Help me find my next amp for my newly adapted "scientific mind-set"

[SuicideSquid]

Hi Folks. I’m planning to upgrade my amplifier with my newly adopted “scientific” perspective.
Please first let me know if I understand this mindset correctly, and then help me choose an appropriate amp.

What this “scientific mindset” means to me is that instead of going after amps with warm, bright, good soundstage, bad soundstage with different “sound signature”, and still be worried about whether they would match my speakers; I choose a good solid, natural amp (with acceptable measurement) and then add my own EQ. This way any amp would match any speaker by tweaking EQ, hence, I make it warm, bright, wider soundstage, narrower soundstage, etc to my liking! Do I get this concept right?

If this assumption is correct then, let me find the best possible amp (before hitting the diminishing return)

My setup is as follows:

- Bluesound Node as Streamer
- RME ADI-2 as an EQ and Preamp
- Yamaha Integrated Amp (NR602) that will be replaced by the new amp
- KEF LS50 as speakers
- KEF Q400b as Sub

A few criteria:

- I don’t want to get into DIY, at this time, and prefer a commercially made reputable, solid, brand that hopefully has good residual value
- I have the following floor speakers in my pipe-line (B&W 702 S2, 803 D4, KEF Reference 3), so the amp should be capable of handling it on its own, or alternatively can be bridged with its sibling (when I upgraded the speakers) to function as a mono-block.
- My speakers said it to be non-efficient so, I was told that I should get a with high current. How can I determine that an amp has a high current?
- I live in Canada

A few uncertainties:
- If I use RME ADI-2 as my pre-amp can I get the most of my amp quality? Or do I lose in quality in compassion by adding another pre-amp? (I only stream so I don’t need phono, line in, etc)
- can I connect my sub to the amp if the amp doesn’t have sub input? In that case, is it safe to do so?
- based on the abuse mindset can I be sure no matter what amp I get, as long as it meets the measurement criteria, will sound good to my speaker just after tweaking the EQ, so I could buy it without even auditioning it?
- do you think this upgrade would have a noticeable impact, as compared to my current amp?

Candidates:

To the best of my research, my good candidate here is NAD C298. People in this forum talk about it. They say it has Purifi, and I suppose it should sound good, I don’t know much about this. Another alternative is Benchmark, or PS Audio?

I don’t want to overspend but I can go as high as needed to get something “for life”

I’m open to your suggestions and perspective.

If you're also considering a speaker upgrade, forgo the amp entirely and buy active speakers.

In a small or medium-sized room, my $1500 Dynaudio Lyd-7 active speakers give my $4,000 Totem Forests connected to $3,000 in amplification a run for their money, at 1/4 the cost. Neumann KH-310 speakers are the best I've ever heard. You can get them for about $5,000 for a pair at Long & McQuade in Canada - a lot less than you'd pay for that NAD amplifier and a pair of B&W floorstanding speakers - and they'll mop the floor with the B&Ws in every respect except maybe maximum output.

 

[TurtlePaul]

Certainly, I will try that. I never thought of this before. Could you briefly tell me what happens in the Pure Direct? Do you think in that case the quality I get can get close to a good amp such as C298?

Pure direct mode connects the analog inputs directly to the amplifier section with only the volume control in the circuit. Without pure direct enabled, the signal goes through all of the tone control circuits and may be converted from analog to digital and back again. In pure direct mode, you lose a lot of the features, but it is a perfectly good amp - albeit less powerful and less clean than the purifi amps you are discussing. I would mention that although the Yamaha amp is less clean, it has an order of magnitude less distortion than even the world's best low distortion speakers.

edit: Regarding pure direct mode vs. the Purifi, pure direct mode will measure much better than with it disabled, but there will still be measurable differences vs. a Purifi Class D amp. Just because we can measure something doesn't mean we can hear it. Enabling pure direct mode on the Yamaha will get you most of the way to a transparent amp. See if you can hear the difference between pure direct on and off. The difference between R-N602 pure direct on and an Purifi amp will be much less than the difference between pure direct on and off. Of course, the biggest difference will be that the R-N602 is basically a 100 watt amp ito 4 or 8 ohms which the NAD is 185 watts into 8 ohm and 340 watts into 4 ohm. Only you know if you will need more than 100 watts of power, which can drive most speakers with average sensitivity and reactance very very loud in normal rooms.

