The Siemens / RFT history, a discussion thread

[kevinkr]

RFT manufactured a lot of different tube types under contract for Siemens & Halske particularly from the mid 1960s at least through the end of the 1970s.

 

[tony4660]

Through the 80s as well. The RFT factory was located in East Germany. Roger A. Modjeski purchased batches of these tubes and tested them on his proprietary computer tester for performance and matching.

 

[kevinkr]

I have a lot of Siemens & Halske D3A here, most of which were made by RFT, I have a few that were made in a Siemens plant in the 1960s, they are hard to distinguish from each other. In terms of life time and performance they are indistinguishable.

Yes I remember RAM tubes which were popular with some of my friends.

 

[tony4660]

From my conversations with Roger all Music Reference RM-9 amplifiers were shipped with these tubes. It was one of my favorite tube amps.

 

[ceylon.mooney]

RFT manufactured a lot of different tube types under contract for Siemens & Halske particularly from the mid 1960s at least through the end of the 1970s.

siemens bought and rebranded a lot of many manufacturers, as did everyone and still do. thats why tubes are identified by manufacture not rebrand, hence my clarifying that these are RFT not siemens.

I have a lot of Siemens & Halske D3A here, most of which were made by RFT,

those are RFT not siemens

I have a few that were made in a Siemens plant in the 1960s,

those are siemens

they are hard to distinguish from each other. In terms of life time and performance they are indistinguishable.

Yes I remember RAM tubes which were popular with some of my friends.

i heard that ram had excellent standards for aftermarket testing.

Through the 80s as well.

ive never seen any siemens-branded RFT tubes made in the 80s. pretty sure siemens wasnt even rebranding tubes then.

 

[as_audio]

Thread Split from

T

For Sale Thread 'NOS Siemens (RFT) EL-34 Tubes - Matched Quads'

Wednesday at 5:10 PM

I have 4 matched quads of Siemens EL34 tubes, purchased from Roger A. Modjeski and matched on his computer tube tester. I originally purchased these as a spare set for my Music Reference RM-9 MkII amplifier but they were never installed and are unused in original boxes. These do not have the RAM TUBES silkscreening common with most of Roger's tubes. Instead, where legible, Siemens branding and other data is on the glass.

Quads are $300 each plus flat $25 shipping to lower US 48 only. Sold as is, no warranty expressed or implied. Payment via PayPal Friends & Family or Zelle only.

• tony4660
• Replies: 3
• Forum: Swap Meet

• 

 

[Rodeodave]

The way I understand it, RFT wasn't really a monolithic manufacturer, but an East German brand used for good manufactured by a group of individual manufacturers. Many of the manufacturers where nationalized branches of West German companies. So RFT branded tubes were generally made in the DDR (GDR).

Here's link to the Goggle translated Wiki article:

https://de-m-wikipedia-org.translat...l=auto&_x_tr_tl=de&_x_tr_hl=de&_x_tr_pto=wapp

 

[as_audio]

It should be noted that RFT EL34 are excellent tubes with high consistency and reliability and in my view the only items that can be used in amps with high plate voltage like Siemens 6S Ela 2805 (100W) and 6S Ela 2796 (250W).

 

[tony4660]

Rodeodave, thanks for the link. it's consistent with what I was told from Roger Modjeski. I worked for Roger for 5 years. As he told it to me, he went on an Eastern European tour of tube factories in the early 80s and acquired large batches of these tubes (totaling over 10,000 pieces), in addition to large batches of Ei (Yugo) tubes. My math might not be the best, but if what he said was true in that every RM-9 amp shipped with these Siemens tubes, then that would account for 8,000 pieces as 1000 of those amps were made.

 

[Rodeodave]

Here's the EL34 from their 1965 catalogue:

 

[as_audio]

This is not a catalogue, but a databook copy.

 

[Rodeodave]

Merriam Webster defines a "catalog" as "a complete enumeration of items arranged systematically with descriptive details" and lists "a catalog of the company's products" as an example.

Maybe you want to discuss the semantics of the word "Röhrentaschenbuch" next?

 

[as_audio]

The factory datasheet looks different