Found some EC8010

[markanica]

Hi all,
Just found a pair EC8010 tubes on a hamradio exchange market
At the pins I can see they are used, they look ok though.
I haven't tested them yet, hope they are ok.....

Did a search on this forum and got lots of threads with EC8010 in them, but they all appeared to be someones nick

Found data sheets plenty, but like to know what was their intended use and in which diy-circuits they excell.....

On the bottom of the tubes is a '6' in the glass and on top one tube is the code 529, the other says 536

Any further info on these tubes would be great

 

[Geek]

Looks like a good general-purpose tube

That open construction will look funky!

Here's some examples I Googled:
http://www.wdehaan.demon.nl/mono/mono/56872.html
http://www.vt52.com/diy/myprojects/amps/lcr/lcr.htm
http://www.vt52.com/diy/myprojects/amps/epilogue/epilogue.htm

And more!
http://www.google.ca/search?num=30&hl=en&safe=off&q=EC8010+tube+amplifier&btnG=Search

 

[markanica]

Hey Geek,
Thanks for your reply, btw. interesting website you got. Spent some time reading stuff....

Saw some GM70 and 300B amps using EC8010 as drivertube, but has anyone experience with EC8010 as small signal amplifier tube especially concerning microphonics?

 

[Geek]

I have personally found microphoniciness of a tube particular to brand of the tube. Not with the 8010 specifically, but all tubes in general. Sylvania for example, have one of the nicest tones, but all are microphonic (even a Sylvania 7025 I have is microphonic), while some other lesser-known-to-audiophile brands, like Rogers, sound "darker" than the rest, but you can tap them with a screwdriver all day and not hear one "ping".

The moral of the story is....make a test jig and try it.

My test jig consists of a breadboard where I bias the tube, usually 100K on the anode, 1K on the cathode bypassed with 10uF, ground the grid, run the anode through a 0.01uF cap out to your soundcard line input. This can be used to measure noise and microphonics.

 

[Zen Mod]

WOT preamp
search for "Choky's wot preamp" here or with google
or just search for "Euridice" preamp

 

[fdegrove]

Hi,

Found data sheets plenty, but like to know what was their intended use and in which diy-circuits they excell.....

If you look at the TFK datasheets it should be rather obvious to see what these tubes were designed for.
Nonetheless they should be great in audio apps where you'd want both low noise and high gain.

Phonopreamps, microphone pres and MC headamp stages come to mind.

Given the tightly clamped build microphony should not be an issue unless you hit a really bad batch of tubes.

Cheers,

 

[Zen Mod]

found it ;

 

[markanica]

thanks

Geek, choky and Frank,

Thanks all for your replies

So these tubes could come in my next phono preamp ( now i use 12ax7's, with a ecl85-0a2 series regulator for each channel for that )

Currently i'm working on a 6c33 circlotron otl, that one gets my full attention first. Takes a lot of time though, since i'm not an electronics scolar at all. But great satisfaction when i get something to work properly

Bye

 

[Zen Mod]

yep-when I manage to stash enough 8010 and/or 8020,I'll start to make my new LR EQ phono stage with lotsa iron and those quties

 

[fdegrove]

Hi,

So these tubes could come in my next phono preamp ( now i use 12ax7's, with a ecl85-0a2 series regulator for each channel for that )

Hmmm....I'm always interested in seeing the schematic of that preamp if you have it...

Currently i'm working on a 6c33 circlotron otl, that one gets my full attention first.

There's a thread here entitled "OTL" in case you're interested.
What's the target poweroutput for that amplifier?

Cheers,

 

[Zen Mod]

Hi,



Hmmm....I'm always interested in seeing the schematic of that preamp if you have it...



There's a thread here entitled "OTL" in case you're interested.
What's the target poweroutput for that amplifier?

Cheers,

at Audio Note England site (don't know exact url ) you can see few modifications for old Audio Inovations preamps ;
there you can find info regarding OA2 + something (5687 ?) in stab. circuit ; I'm pretty sure that I have somewhere these few pages,in case....
I still prefer pure shunt tube,without active element ,but-everyone have own cup of tea ........

 

[fdegrove]

Hi,

there you can find info regarding OA2 + something (5687 ?) in stab. circuit ; I'm pretty sure that I have somewhere these few pages,in case....

Thanks, Choky.
I'm quite familiar with that circuit, the author happens to be an old acquaintance of mine.

I still prefer pure shunt tube,without active element ,but-everyone have own cup of tea ........

Sure...
You could also combine a series (pre)regulator with a shunt regulator, choke filter/reg plus a shunt, etc...

Markanica was however refering to a series reg using the ECL85 and OA2 which drew my attention as I once designed a very similar one but using the 85A2 or (better still) the 5651A as a voltage reference for a phono preamp.
The diagram was posted somewhere in the "Frank's ultimate preamp" thread IIRC.

BTW, keep us informed on your LCR RIAA phono project. I'm sure that would be something pretty special.

Cheers,

 

[markanica]

Hi,



Hmmm....I'm always interested in seeing the schematic of that preamp if you have it...

I got it somewhere, but the scanner is out of order since it doesn't run with winXP and i haven't found an easy to use schematics drawing program yet....so no schematic at this moment.

There's a thread here entitled "OTL" in case you're interested.
What's the target poweroutput for that amplifier?
[/B]

Yeah, I've read most of that thread.
In the end I decided for a circlotron, because of short signalpath and a minimum of capacitors in the signal.... Well, there are a lot of supplycaps still. Also the working of a circlotron is quite straightforward, without the complications of the SEPP output...
So, easier for me, that is.

The amp will be a Graaf GM20- alike, so around 20W @ 8 Ohms
The schematic is here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=34687&perpage=10&pagenumber=5

bye

 

[markanica]

Phono & Reg schematics

Allright, I just used the camera as a scanner, works just as well

The phono preamp is from an Audio&Techniek magazine (Dutch) of the year 1994. It might be copyrighted so I left the values out. I hope that is ok.

The reg is based on a CROFT charisma preamp from around 1990, but slightly altered.

In my preamp the reg also feeds the linestage with ECC88 Mu follower.
Works ok on phono, but too much gain on line inputs.

All in all a lot of copying from my side, but hey I don't want to invent the wheel again...

bye

 

[markanica]

and here is the reg

 

[Zen Mod]

Hi,



Thanks, Choky.
I'm quite familiar with that circuit, the author happens to be an old acquaintance of mine.



Sure...
You could also combine a series (pre)regulator with a shunt regulator, choke filter/reg plus a shunt, etc...

Markanica was however refering to a series reg using the ECL85 and OA2 which drew my attention as I once designed a very similar one but using the 85A2 or (better still) the 5651A as a voltage reference for a phono preamp.
The diagram was posted somewhere in the "Frank's ultimate preamp" thread IIRC.

BTW, keep us informed on your LCR RIAA phono project. I'm sure that would be something pretty special.

Cheers,

hm ,seems that I'll wait a little for that pet project- I'm pretty tight with free (spare) time this months,so I can just dreaming .........
in fact-my best sounding gadgets are made that way-lotsa dreaming,after that just manufacture ( fun also ,naturaly !)
btw-I really like old repeater 600:600 and 600:1200 toroids ......
they can make wonders even on crappy comercial CD player outputs ;
just for fuin-it is interesting when you try to connect any decent head through that sort of jewell xformer......
all is about fun ,we agree