 

[Mehdiem]

If you're also considering a speaker upgrade, forgo the amp entirely and buy active speakers.

In a small or medium-sized room, my $1500 Dynaudio Lyd-7 active speakers give my $4,000 Totem Forests connected to $3,000 in amplification a run for their money, at 1/4 the cost. Neumann KH-310 speakers are the best I've ever heard. You can get them for about $5,000 for a pair at Long & McQuade in Canada - a lot less than you'd pay for that NAD amplifier and a pair of B&W floorstanding speakers - and they'll mop the floor with the B&Ws in every respect except maybe maximum output.

Interesting view, I had never taken active speakers seriously for my music listening, although I have good active monitors (Adam-T7) for playing instruments, they are too directional.

 

[SuicideSquid]

Interesting view, I had never taken active speakers seriously for my music listening, although I have good active monitors (Adam-T7) for playing instruments, they are too directional.

Depends on the speakers and the room - I wouldn't use them in a large room, but in a small- or medium-sized listening space, if I were building a stereo system from scratch I'd take Dynaudio or Neumann monitors over just about anything.

Adam T7's are decent speakers but they're fairly entry-level. There's a big jump in quality moving to something like a Dynaudio Lyd-7 or Mackie HR624mkii - check those out if you have a chance.

 

[ahofer]

Hi Folks. I’m planning to upgrade my amplifier with my newly adopted “scientific” perspective.
Please first let me know if I understand this mindset correctly, and then help me choose an appropriate amp.

What this “scientific mindset” means to me is that instead of going after amps with warm, bright, good soundstage, bad soundstage with different “sound signature”, and still be worried about whether they would match my speakers; I choose a good solid, natural amp (with acceptable measurement) and then add my own EQ. This way any amp would match any speaker by tweaking EQ, hence, I make it warm, bright, wider soundstage, narrower soundstage, etc to my liking! Do I get this concept right?

If this assumption is correct then, let me find the best possible amp (before hitting the diminishing return)

My setup is as follows:

- Bluesound Node as Streamer
- RME ADI-2 as an EQ and Preamp
- Yamaha Integrated Amp (NR602) that will be replaced by the new amp
- KEF LS50 as speakers
- KEF Q400b as Sub

A few criteria:

- I don’t want to get into DIY, at this time, and prefer a commercially made reputable, solid, brand that hopefully has good residual value
- I have the following floor speakers in my pipe-line (B&W 702 S2, 803 D4, KEF Reference 3), so the amp should be capable of handling it on its own, or alternatively can be bridged with its sibling (when I upgraded the speakers) to function as a mono-block.
- My speakers said it to be non-efficient so, I was told that I should get a with high current. How can I determine that an amp has a high current?
- I live in Canada

A few uncertainties:
- If I use RME ADI-2 as my pre-amp can I get the most of my amp quality? Or do I lose in quality in compassion by adding another pre-amp? (I only stream so I don’t need phono, line in, etc)
- can I connect my sub to the amp if the amp doesn’t have sub input? In that case, is it safe to do so?
- based on the abuse mindset can I be sure no matter what amp I get, as long as it meets the measurement criteria, will sound good to my speaker just after tweaking the EQ, so I could buy it without even auditioning it?
- do you think this upgrade would have a noticeable impact, as compared to my current amp?

Candidates:

To the best of my research, my good candidate here is NAD C298. People in this forum talk about it. They say it has Purifi, and I suppose it should sound good, I don’t know much about this. Another alternative is Benchmark, or PS Audio?

I don’t want to overspend but I can go as high as needed to get something “for life”

I’m open to your suggestions and perspective.

Is it possible that the “scientific” solution here is to not spend money on a new amp? What’s driving the upgrade desire.

For attractively priced Class D, I bought March Audio. Never looked back. Last amp was a 300W monster Nelson Pass design (Adcom).

