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This is my subjective review.

This is a cheap amp! I think I got mine for under $200 new about 6 months ago. I've had it in mi car since. This amp is driving a set of IA C6 and a pair of SWR-T12's active.

I have used another NVX amp in the past and I had a terrible time with the volume knob being an all or nothing kind of deal. I was told that my gains may have been setup too high, which could be the case. For this amp I am NOT using the bass knob as I have no need for it, I control the sub level through my processor and I am not experiencing this issue.

For being a cheap amp it has worked non stop for six months with absolutely no issues. No noises, no weird stuff at all.

Does it have enough power? That is subjective. To give you and Idea, I drive a car with a V8 engine and an aftermarket muffler, so it is louder than stock. In a highway I can listen to music and totally drown out the muffler at about half volume. So there is a lot of room to get louder. I like my music loud and this amp has power to spare. Some people are concerned about the sub channel not being able to power up subs, not an issue with this amp. I have my gains at just over half and there is plenty of power to shake my rear view mirror. I like my tunes a bit bassy and this amp has no problems.

The amp does not get too hot at all, you can drive it hard for a long time and it will only be a little warm.

Footprint is not the smallest of them all, but it isn't that big either. It can easily fit under the seat of a car.

This amp sounds just as good as other amps I've had in the past. I can tell that when compared to my xtant amps (604x and 1001x, these are the older ones) it has less power. The xtants were very powerful amps. This little amp has just about the same power as my DLS Ultimate A4 and A6. These DLS were big and have just about the same power to my ears. This amp is also more powerful than my Helix Ultimate B2/B4 combo. But I may eventually revert back to the Helix only because they are sexier. This amp is just a black box, nothing pretty about it but it gets the job done.

As far as sound quality goes, I don't know. I honestly can't tell which amp I have owned sounds better than the others. when it comes to tuning my system, this amp will play what ask it to play. Want strong bass? I get strong bass. Want bright highs, I get it. I recently posted a review of the Carbon C6 and the listening was done with this amp. Can this amp play clean and loud? Yes, it can.

Would I recommend this amp? Sure. I think it is awesome bang for the buck and it gets the job done very well.
 

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Nce review. Ive literally owned 10 different 5- channel amp over the past 8 years, because I love the idea of 1-amp active solutions. Its just so clean and simple.
 

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Which one is ya fav?
I have used a bunch of different ones. I'll do my best to run down the good and the bad. Overall, I'd take the NVX over the others, as long as I had a clean unbalanced signal to feed it. I recently bought a new Tundra and want to retain the Factory HU. Unfortunately, if I tap the signal before the factory amp, it's balanced and the NVX won't accept balanced inputs. So my NVX is available if anyone's looking for a great 5-channel.

Best Overall - NVX JAD900.5
~Has adequate 3-way crossovers to take a 2-channel input and give you really any low-pass, band-pass, and high-pass you'd want in a vehicle. I've ran sub/mid/tweet -and- sub/mid-bass/wide-band on this amp with great success. Also has a subsonic filter, which is a must if you use ported subs.

Runner-up - TIE-JL Audio XD1000/5v2 & XD700/5v2
~They have adequate 3-way crossovers to take a 2-channel input and give you really any low-pass, band-pass, and high-pass you'd want in a vehicle. I've ran sub/mid/tweet -and- sub/mid-bass/wide-band on each of these amps with great success. No subsonis filter, but the JL's will accept balanced differential inputs, while the NVX only accepts unbalanced inputs.

Best sounding - Zuki Hybrid 5-Channel
~Some will debate that all amps sound the same. All I can say is that my truck never sounded so musical. Not a flexible crossover, so as long as you have external processing you should be good.

Others used:
JBL GTO-5EZ ~ Lots of clean power, not a flexible crossover.
JL Audio HD900/5 ~ Lots of clean power, not a flexible crossover.
JL Audio 500/5 ~ Not enough power on sub, big, but old & sexy.
Audison SR5 ~ Not enough power, somewhat flexible crossover, complicated setup.
Alpine MRV-75 ~ Not enough power, not a flexible crossover.
Alpine PDX-5 ~ Had some noise issues, snap, crackle, pop!
US Amps AX5600 ~ Never worked correctly.
 

