E130L PP Power Amplifier

[frentec]

Well I wasn’t expecting such a big response, anyway I have to thank everyone who has contributed to this post & hope it benefits others too.

So I’m think that I need perhaps 2 CCS boards, 1 feeding each LTP on each phase splitter, to balance non matched tubes?

 

[frentec]

This is what I would build...

Artsalo, SS is no problem at all, I like the idea of that a lot!

 

[frentec]

AC/DC

Also would you guys run the heaters on AC or DC?

 

[artosalo]

So I’m think that I need perhaps 2 CCS boards...

Boards ?? For a CCS only 3...4 components are needed.
These may be useful: 20PCS/Lot 5x7 4x6 3x7 2x8cm Double Side Prototype Diy Universal Printed Circuit PCB Board Protoboard pcb kit|pcb board|double side prototypeprotoboard pcb - AliExpress

Also would you guys run the heaters on AC or DC?

AC is fine. DC for heaters is needed typically when very low level signals are amplified, like in case of phono amplifiers.

 

[Ketje]

As a tubes-only version, I would build this:

Another one only tubes but with CCS 😀
The CCS screen resistor (82k) probably need adjusted to get the right current.
Mona

 

[artosalo]

Wait for a while and someone says that you should use cascode tubes for CCS😉

 

[Ketje]

Wait for a while and someone says that you should use cascode tubes for CCS😉

That needs much more voltage and you and up with a separate heater supply for the top-tube to get the Vfk within the max spec.
A pentode is a nice CCS at rather low anode voltage.
Mona

 

[Kay Pirinha]

Exactly. The cascode has just been invented as something that resembles a pentode's properties (high gain, high plate impedance), but avoids it's partition noise.
Best regards!

 

[frentec]

CCS

Boards ?? For a CCS only 3...4 components are needed.
These may be useful: 20PCS/Lot 5x7 4x6 3x7 2x8cm Double Side Prototype Diy Universal Printed Circuit PCB Board Protoboard pcb kit|pcb board|double side prototypeprotoboard pcb - AliExpress

So 6n6p is dual triode, so you would control each triode with it's own CCS, to balance desired current on each E130 tube? I'll get to the extra tube ahead of the phase splitter soon as gain is an issue here I think.


AC is fine. DC for heaters is needed typically when very low level signals are amplified, like in case of phono amplifiers.

 

[frentec]

CCS

Boards ?? For a CCS only 3...4 components are needed.
These may be useful: 20PCS/Lot 5x7 4x6 3x7 2x8cm Double Side Prototype Diy Universal Printed Circuit PCB Board Protoboard pcb kit|pcb board|double side prototypeprotoboard pcb - AliExpress
I have some IXYS IXTP08N100D2's & 1k pots, which could be implemented they will work at low voltage




AC is fine. DC for heaters is needed typically when very low level signals are amplified, like in case of phono amplifiers.

 

[gorgon53]

With only 250V max on G2 ( and typical 150V ) this is not a tube for ultralinear or triode mode in push-pull , even if you want . Maybe for single-ended .
So the best option is a stabilized G2 voltage , 150V or so .
Very similar with horizontal sweep tubes , wich have low voltage G2

This tube works in triode like a charm. In PP it gives easily at least 30W at low distortion and over 40% efficiency, try that with a 6L6 or EL34 or even a KT88.
If you want "UL" use part of the output cathode loaded.

 

[Ketje]

Looks like every one is fallen asleep here 😉 time to wake up 😛
Why not use some nice looking locktal tubes 😎
One side with, the other without, the decoupling C in the first stage to show the difference.
No delay on the high voltage needed, the auto bias turns on when the first 7N7 heats-up.
Mona

 

[painted]

Another one only tubes but with CCS 😀
The CCS screen resistor (82k) probably need adjusted to get the right current.
Mona

Elegant solution Ketje. If I had the appropriate OT I would build it.

 

[bohrok2610]

Most E130Ls work fine as triode. Here is one E130L as triode traced with uTracer.

 

[bohrok2610]

As a side note IMO E130L triode needs a follower (source or cathode) as a driver.

 

[Kay Pirinha]

Any triode works better (more efficienctly) in A2 or AB2 mode, given that the control grid copes with grid current.
Best regards!

 

[gorgon53]

Only lowish gm/highish mu tubes need grid current, not the E130L.
Or do you want to run that tube in A2 triode with a load below 400 ohm?

 

[gorgon53]

As a side note IMO E130L triode needs a follower (source or cathode) as a driver.

based on what?

 

[Depanatoru]

The topic is about a push-pull , so triode mode up to 250V what power will give ?

 

[bohrok2610]

based on what?

If you want to get the most power out of E130L you will end up with positive grid current. IME source follower is beneficial especially in SE mode.