I got a line driver for my 420!

[talltigeguy]

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.

[shawndoggy]

So is it safe to say that the aux input on your ws420 sounds WAY undergained now?

[sincity]

I have the same hiss across my samson HLCD's, butt only on the HLCD's, it is only noticeable when the volume is all the way down, butt I have no volume problems, the sound is very clean to my ears, especially after I switched to the alpine cda118 m from the clarion cdm7, it has a higher signal to noise ratio which was quite a difference in sound quality, I had to turn the gains down. In my experience as the quality of your speakers go up, the better sound reproduction you get, so any type of noise your system has, your now going to here, your line driver I believe just boosts your preamp voltage to your amps giving them a hotter signal, I will by pass my 420 tomorrow and see if the hiss goes away, the 420 is the only piece of wet sounds equipment I have.
Sin city

[Wakeman22]

All this is very interesting. Would like to hear Phil's and chpthril's input on this. I will be hooking up my WS420 this weekend and I will see if I get the same hiss. I hope not.

[shawndoggy]

i always had some hiss with the ws420 in my old boat. My cheap, disposable, pos clarion eqs746, none.

[talltigeguy]

So is it safe to say that the aux input on your ws420 sounds WAY undergained now?

Correct. That is why I insisted initially on trying it between the 420 and Tower amp first. 95% of all of the music I listen to is from that AUX input on the 420. So that is now not an option. But my HU has Ipod capability, so not all is lost. I actually will upgrade the HU to one with an AUX input, as scrolling through the screens is painful, especially while trying to drive. I like just giving the ipod on the cable to the passenger and focusing on driving.

Shawndoggy, did you get your other amp hooked up yet? I was eager to see if you feel it livens up the system as much as we are hoping. WIth the new line driver, I am content to leave well enough alone now.

[talltigeguy]

I have the same hiss across my samson HLCD's, butt only on the HLCD's, it is only noticeable when the volume is all the way down, butt I have no volume problems, the sound is very clean to my ears, especially after I switched to the alpine cda118 m from the clarion cdm7, it has a higher signal to noise ratio which was quite a difference in sound quality, I had to turn the gains down. In my experience as the quality of your speakers go up, the better sound reproduction you get, so any type of noise your system has, your now going to here, your line driver I believe just boosts your preamp voltage to your amps giving them a hotter signal, I will by pass my 420 tomorrow and see if the hiss goes away, the 420 is the only piece of wet sounds equipment I have.
Sin city

When you said that the Alpine HU was much better, I initially wondered if it might be due to more voltage in the preamp as well. But I see it has just 2 volts. I wonder if the CLarion put out even less. A quick search and I cannot find the specs.

I think a very tiny bit of hiss is next to impossible to get rid of when you have a lot of power going through the HLCD's, but mine was enough that I decided to give it a try. But the real issue was me wondering if they were capable of more volume, and I have found that the REV's were capable of even a bit more than what I previously had.

[shawndoggy]

Correct. That is why I insisted initially on trying it between the 420 and Tower amp first. 95% of all of the music I listen to is from that AUX input on the 420. So that is now not an option. But my HU has Ipod capability, so not all is lost. I actually will upgrade the HU to one with an AUX input, as scrolling through the screens is painful, especially while trying to drive. I like just giving the ipod on the cable to the passenger and focusing on driving.

I don't know about yours, but mine always seemed way undergained (I never put a line driver to the HU input).

Here's a thought... what about flipping the inputs around, so that your HU goes into the AUX side, and the ipod goes into the HU side? I remember reading that for folks that were going to go "headless" that the HU side was the better place to plug in the ipod because the AUX was undergained on the EQ. Well with a line driver that shouldn't be a problem.

EDIT: I hope to put power to amp this weekend. been cleaning up install bits and adding stuff and moving stuff around and ....

[houstonshark]

I have the same hiss from my 4 Rev10's and WS420. It drives me crazy. Turning the gains down on the 2 JL MHD750/1's that power them doesn't help much. I'll try the line driver trick. I have a Tru Technologies SSLD6i laying around. It's a bit of overkill as it is a 6ch line driver that has several upgraded audiophile components. Max output of it is around 13V if I remember.

I might have time to pop it in tomorrow afternoon. I'll report back if I do. Did you lower the volume on the head unit afterwards? I normally run the volume of my factory Clarion HU at 28.

[neildorin]

Professional sound, recording and Hifi have been an integral part of my career for 10 years.

