NOS RFT EL34's manufactured in the early 60'

[novosibir]

Santa Claus was already here on last Tuesday...
... and he brought me 60 new tubes in their original packaging
But not just any tubes, but good old NOS RFT EL34's from former East German production.
But not the relatively unreliable RFT's from the late 80's productions
Not even the very reliable RFT's from the late 60's to mid 80's productions
But the extremely reliable RFT's from early 60' productions - recognizable by the slightly flatter tube base compared to later productions.
In addition, the tubes are provided with the printed number "1" in the triangle, which means that they are selected first-class export quality

Every insider knows that next to the legendary Mullard EL34 the East German RFT EL34 is the best sounding EL34 ever produced

I still can't quite believe that I was given such a princely gift and I have to admit that I was starting to doubt whether Santa Claus really exists...
... but that's the proof that Santa Claus really exists

But now look what I got:

And woohoo - they are measuring great. Very strong tubes

This ensures the supply of the next 15 Larry amps with unrivalled great & reliable power tubes

To put it in concrete terms - for the next 15 Larry amps, which will be added to my list as an order after I have finished my order stop again, because for the currently ordered but not yet built Larry amps all the necessary NOS Tungsram ECC83's and NOS RFT EL34's are already sitting on the shelf.

 

[Hiwatts-n-Gibsons]

Santa Claus was already here on last Tuesday...
... and he brought me 60 new tubes in their original packaging
But not just any tubes, but good old NOS RFT EL34's from former East German production.
But not the relatively unreliable RFT's from the late 80's productions
Not even the very reliable RFT's from the late 60's to mid 80's productions
But the extremely reliable RFT's from early 60' productions - recognizable by the slightly flatter tube base compared to later productions.
In addition, the tubes are provided with the printed number "1" in the triangle, which means that they are selected first-class export quality

Every insider knows that next to the legendary Mullard EL34 the East German RFT EL34 is the best sounding EL34 ever produced

I still can't quite believe that I was given such a princely gift and I have to admit that I was starting to doubt whether Santa Claus really exists...
... but that's the proof that Santa Claus really exists

But now look what I got:


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View attachment 427163


And woohoo - they are measuring great. Very strong tubes


View attachment 427164


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This ensures the supply of the next 15 Larry amps with unrivalled great & reliable power tubes

Damn, I would love to get a quad of those for my Reeves Custom 100 to go with the Mullard EL34's in my Hiwatt Custom 100.

Awesome score man.

 

[Geo]

I have a set in my Metro build from the year 2000ish.

The set cost me $225 back then, which seemed kinda pricey at the time but they have been super reliable and sound great.

 

[novosibir]

I have a set in my Metro build from the year 2000ish.

The set cost me $225 back then, which seemed kinda pricey at the time but they have been super reliable and sound great.

Yes these RFT EL34 have an almost unlimited lifespan, similar to the RCA 6L6GC black plate output tubes from the 60'

The purchase price is high, very high even compared to the price of tubes currently produced in the Czech Republic, Russia or in China.

However, if you consider that with a set of NOS output tubes you save up to 10 or even more tube changes when using currently produced tubes, then from an economic point of view you have actually saved yourself a lot of money over time.

There is additional the advantage that NOS tubes sound remarkably better and are significantly more reliable than any tubes currently being produced.

And - nothing is more embarrassing than when your amp suddenly dies on stage in the middle of your most beautiful solo because another power tube fails due to a short and the amp's fuse blows.

 

[Geo]

Yes these RFT EL34 have an almost unlimited lifespan, similar to the RCA 6L6GC black plate output tubes from the 60'

The purchase price is high, very high even compared to the price of tubes currently produced in the Czech Republic, Russia or in China.

However, if you consider that with a set of NOS output tubes you save up to 10 or even more tube changes when using currently produced tubes, then from an economic point of view you have actually saved yourself a lot of money over time.

There is additional the advantage that NOS tubes sound remarkably better and are significantly more reliable than any tubes currently being produced.

And - nothing is more embarrassing than when your amp suddenly dies on stage in the middle of your most beautiful solo because another power tube fails due to a short and the amp's fuse blows.

When I bought those tubes, the seller told me I should keep the plate voltage below 400v. I have no idea why he would say that to me, I was new to the whole amp building/retubing thing. Any idea why he would say that? The plates are running about 540v which is well in spec for those tubes. And no issues at all.

 

[novosibir]

When I bought those tubes, the seller told me I should keep the plate voltage below 400v. I have no idea why he would say that to me, I was new to the whole amp building/retubing thing. Any idea why he would say that? The plates are running about 540v which is well in spec for those tubes. And no issues at all.

The statement with "keep the plate voltage below 400V" is definitely wrong!

The fact is that good RFTs can tolerate up to 550V on the plates in push-pull A/B mode and up to over 800V on the plates in push-pull B mode.

By 'good' I mean all RFT productions up to 1986
From the years 1987 until the factory closed in 1989, the reliability and electrical strength became noticeably worse and the tolerances increased, as from 1987 onwards the machines were no longer maintained, from 1988 onwards inferior materials were used and the vacuum in the tubes was no longer of the same quality as it used to be earlier.

From the 1987 production onwards I would no longer exceed a plate voltage of 450V.

Too many RFT EL34s from the last production batches died in the past in my amps and sometimes already on the tester.

 

[Geo]

The statement with "keep the plate voltage below 400V" is definitely wrong!

The fact is that good RFTs can tolerate up to 550V on the plates in push-pull A/B mode and up to over 800V on the plates in push-pull B mode.

By 'good' I mean all RFT productions up to 1986
From the years 1987 until the factory closed in 1989, the reliability and electrical strength became noticeably worse and the tolerances increased, as from 1987 onwards the machines were no longer maintained, from 1988 onwards inferior materials were used and the vacuum in the tubes was no longer of the same quality as it used to be earlier.

From the 1987 production onwards I would no longer exceed a plate voltage of 450V.

Too many RFT EL34s from the last production batches died in the past in my amps and sometimes already on the tester.

Thanks for the info.

I will have to check the date codes. I have quite a few hours on them now and they owe me nothing but if they were made between 87 and 89 maybe I should move them to a different amp just for the sake of being safe.

 

[novosibir]

Are yours RFT labelled or do they wear a different brand's name?