Bonified, Certified High Quality Amps

[Papermaker85 5,000+ posts]

thing that makes me spend the 2x for a great amp is the better s/n ratio channel seperation better slew rate(being able to differentiate multipal sorces/material) fact that it will do rated power @ 12 volts with inaudible thd, excellent crossovers, flexibility, excellent QC and well built products... DF is not a huge concern in midrange to high end, but is does contribuite to inductance/reactence.. which CAN contribute to higher freuqncy extention power handling and lower THD.. anyways like i said i love music and i fell its worth the extra green backs...

 

[Papermaker85 5,000+ posts]

LOL, not implying rap music is for SQ.... Just a point about the source. Todays rock music (if you want to call it that) is too busy too... way too much cymbal and drums are too busy. And the distortion from the guitars in the back ground could probably fry your tweeters quickly... even if setup properly and a robust tweeter...

even though im young, i do love older music.. but honestly there are alot of artist out htere that simply are retards, not worth buying there CDs..Now there are some that just go above and beyond to make excellent material.. im going to get ***** for this but namely lil wayne uses EXCELLENT recording equipment.. yes he does use abit of eq here and there but thats not the point.. its that fact that i love it when i can turn it up and it sounds like im in the studio with him, hearing his voice like it was coming out of his mouth VS threw a mic anmp and some speakers.. to say all amps are the same is just silly..

 

[dB-r 10+ year member]

I think most people's problem with that is that the drivers that are availible aren't good enough to exploit the amplifiers characteristics, unless you spend a small fortune on drivers, AND amplifiers AND a good source unit you won't be able to tell those differences. ALL of the equipment has to be "top notch" or SQ is FAIL. Not to mention placement and tuning.... tedius, and sometimes placement is impossible in a car without extreme modifications which goes far beyond the scope of most people who put things together and also end up with undesirable asthetics (sp?) in their vehicle also. That's why I said SQ is a game inside of car audio, not car audio itself. I guess I should have said REAL SQ, not just average SQ, but the exceptional. No market for the stuff = no production of the stuff to accomplish it. Markets are driven by money.

 

[ciaonzo 5,000+ posts]

No, they don't have to be exotic. And being exotic doesn't necessarily indicate that an audible difference will be heard either.
But my point was more to the context to which this thread applies to many of the specifics you've mentioned. Of the specifics you've mentioned thus far was the current source vs voltage source and difficult load drivers. Ignoring specifics of the sound debate for a moment....In the context of this forum (car audio)....how many current source amplifiers are there to make this comparison in our cars? How many difficult load speakers are there? How many 8 or 9 watt tube amps are there? How many 12 component amps are available for car audio? Virtually none. So bringing those up in this thread is like bringing up Ford vs Chevy. It's completely off topic to the context in which the topic should be discussed. How many Nelson Pass zero feedback style amps are available for car audio? So why does he or his products apply to this thread? We can't buy one of his amps and throw it in my car. None of it applies to the products we have available. We have run-of-the-mill solid state amps where the main differences in sound are either going to come from frequency response anomolies which can be adjusted with EQ or unacceptable levels of distortion or noise which is indicative of either an amplifier not worth owning or that's broken.

I happen to own and use plenty of drivers that present a difficult load to some amplifiers and single-ended push-pull, zero feedback amplifiers that are indeed full fledged car audio products and as long as they exist they are part of this topic. My only point from the start was that not all amplifiers sound the same. I can hear that and I maintain that.

I think most people's problem with that is that the drivers that are availible aren't good enough to exploit the amplifiers characteristics, unless you spend a small fortune on drivers, AND amplifiers AND a good source unit you won't be able to tell those differences. ALL of the equipment has to be "top notch" or SQ is FAIL. Not to mention placement and tuning.... tedius, and sometimes placement is impossible in a car without extreme modifications which goes far beyond the scope of most people who put things together and also end up with undesirable asthetics (sp?) in their vehicle also. That's why I said SQ is a game inside of car audio, not car audio itself. I guess I should have said REAL SQ, not just average SQ, but the exceptional. No market for the stuff = no production of the stuff to accomplish it. Markets are driven by money.

This is reinforcing what I stated earlier.


Furthermore, papermaker is correct in stating that no one will ever win the RC challenge strictly based on the criteria. It's a setup from the start. I almost think he's having a laugh at all of us.

 

[JimJ 5,000+ posts]

Most people like the sound of tube amps. If they don't know what they are listening to, and you switch them from a solid state to a tube amp they like the sound of the tube amp better, which is funny because most of them are like 10% THD if I remember right... LOL...

