Best Drive for EL34

[navidstat]

Hi

I have Single ended Amp (DIY) with two El34, and drive them with ECC81.
one Section for each el34 and plate choke instead of resistor.
about 200 volt on Anode with 4mA.

what kind of topology (SRPP , Cascode or Anode follower ) is best for Drive El34?
thanks

 

[DF96]

Ordinary grounded-cathode can drive an EL34. For low distortion try an ECC83 with a CCS as anode load.

 

[navidstat]

thank

what is ypur idea about my circuits? ecc81 with plate chock?

 

[DF96]

I have never used a plate choke. I would not use an ECC81 as an SE driver as it is less linear than ECC83. OK as a phase splitter, as then you get some cancellation, or for small signals.

 

[death]

Hi, and glad to see someone from my country , once i have made an el34 push pull once and tried a lot of tubes for voltage amp or driver and got the best result with ecc82 with no feedback , because of its lower gain than ecc83. i hope than this is useful for your amp.

 

[hooman]

I have never used a plate choke. I would not use an ECC81 as an SE driver as it is less linear than ECC83. OK as a phase splitter, as then you get some cancellation, or for small signals.

what is your ecc83 brand?

 

[DF96]

I don't have an SE amp. My P-P amp uses ECC83 as a LTP phase splitter. I think it uses Brimar or Mullard - can't remember. Brand is, of course, meaningless - it is manufacture which counts and even that does not mean as much as some people think.

 

[Brouilly]

Check out Tubelab Simple SE

 

[Wavebourn]

Here is the best drive for EL34: http://www.diyaudio.com/forums/tube...artial-feedback-se-amplifier.html#post2709572

 

[hooman]

Check out Tubelab Simple SE

yes and find :I settled on the 12AT7 - ECC81. This tube works almost as well as the 5842 and is available world wide for a reasonable cost.(Tubelab Home)
12at7 works well in se amps and people cant find mullard or telefunken ecc83 easily but more chance for best product ecc81.hifi tubes are different to radio tubes .Different Tube Brands ..... different sound and different price.

 

[soulmerchant]

There are many cheeper ecc83 out there. I have some very inexpensive Chinese ones that sound surprisingly like Telefunken or Mullard..

Is 200V enough for ecc83? I find ecc83 sounds better with HT at 280V ...

If you don't need all that gain, and can't boost the volts then e88cc (or pcc88) could be a choice. You may need to elevate the heaters on e88cc though...

Personally, I would probably use ecc99 if it was 9-pin

 

[Davec113]

I am using a 12bh7a to drive my el34s... I like it better than the ecc99 with both running about 300V and 10 mA per side. Gain is about the same.

 

[hooman]

There are many cheeper ecc83 out there. I have some very inexpensive Chinese ones that sound surprisingly like Telefunken or Mullard..

 

[ChrisA]

Hi

I have Single ended Amp (DIY) with two El34, and drive them with ECC81.
one Section for each el34 and plate choke instead of resistor.
about 200 volt on Anode with 4mA.

what kind of topology (SRPP , Cascode or Anode follower ) is best for Drive El34?
thanks

One of the things you can do is use a 12AX7 but with local feedback. Conn an (about) 1Meg resister from the output back to the grid. Choose the resister to give the gain that is required for that stage. This does two things
1) greatly reduces distortion and controls the stage such that it makes not difference at all which brand tube you use. The stage will be linear.
2) Lowers the output impedance of the tube so it can better drive the power tube.

It is a very low cost solution too. About 5 cents of added cost for the resistor. I'd use the "AX" tube because it has the most gain of tube in that series and you need open loop gain if using local NFB.

 

[costis_n]

May I recommend a very linear one, with healthy current: The EF80 or the EF184 (frame grid, higher gain) triode connected. That's what I use in my EL34 SE. Since you seem concerned with brands, note that you can find Mullards, Telefunkens etc for very cheap.

 

[navidstat]

Thanks for your comments.

Nobody suggested a topology like SRPP or cascode for this drive. Why?
Are they bad or useless?

Then I have planned to test some tube like 12AX7 and 12AT7 and ... and write result as soon as possible.

 

[costis_n]

Thanks for your comments.

Nobody suggested a topology like SRPP or cascode for this drive. Why?
Are they bad or useless?

Then I have planned to test some tube like 12AX7 and 12AT7 and ... and write result as soon as possible.

SRPP has too much gain, so if you don't need feedback there is no use for it. t is favored by the Chinese manufacturers for this reason.

 

[aroS3]

You should also try the 6e5p, triode connected. It's always an excellent driver ...!!!!

 

[navidstat]

thanks Costis_n.

find some Ef80 Philips Miniwatt made in Holland.

what schematic is suggestion. can i use it with plate choke?

 

[costis_n]

not needed, my schematic has simple resistors only.