Zen I/V Converter - Page 13

apolon34 · 16th September 2010, 10:14 AM

The input impedance of the jfets will be higher, due to transconductance being inferior to bjt. Input offset will also be higher with jfets due to mismatch between devices.

bjt input offset should be really close to zero, especially if you use dual matched monolitic (ssm2210 / 2220 for example).

stefanobilliani · 16th September 2010, 10:40 AM

Quote:

Originally Posted by apolon34

The input impedance of the jfets will be higher, due to transconductance being inferior to bjt. Input offset will also be higher with jfets due to mismatch between devices.

bjt input offset should be really close to zero, especially if you use dual matched monolitic (ssm2210 / 2220 for example).

JFet JFet JFet

regal · 17th September 2010, 11:11 AM

I don't have LTSPICE but I would think the outputs could be combine with a cascode and this servoed so that the coupling caps could be eliminated. Has anyone tried this?

EUVL · 17th September 2010, 12:22 PM

Post #3, 14.

regal · 17th September 2010, 12:40 PM

Quote:

Originally Posted by EUVL

Post #3, 14.

But you need differential in and get differential out. Adds tremendous amount of complexity and cost, which is fine for some (just not most of us.) But I was thinking a single ended design could be done without the caps.

juma · 17th September 2010, 05:42 PM

Quote:

Originally Posted by regal

I don't have LTSPICE but I would think the outputs could be combine with a cascode and this servoed so that the coupling caps could be eliminated. Has anyone tried this?

Since it's your idea, it would be only fair from you to make it work...

EUVL · 17th September 2010, 05:57 PM

What stops you from using one half (left or right) of the balanced circuit ?

Nelson Pass · 18th September 2010, 12:59 AM

The symmetry police?

The Spanish Inquisition?

EUVL · 04:38 AM

> The symmetry police?

That is brilliant !!!

Patrick

ggetzoff · 18th September 2010, 04:35 AM

Nobody expects the Spanish Inquisition!

18th September 2010, 04:32 AM	#129
EUVL diyAudio Member Join Date: Oct 2003	> The symmetry police? That is brilliant !!! Patrick Last edited by EUVL; 18th September 2010 at 04:38 AM.

18th September 2010, 04:35 AM	#130
ggetzoff diyAudio Member Join Date: Nov 2004 Location: Southwest	Nobody expects the Spanish Inquisition! __________________ Airline Pilot-If it's not Boeing I'm not going. "Brain as big as a planet..." {sic} Nelson Pass

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Zen I/V Converter	Nelson Pass	diyAudio.com Articles	13	19th June 2011 11:04 PM
FS: Big Zen Amp, Zen 4 stuff, misc.	picker	Swap Meet	7	11th November 2007 12:06 AM
Zen & Zen Variations-Part.2	billy	Pass Labs	1	7th August 2002 06:24 PM
Bride of Zen or Balanced Zen Line Stage?	Mach_Y	Pass Labs	9	28th November 2001 11:07 PM
Zen or Bride of Zen as Headphone AMP?	Hauke	Headphone Systems	5	2nd October 2001 06:33 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

16th September 2010, 10:14 AM	#121
apolon34 diyAudio Member Join Date: Jan 2004 Location: rouen	The input impedance of the jfets will be higher, due to transconductance being inferior to bjt. Input offset will also be higher with jfets due to mismatch between devices. bjt input offset should be really close to zero, especially if you use dual matched monolitic (ssm2210 / 2220 for example).

17th September 2010, 11:11 AM	#123
regal diyAudio Member Join Date: Jan 2004 Location: MD	I don't have LTSPICE but I would think the outputs could be combine with a cascode and this servoed so that the coupling caps could be eliminated. Has anyone tried this?

17th September 2010, 12:22 PM	#124
EUVL diyAudio Member Join Date: Oct 2003	Post #3, 14.

17th September 2010, 05:57 PM	#127
EUVL diyAudio Member Join Date: Oct 2003	What stops you from using one half (left or right) of the balanced circuit ?

18th September 2010, 12:59 AM	#128
Nelson Pass The one and only Join Date: Mar 2001	The symmetry police? The Spanish Inquisition?