[Zachik]

They look very nice, but I'm sure the price is outrageous, considering what I paid for their sockets!

Haha. When I saw "Yamamoto" - my 1st thought was: $$$$$

 

[whirlwind]

Haha. When I saw "Yamamoto" - my 1st thought was: $$$$$

I am assuming that your new amp has the Yamamoto sockets...I think Glenn will only use these sockets for EL3N tubes now.
They do leave their Chinese counterparts in the dust. I found the cheaper EL3N sockets to be pretty poorly made.

 

[chrisdrop]

I got this pair of 6J5GT valves via eBay which just arrived. Do they look like genuine Fivre tubes? The only other ones I can find pictures of have different labels and more frosted writing on the glass itself. These have a faint "MM" printed on the glass, that is all. The seller said the MM is for Navy (I guess like Italian version of JAN?) That seems to line up here.

 

[leftside]

I got this pair of 6J5GT valves via eBay which just arrived. Do they look like genuine Fivre tubes? The only other ones I can find pictures of have different labels and more frosted writing on the glass itself. These have a faint "MM" printed on the glass, that is all. The seller said the MM is for Navy (I guess like Italian version of JAN?) That seems to line up here.

Look good and in great shape. I think I have a pair like that. As with most tube manufacturers, there are multiple variations depending upon the year produced.

 

[chrisdrop]

Look good and in great shape. I think I have a pair like that. As with most tube manufacturers, there are multiple variations depending upon the year produced.

I took a flyer on them for ~30EUR. According to the seller, they were were in his preamp for a few months, then he sold the preamp. No box, sparse post text in Italian. Not NOS, but used. The seller had not too many sales, no tube sales. I thought it was worth the shot however. They arrived 100% intact. They are just in now - nice and quiet/ noise free.

 

[L0rdGwyn]

I took a flyer on them for ~30EUR. According to the seller, they were were in his preamp for a few months, then he sold the preamp. No box, sparse post text in Italian. Not NOS, but used. The seller had not too many sales, no tube sales. I thought it was worth the shot however. They arrived 100% intact. They are just in now - nice and quiet/ noise free.

Most definitely legit Fivre 6J5GT and are in great condition! You got a good deal on those tubes I would say

 

[L0rdGwyn]

I'm happy - Glenn told me that he will do an anodized chassis in my selected color at a very reasonable price. He said it will be a little smaller but he prefers it that way (I do too) and will get back to me as things evolve with his transition.


For your next vintage design, why not something 'eye catching' like one of these:


:

Those certainly are vintage! Cleaned up, I'm sure they look very nice, I'll keep them in mind. Ultimately have to finalize the design and prototype it before committing to a chassis, so we'll see what we end up with, 801A is a tricky tube to design around.

 

[Zachik]

I am assuming that your new amp has the Yamamoto sockets...I think Glenn will only use these sockets for EL3N tubes now.

Correct - Glenn would only use Yamamoto sockets for EL3N. Having 6 of them been a significant % of the BOM... A good investment for the long run, though!

 

[felix3650]

Correct - Glenn would only use Yamamoto sockets for EL3N. Having 6 of them been a significant % of the BOM... A good investment for the long run, though!

Yup! PTFE (or more commonly known as Teflon) sockets used by Yamamoto have a very nice feeling to the touch. Smooth, non-sticking, hydrophobic and with antibacterial properties (ie bacteries don't stick to it), it's the perfect material for tube sockets. All this goodness comes with a price though...
I'm glad however that Glenn uses them for his top amp

 

[JazzVinyl]

I got this pair of 6J5GT valves via eBay which just arrived. Do they look like genuine Fivre tubes? The only other ones I can find pictures of have different labels and more frosted writing on the glass itself. These have a faint "MM" printed on the glass, that is all. The seller said the MM is for Navy (I guess like Italian version of JAN?) That seems to line up here.

Hello Chris!!

Can't wait to hear your listening impressions of these jewels!!!
.

 

[JazzVinyl]

Came across this Acorn tube - a RCA 955. It is a triode, first appearing in 1934. Anybody knows anything about it?

Looks like a space ship!

