Zenquito Variants - SK170 SJ74 ...drive 2SK1058

lineup · 26th June 2008, 06:08 PM

Experiences with using 2SK170 + 2SJ74 for Zenquito ?

How about voltage? SJ74 is max 25 Volt. SK170 = 40 Volt, alright.
For +/- 34 Volt I will need some cascoding.
With bipolar? Maybe BC550C/BC560C?

The Zenquito version I have in mind, see Schematic below.
Uses 2SK246 + 2SJ103 and I can not easily get those.
But I can find supplier in my country for SK170/SJ74.

Thanks for any useful information for the interesting Zenquito amplifier.

Muchos Regardas, Lineup

jackinnj · 26th June 2008, 07:20 PM

The forward admittance of the K170/J74 are much higher than the K246/J103 -- about 10x higher. You might want to check out the Vishay, OnSemi or Fairchild JFETs -- although their noise stats are much worse.

darian · 26th June 2008, 08:52 PM

No problem with the higher transconductance of these devices. There will just be some more gain at the first stage and so, some more open loop gain. No stability issues. Actually, there is many version of the Zenquito/Buzquito using these too.

darian · 26th June 2008, 08:54 PM

Just use cascoding like this Buzquito version...

darian · 26th June 2008, 08:55 PM

Sorry I forgot to attach the schematic...

lineup · 31st March 2011, 10:10 PM

Using the straightforward Zenquito concept
to drive a pair 2SK1058/SJ162
it is possible to make a real HiFi amplifier.

Image shows the simplified Zenquito concept.

lineup · 31st March 2011, 10:23 PM

This configuration shows very little distortion.
1 Watt 8 Ohm, THD 0.00044%

Max output at +21/-21 Volt is more than 16 Watt.

MiiB · 31st March 2011, 11:00 PM

If you add a current mirror the higher order harmonics will be even lover...

and you have a fully scalable design.. if you then split the supplies...the amp could be very good..

lineup · 05:30 PM

I will try.
What you mean split supplies?
And how should I put mirrors?

WuYit · 3rd April 2011, 08:45 AM

lineup,
I would keep the common source output stage topology.

1st April 2011, 05:24 PM	#9
lineup diyAudio Member Join Date: Dec 2005 Location: the north	I will try. What you mean split supplies? And how should I put mirrors? __________________ lineup Last edited by lineup; 1st April 2011 at 05:30 PM.

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
Strange Variants of the T-Amp	EdT	Class D	3	11th February 2007 11:07 PM
6CY7 Variants	wrenchone	Tubes / Valves	7	23rd December 2006 04:13 AM
Q about building the Zenquito amp with 2SK1058 / 2SJ162	sinigersky	Solid State	0	23rd September 2004 03:15 PM
JFET Buffered Gainclone-substitute for "SK170	hifileslie	Chip Amps	10	21st August 2003 07:09 AM
6H30Pi variants	Jesse	Tubes / Valves	22	9th April 2003 01:09 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

26th June 2008, 07:20 PM	#2
jackinnj diyAudio Member Join Date: Apr 2002 Location: Llanddewi Brefi, NJ	The forward admittance of the K170/J74 are much higher than the K246/J103 -- about 10x higher. You might want to check out the Vishay, OnSemi or Fairchild JFETs -- although their noise stats are much worse.

26th June 2008, 08:52 PM	#3
darian diyAudio Member Join Date: Mar 2006 Location: Paris	No problem with the higher transconductance of these devices. There will just be some more gain at the first stage and so, some more open loop gain. No stability issues. Actually, there is many version of the Zenquito/Buzquito using these too.

26th June 2008, 08:54 PM	#4
darian diyAudio Member Join Date: Mar 2006 Location: Paris	Just use cascoding like this Buzquito version...

31st March 2011, 11:00 PM	#8
MiiB diyAudio Member Join Date: May 2005 Location: Denmark	If you add a current mirror the higher order harmonics will be even lover... and you have a fully scalable design.. if you then split the supplies...the amp could be very good..

3rd April 2011, 08:45 AM	#10
WuYit Banned Join Date: Oct 2010	lineup, I would keep the common source output stage topology.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)