Too many processors ?
01-04-2004, 10:33 AM
#1
500 Watt CAFz'r
Thread Starter
Join Date: Jul 2003
Posts: 756
Well, it certainly has been a very mild winter so far, but it is winter none the less 
Hang in there..
I've been contemplating my pre-amp path over the last couple of days. My source unit is a nakamichi cd-400 which outputs a 4v unbalanced signal. I own both an audiocontrol 4.1i EQ/Line driver that has a ~9V RMS balanced output. I also own a pair of Image Dynamics IDQ31 mono 1/3octive EQs. The signal will end at an Xtant 603X which can accept up to a 17V Balanced signal.
I was just looking for some feedback on what everyone thinks. I personally don't like to have a whole slew of processors in my signal path. The Audiocontrol 4.1i is probably the one component that I don't really think I will use much for tweaking the sound, however I do like the fact that it will output both a high voltage signal, as well as a balanced signal. The Image Dynamics IDQ31s will accept balanced inputs and outputs, however will not convert an unbalanced signal to a balanced one, nor will it provide any sort of line driving. Both the audiocontrol and ID EQs are quite good quality, and I don't think they should induce any significant amount of noise into the system, although I wont know until I try them. The RCAs I'm using are streetwires ZN6 twisted/balanced cables. I guess the real benefit of my Xtant amplifier receiving a high voltage balanced signal, is that I can crank the gains down, and possibly receive a cleaner signal. I never really had noise induction issues or ground loop noise in the past with unbalanced signals, so I'm questioning the need.
Any feedback would be appreciated.
Hang in there..I've been contemplating my pre-amp path over the last couple of days. My source unit is a nakamichi cd-400 which outputs a 4v unbalanced signal. I own both an audiocontrol 4.1i EQ/Line driver that has a ~9V RMS balanced output. I also own a pair of Image Dynamics IDQ31 mono 1/3octive EQs. The signal will end at an Xtant 603X which can accept up to a 17V Balanced signal.
I was just looking for some feedback on what everyone thinks. I personally don't like to have a whole slew of processors in my signal path. The Audiocontrol 4.1i is probably the one component that I don't really think I will use much for tweaking the sound, however I do like the fact that it will output both a high voltage signal, as well as a balanced signal. The Image Dynamics IDQ31s will accept balanced inputs and outputs, however will not convert an unbalanced signal to a balanced one, nor will it provide any sort of line driving. Both the audiocontrol and ID EQs are quite good quality, and I don't think they should induce any significant amount of noise into the system, although I wont know until I try them. The RCAs I'm using are streetwires ZN6 twisted/balanced cables. I guess the real benefit of my Xtant amplifier receiving a high voltage balanced signal, is that I can crank the gains down, and possibly receive a cleaner signal. I never really had noise induction issues or ground loop noise in the past with unbalanced signals, so I'm questioning the need.
Any feedback would be appreciated.
01-04-2004, 05:06 PM
#2
Join Date: Apr 2000
Posts: 1,220
the audiocontrol pieces are not a true balanced signal. A lot of people get mixed up in AC's balanced crap. Just remember this, to have a balanced signal you need 3 conductors. 1 ground, 1 positive signal, 1 negative signal.
Anyway, unless you want to have some adjustablty from the front seat. I would drop the 4.1. If you want to run a balanced cable from the id eq's to the amp thats up to you.. But if that cable is only 2ft theres no point.
Anyway, unless you want to have some adjustablty from the front seat. I would drop the 4.1. If you want to run a balanced cable from the id eq's to the amp thats up to you.. But if that cable is only 2ft theres no point.
01-04-2004, 06:59 PM
#3
1000 Watt CAFz'r
Join Date: Oct 2003
Posts: 1,783
My personal opinion on the Four.1i is that the 9 volt output is it's maximum output. I'll explain this a bit more.
I had the Four.1i in my signal path, between my 4 volt output from my deck and my A/C DQX. I found that removing the Four.1i resulted in no signal level drop or increased noise. I brought this up before, but I think it was misunderstood.
I had the input gains maximized on the Four.1i, and the volume **** turned all the way up. (There was no EQ boost on any freq.) Removing the Four.1i, and hooking the interconnect going to the DQX directly to the head unit resulted in no level drop with the deck turned all the way up. In fact, I found a slight increase in the level.
My only explaination is that the Four.1i output is designed to accomadate any possible EQing. So for example, with the Four.1i volume **** turned all the way up, and all the EQ bands BOOSTED 12db, the output would then be 9 volts.
