How do you tell if an amp is bridgeable?

renfrow · 21st November 2006, 08:32 PM

Ok, what I'm actually asking about is a receiver. I have boatloads of jazz and classical music from the 50's and earlier that is mono. What I'd like to do is build a single speaker just for listening to this, and hook it up to the B outputs of a receiver. I'd prefer to not to have to build an amp (sorry

) just for this, though I'm willing to build a speaker

.

Thanks!
Tom.

mikee55 · 21st November 2006, 09:58 PM

Hi renfrow,
Why don't you just listen in mono from the stereo you have? Mono comes out in mono on a stereo.
Briding an amp is adding distortion. When a class a/b amp is used as most are, you have a crossover distortion, yeah? If you bridge you'll get twice the crossover distortion, and supposedly more power avaiable to a speaker. Why don't you use a splitter and split the mono to Left and Right inputs or better still use a PC audio editor and create a synthesized stereo. Apparently, if you put a mono signal into a stereo reverb, technicaly the output is stereo. I think if you try and add just a slight echo and try and create the ambience of an average sized studio (or hall if a live recording), this wouldn't too far from mono rather than pan and expand(which could create a hole in the soundstage), and would be an interesting project. Am I to assume your recordings are vynil? Archiveing them digitaly would allow you to preserve the originals. I'm no expert, but going the digital route with an editor such as Wavelab or Soundforge, (there is Freeware editors out there on the www too), and if you had a decent soundcard and cd writer, you wouldn't go far wrong.

What do you think?

Cheers Mike

K-amps · 22nd November 2006, 11:01 AM

Hello Tom:

Let me try and answer the question without being a prude

.

Your amp is bridgeable if it's outputs are grounded one one side. i.e. the "black" speaker posts have zero volts while driving the load and the "red" posts provide the voltage/current.

It both sides are hot i.e. drving the load, then it is already bridged and cannot be bridged again.

As far as how you bridge it is another story...

sreten · 22nd November 2006, 11:46 AM

Hi,

Some of us prefer the "floating" presentation of mono material over
a stereo pair of speakers but if you want one speaker fair enough.

Also note addding a mono button to your turntable (if the amplifier
doesn't have one) will significantly reduce apparent surface noise.

If you add a mono button simply use one speaker off one B-channel,
the other channel you can put a dummy load on, say a 50R 3W resistor.

/sreten.

jackinnj · 22nd November 2006, 12:09 PM

Quote:

Originally posted by mikee55

Briding an amp is adding distortion. When a class a/b amp is used as most are, you have a crossover distortion, yeah?

Do you want to demonstrate that empirically?

mikee55 · 22nd November 2006, 09:21 PM

http://sound.westhost.com/project14.htm

jackinnj · 22nd November 2006, 09:40 PM

Here's what I found (empirically) -- both amps were run from the same power supply with the identical signal source.

K-amps · 23rd November 2006, 12:32 AM

As far as non-empirical evidence goes, I have always liked the less grainy and less fatiguing sound of bridged amps.

21st November 2006, 08:32 PM	#1
renfrow diyAudio Member Join Date: May 2005 Location: Salt Lake City, Utah, USA	How do you tell if an amp is bridgeable? Ok, what I'm actually asking about is a receiver. I have boatloads of jazz and classical music from the 50's and earlier that is mono. What I'd like to do is build a single speaker just for listening to this, and hook it up to the B outputs of a receiver. I'd prefer to not to have to build an amp (sorry ) just for this, though I'm willing to build a speaker . Thanks! Tom. __________________ Now, we can do this the hard way, or... well, actually there's just the hard way. -- Buffy Summers (Buffy the Vampire Slayer)

21st November 2006, 09:58 PM	#2
mikee55 diyAudio Member Join Date: Dec 2005 Location: West Howe	Bridge circuit needed Hi renfrow, Why don't you just listen in mono from the stereo you have? Mono comes out in mono on a stereo. Briding an amp is adding distortion. When a class a/b amp is used as most are, you have a crossover distortion, yeah? If you bridge you'll get twice the crossover distortion, and supposedly more power avaiable to a speaker. Why don't you use a splitter and split the mono to Left and Right inputs or better still use a PC audio editor and create a synthesized stereo. Apparently, if you put a mono signal into a stereo reverb, technicaly the output is stereo. I think if you try and add just a slight echo and try and create the ambience of an average sized studio (or hall if a live recording), this wouldn't too far from mono rather than pan and expand(which could create a hole in the soundstage), and would be an interesting project. Am I to assume your recordings are vynil? Archiveing them digitaly would allow you to preserve the originals. I'm no expert, but going the digital route with an editor such as Wavelab or Soundforge, (there is Freeware editors out there on the www too), and if you had a decent soundcard and cd writer, you wouldn't go far wrong. What do you think? Cheers Mike __________________ If it don't work, I'll fix it in the mix! Or visit http://lsdp.proboards.com/index.cgi

22nd November 2006, 09:21 PM	#6
mikee55 diyAudio Member Join Date: Dec 2005 Location: West Howe	Link http://sound.westhost.com/project14.htm __________________ If it don't work, I'll fix it in the mix! Or visit http://lsdp.proboards.com/index.cgi

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

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

22nd November 2006, 11:01 AM	#3
K-amps diyAudio Member Join Date: Nov 2003 Location: Indiana	Hello Tom: Let me try and answer the question without being a prude . Your amp is bridgeable if it's outputs are grounded one one side. i.e. the "black" speaker posts have zero volts while driving the load and the "red" posts provide the voltage/current. It both sides are hot i.e. drving the load, then it is already bridged and cannot be bridged again. As far as how you bridge it is another story...

22nd November 2006, 11:46 AM	#4
sreten diyAudio Member Join Date: Nov 2003 Location: Brighton UK	Hi, Some of us prefer the "floating" presentation of mono material over a stereo pair of speakers but if you want one speaker fair enough. Also note addding a mono button to your turntable (if the amplifier doesn't have one) will significantly reduce apparent surface noise. If you add a mono button simply use one speaker off one B-channel, the other channel you can put a dummy load on, say a 50R 3W resistor. /sreten.

22nd November 2006, 09:40 PM	#7
jackinnj diyAudio Member Join Date: Apr 2002 Location: Llanddewi Brefi, NJ	Here's what I found (empirically) -- both amps were run from the same power supply with the identical signal source.

23rd November 2006, 12:32 AM	#8
K-amps diyAudio Member Join Date: Nov 2003 Location: Indiana	As far as non-empirical evidence goes, I have always liked the less grainy and less fatiguing sound of bridged amps.

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