Using LMH6642 as a buffer in PIMETA?

TheSeekerr · 8th July 2008, 10:23 PM

Hi all, a quick question, right as it says on the tin: I want to build the PIMETA headphone amp, but the cost of BUF634 is far too high for the build to be economical, and I'm unconvinced that the simpler alternatives like the Sijosae discrete mini-buffer deliver enough current to make them worth having at all.

My first thought was the OPA551, but I'm told that the low bandwidth will likely cause oscillation when it's inside the feedback loop of OPA2227.

So, my second thought: LMH6642. Since pin 1 on LMH6642 is unused, and pin 2 on BUF634 is unused, it seems to me that I should be able to leave the bandwidth setting circuitry in place for the BUF634, and add a short between pins 6 and 2 (that is, between OUT and -IN on the LMH6642), and still be able to use each interchangeably.

Of course, I'll need an SOIC to DIP converter board, but that's easy enough.

So, would it work? Would it work well?

Thanks for your advice!

TheSeekerr · 9th July 2008, 09:16 AM

Surely somebody out there knows something about using this opamp?

TheSeekerr · 10th July 2008, 12:59 PM

For anyone who happens to find this and be interested (since this thread, despite its emptiness, now tops the google results for "LH6642 buffer"), there is some discussion unfolding over at headwize: http://headwize.com/ubb/showpage.php?fnum=3&tid=7437

8th July 2008, 10:23 PM	#1
TheSeekerr diyAudio Member Join Date: Jan 2008	Using LMH6642 as a buffer in PIMETA? Hi all, a quick question, right as it says on the tin: I want to build the PIMETA headphone amp, but the cost of BUF634 is far too high for the build to be economical, and I'm unconvinced that the simpler alternatives like the Sijosae discrete mini-buffer deliver enough current to make them worth having at all. My first thought was the OPA551, but I'm told that the low bandwidth will likely cause oscillation when it's inside the feedback loop of OPA2227. So, my second thought: LMH6642. Since pin 1 on LMH6642 is unused, and pin 2 on BUF634 is unused, it seems to me that I should be able to leave the bandwidth setting circuitry in place for the BUF634, and add a short between pins 6 and 2 (that is, between OUT and -IN on the LMH6642), and still be able to use each interchangeably. Of course, I'll need an SOIC to DIP converter board, but that's easy enough. So, would it work? Would it work well? Thanks for your advice!

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
Best buffer for PIMETA?	slowpogo	Chip Amps	41	26th November 2010 06:11 AM
Debugging a PIMETA headphone amp	Atilla	Headphone Systems	3	23rd April 2009 05:12 PM
[help] pimeta ground buffer heating up	jchanhm	Chip Amps	0	6th June 2007 04:38 AM
Diamond buffer in PIMETA	slowpogo	Chip Amps	3	19th April 2007 05:58 AM
Just how good is the PIMETA?	slowpogo	Solid State	3	8th March 2007 03:40 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

9th July 2008, 09:16 AM	#2
TheSeekerr diyAudio Member Join Date: Jan 2008	Surely somebody out there knows something about using this opamp?

10th July 2008, 12:59 PM	#3
TheSeekerr diyAudio Member Join Date: Jan 2008	For anyone who happens to find this and be interested (since this thread, despite its emptiness, now tops the google results for "LH6642 buffer"), there is some discussion unfolding over at headwize: http://headwize.com/ubb/showpage.php?fnum=3&tid=7437

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