Has anyone used Erno Borbely EB-201/168

[ANALOG GUY]

Let's see.

http://www.borbelyaudio.com/eb201168.asp

I seen this circuit from his website but I can't find parts list of them,where ?

Could anybody suggest me for build them ?

PS, I like all jfet more than hybrid or pure tube :-)

Regard
analog guy

[AndrewT]

Hi,
I thought the articles on the Borbely site gave all the info, but I may be wrong.
I think he intended selling you the kit, although his design articles are very full of (free) information.

[Leolabs]

And I wonder why his design is quite complex???

[fab]

Originally posted by Leolabs
And I wonder why his design is quite complex???

It is not more complex than some other designs but maybe more innovative. Erno prefers the use of jfet and mosfet in cascode arrangement. The general topology is simply a fully symetrical amp driver with diff input, folded cascode VAS, Bias circuit and DC servo. Erno has designed the Hafler DH-200/220 amp in the end of the 70s. This circuit seems to be an evolution of the DH-200 design concept in my opinion.

[lineup]

Originally posted by ANALOG GUY
Let's see.

http://www.borbelyaudio.com/eb201168.asp

I seen this circuit from his website but I can't find parts list of them,where ?

Could anybody suggest me for build them ?

PS, I like all jfet more than hybrid or pure tube :-)

Regard
analog guy

As usual when using fully symmetrical all JFET amplifier design
problem is finding complementary JFET.

If you do not find any nice P-JFETs to match your N-JFETs
your amplifier will be highly un-symmetrical

[fab]

Originally posted by lineup


As usual when using fully symmetrical all JFET amplifier design
problem is finding complementary JFET.

If you do not find any nice P-JFETs to match your N-JFETs
your amplifier will be highly un-symmetrical

Yes that is correct. Erno sells matched N and P parts but at a higher price though. Erno's kits are quite expensive but they uses expensive parts also (caddock resistors, ...). Although this specific circuit may not include parts list, you can guess the parts of the circuit from his other circuits and its section "audiophile components" on his web site. Usually the parts used for jfet have a transconductance range suffix (V, GR, BL). But even then, you still have to match them using probably lots of jfet if you are not lucky. I have ordered some complementary jfets from Ampslab using the same transconductance suffix but I may have to order matched jfet from Erno if I am unlucky.

[ANALOG GUY]

Now I decide to use 2n5458 and 2n5461 jfet for complementary input, cascode, vas and some mosfet are irf610/9610 but I can't calculate for value of resistors, capacitors, diode :-(

My country there're no 2sk389, 2sj109, other zvp****, zvn**** etc if somebody have parts list please show your share about part which instead.

PS.where can I find hafler schematic ?

regard
analog guy

[AndrewT]

Hi Analog,

you keep your location secret.

How do you expect others to be able to help you source local components when none, bar you, know where local is?

Be helpfull and don't copy this silly trait adopted by some others.

[fab]

Originally posted by ANALOG GUY
Now I decide to use 2n5458 and 2n5461 jfet for complementary input, cascode, vas and some mosfet are irf610/9610 but I can't calculate for value of resistors, capacitors, diode :-(

My country there're no 2sk389, 2sj109, other zvp****, zvn**** etc if somebody have parts list please show your share about part which instead.

PS.where can I find hafler schematic ?

regard
analog guy

Hi Analog guy

Unless you have the agreement of Erno Borbely to use this specific Borbely design or it is fully pulished somewhere, I feel uncomfortable to try to reverse engineer this amp on the public domain. It is a question of respect to the designer when he does not want to disclose fully his design yet probably for commercial reason. Try other Erno's design which he has published and contain all details.

Furthermore, if you want to use different active components then you are changing the design and it is a lot more complex exercise since you will have to re-establish several parameters like bias, stability margin, gain, etc. I do not know your electronic background but biasing a jfet is not as simple as a bjt. 2N5458 has different characteristics than 2SK170.

To get parts from another country it is quite easy to order parts via airmail with the web.

Hafler schematics are at several places on this forum. Just do a search in the Hafler DH-200/220, etc .. threads.

[fab]

Analog,

I did not mean to discourage you. You may still develop your own amp design using Erno's similar circuit topology for your own personal use. If you want to use 2N5458/2N5461 the Idss variation is from 1ma to 5ma. You will have to use a trim pot to compensate if you can not get the "perfect" parts for your circuit. See example of jfet input stage at http://www.diyaudio.com/forums/showt...61#post360361. I would not use this design as-is today though (not optimised) . This was an old experiment but it gave very good sound results for a preamp.

IRF610-9610 are vertical mosfet with high Vgsoff. I would personnaly use more 2SK216/2SJ79 (VGSoff about 1 volt) types for VAS.

Good luck