 

[Mehdiem]

Pure direct mode connects the analog inputs directly to the amplifier section with only the volume control in the circuit. Without pure direct enabled, the signal goes through all of the tone control circuits and may be converted from analog to digital and back again. In pure direct mode, you lose a lot of the features, but it is a perfectly good amp - albeit less powerful and less clean than the purifi amps you are discussing. I would mention that although the Yamaha amp is less clean, it has an order of magnitude less distortion than even the world's best low distortion speakers.

edit: Regarding pure direct mode vs. the Purifi, pure direct mode will measure much better than with it disabled, but there will still be measurable differences vs. a Purifi Class D amp. Just because we can measure something doesn't mean we can hear it. Enabling pure direct mode on the Yamaha will get you most of the way to a transparent amp. See if you can hear the difference between pure direct on and off. The difference between R-N602 pure direct on and an Purifi amp will be much less than the difference between pure direct on and off. Of course, the biggest difference will be that the R-N602 is basically a 100 watt amp ito 4 or 8 ohms which the NAD is 185 watts into 8 ohm and 340 watts into 4 ohm. Only you know if you will need more than 100 watts of power, which can drive most speakers with average sensitivity and reactance very very loud in normal rooms.

Wow! That's comforting! I have already put it on Pure Direct, though I haven't done the A/B testing yet, I'm certain that I will make a difference due to bypassing the tone control board. This is really good. I underestimated this amp. You are right. I would listen to this a few days (since I just got my RME last week). Meanwhile, I will make up my mind to see if the upgrade worth it.


"Only you know if you will need more than 100 watts of power"

I don't often listen to loud music, the only question is whether more power will result in less distortion given the same level of output at higher levels.

For example with my current setup: Yamaha, Pure Direct @ 0 dB, RME max volume that I can listen to would go up -18 dB (I normally listen around -25db). Now at -18dB listening to Diana Krall - Wonderful, I hear an annoying sound not as clean and precise as what I can get at lower levels, however, when I lower the RME to -28dB I have the sweet spot of clarity. So, I'm wondering with C298 can I have the same clarity of -28dB at 18dB?

 

[Mehdiem]

Is it possible that the “scientific” solution here is to not spend money on a new amp? What’s driving the upgrade desire.

For attractively priced Class D, I bought March Audio. Never looked back. Last amp was a 300W monster Nelson Pass design (Adcom).

Is it possible that the “scientific” solution here is to not spend money on a new amp? What’s driving the upgrade desire.

Lool. Of course. That's why I'm here. Even though it would go against my mind-biases, I can accept and make decisions based on quant.

My main motivation for upgrading is to get the same clarify at higher volumes -18 vs. -28dB as I mentioned in the prior comment

 

[Mehdiem]

Depends on the speakers and the room - I wouldn't use them in a large room, but in a small- or medium-sized listening space, if I were building a stereo system from scratch I'd take Dynaudio or Neumann monitors over just about anything.

Adam T7's are decent speakers but they're fairly entry-level. There's a big jump in quality moving to something like a Dynaudio Lyd-7 or Mackie HR624mkii - check those out if you have a chance.

I live in a large basement. So, the room creates issues of its own.

 

[SuicideSquid]

"Only you know if you will need more than 100 watts of power"

I don't often listen to loud music, the only question is whether more power will result

Wow! That's comforting! I have already put it on Pure Direct, though I haven't done the A/B testing yet, I'm certain that I will make a difference due to bypassing the tone control board. This is really good. I underestimated this amp. You are right. I would listen to this a few days (since I just got my RME last week). Meanwhile, I will make up my mind to see if the upgrade worth it.


"Only you know if you will need more than 100 watts of power"

I don't often listen to loud music, the only question is whether more power will result in less distortion given the same level of output at higher levels.

For example with my current setup: Yamaha, Pure Direct @ 0 dB, RME max volume that I can listen to would go up -18 dB (I normally listen around -25db). Now at -18dB listening to Diana Krall - Wonderful, I hear an annoying sound not as clean and precise as what I can get at lower levels, however, when I lower the RME to -28dB I have the sweet spot of clarity. So, I'm wondering with C298 can I have the same clarity of -28dB at 18dB?

Out of curiousity, have you taken steps to ensure the "annoying sound" you're hearing is coming from your sound system and not your room?

[edit] You beat me to the punch!

Were I in your shoes the first thing I'd do is invest in a few diffusers and absorbers and place them strategically around the room. In the space you're in I'd put money on that make a *far* bigger impact on sound quality that upgrading your amplifier, or potentially even your speakers, will.

