What makes a amplifier sound clean?

[chipper]

What makes some amps sound cleaner than others? I have a Sony 4-channel car amp that is suppose to be 600 watts i put this in to power speakers in place of my Rockford Punch 160.4 thats 20 watts a channel i'm not trying to say this vs that but trying to figure out why the Rockford sounded more warmer and cleaner? I tuned that amp as best as i could and on my Kenwood EQ to get the sound of the Rockford. had to turn it up for it to sound good. The difference is day and night between the two amps. I like loud clean sounds if you were wondering but not abusive. Is it because the components used in the amplifers? And yes i checked all of my wires and rca cables and its not my install i don't think the amp is defective it just doesnt have that clear and warm sound to it idk why Rockford really did it when i had it in.

[Perry Babin]

The actual power amplifier sections of most all solid state amplifiers sound the same. The high level of negative feedback ensures that the only difference between the input to the power amplifier circuit and the output at the speaker terminals is the level. This only applies if both amplifiers are in proper working order. For amplifiers that sound better, it's possible that the crossovers and boost circuits are better designed.

[jol50]

The old RF amps (or some of them) are said to have sort of a loudness circuit in them that is on all the time, however you should be able to duplicate this with another amp and an EQ....unless your system response is way off and you run out of EQ or the EQ is of poor quality, etc. You will find this in old amps much more than new amps, and back then (late 80s) it was great since few people even had an EQ. Some RF even had bass and treble on them. This can also minimize typical response issues in cars such as reflections that happen at typical frequency ranges, etc. So you have to be very careful to differentiate between response issues (EQ) and actual quality issues (THD, etc). Another issue is how the amp clips, certainly many old amps will clip far nicer than new amps in particular cheaper new amps. But that is only an issue at max power for a given amp, and new amps have plenty of power so you can avoid that issue if you get a large enough one. That said I have no problem running older amps on mids and highs where power is not much of an issue, or not for me anyway. But often it depends on the install for what I end up liking better.

[chipper]

Originally Posted by jol50

The old RF amps (or some of them) are said to have sort of a loudness circuit in them that is on all the time, however you should be able to duplicate this with another amp and an EQ....unless your system response is way off and you run out of EQ or the EQ is of poor quality, etc. You will find this in old amps much more than new amps, and back then (late 80s) it was great since few people even had an EQ. Some RF even had bass and treble on them. This can also minimize typical response issues in cars such as reflections that happen at typical frequency ranges, etc. So you have to be very careful to differentiate between response issues (EQ) and actual quality issues (THD, etc). Another issue is how the amp clips, certainly many old amps will clip far nicer than new amps in particular cheaper new amps. But that is only an issue at max power for a given amp, and new amps have plenty of power so you can avoid that issue if you get a large enough one. That said I have no problem running older amps on mids and highs where power is not much of an issue, or not for me anyway. But often it depends on the install for what I end up liking better.

Yeah I've decided to keep my RF channel. It sounds just great makes my highs scream! I've always used old RF for my bass those also got the power. I try other brand equipment newer stuff and it just doesn't got the same awesomeness sound as the fosgates do even with out the EQ they still clean & clear. Right now I'm running a Punch 40x2 for bass and a RF Punch HE best sound I've heard. I also have other RF amplifiers to use but these suit me best. Also can i paint a heat sink? The 160.4 is in really bad condition not the amp its self but the heat sink is all scrathed.

[Perry Babin]

In some of the early Rockford amps, the bass boost never went completely off. That could account for the difference in sound. Later, they modified the bass boost circuit so it would go completely flat.

[jol50]

You can paint sinks, but paint build up can increase temperatures inside so it is nicer to replace what they did. Some strip them some not, some send them in for anodizing. If its black paint and kind of flat, what can work nice is the spray for bumper rub strips on cars. Most stores here have spray cans of it. Air dry paint is not the best but what most have access to.

[chipper]

Originally Posted by Perry Babin

In some of the early Rockford amps, the bass boost never went completely off. That could account for the difference in sound. Later, they modified the bass boost circuit so it would go completely flat.

Yeah this is for the mid 90's RF amps right? Like a 40x2 and 160.4. I also noticed that the 1997 Punch 40.2 was the same as the 1996 Punch 40x2. The 97 series didn't have the PSD connection but had the area where it was suppose to be. Very good little amps pushed a variety of speakers I had.

[Perry Babin]

I think the transition came in about 2002/2003. The 301M had the old circuit. The schematic has a date of 9/19/02. The T5002 has a date of 12/15/03 and uses the new circuit.

[chipper]

How bad have you seen badly blown RF amps? I was browsing ebay for some amplifiers. I see some that are badly fried the power supply is badly burned up. Why do they do that? Seems like when they fail they burn up parts of the board too. Why do they burn the heck up like that? Mostly the DSM, ".2" and "A" series I've seen that were badly burned.

[Perry Babin]

Many times, the FETs fail and blow soot all over the board. This can make it look really bad when it's not. In some instances, the board does get burned (can happen to virtually any amp). Unless the images are of good enough resolution to determine if the board is intact, it would probably be best not to buy the amp.