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I have used a bunch of different ones. I'll do my best to run down the good and the bad. Overall, I'd take the NVX over the others, as long as I had a clean unbalanced signal to feed it. I recently bought a new Tundra and want to retain the Factory HU. Unfortunately, if I tap the signal before the factory amp, it's balanced and the NVX won't accept balanced inputs. So my NVX is available if anyone's looking for a great 5-channel.

Best Overall - NVX JAD900.5
~Has adequate 3-way crossovers to take a 2-channel input and give you really any low-pass, band-pass, and high-pass you'd want in a vehicle. I've ran sub/mid/tweet -and- sub/mid-bass/wide-band on this amp with great success. Also has a subsonic filter, which is a must if you use ported subs.

Runner-up - TIE-JL Audio XD1000/5v2 & XD700/5v2
~They have adequate 3-way crossovers to take a 2-channel input and give you really any low-pass, band-pass, and high-pass you'd want in a vehicle. I've ran sub/mid/tweet -and- sub/mid-bass/wide-band on each of these amps with great success. No subsonis filter, but the JL's will accept balanced differential inputs, while the NVX only accepts unbalanced inputs.

Best sounding - Zuki Hybrid 5-Channel
~Some will debate that all amps sound the same. All I can say is that my truck never sounded so musical. Not a flexible crossover, so as long as you have external processing you should be good.

Others used:
JBL GTO-5EZ ~ Lots of clean power, not a flexible crossover.
JL Audio HD900/5 ~ Lots of clean power, not a flexible crossover.
JL Audio 500/5 ~ Not enough power on sub, big, but old & sexy.
Audison SR5 ~ Not enough power, somewhat flexible crossover, complicated setup.
Alpine MRV-75 ~ Not enough power, not a flexible crossover.
Alpine PDX-5 ~ Had some noise issues, snap, crackle, pop!
US Amps AX5600 ~ Never worked correctly.
I recently went with the JAD900.5 have not installed it because the speakers I want are on back order. I'm excited about this amp. All my processing will be from my Pioneer. I agree all amps don't sound the same by any means. People that try different combos in the same car and listen to the same songs can tell. I know one day I was at my friends house back about 10 years ago and had 2 Fosgate P3's, JL W6 10, 2 Pioneer 12's, 2 different Kenwood amps, 1 Fosgate amp and a few other things. It was a day I was just swapping stuff in and out playing with gains, EQ just to hear the differences in the same 2 or 3 songs. And everything was just different, at least to my ears. One setup could sound cleaner, one could get louder, so on and so on. So now that I'm older and been around the block, I try to be very critical of my buying decisions, especially on a budget going after a $225 amp rather than a high dollar $1000 amp.
 

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I have used (briefly) the Polk Audio variant of the NVX 5 channel reviewed here. The Polk's sub channel is stable to 1 ohm and supposedly produces 500 watts at that resistance. It was VERY powerful and compared to its NVX, SoundStream and PPI twins, its cosmetics are my favorite.
If I were to choose a single-amp solution and wanted to keep my budget around $250-$300 I would probably go with the Polk. If the budget were higher, I'd probably choose the JL Audio XD700/5.
Another option that I haven't yet heard might be the new JL Audio RD900/5.
 

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My system starts with a NVX JAD 900.5, which internal design and boards are shared by a number of companies, both big name, as well as private and not-so-big vendors. Upon receipt, I opened the case to examine components and solder quality, and found what is ever present in auto amps, and that is signal components, like op-amps and electrolytic caps of poor quality and inexpensive price, seriously degrading the ability of the amp to produce true high-quality sound. There is a HUGE difference between noise, and being-there type of reproduction. Loud isn't better. It's just noisy.