 

[TurtlePaul]

It looks like you sit a decent distance away from the speakers. I wouldnt be surprised if the LS50s were reaching their limits at those volumes. I would add that to the list of possible causes of the congestion at -18 dB. Amir measured those and the low frequency distortion was starting to rise at 86 dB @ 1 meter and you are probably listening louder than that (I think you are sitting ~ 3-4 meters).

Off topic room advice:
- Make you speakers wider apart if possible ( I would switch the right speaker with the sub)
- Pull your speakers away from the wall a little more if you can
- Your sub can go 2-3 inches from the wall and doesnt need to be pointed at you / toed in.

 

[Mehdiem]

Out of curiousity, have you taken steps to ensure the "annoying sound" you're hearing is coming from your sound system and not your room?

[edit] You beat me to the punch!

Were I in your shoes the first thing I'd do is invest in a few diffusers and absorbers and place them strategically around the room. In the space you're in I'd put money on that make a *far* bigger impact on sound quality that upgrading your amplifier, or potentially even your speakers, will.

This annoying sound that I'm talking about is more perceived as "distortion", "congestion", etc. so I thought other sound issues such as humming, ambiguity, lack of bass tightness, could be the room issue. So do you think room could cause "distortion" as well?

Nevertheless less, I will pursue room treatment. I was planning to perform REW and just need to find a good mix to buy. Do you have any resource or link that shows me step by step guide for this particular treatment that you noted? I'm a bit clueless on what to buy, where to buy it, where to position it

 

[Mehdiem]

It looks like you sit a decent distance away from the speakers. I wouldnt be surprised if the LS50s were reaching their limits at those volumes. I would add that to the list of possible causes of the congestion at -18 dB. Amir measured those and the low frequency distortion was starting to rise at 86 dB @ 1 meter and you are probably listening louder than that (I think you are sitting ~ 3-4 meters).

Off topic room advice:
- Make you speakers wider apart if possible ( I would switch the right speaker with the sub)
- Pull your speakers away from the wall a little more if you can
- Your sub can go 2-3 inches from the wall and doesnt need to be pointed at you / toed in.

That's ingesting. This was the isssue that I never thought about. It make a lot of sense to me now, that I'm expecting more that what Ls50 could deliver! Practicality in such a big room.

As for speaker placement. You are right, when I put them closer to me, I have a better experience. I will try this again tonight.

As for the distance between speakers, my current setting makes a triangle, so if I move them further apart, there won't be a triangle anymore. Wouldn't this defeat the purpose? Or triangle doesn't matter?

 

[SuicideSquid]

This annoying sound that I'm talking about is more perceived as "distortion", "congestion", etc. so I thought other sound issues such as humming, ambiguity, lack of bass tightness, could be the room issue. So do you think room could cause "distortion" as well?

Nevertheless less, I will pursue room treatment. I was planning to perform REW and just need to find a good mix to buy. Do you have any resource or link that shows me step by step guide for this particular treatment that you noted? I'm a bit clueless on what to buy, where to buy it, where to position it

There's a whole sub-forum here on room treatment - definitely troll through there!

 

[phoenixdogfan]

I live in Canada. I can get C298 at 16% discount from its Canadian price (on top of that CAD$ is cheaper than USD$). Having said that, do you think VTV Purifi is superior to NAD C298? There is no review of C298 from Amir. I see that some people objected to the Audiophile review of C298. Also, I see some people being worried about "continues gain control" as opposed to fixed gain control on M23, which might cause an imbalance. Honesty, I don't understand the technical language (neither understand how this possible shortcoming might impact me?) so I am lost.

I am just going by Amir's reviews of amps using the Purifi amp board. A number of OEM companies like NAD are implementing their own buffer board using "upgrades" like the Sparkos op-amps. In almost every review these higher priced (in many cases far higher priced) exhibit inferior measured performance. I don't know (and I highly doubt) I could distinguish the better sounding Purifi version in a double blind listening test, But even so, why should I or anyone pay more than what VTV demands when their amp exhibits the second lowest measured noise and distortion of anything that's ever been measured--especially when it's not even reasonable to believe that better measured performance than that version will be audibly superior?

 

[TurtlePaul]

As for the distance between speakers, my current setting makes a triangle, so if I move them further apart, there won't be a triangle anymore. Wouldn't this defeat the purpose? Or triangle doesn't matter?

