Speaker level to line level converters

qguy · 7th December 2007, 12:08 AM

How does the plate amp for subwoofers convert the speaker level to a line level ?

planet10 · 7th December 2007, 04:49 AM

A couple large value resistors - 47k in the example i found.

dave

Kevin_Murray · 9th December 2007, 03:58 PM

Further to what Dave said, when a design sums the left and right inputs, the attenuated L&R signals are often fed through opamps in a differential scheme before summing. This is not for signal quality but rather to prevent problems when connecting amplifiers which have BTL outputs (Bridge-Tied-Load or "bridged"). The L&R "-" speaker outputs on these amps are not a common electrical point, to short them together would severely damage the amplifier. While very uncommon, amplifiers (receivers) with this output configuration do exist. Mostly inexpensive models.

Kevin

7th December 2007, 12:08 AM	#1
qguy diyAudio Member Join Date: Mar 2005 Location: Burnaby	Speaker level to line level converters How does the plate amp for subwoofers convert the speaker level to a line level ? __________________ na

7th December 2007, 04:49 AM	#2
planet10 frugal-phile(tm) diyAudio Moderator Join Date: Oct 2001 Location: Victoria, BC, NA, Sol III Blog Entries: 5	A couple large value resistors - 47k in the example i found. dave __________________ community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi p10-hifi forum here at diyA

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
Convert Line Level to Electric Guitar Level	miallen	Solid State	4	16th May 2010 01:22 PM
speaker level input vs line level question	crippledchicken	Subwoofers	4	17th July 2007 03:36 AM
lesser of two evils, high level -> line level, digital volume control	mazurek	Solid State	3	19th November 2006 12:25 AM
Speaker Level Converters	Mikett	Car Audio	1	27th September 2004 05:21 AM
how to bring down line level signal to preamplifier level	deji	Solid State	15	15th April 2004 04:13 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 December 2007, 03:58 PM	#3
Kevin_Murray diyAudio Member Join Date: Sep 2007	Further to what Dave said, when a design sums the left and right inputs, the attenuated L&R signals are often fed through opamps in a differential scheme before summing. This is not for signal quality but rather to prevent problems when connecting amplifiers which have BTL outputs (Bridge-Tied-Load or "bridged"). The L&R "-" speaker outputs on these amps are not a common electrical point, to short them together would severely damage the amplifier. While very uncommon, amplifiers (receivers) with this output configuration do exist. Mostly inexpensive models. Kevin