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?
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...
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.
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.
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
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
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
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
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