I got a line driver for my 420!
I have a pretty decent stereo. I have been pretty pleased with it overall. But the tower speakers have not quite lit up as well as I think they could. I have 4 REV 10's being powered by an Arc Audio ks600.2. This gives 300 watts to each unit, which is what WS recommends. I talked to the designers at Arc about getting another 600.2. That amp will put out 400 X 2 if each channel is run to just 1 speaker. I figured the extra power would do it some good. But the guys at Arc didn't really think that it would make a whole lot of difference since they had already designed the amp with the REV's in mind. They also tend to underrate their amps some already anyways.
In order to get pretty close to the output I expect, I have the gains about 1/2 way up, and the speakers have a substantial hiss. Not really annoying, but loud enough that you hear it. Enough to bother me when the tower speakers are not playing, or are at low volumes. After double and triple checking everything, the noise comes from the 420 equalizer. All grounds are run to the same place. New RCA cables did not fix it....lots of other things were done to track this down, and nothing except removing the 420 would take the hiss out.
I was telling Andrew (SPBFan) about this since he is my Arc audio supplier. The techs at Arc have sold him on using an Arc Audio line driver together with the 420. We have had a bit of a discussion in a previous thread about this concept. I chimed in, along with most others about how dumb it seems to have a line driver and and EQ that is supposed to be a line driver as well. What kind of idiot has 2 line drivers in series? BTW, My HU is already a quality Alpine HU as well, but only puts out 2V on the RCA outputs.
SPBFan happened to be in town this week and told me he was so sure that this would awaken my system that he would bring it and help me get it installed without charging me for it. Then if I don't like it, we just take it out and it costs me nothing. Didn't seem like a bad offer. For sure wouldn't hurt.
Since the tower speakers were the main problem, I convinced Andrew to first put the line driver between the 420 and tower amp. I still had the annoying hiss. Then we put the line driver between the HU and 420. All that I can say is WOW! The system sounds cleaner and louder. The tower speakers in particular are even better. The annoying hiss is all but gone. So this has not only solved my gain hiss issue, it brought the tower speakers up a notch.
I am not sure that I know why it fixes the problems, but it does. A whole lot cheaper than another amp too. Andrew has seen several guys send back their 420 concerned it is not right, because of the same issue. WS then says that nothing is wrong with it when they test it. My other option is to get a different 420, and see if it does the same thing. But frankly, I think this is a better solution. Just thought I would pass along my experience, and would suggest the same if others have similar issues. I am sure to get flamed...but I can tell you my stereo is better than it was (in fact, before wednesday, I would have added fuel to the fire). So feel free to beat me up over it, but come and listen, and you might become a believer too.
Be excellent to one another.