Bottlehead Forum

Welcome! Need support, you got it. Or share you ideas and experiences.

Bottlehead Forum

Re: e-mail from Thomas Mayer about EC8020

193.113.57.161

[ Follow Ups ] [ Post Followup ] [ Bottlehead Forum ] [ FAQ ]

In Reply to: Re: e-mail from Thomas Mayer about EC8020 posted by Scholl on August 08, 2000 at 12:14:55:

I have some Siemens EC8010 marked as EC8010/8556 on the boxes and the plate structure is very similar to the Telefunken EC8020 in the picture that dave posted.
I know that Simon Shilton of SJS has had problems in the past. He bought what he thought were EC8020 which were labelled as 8556/EC8010/EC8020 but were actually EC8010 and NOT EC8020.
John D.

Follow Ups:

Re: e-mail from Thomas Mayer about EC8020 Thomas Mayer 06:33:43 08/09/00 (1)
All,
just a few more comments about the EC8020/EC8010 issue.
First I'd like to make clear that I did not intend to create
confusion about this tube. And I also don't want to imply that
only the Telefunken EC8020s are the real thing. It might well
be that Scott has genuine EC8020s. But what I saw on the photo
looked suspicious to me.
I got my Telefunkens from a german supplier. After I got the
first batch and planned to use them, I asked the same supplier
if he has more. They didn't have any on stock, but mentioned they
can order some. A few weeks later I got them. They have been
labelled EC8010/EC8020/8556. Since I have some Siemens EC8010s
I realized that they are just that a EC8010. I had a discussion
with a person from that supplier who was their tube expert.
He said that since certain types are scarce or no longer manufactured,
current manufactueres tend to use the same tube and label it
with different types as long as their specs are close enough.
The EC8010 might work well in many applications which have been
designed around the EC8020. They are pin compatible and both have
a rather high transconductance. The EC8010 is about half a EC8020
in terms of transconductance and plate dissipation.
A unique feature of the EC8010 is the fact that cathode, grid
and plate are assembled in a row. The plate does not enclose
grid and cathode. This leaves the cathode exposed at one side,
so that you can see it's glow very nicely. If Scott's tubes have
that feature, I'm pretty sure they are EC8010s. The spave on just
one side of the cathode would not allow a plate structure big
enough to dissipate 8W.
Scott, can you check that ? How thick is the metal of the plate ?
Similar to the usual miniature tubes ? Or is it a hefty plate
with metal about 1mm thick?
The intention of my mail was just to give a warning to carefully
check what you buy. If these are EC8010s, 50$ would be a hefty price.
I'm curious what Richardson has to say about this.
Ciao ... Thomas
- Re: e-mail from Thomas Mayer about EC8020 Scholl 06:47:49 08/09/00 (0)
  Yes the plate structure is as you discribe. I hope to have a responce from Richardson soon. I would like to stick with EC8020s for this design. Could you direct me to a source for 8020s? And thank you for you input even if it did rain on my parade. Honesty IS the best policy and I'll do what I can to correct the misslableing issue. The Nor'Easter is a very good sounding amp that solves a lot of power supply issues very simply, but the EC8010 used is being run at twice the rated plate dissipation but the dang think can really drive (might be time to move on from 5842s) and has been in operation this way for 4-5 months with very good results.

This post is made possible by the generous support of people like you and our sponsors:

Schiit Audio

You can not post to an archived thread.