If it is an equilateral triangle you are good. I was just going off the photo and cameras can be deceptive.

 

[Mehdiem]

If it is an equilateral triangle you are good. I was just going off the photo and cameras can be deceptive.

Speaker to speaker 2.55-meter speaker to me 2.65 meter. Speaker to wall 30 inches I moved my sub closer to the wall now. Is this good or should bring them closer to me and reduce the overall triangle?

 

[TurtlePaul]

Speaker to speaker 2.55-meter speaker to me 2.65 meter. Speaker to wall 30 inches I moved my sub closer to the wall now. Is this good or should bring them closer to me and reduce the overall triangle?

What matters is the distance of the front (the drivers) of the main speakers to the wall. The sound waves coming out of the speaker will bounce off the wall behind them and they at certain frequencies that bounce will partially cancel the direct sound.

The further you pull out the speakers out from the wall the less the cancelation will be and the lower the frequency of the cancelation. Pull them out far enough and the cancelation will be at a frequency which is handled by the sub.

The closer the sub is to the wall, the higher frequency of the cancelation, if it is right near the wall it should be at a frequency above the subs range (handled by the mains).

You speaker spacing is fine, the photo is wider than what I expected.

 

[Mehdiem]

What matters is the distance of the front (the drivers) of the main speakers to the wall. The sound waves coming out of the speaker will bounce off the wall behind them and they at certain frequencies that bounce will partially cancel the direct sound.

The further you pull out the speakers out from the wall the less the cancelation will be and the lower the frequency of the cancelation. Pull them out far enough and the cancelation will be at a frequency which is handled by the sub.

The closer the sub is to the wall, the higher frequency of the cancelation, if it is right near the wall it should be at a frequency above the subs range (handled by the mains).

Your speaker spacing is fine, the photo is wider than what I expected.

Your speaker spacing is fine, the photo is wider than what I expected.

You are right, I used a wide camera setting on my iPhone.

Can you take a look at sub placement to see if it is better now? It's not pointing at me at all. (The picture is standard) the center of the sub is almost 150" away from the center where I sit.

Also, do you mind taking a look at my sub-setting? Can I do any better with the setting?

Another question: I have a choice to connect the sub directly to Bluesound Node, as opposed to the amp. Do I get any benefit from doing that?

 

[Mehdiem]

I am just going by Amir's reviews of amps using the Purifi amp board. A number of OEM companies like NAD are implementing their own buffer board using "upgrades" like the Sparkos op-amps. In almost every review these higher priced (in many cases far higher priced) exhibit inferior measured performance. I don't know (and I highly doubt) I could distinguish the better sounding Purifi version in a double blind listening test, But even so, why should I or anyone pay more than what VTV demands when their amp exhibits the second lowest measured noise and distortion of anything that's ever been measured--especially when it's not even reasonable to believe that better measured performance than that version will be audibly superior?

I hear you. I agree that if the quality of both is at par, it doesn't make sense to overpay for brand name premium if the difference I price is considerable. However, if the difference is less significant I feel differently. For example, VTV + trigger + shipping cost me $1,650 CAD, on the other hand, I can get the C298 for $2,400. I feel comfortable paying this premium ($750) knowing that I get a nicer casing, and good residual value, anytime I decide to sell, I can instantly sell it. Now, the only thing stopping me to do that is that if I know that I pay the premium for NAD and I still get less quality (as compared to VTV)

 

[TurtlePaul]

Can you take a look at sub placement to see if it is better now? It's not pointing at me at all. (The picture is standard) the center of the sub is almost 150" away from the center where I sit.

Also, do you mind taking a look at my sub-setting? Can I do any better with the setting?

Another question: I have a choice to connect the sub directly to Bluesound Node, as opposed to the amp. Do I get any benefit from doing that?

Sub placement looks good (if it sounds good). I would tinker with setting the crossover frequency between 60 hz and 70 hz because I suspect there will be a dip in response due to how low the LS50s can go. It is hard to give advice because ultimately room interactions dominate bass response so the optimal subwoofer settings and placement vary room to room.

If you want to go down the sub optimization rabbit hole, you can get a UMIK-1 to measure your bass response and flatten the frequency response with the parametric EQ filters which are available in the ADI-2.

I don't think that you would note much difference connecting the sub to a different device, do whatever works for you.