Balanced SE All-JFET Line Aamplifier

[AndrewT]

I got that Way Back site to work.
Clicked on "articles" and it gave a listing of amps and others.
Each link came up with an article & sch.

 

[rookakoma]

vdi , try here : Erno Borbely site , zip file – for benefit of DIY community | Zen Mod Blog

Thank You ZM!

 

[AndrewT]

Rooka, did you get that site to work?

 

[rookakoma]

Yes, click on the index.html .
I tried it with firefox and safari, works with both browsers.

 

[AndrewT]

I tried that a few days ago. Today I get the same message.
File not found.

 

[didiet78]

You must extract it

 

[rookakoma]

Isn't the borbelyaudio.com folder empty?

 

[Zen Mod]

that zip file is 228MB extracted

there is no borbelyaudio.com folder

check proper name of what you are asking for

 

[rookakoma]

There are the contents, I think.
It works properly, I tried it on 3 different computer (with macOS).

 

[AndrewT]

Zen,
could you post some instruction on how to access the information?

 

[Zen Mod]

There are the contents, I think.
It works properly, I tried it on 3 different computer (with macOS).

sorry , there is >www.borbelyaudio.com< folder, my Brainfart ...... again

I forgot that forum software is hiding that www part

 

[merlin el mago]

Special Articles

 

[merlin el mago]

Works the link?

 

[nr12]

Yes, the link works.
Thank you.

 

[oltos]

BA-3 or what balanced line stage to drive F4 mono blocks to push Acorn ESLs?

My two F4 amps can each be configured as either balanced mono (up to 100w into 8 ohms) or unbalanced mono (up to 100w into 2 ohms).

If a line stage could deliver 26V rms balanced to each F4 amp, could they drive
the 86db ER Audio Acorn ESLs' Acorn Electrostatic Loudspeaker Kit well enough to realize their claimed 35 to 30Hz bass response in a 12 ft by 14 ft room?

Can the BA-3, Pumpkin preamp, or another Class A, zero overall feedback, all JFET dc coupled Nelson Pass design produce the 26v rms balanced output?

 

[Zen Mod]

yes

as long those preamps are made with same (or slightly higher) rail voltages as intended output, they'll drive F4-like (simply put - source follower stage) OS to clipping

for balanced OS , speaking of BA3 FE - you need BA3 Bal FE

btw. is constructed with +/-36V rails , so go figure what's voltage output capability .......


spks - 26Vrms is around 85W/8R ....... so still less than F4 balanced power

 

[oltos]

yes

as long those preamps are made with same (or slightly higher) rail voltages as intended output, they'll drive F4-like (simply put - source follower stage) OS to clipping

for balanced OS , speaking of BA3 FE - you need BA3 Bal FE

btw. is constructed with +/-36V rails , so go figure what's voltage output capability .......


spks - 26Vrms is around 85W/8R ....... so still less than F4 balanced power

I don't quite follow. What is "FE"?

And are you saying that a pair of F4 mono blocks, each driven with 26v, will have trouble or no trouble driving the 86db Acorn ESLs in a small room?

 

[Zen Mod]

Front End
Output Stage

100W/8R is 28.28Vrms

26Vrms will throw you out of your shoes , anyway

 

[oltos]

Okay, so P= E2/R, (26v)2/8R = 84.5W. Yes, that should push the Acorns, just as well as the XA30.5 would, yes??

If so, there's still two problems. As shown on page 5 here http://www.firstwatt.com/pdf/art_ba_3.pdf , the BA-3 FE no balanced differential input/output. Can it be re-configured as a fully balanced circuit from input to output?

However, even if yes, I don't have quite enough theoretical knowledge and zero time to build any such line stage. Would anyone here, or someone they know, be wiling and able to build such a balanced stereo line stage for me? If yes, could a wireless remote volume/mute be added?

 

[Zen Mod]

there is a thread , named BA3 Balanced ....... or something as that

or just buy