. Photos work better when they accompany descriptive text, because there are some very subtle differences sometimes.
The information is scattered in several places. Honestly, I haven't bought tubes in years, so I'm getting back the links I used to have, plus books like Tube Lore and magazines like Vacuum Tube Valley. I'm a little rusty.
Greetings

 

RE: E188CC identification, posted on December 25, 2020 at 12:24:42
Jonesy
Audiophile

Posts: 2387
Location: Winnipeg, Manitoba
Joined: September 1, 2005
Contributor
  Since:
March 1, 2018
Ah! You have some excellent resources.

Yes, photos are great for illustrating subtle differences.

Happy tubing!

Jonesy




"I know just enough to get into trouble. But not enough to get out of it."




 

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