One of these in this amp, was the use of TI's TL072 op amps for all buffering and signal conditioning. This device, produced since the 70's was one of the first JFET op-amps widely used for high-impedance input circuits, and was quickly overshadowed by the NE5532 for audio usage. This $0.37 part is best used to control a variable speed motor, and not audio, since there are numerous selections of much better audio quality. With 18nV of noise, it produces a constant hiss that is audible in the output section. And while it's slew speed is 13V/us, which is considered tabletop radio quality, the most important factor of the TL072, is the phase shift over the audio spectrum, which changes more than 120 degrees over just a few octaves. In fact, when driven at modest voltages, it can change polarity, causing 180 degree cancellation of frequencies. (phase reversal) This is very bad for your audio, in fact, it's unacceptable. Needless to say, the bean-counters, who opted for least cost, gave it to us with no regard to what is given up in audio quality. This is indicative of all amps on the market today, even in the home audio arena. (My high-end Yamaha AVENTAGE RX-A2030 even suffered from this cost cutting oversight in using low-cost poor-performing op-amps)

So what I've done is to use TI's recommended replacement for input designs that have utilized JFET op-amps, like the TL072, using the Burr-Brown OPA-1642. This op-amp brings with it a number of really impressive performance upgrades. One, comparing it to the TL072, who's THD was 0.003%, with the new, gains me a very impressive 0.00005% total THD, with less than 1/4 of the noise. It's slew rate is almost double of that of the TL072, and gets into the 20V/us slew rate, which can handle complex audio without losing detail. It takes less current to run it, and makes a good drop in replacement without having to redesign the circuit. The real advantage to this change, comes from the most important factor, and that is phase. Your ears are incredibly sensitive to phase, and audio phase is one of the most important things in creating sinusoidal waves that sound "real". The OPA-1642 is phase stable (no shift) throughout the entire audio spectrum all the way up into the MHz range. The soundstage with the new op-amps is nothing short of incredible, and places it in a performance category with some of the finest home audio out there. Channel separation went from around 90dB of separation to almost 130dB, and CMRR went from -86dB to -128dB. Talk about now having an extremely quiet, and low distortion amp. Mono blocks don't perform better than this folks.

All of the signal electrolytic caps were replaced with ELNA's SILMIC II silks, which has become the defacto-standard of audio signal caps these days, and bring with them a very warm and inviting sound.

All of this was done with a little rework time and less than $50. Now, this $250 investment can rival performance of amps 10 times it's cost. The finest investment one can make in their car audio systems, is the attention to detail in the input section of their amplifier, and since all amps suffer this, is the first place to spend attention to really create a soundstage in your vehicle that will rival any out there. It's all about making a correctly phased and uncolored sinusoidal wave for your ear. The manufacturer's bean-counter ripped you off.
 

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I enjoy my Soundstream T5.2500DL 5-channel amp. It is huge, lots of crossover flexibility, 100AMP fuse.
 

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Discussion Starter #10
My system starts with a NVX JAD 900.5, which internal design and boards are shared by a number of companies, both big name, as well as private and not-so-big vendors. Upon receipt, I opened the case to examine components and solder quality, and found what is ever present in auto amps, and that is signal components, like op-amps and electrolytic caps of poor quality and inexpensive price, seriously degrading the ability of the amp to produce true high-quality sound. There is a HUGE difference between noise, and being-there type of reproduction. Loud isn't better. It's just noisy.

One of these in this amp, was the use of TI's TL072 op amps for all buffering and signal conditioning. This device, produced since the 70's was one of the first JFET op-amps widely used for high-impedance input circuits, and was quickly overshadowed by the NE5532 for audio usage. This $0.37 part is best used to control a variable speed motor, and not audio, since there are numerous selections of much better audio quality. With 18nV of noise, it produces a constant hiss that is audible in the output section. And while it's slew speed is 13V/us, which is considered tabletop radio quality, the most important factor of the TL072, is the phase shift over the audio spectrum, which changes more than 120 degrees over just a few octaves. In fact, when driven at modest voltages, it can change polarity, causing 180 degree cancellation of frequencies. (phase reversal) This is very bad for your audio, in fact, it's unacceptable. Needless to say, the bean-counters, who opted for least cost, gave it to us with no regard to what is given up in audio quality. This is indicative of all amps on the market today, even in the home audio arena. (My high-end Yamaha AVENTAGE RX-A2030 even suffered from this cost cutting oversight in using low-cost poor-performing op-amps)

