Summing at the LTPI

memphissound · 11th January 2008, 02:52 PM

Does anyone have some experience using a Long Tail Phase Inverter as a summing amp (passive summing at the 1st input)? What were the results? Any thing to watch for in such a design?

peace,
memphissound <><

kevinkr · 11th January 2008, 03:54 PM

I used to build all of my bigger (>60W) PP amplifiers using global feedback fed to the inverting input of an LTP input stage.. Worked just fine.

Designed a 0 global feedback PP 300B amplifier that was published in VTV with an LTP as input stage with a balanced input option. Built a similar stereo 300B PP amplifier commercially, no global feedback with an LTP input normally configured for a single ended input, a balanced option was available, but no one requested it.

All worked just fine.

The VTV article is available on my site.

memphissound · 11th January 2008, 04:36 PM

That's about what I'm looking for. PP power amp in the 40-60W range (instrument app.). After posting here I thought about the old Fender stand alone reverb unit which basically does what I'm interested in. Thanks much.

peace,
memphissound <><

11th January 2008, 02:52 PM	#1
memphissound diyAudio Member Join Date: Aug 2005	summing at the LTPI Does anyone have some experience using a Long Tail Phase Inverter as a summing amp (passive summing at the 1st input)? What were the results? Any thing to watch for in such a design? peace, memphissound <><

11th January 2008, 03:54 PM	#2
kevinkr diyAudio Moderator Join Date: Sep 2004 Location: Boston, Massachusetts Blog Entries: 6	I used to build all of my bigger (>60W) PP amplifiers using global feedback fed to the inverting input of an LTP input stage.. Worked just fine. Designed a 0 global feedback PP 300B amplifier that was published in VTV with an LTP as input stage with a balanced input option. Built a similar stereo 300B PP amplifier commercially, no global feedback with an LTP input normally configured for a single ended input, a balanced option was available, but no one requested it. All worked just fine. The VTV article is available on my site. __________________ www.kta-hifi.net

11th January 2008, 04:36 PM	#3
memphissound diyAudio Member Join Date: Aug 2005	thanks That's about what I'm looking for. PP power amp in the 40-60W range (instrument app.). After posting here I thought about the old Fender stand alone reverb unit which basically does what I'm interested in. Thanks much. peace, memphissound <><

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