 

[JazzVinyl]

More R&R (resume and resubmit):
This morning I turned on my GOTL. NOTHING. No power - the reassuring blue light on the power button is gone.
Pulled out the driver tube I just put in, tried without it, but no power.
A quick mental check - no power outages or storms; could it be a tripped circuit breaker. Checked the outlet - works fine.
Checked my mental file cabinet: Oh yes, didn't JV tell me once that the fuse went in his GOTL for no apparent reason (he has the same one as me)?
Disconnected everything, pulled out the amp. Where is the fuse? (Hint: Time to write a manual - at least two pages...)Then I remembered that JV said that it is a little drawer under the power cord receptacle.

Since the writing was upside down I had to stand on my head to read it - just kidding; I took a picture with my phone and turned the phone upside down. And magnified it - comes with the age.....
Yep, that's it - took a little flat blade screwdriver and pried it open a little and then pulled out the drawer:

Let me see - it looks like the fuse blow. Why? Don't know; didn't do anything different - have to ask Glenn why. Maybe he anticipated this - the amp came with 4 fuses.
Here is the perp:

Put in the new fuse, and I am happy to report, all is well and back to normal.
Rest and Relaxation.
Another day in the life of a tube roller......

Hello Mordy...

I had a fuse blow some months ago, like you, no idea what would have caused it. Replaced it with one that Glenn supplied, no problems since.

Cheers!

 

[DecentLevi]

I got this pair of 6J5GT valves via eBay which just arrived. Do they look like genuine Fivre tubes? The only other ones I can find pictures of have different labels and more frosted writing on the glass itself. These have a faint "MM" printed on the glass, that is all. The seller said the MM is for Navy (I guess like Italian version of JAN?) That seems to line up here.

Those have the same construction of the ones I bought last week. I'd also like to hear your impressions.

 

[chrisdrop]

Impressions on the new valves ASAP . I enthusiastically popped the Fivres in yesterday - but only for a bit. Given what I thought of as "questionable provenance" of the Fivres and their "used" status, I gave them an hour to warm, then around an hour on the sacrificial headphones. I was able to say "quiet" and a quick listen on my normal headphones said; "probably very nice".

I then realised I had just a few hours before swapped in Mullard EL32 shoulder-types seen in the C3g slots pictured below. They are new and sound like they need time to burn in. I have had my "go-to" GEC 6J5 inputs w/ the EL32 straight tubes (postal tubes like JV has). I think that is my most reliable, often returned to configuration. I want to get the shoulder-type Mullards burned in, and to isolate the effect of just changing those tubes. Therefore, I put the setup back as pictured. I'll let the EL32s pictured go for a week of many hours/day use. THEN I'll come back to the Fivres.



I am hoping the Mullard EL32s do burn in. So far, I have not had the patience to really let the Marconi straight glass EL32s or these Mullard shoulder types really burn in because the straight postal tubes are fully settled and sound so nice in this setup! I think the EL32s run pretty cool, so it may take a while...

Here are the "GPO" postal Mullard EL32s that have maintained their position int he amp for a while now...



I have been googling a bit to decipher the codes on these. General info on these tubes labelled CV 1052

It looks like:

• CV = Valves used by the British military Armed Services were marked with a CV or "common valve" name which was defined by the Inter-Service Technical Valve Committee in 1941
• KB/DA (via this link)
  • K = designates a valve manufactured to specification K1001 or K1006;
  • B = denotes qualification by a UK authority
  • DA = Mullard Radio Valve Co., Blackburn

How about the printed values visible on the left tube? These look like "MO 2" and "39 C2". Both tubes have the same markings. Not sure how to date them from this? Also, what is the "6914 with the up arrow looking thing" visible on the right tube? All fascinating!

Happy listening all.

 

[mordy]

Hi chrisdrop,
The most important symbols as far as we are concerned are the almost invisible gray letters on the bottom of the glass:

This is an EL32 tube that I have. The bottom row is the factory code and date code - it reads
B 4 L 1.
B = Blackburn
4 = the year: 1964
L = the month (count the ABC on your fingers; when you run out of fingers and one more it is November lol):
1 = week of the month
Your tube shows the following code: B 9 C 2. - Blackburn 1969 March second week.
What about the 6914 on your tube?
There is an old saying in medicine: "If you see hoof prints in the sand, think horse and not zebra."
So 6914 is the 14th week of 1969 - Voila! Second week of March 1969!
http://www.audiotubes.com/mullcode.htm