So what I've done is to use TI's recommended replacement for input designs that have utilized JFET op-amps, like the TL072, using the Burr-Brown OPA-1642. This op-amp brings with it a number of really impressive performance upgrades. One, comparing it to the TL072, who's THD was 0.003%, with the new, gains me a very impressive 0.00005% total THD, with less than 1/4 of the noise. It's slew rate is almost double of that of the TL072, and gets into the 20V/us slew rate, which can handle complex audio without losing detail. It takes less current to run it, and makes a good drop in replacement without having to redesign the circuit. The real advantage to this change, comes from the most important factor, and that is phase. Your ears are incredibly sensitive to phase, and audio phase is one of the most important things in creating sinusoidal waves that sound "real". The OPA-1642 is phase stable (no shift) throughout the entire audio spectrum all the way up into the MHz range. The soundstage with the new op-amps is nothing short of incredible, and places it in a performance category with some of the finest home audio out there. Channel separation went from around 90dB of separation to almost 130dB, and CMRR went from -86dB to -128dB. Talk about now having an extremely quiet, and low distortion amp. Mono blocks don't perform better than this folks.

All of the signal electrolytic caps were replaced with ELNA's SILMIC II silks, which has become the defacto-standard of audio signal caps these days, and bring with them a very warm and inviting sound.

All of this was done with a little rework time and less than $50. Now, this $250 investment can rival performance of amps 10 times it's cost. The finest investment one can make in their car audio systems, is the attention to detail in the input section of their amplifier, and since all amps suffer this, is the first place to spend attention to really create a soundstage in your vehicle that will rival any out there. It's all about making a correctly phased and uncolored sinusoidal wave for your ear. The manufacturer's bean-counter ripped you off.
There is a niche business opportunity for you if you are interested. I would love to see some sort of AB comparison between the original amp and the one you modified.
 

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There is a niche business opportunity for you if you are interested. I would love to see some sort of AB comparison between the original amp and the one you modified.
I know that finding folks who do rework is rather far and few between. The investment in SMD rework equipment can be rather expensive.

I wouldn't mind seeing an A/B comparison and listening test, but I have the luxury of having listened myself. It does make a marked difference.
 

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My system starts with a NVX JAD 900.5, which internal design and boards are shared by a number of companies, both big name, as well as private and not-so-big vendors. Upon receipt, I opened the case to examine components and solder quality, and found what is ever present in auto amps, and that is signal components, like op-amps and electrolytic caps of poor quality and inexpensive price, seriously degrading the ability of the amp to produce true high-quality sound. There is a HUGE difference between noise, and being-there type of reproduction. Loud isn't better. It's just noisy.

One of these in this amp, was the use of TI's TL072 op amps for all buffering and signal conditioning. This device, produced since the 70's was one of the first JFET op-amps widely used for high-impedance input circuits, and was quickly overshadowed by the NE5532 for audio usage. This $0.37 part is best used to control a variable speed motor, and not audio, since there are numerous selections of much better audio quality. With 18nV of noise, it produces a constant hiss that is audible in the output section. And while it's slew speed is 13V/us, which is considered tabletop radio quality, the most important factor of the TL072, is the phase shift over the audio spectrum, which changes more than 120 degrees over just a few octaves. In fact, when driven at modest voltages, it can change polarity, causing 180 degree cancellation of frequencies. (phase reversal) This is very bad for your audio, in fact, it's unacceptable. Needless to say, the bean-counters, who opted for least cost, gave it to us with no regard to what is given up in audio quality. This is indicative of all amps on the market today, even in the home audio arena. (My high-end Yamaha AVENTAGE RX-A2030 even suffered from this cost cutting oversight in using low-cost poor-performing op-amps)

So what I've done is to use TI's recommended replacement for input designs that have utilized JFET op-amps, like the TL072, using the Burr-Brown OPA-1642. This op-amp brings with it a number of really impressive performance upgrades. One, comparing it to the TL072, who's THD was 0.003%, with the new, gains me a very impressive 0.00005% total THD, with less than 1/4 of the noise. It's slew rate is almost double of that of the TL072, and gets into the 20V/us slew rate, which can handle complex audio without losing detail. It takes less current to run it, and makes a good drop in replacement without having to redesign the circuit. The real advantage to this change, comes from the most important factor, and that is phase. Your ears are incredibly sensitive to phase, and audio phase is one of the most important things in creating sinusoidal waves that sound "real". The OPA-1642 is phase stable (no shift) throughout the entire audio spectrum all the way up into the MHz range. The soundstage with the new op-amps is nothing short of incredible, and places it in a performance category with some of the finest home audio out there. Channel separation went from around 90dB of separation to almost 130dB, and CMRR went from -86dB to -128dB. Talk about now having an extremely quiet, and low distortion amp. Mono blocks don't perform better than this folks.