So in summation, if you don't have the EQs turned all the way up, you probably will have less than 9 volts output from the Four.1i. And in my experience, if you aren't EQing that much, the line level will not be boosted above what a 4 volt pre-out deck can provide.
I hope I'm understood a bit better this time.
One final point. I found the sound quality improved quite a bit by removing the Four.1i from my signal path. Everything just sounded more real.(without any EQing applied)
If anyone wants to buy a barely used A/C Four.1i, I have one sitting in a box in my basement.
Adam
I had the Four.1i in my signal path, between my 4 volt output from my deck and my A/C DQX. I found that removing the Four.1i resulted in no signal level drop or increased noise. I brought this up before, but I think it was misunderstood.
I had the input gains maximized on the Four.1i, and the volume **** turned all the way up. (There was no EQ boost on any freq.) Removing the Four.1i, and hooking the interconnect going to the DQX directly to the head unit resulted in no level drop with the deck turned all the way up. In fact, I found a slight increase in the level.
My only explaination is that the Four.1i output is designed to accomadate any possible EQing. So for example, with the Four.1i volume **** turned all the way up, and all the EQ bands BOOSTED 12db, the output would then be 9 volts.
So in summation, if you don't have the EQs turned all the way up, you probably will have less than 9 volts output from the Four.1i. And in my experience, if you aren't EQing that much, the line level will not be boosted above what a 4 volt pre-out deck can provide.
I hope I'm understood a bit better this time.
One final point. I found the sound quality improved quite a bit by removing the Four.1i from my signal path. Everything just sounded more real.(without any EQing applied)
If anyone wants to buy a barely used A/C Four.1i, I have one sitting in a box in my basement.
Adam
01-06-2004, 04:05 PM
#4
Guest
Posts: n/a
Audio Control made a conscious decision to eliminate input gain from their products, since people didn't know how to use it. The Four.1 does however have 20dB of gain.
I can't imagine that you couldn't clip the living daylights out of any signal provided to the unit, especially from a deck that claims to be a 4V unit.
10 dB would be 10x the input signal and 20dB is 100x the input signal. That means that at full gain, an input signal of 0.1V can be increased to 10V.
Not saying something weird wasn't happening, but it seems odd that you heard no difference in level with the unit in or out of the loop.
Oh, and Audio Control units are essentially balanced inputs, but are better described as differential inputs. Any signal common to the hot conductor and the shield of the RCA is reduced by up to 65dB (as I recall from my training almost a decade ago). This is similar in theory to how a balanced signal works.
I can't imagine that you couldn't clip the living daylights out of any signal provided to the unit, especially from a deck that claims to be a 4V unit.
10 dB would be 10x the input signal and 20dB is 100x the input signal. That means that at full gain, an input signal of 0.1V can be increased to 10V.
Not saying something weird wasn't happening, but it seems odd that you heard no difference in level with the unit in or out of the loop.
Oh, and Audio Control units are essentially balanced inputs, but are better described as differential inputs. Any signal common to the hot conductor and the shield of the RCA is reduced by up to 65dB (as I recall from my training almost a decade ago). This is similar in theory to how a balanced signal works.
01-07-2004, 09:50 AM
#5
Yesterday I added a Four.1 in between my Alpine 7894 (4 volt preouts) and my RF 160x4 amp. Prior to adding it, I had my gain on the bridged back half of the amp at 2/3, and the sub level on the deck around 10-12 out of 15 at all times. After adding in the Four.1, I dropped the amp gain to 1/4, the sub level on the deck is now sitting around 1-4 out of 15, and the sound improvement from the sub is very noticeable. I think the truth is that most of these decks out there(or maybe just my Alpine) highly overrate the preout voltage, just my .02 cents. I know this issue has been discussed a lot on the board already. I also dig the Para-Bass EQ, makes the sub sound a lot fuller. Not really using any of the other eq functions though, kind of wish it had front and rear inputs, so I could keep my fronts and sub-level tweaking separate. [img]smile.gif[/img]
01-07-2004, 06:55 PM
#8
If the four.1 isn't giving a true balanced signal, you don't need it just for a voltage boost. Your EQ's can do that. They have those master controls on the output. I daisy chain 2 amps together and I don't even have them up all the way.
But if when removing and replacing the four.1, you hear no difference, and you like having it up front, just leave it.
But if when removing and replacing the four.1, you hear no difference, and you like having it up front, just leave it.