A common misconception about audio is that a good power amplifier or speakers are what will make the most difference on a system.

In reality, to maintain the highest quality you should start at the source and work towards the destination. Having only a 2V preout on a HU means a significantly higher noise floor at the next gain stage. Using a line driver as a pre-amplifier will greatly drop the noise floor (hiss) and allow the power amplifiers to be much more efficient at the second gain stage.

For an amplifier to perform its best it needs to receive the cleanest, highest gain signal to its input without clipping.

[shawndoggy]

Professional sound, recording and Hifi have been an integral part of my career for 10 years.

A common misconception about audio is that a good power amplifier or speakers are what will make the most difference on a system.

In reality, to maintain the highest quality you should start at the source and work towards the destination. Having only a 2V preout on a HU means a significantly higher noise floor at the next gain stage. Using a line driver as a pre-amplifier will greatly drop the noise floor (hiss) and allow the power amplifiers to be much more efficient at the second gain stage.

For an amplifier to perform its best it needs to receive the cleanest, highest gain signal to its input without clipping.

I think the surprising part here is that I thought that the WS420 was a line driver and was supposed to take care of these issues. Not that you'd have to give it a line driver.

[houstonshark]

I think the surprising part here is that I thought that the WS420 was a line driver and was supposed to take care of these issues. Not that you'd have to give it a line driver.

I thought the same and was told that a line driver with the 420 was not needed. I'm certain my Tru Technologies line driver is not necessary in the boat but I can use it to test at least as then get a more modestly priced one.

[neildorin]

I was looking at the WS420 the other day to put in the new Z3 for Independant adjustment of the tower speaker volume and the mic talk back at some point. I haven't seen or installed one in person but I was reading the manual and although it's not mentioned I swear I just watched a video on the website recently of a WS420 install that showed the waterproof plugs that cover the input gain pots. In the manual it does talk about the WS420 being a line driver so I would imagine that adjusting the input gain on the recessed pots would compensate for the 2V input from the Alpine HU. It would also likely give you the ability to balance the main input to the local Aux input.

Lastly, they have a pretty good write up that gives a layman's description of how to set up the system originally. I'd take it a step farther. The first instruction is to set the output of your HU to 85% of max. While this is a pretty good guide and in most cases pretty accurate, what they're after is a 0dB output level from the source. If you can get your hands on a meter and measure the output of the HU while playing pink or white noise tones (preferably white) you'll guarantee you're getting the most clean gain out of the HU's 2V preout. A 1-2dB quieter signal at the input side can mean a 10-20% higher noise floor and that much less volume from the power amplifiers.

[shawndoggy]

I was looking at the WS420 the other day to put in the new Z3 for Independant adjustment of the tower speaker volume and the mic talk back at some point. I haven't seen or installed one in person but I was reading the manual and although it's not mentioned I swear I just watched a video on the website recently of a WS420 install that showed the waterproof plugs that cover the input gain pots. In the manual it does talk about the WS420 being a line driver so I would imagine that adjusting the input gain on the recessed pots would compensate for the 2V input from the Alpine HU. It would also likely give you the ability to balance the main input to the local Aux input.

Lastly, they have a pretty good write up that gives a layman's description of how to set up the system originally. I'd take it a step farther. The first instruction is to set the output of your HU to 85% of max. While this is a pretty good guide and in most cases pretty accurate, what they're after is a 0dB output level from the source. If you can get your hands on a meter and measure the output of the HU while playing pink or white noise tones (preferably white) you'll guarantee you're getting the most clean gain out of the HU's 2V preout. A 1-2dB quieter signal at the input side can mean a 10-20% higher noise floor and that much less volume from the power amplifiers.

there have been several generations of the WS420. Seems like they change something once a year or so. Since at least the fall of 2009, the gains (input or output) have not been adjustable.

[houstonshark]

Well, I just put my line driver in and it worked to remove about 90% of the hiss. I have the head unit volume set at 28 and ended up adjusting the gain of the line driver all the way up. Initially, the hiss was still there. I turned the gains down on all of the amplifiers and adjusted it for a little bit.

I ended up turning the amp gains all the way down (most of them were somewhere between 40-50%). The system still seemed to have plenty of volume. I'm at my main house right now and don't think my neighbors would appreciate me tuning the system here. I'll play with it tomorrow on the water but for now I'm pretty happy to have the majority of the hiss gone from the tower speakers.

Maybe Wet Sounds will come out with a new EQ that will help this issue and not 'amplify' it so to speak.