Tubes and ESL's

[Calvin]

Hi,

@Ben:
I see,You are talking of resistors as Anode loads of the Tubes, connected towards the HV-supply.
The Sanders Amp -after the article from 1976 used 40k and 2.2kV (55mA).
Running in class-A that is not much current into the load, hence only possible with low-cap panels .... at least low-cap >>1kHz.
As each stator is driven in SE-class-A the maximum efficiency of each SE-amp part is 12% at best.
Amps like the Beveridge or Acoustat made use of active modulated current sources, SRPP-like structures, as loads, to achieve higher efficiency.
Just as an example: A 500pF panel already required ~140mAp-p current for a signal voltage of 2.2kVp-p at 20kHz.

jauu
Calvin

 

[George Schmermund]

OK, I surrender. 20 replies and not one question about how to build the tubes. I guess it's 'the elephant in the room' paradox. I'll try starting another thread and only give the vaguest hint that the tubes can be used for any specific application.

 

[tyu]

I well say...I have tubes playing Now.....60 tube watts driving a pr of Ezey to drive 1987 MG2c Magnepans..an 60 tube watts well drive my Acoustats As well as any OTL right thought the Interfaces....
Do I think the tubes sound Better than SS Amps....are do I just like the noise thay add to the sound....who knows..
I do know tubes play the feedback thay get...of the sound we play thought them ...from the speakers in the room like a loop...an I think panels give more of what ever the loop is...is...added too the overall sound...looks right on paper an my ear..must be more....SS dose not do this...No loop...less you add it...
Making A power tube.... that well drive a ESL panel....It can be done already.. with old Dyanco MK3 60watt Amp..I have...Sounds good.. Not better Than SS....
So for me to Diy A Tube...NO!...not for..just this one man...
.looks vary cool....thanks for your input...hope you can find others that well....

 

[supra]

OK, I surrender. 20 replies and not one question about how to build the tubes. I guess it's 'the elephant in the room' paradox. I'll try starting another thread and only give the vaguest hint that the tubes can be used for any specific application.

Hey George i think there's interest, I'd love to see a fresh new tube circuit for direct drive of esl panels, but people get discouraged because no one ever delivers, lots of talk but it never happens. There must be some clever tube designers around who could do something new, maybe the high HT voltages and
low interest discourages them. I've heard the Modjeski direct drive tube amp into acoustat panels and it is very good. But I think my big SS amps into my transformer based Acoustats is also very good.
So I'm not inclined to pursue the direct drive way, but I'd like to see a new circuit, maybe it would encourage a bit of interest.

 

[bentoronto]

I like to post to threads where I don't need to run into rude people. Could that explain something?
B.

 

[tyu]

How about this....A tube amp ...with A NEW type output tranfourmer ...made for driving ESL interfaces.....so I gess it would be a transfourm for driving transfourms...what would that be a Autoformer.....like the ZERO...I gess Paul Speltz has done that....But hay....tubes have been around for 100 years...is there room for a new tubes....yes...I gess well be waiting...life is short..
.Diy tubes....cool

From what I see there still work to be done on these ESL interfaces....To get better output out of ESl...I don't think the direct drive amps we have are the prob...

 

[supra]

I like to post to threads where I don't need to run into rude people. Could that explain something?
B.

The name of this forum is diyaudio where people contribute ideas and information, like circuits etc, all you contributed was vague descriptions and you expected applause for it?
Talk about thin skinned.

 

[Calvin]

Hi,

I admit that I overead the DIY in the following quote from #1.

My plan was to drive each speaker with a DIY triode that could hold off 10 KV and drive the panels directly off the plates.

But then, the suggested 10kV anode voltage seems the only specification.
Then we learn, that You used a ´something´ for tests that happened to be around the lab.
In the same post, #10, You complain about the thread drifting into ESL talk.
Well, its a thread in the Planars & ESL forum, not the Tubes forum in first place. 😉
Secondly one may build a amplifing device for whatever but without sensible useage if designed without the load in min.
As pointed out earlier -and not only in this thread- there´s not the ESL with a certain set of common specs.
And there can´t be the ESL-amplifier.
Without specifing the load for the amplifier the chance of just wasting time is high.
In tendency a non-segmented panel required less voltage- but more current-capability from the amp, while a segmented panel required more voltage- and lower current-capablity.
The differences could add up to a power demand of 10:1, and we´re talking of power in a range of several hundred W up to a few kW.
That´s not kiddies stuff but a Tim Allen´s kind of power machine. 😎

jauu
Calvin

 

[tyu]

Prijs - BLANKO.NU vary tube like...hehe

 

[tyu]

how about this trans......may be key.....
well there be feed back from the tubes......yes..in more way than one......cool look..........

 

[bolserst]

... I'd like to do a 'reset' here and bring us back to what the project was all about...

I thought the project was about designing "an ESL System".
That would comprise an ESL, some HV tubes, and the interface circuit between them. I was trying to help out with the ESL portion, to ensure the system had the best possibility of success. Others asked about the interface circuit, or how best you think the tube should be used to drive the ESL.

OK, I surrender. 20 replies and not one question about how to build the tubes. I guess it's 'the elephant in the room' paradox. I'll try starting another thread and only give the vaguest hint that the tubes can be used for any specific application.

Ok, so you are only interested in the tubes themselves. It is up to others to decide how best to use them, and preferably discuss that in another thread.

I am still interested in your tube design/build, hopefully you will post your progress in this thread.
Related to the tubes themselves, any ball park numbers for the transconductance and plate resistance these 10kV tubes will have?