Lm4702 - Page 49 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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
Reply
 
Thread Tools Search this Thread
Old 3rd November 2012, 03:47 PM   #481
ingo50 is offline ingo50  Germany
diyAudio Member
 
Join Date: Aug 2012
Location: Berlin , GER
to rambojj
those chips do different jobs: LM 4702 has the diff.input and the VAS without the currant-gain outpt-stage but has two chanels , whilst the LM 3875 contains a complete midpower opamp
see also: www.ti..... You can not compare apples with pears as we say in german
ingo
  Reply With Quote
Old 21st December 2013, 12:22 PM   #482
bra is offline bra
diyAudio Member
 
Join Date: Dec 2002
Location: poland
Here is Arcam's way - maybe the best way :-)
Attached Images
File Type: jpg AVR600 1.jpg (233.7 KB, 298 views)
File Type: jpg AVR600 2.jpg (233.7 KB, 292 views)

Last edited by bra; 21st December 2013 at 12:26 PM.
  Reply With Quote
Old 21st December 2013, 12:29 PM   #483
bra is offline bra
diyAudio Member
 
Join Date: Dec 2002
Location: poland
and power stage - they use the same in new AVR750 so it have to be very good amplifier - I want use the voltage stage in my Primare SPA20
Attached Images
File Type: jpg AVR 600 power stage.jpg (238.7 KB, 287 views)
  Reply With Quote
Old 21st December 2013, 05:19 PM   #484
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally Posted by bra View Post
Here is Arcam's way - maybe the best way :-)
The best way is to buffer the input, invert, and feed the inverting input of the LM4702. I used the OPA2604 -- it really sounds nice. I had some boards made up for a LM4702 project which was published in AudioXpress and found that I could fit the OPA2604 and associated components in the space of the rather large capacitor I was using.
  Reply With Quote
Old 28th December 2013, 01:07 PM   #485
microx is offline microx  Spain
diyAudio Member
 
Join Date: Jun 2005
Location: Alicante
Default suitable mosfets

I have two pairs of Exicon 10P16/10N16 lateral mosfets I would like to use with a LM4702. I plan a 2K preset across the gates for bias adj and 220R gate stoppers. Anything else I should bear in mind.
  Reply With Quote
Old 6th January 2014, 09:59 AM   #486
bra is offline bra
diyAudio Member
 
Join Date: Dec 2002
Location: poland
i have done, now my primare has lm4702 with original power emiter follower and it sounds great with my Dali Grand, i am very happy with it.
sound i precise, dynamic with wide and deep soundstage.
lm4702 is a high end chip in my opinion.
  Reply With Quote
Old 24th January 2014, 07:58 PM   #487
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally Posted by microx View Post
I have two pairs of Exicon 10P16/10N16 lateral mosfets I would like to use with a LM4702. I plan a 2K preset across the gates for bias adj and 220R gate stoppers. Anything else I should bear in mind.
Use a 1k potentiometer between the SINK and SOURCE outputs of the LM4702so that you can set the bias, AND a 47k resistor from SINK to ground. Bias for about 120mA.
  Reply With Quote
Old 15th February 2015, 11:46 PM   #488
diyAudio Member
 
terranigma's Avatar
 
Join Date: Feb 2007
Hi,

I'm going to build a kit based on schematic below. I couldn't figure out the function of R3(180 ohms) in the schematic between emitters of driver transistors. Should I avoid it?

Thanks.
Attached Images
File Type: jpg lm4702-bjt.jpg (83.4 KB, 166 views)
  Reply With Quote
Old 16th February 2015, 01:53 AM   #489
diyAudio Member
 
Join Date: Mar 2002
Location: Boulder Creek, CA
The simpler the better. Have been using this circuit for over 5 years and sounds outrageous. I use two 4702s....one for for each channel and ground the unused inputs on the other unused channel. Dual mono is always better. I use a single power transformer for each channel but rectify it twice so I have a separate power supply for the 4702 and for the output mosfet stage....very important for great sound. I use nude Vishay resistors, damped heatsinks, damped soft recovery diodes, binding post bypass system, nude Blackgate N in feedback with nude modded Wima bypass and modified Wima Bypasses on all power supplies. You do not need the zobel network or inductor on the output if you are driving non capacitive normal speakers. Driving electrostats will require a zobel and maybe the inductor.
Attached Files
File Type: pdf IMG_0004.pdf (146.8 KB, 26 views)
  Reply With Quote
Old 16th February 2015, 01:57 AM   #490
diyAudio Member
 
Join Date: Mar 2002
Location: Boulder Creek, CA
How do you attach a picture as a thumbnail?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lm4702 Mike Gergen Chip Amps 109 31st August 2008 01:30 AM
Lm4702 Bpa halo0925 Chip Amps 19 13th November 2006 04:47 AM
Lm4702 BPA halo0925 Solid State 0 9th November 2006 10:26 PM


New To Site? Need Help?

All times are GMT. The time now is 09:33 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright 1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2