NOS Valvo El84 Question

[Timbre Wolf]

Originally Posted by larrylover

I have Siemens E84Ls in the amp now -- can take higher plate voltages, last longer and have a bit more headroom than el84s. I really like those. I am interested to hear the Valvos in the amp

Here's a factoid to further confuse tube i.d. issues: "Siemens"-labeled tubes have often turned out to be RFT-made (East German company, not the West German Siemens). The "=" with a slash through it is the etch code symbol for true Siemens tubes, such as those you've got labeled "Valvo."

- T

[bluesforstevie]

No, the real NOS lettering is not only very fragile, but turns brown quickly. You may also smell the paint from the lettering burning on a new pair of tubes..Once this happens though, the tubes will be stable, and so will the logo.

This is good. Means your tubes haven't been in a circuit previously.

[larrylover]

Originally Posted by cochese

The amp I use was designed around current EL84's. NOS tubes are not recommended by the manufacturer. The EL84's on my amp see 400+ VDC at the plates. NOS tubes are rated for 300 volts DC. You should probably check with amp designer to see what tubes are recommended.

The following is only my opinion so take it for what it's worth. When an an amp is designed around specific components (say newer tubes) using older tubes may not always give you better sound. I think the NOS tube use is better suited to older amplifiers that were designed around these tubes. Some amps are designed around inefficient tubes for a reason. The break up quicker and have a different response than a more efficient tube. In the end I think you have to look at the overall design and not base everything on a single component. My old Rivera amp used German EL34's and had two channels. One was a Fender sound and the other a Marshall sound. To me the amp always sounded better doing the Fender thing versus the Marshall thing and this was using EL34's instead of 6L6's.

Thanks for the advice. The amp designer sold me the NOS preamp tubes to use in his amp. He also highly recommended NOS power tubes. His view is that reliability can be maximized with using new tubes, but these tubes cannot touch the sound quality of NOS.

[larrylover]

Originally Posted by Timbre Wolf

Here's a factoid to further confuse tube i.d. issues: "Siemens"-labeled tubes have often turned out to be RFT-made (East German company, not the West German Siemens). The "=" with a slash through it is the etch code symbol for true Siemens tubes, such as those you've got labeled "Valvo."

- T

Thank you. Yes, I am aware of the RFT/Siemens thing and the significance of the "=" with slash. Apparently, some tubes -- EL34, I think, labeled Philips were also made by RFT, while some Philips-labeled EL34 tubes -- Philips owned Mullard -- were made in the Mullard Blackburn plant. And, I have some RFT-made EL34 tubes for which I paid $70 for the pair -- a veritable bargain in NOS EL34 tube land -- that are incredibly good. And, as is readily apparent from this thread, I am a piker and newcomer to this.

Thank you again for all of your help. I really appreciate it.

[larrylover]

Originally Posted by bluesforstevie

No, the real NOS lettering is not only very fragile, but turns brown quickly. You may also smell the paint from the lettering burning on a new pair of tubes..Once this happens though, the tubes will be stable, and so will the logo.

This is good. Means your tubes haven't been in a circuit previously.

Interesting. I have seen the coloration happen over much longer periods of use, not as quickly as this. But this is good to know. Thank you.