All of the signal electrolytic caps were replaced with ELNA's SILMIC II silks, which has become the defacto-standard of audio signal caps these days, and bring with them a very warm and inviting sound.

All of this was done with a little rework time and less than $50. Now, this $250 investment can rival performance of amps 10 times it's cost. The finest investment one can make in their car audio systems, is the attention to detail in the input section of their amplifier, and since all amps suffer this, is the first place to spend attention to really create a soundstage in your vehicle that will rival any out there. It's all about making a correctly phased and uncolored sinusoidal wave for your ear. The manufacturer's bean-counter ripped you off.
I agree with everything said here. front stage is what creates amplifier sound signature.
 

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So...if I was to purchase a pair of these amps...who would I go to have the upgrades done? I agree with what was said but I don't have the connections to have it done.
 

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So...if I was to purchase a pair of these amps...who would I go to have the upgrades done? I agree with what was said but I don't have the connections to have it done.
Well, finding a repair shop isn't all that hard. (Google is your friend) There are numerous facilities across the nation who can do repair/mods to car audio amps. You obviously would have to see if they work with surface mount, (which most do) describe what you are looking to do, and then negotiate a price.
 

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My only concern with this amp is can it really power a SQ sub like a IDQ12 or Dayton HO 12. Anyone have opinions and ran it on 1 of those subs or something similar
 

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I just ordered one of these for my son's car (97 Miata). It's replacing 2 old school Rockford amps. I'll report back once i get it installed!
 

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So...if I was to purchase a pair of these amps...who would I go to have the upgrades done? I agree with what was said but I don't have the connections to have it done.
Well, finding a repair shop isn't all that hard. (Google is your friend) There are numerous facilities across the nation who can do repair/mods to car audio amps. You obviously would have to see if they work with surface mount, (which most do) describe what you are looking to do, and then negotiate a price.
Did you do the work yourself or have someone do it for you? Where would one buy the replacement parts?

I just purchased the JAD800.4 & JAD1200.1 a few days ago and would be willing to pay if it makes the difference as stated.
 

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I would look for a shop but I would need a break down of everything that was suggested and the part numbers. I swear I'd buy a pair of these 5 channel and call it a day. Also Deltab I would some gut shots of your modified amp. This is something I'm really considering.
 

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Did you do the work yourself or have someone do it for you? Where would one buy the replacement parts?

I just purchased the JAD800.4 & JAD1200.1 a few days ago and would be willing to pay if it makes the difference as stated.
Answering the question of doing it myself, yes, I do my own work. And while there are various sources for parts, I use Mouser when I can. This is the device that I chose for this project and can be purchased in quantities as small as 1. For this project I purchased 10, which is roughly $30 for the op-amps.

http://www.mouser.com/ProductDetail/Texas-Instruments/OPA1642AIDR/?qs=sGAEpiMZZMtxdzBvM0rKcTv7Ysc73uR4Hw9tGvON1jU%3d

This is the most important component, since TL072's should never have been chosen and has no place in audio amps, especially for low frequency. The capacitors are a personal choice from my own personal experience, and also a very worthwhile part of this upgrade recommendation. All signal caps which the actual analogue signal passes is the object of attention. Various capacitance is used, but the most frequent one you'll need is 10uF and don't use less than 16v rating in the signal path. They will run you about 0.20~0.30 USD each, depending on quantity you purchase.

http://www.mouser.com/ProductDetail/Elna/RFS-35V100ME35/?qs=sGAEpiMZZMtZ1n0r9vR22Vaq1AHMe%252bCMT8zUcxzUcsM%3d

If I didn't use ELNA SilMic II, I would choose Nichicon Muse. Both specifically designed for audio usage, and it shows when used compared to the originals.

For me, audio sound quality has always been the primary focus when selecting components to be used in my projects, and for a Class D auto audio amp, this platform is a pretty good start. The power supply section is adequate, the gate driver and MOSFET output section is well thought out and a viable platform to really enjoy some great sound from your vehicle. Overall, I'm very pleased with this upgraded choice to my XJ8 sound system.
 

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I wonder if the Hertz version of this amp has the upgraded caps and op amps.
 
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