A 300B (a pretty typical low power triode) is 5% max in Class A1, single ended: http://www.westernelectric.com/products/300b/300B.pdf

The tubes I'm using now are 1% max in SE: http://audioportal.su/tubes/svetlana/graphics/products/pdf/SV811-10.pdf

But it's not quite directly comparable to distortion measurements of a Sundown being driven to its saturation point, as the makeup is different. Much more even-order than odd.

 

[dB-r 10+ year member]

A 300B (a pretty typical low power triode) is 5% max in Class A1, single ended: http://www.westernelectric.com/products/300b/300B.pdf
The tubes I'm using now are 1% max in SE: http://audioportal.su/tubes/svetlana/graphics/products/pdf/SV811-10.pdf

But it's not quite directly comparable to distortion measurements of a Sundown being driven to its saturation point, as the makeup is different. Much more even-order than odd.

But add the distortion added by any pre-amplifier stages including the first source unit to that also, don't forget that.

Like I said earlier too, the musical material these days is yuck for SQ IMO. Too busy, too much distortion and synthesizer.

 

[Ctesibius 10+ year member]

in reply o not know slew rate DF etc... many people say that anything above 200 is plenty, but one thing i CAN say is that under demanding loads your GOING to hear a difference.. simply put not all amplification is the same.

Both slew rate and damping factor are not "higher is better" specifications. Once the amp has adequate enough slew rate or adequate enough damping to not audibly affect the signal.....that's it. Going higher will not yield audibly different results. And actually, a lot of people suggest that anything above 20 is sufficient for proper damping. See:

Richard Clark

http://www.monstercable.com/mpc/stabletechA2412_Damping_Factor_Article.pdf

"From the damping factor chart it is obvious that the most damping we can expect from our amp/speaker combination is only about two. An amplifier with a damping factor exceeding 10 times this amount is no longer going to play a significant role in this overall calculation. This would yield a practical limit on amplifier damping requirements to about twenty"

Stephen Mantz

http://zedaudiocorp.com/Technical/ZedManual-GREYSCALE.pdf

"We see that the DCR of the speaker swamps all other resistances in the speaker circuit and the .004 ohms amplifier output impedance is almost meaningless. It has been found that a DF of about 20 is quite sufficient to dampen the voltage spikes from the speaker."

Audioholics Article

http://www.audioholics.com/education/amplifier-technology/damping-factor-effects-on-system-response

"All this is well and good, but the argument suggesting that these minute changes may be audible suffers from even more fatal flaws. The differences that we see in Q figures up to the point where the damping factor is less than 10 are far less than the variations seen in normal driver-to-driver parameters in single-lot productions. Even those manufacturers who deliberately sort and match drivers are not likely to match a Q figure to better than 5%, and those numbers will swamp any differences in damping factor greater than 20.

...........

There may be audible differences that are caused by non-zero source resistance. However, this analysis and any mode of measurement and listening demonstrates conclusively that it is not due to the changes in damping the motion of the cone at the point where it's at it's most uncontrolled: system resonances. Even considering the substantially larger response variations resulting from the non-flat impedance vs. frequency function of most loudspeakers, the magnitude of the problem simply is not what is claimed.

Rather, the people advocating the importance of high damping factors must look elsewhere for a culprit: motion control at resonance, or damping, simply fails to explain the claimed differences."

RCs test is impossible to win. because its a totaly fail at what a normal application is..

Then you don't understand the point of the challenge //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

tell me i can't hear adifference under clipping ill tell you ill prove it..

Fine. Go take RC's challenge, prove it to everyone and make yourself $10k richer in the process. I don't see the problem here? The challenge has been open for 10 years.....you've had ample opportunity to go take it. So, what's the hold up?

 

[Ctesibius 10+ year member]

I happen to own and use plenty of drivers that present a difficult load to some amplifiers and single-ended push-pull, zero feedback amplifiers that are indeed full fledged car audio products and as long as they exist they are part of this topic.

Please, share what amplifier that would be. I'm very interested to know, honestly.

Furthermore, papermaker is correct in stating that no one will ever win the RC challenge strictly based on the criteria. It's a setup from the start. I almost think he's having a laugh at all of us.

Oohh....I'd love to hear further explanation of this as well //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Papermaker85 5,000+ posts]

I agree that DF now in days is plenty high.. DF is the amps abilitly to cotrol back EMF.. few applications like high inductance/reactence driver will affect amps.. slew rate on the other hand DOES make a difference.. not sure as to what the inaudible limit is but id perfer a higher slew rate.. very few companies even publish the spec and imo its worthy of being published..

I already told you im alot of high output systems, s/n ratio as well as channel spereation CAN be distungished, even under clipping.. Ive read the RC test and its simply not apples to apples.. he explain in the amps linear output a watt is a watt.. but thats simply not nearly 99% of applications.. he bypasses the internal xovers etc... im not going to arguewith anyone, im just saying the amps i named are excellent amps all around, and imo if you have the money there worth it...

