Potentiometer choice for bi-amping

chipco3434 · 28th January 2005, 02:02 PM

Planning a new amp for biamping... most likely based on yet another BrianGT board set. Four channels total with L/R on woofers & tweeters. Separate line levels in will be controlled by mox boards but I will need a volume control for all four channels. Can somebody direct me to a decent four deck log pot?

Tekko · 28th January 2005, 03:04 PM

ALPS are pretty good pots. Check them out

chipco3434 · 28th January 2005, 03:24 PM

Got a part number for a four deck???

Tekko · 28th January 2005, 03:45 PM

i only got a dual gang and six gang pot with motor drive.

chrish · 29th January 2005, 12:47 AM

Not quite sure why you need a four channel pot. If you are running bi-amped, don't you just need a way of trimming the tweeter and/or woofer? I am assuming that the "vox board" has a trim pot for adjusting the output. If this is the case, once you have set this, you will only need a stereo pot...

chipco3434 · 29th January 2005, 01:31 AM

This is how I think it should work...

Source ->active crossover (MOX board)
MOX board -> High pass and low pass out

HP->pot->input of amp
+
LP->pot->input of amp

all this times two=4 pots for stereo bi-amping

Yes the MOX boards do have trimmers but you will need a volume control for the amp.

chrish · 29th January 2005, 06:21 AM

I am doing a similar thing, but using Rod Elliot's crossover boards to active crossover for stereo sub woofers, but the priciple is the same.

for each channel:

volume control (or from pre amp) => input of active crossover

HP => amp => speaker

LP => amp => speaker

Same for other channel. This way you use two channel volume control. Use trimmers on the boards to trim for level between tweeter and woofer. Once this is initially set you do not need to touch it again. You then use your normal two channel volume pot (or your pre-amp) to set your volume.

In other words, put your volume control before the input to your active crossover.

Cheers,

Chris

chipco3434 · 29th January 2005, 11:29 AM

I guess I wanted the pot integrated in the power amp. However, I see no reason not to do it with the pot immediately after the source like you suggest.

chrish · 29th January 2005, 03:36 PM

Thinking about it further, integrating the pot into the power amp as you were originally thinking has some other disadvantages.

1. Complexity

2. Cost - cost extra for four channel pot (if you can find one)

3. If the log taper characteristics of the pots do not exactly match for each of the channels, you will change the crossover characteristics as you change the volume - destroying some of the advantages of going with the active crossover in the first place.

Good luck with the project!

As an aside, it is sometimes a little frustrating when someone points out the simple solution to something you have been spending hours contemplating. When I was building my Ariel loadspeakers, I was describing to my friend how I was going to make two templates for the internal baffling, one for the each side of the speaker cabinet. Then he said "why don't you just make one, then flip it over for the mirror image?, Then both sides will mach perfectly..." DOH! I felt like a fool

Cheers,

Chris

chipco3434 · 29th January 2005, 08:04 PM

Frustrating, no way... that's why I posted, thanks.

28th January 2005, 02:02 PM	#1
chipco3434 diyAudio Member Join Date: Feb 2004 Location: Racine, Wisconsin	Potentiometer choice for bi-amping Planning a new amp for biamping... most likely based on yet another BrianGT board set. Four channels total with L/R on woofers & tweeters. Separate line levels in will be controlled by mox boards but I will need a volume control for all four channels. Can somebody direct me to a decent four deck log pot?

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
Bi amping	adventfan	Solid State	14	26th June 2008 03:28 PM
Bi-Amping.....Which one where?	THUMP LUMP	Solid State	3	17th December 2007 08:24 PM
Bi-amping	diyman	Multi-Way	9	10th January 2005 07:55 PM
Tri amping SOZ	Magura	Pass Labs	6	8th January 2004 08:51 PM
Bi amping help.	CryingDragon	Parts	2	25th September 2002 08:17 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

28th January 2005, 03:04 PM	#2
Tekko diyAudio Member Join Date: Jan 2005	ALPS are pretty good pots. Check them out

28th January 2005, 03:24 PM	#3
chipco3434 diyAudio Member Join Date: Feb 2004 Location: Racine, Wisconsin	Got a part number for a four deck???

28th January 2005, 03:45 PM	#4
Tekko diyAudio Member Join Date: Jan 2005	i only got a dual gang and six gang pot with motor drive.

29th January 2005, 12:47 AM	#5
chrish diyAudio Member Join Date: Oct 2003 Location: Sydney	Not quite sure why you need a four channel pot. If you are running bi-amped, don't you just need a way of trimming the tweeter and/or woofer? I am assuming that the "vox board" has a trim pot for adjusting the output. If this is the case, once you have set this, you will only need a stereo pot...

29th January 2005, 01:31 AM	#6
chipco3434 diyAudio Member Join Date: Feb 2004 Location: Racine, Wisconsin	This is how I think it should work... Source ->active crossover (MOX board) MOX board -> High pass and low pass out HP->pot->input of amp + LP->pot->input of amp all this times two=4 pots for stereo bi-amping Yes the MOX boards do have trimmers but you will need a volume control for the amp.

29th January 2005, 06:21 AM	#7
chrish diyAudio Member Join Date: Oct 2003 Location: Sydney	I am doing a similar thing, but using Rod Elliot's crossover boards to active crossover for stereo sub woofers, but the priciple is the same. for each channel: volume control (or from pre amp) => input of active crossover HP => amp => speaker LP => amp => speaker Same for other channel. This way you use two channel volume control. Use trimmers on the boards to trim for level between tweeter and woofer. Once this is initially set you do not need to touch it again. You then use your normal two channel volume pot (or your pre-amp) to set your volume. In other words, put your volume control before the input to your active crossover. Cheers, Chris

29th January 2005, 11:29 AM	#8
chipco3434 diyAudio Member Join Date: Feb 2004 Location: Racine, Wisconsin	I guess I wanted the pot integrated in the power amp. However, I see no reason not to do it with the pot immediately after the source like you suggest.

29th January 2005, 03:36 PM	#9
chrish diyAudio Member Join Date: Oct 2003 Location: Sydney	Thinking about it further, integrating the pot into the power amp as you were originally thinking has some other disadvantages. 1. Complexity 2. Cost - cost extra for four channel pot (if you can find one) 3. If the log taper characteristics of the pots do not exactly match for each of the channels, you will change the crossover characteristics as you change the volume - destroying some of the advantages of going with the active crossover in the first place. Good luck with the project! As an aside, it is sometimes a little frustrating when someone points out the simple solution to something you have been spending hours contemplating. When I was building my Ariel loadspeakers, I was describing to my friend how I was going to make two templates for the internal baffling, one for the each side of the speaker cabinet. Then he said "why don't you just make one, then flip it over for the mirror image?, Then both sides will mach perfectly..." DOH! I felt like a fool Cheers, Chris

29th January 2005, 08:04 PM	#10
chipco3434 diyAudio Member Join Date: Feb 2004 Location: Racine, Wisconsin	Frustrating, no way... that's why I posted, thanks.

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