 

[Keyboard_Rambo 10+ year member]

When it comes to damping factor, I thought that was more of an issue in the pro audio world where the speaker wire runs can be 50 to 100, or more, feet.

As for RC's test, I thought his philosophy was amplifiers that measure the same will sound the same... Since he has his own tricks to level the playing field, I highly doubt ANYONE will ever take his $10,000.

 

[600HPSVT 10+ year member]

Wow, lots of posts! I could not login for a few days because of brief hospitol stint. As for the amp question, lots of advice I see! A few guys ask the question of what speakers/ohms will be used here. I will be running 3 sets of PVI series Quarts at 4ohms each (2 sets off the 4-ch amp (F & R) and another set off the deck in Q-forms). The subs are JL10W6V2's in parallel/parallel to be run at 1ohm. The deck is a Premier P800PRS.

I had all late 90's PPI equipment in the past that never once had a problem in 10+ years of ownership. Unfortunately, sombody thought they needed them more than I did. Anyway, I really just want something dependable, long lasting, and most importantly, an amp that produces clean power. My old PPI's had plenty of head room and never ran hot, only lukewarn. Besides the fact that the amps were just built well, running cool all those years probably played a part in their lasting so long. This is what I would love to find again. After spending the time to design the custom install and get it in place, all I need to do is just sit back enjoy the music... for years to come!

 

[600HPSVT 10+ year member]

lunar helix auison soundstream zapco mac focal polk ID arc... id run any of those in a heartbeat.. im really thinking about tring the new reference 4.920... old school design decent parts.. honestly looks like the best design for under 700 bucks...

I was actually looking to go with a Ref4.920 for my Quarts and a Ref1.1000 for my JL's. They look nice and the specs are there but what about the quality? I called SS and they said the 1000 was out and the 920 would be out in June. Have you heard anything about reliability and/or a release date?

 

[FJF 10+ year member]

Since he has his own tricks to level the playing field, I highly doubt ANYONE will ever take his $10,000.

FWIW, similar challenges have been around for ages, typically driven by sheer zealotry and religious fervor. None have really come to fruition. This wasn't due to a lack of folks willing to go through with it; it was due to differences in proposed testing protocols. As implied above, the protocol will made or break a DBT. Similarly, the protocol can easily screw the results in a given direction. The bulk of the individuals citing DBT have no idea, whatsoever, what it takes to perform a valid test and which constraints need to be addressed. As such, grandiose, hyperbolic challenges are issued with no effect besides serving as a weapon of ignorance.

 

[Ctesibius 10+ year member]

I slew rate on the other hand DOES make a difference.. not sure as to what the inaudible limit is but id perfer a higher slew rate.. very few companies even publish the spec and imo its worthy of being published..

Slew rate doesn't matter once it's high enough to not audibly affect the signal. If sufficient slew rate is X, then an amplifier having a slew rate of X*2 is not going to sound any better or different (due to having a higher slew rate).

I already told you im alot of high output systems, s/n ratio as well as channel spereation CAN be distungished, even under clipping..

And I can tell you elephants can fly. So what?

Of course SNR and channel separation can be distinguished at a certain level of inadequacy.....but I've yet to see any conclusive evidence that either of these measurements cause any audible difference once they outside the range of audibility (as they are in most any competently designed amplifier these days). Is a SNR of 110db going to sound better than a SNR of 90db? I've yet to see any evidence to support that it does. To the contrary, in fact.

And really, it doesn't make sense that SNR would be more noticeable in a high powered system since SNR would improve as power input increased. If two amplifiers both have the same noise floor, we test one at 1w and one at 100w....the amplifier outputting 100w would have a higher SNR.

he bypasses the internal xovers etc...

The challenge is intentionally not designed to test this. If you understand the test, you'll understand why. Not to mention the difficulty in such a comparison given the wide variety of filter types.

But if amp A has a crossover section much better suited to your needs than amp B....then that is certainly a valid reason for choosing amp A. I don't think anyone would disagree with you there.

 

[Grinder1989 5,000+ posts]

High quality comes from the build of the amp, components used and whether the amp does it's rated power. They all sound the same. RF has a longggg history of building reliable amps that last for a very long time. Look at some of the reviews that were done on the RF T600-2, T1000-4 and T2500-1BD. If you have never used any of the current RF Power series amps for any amount of time then your opinions are not valid.//content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

The new rockford amps are built well in my opinion, however, the drive circuitry sucks and they use junk parts. Now if the circuitry was improved and the parts were replaced with good parts, they wouldn't be so bad. RF and MTX are not high quality amps.