March P452 eta

[Deleted member 23424]

Mmm, let me think about it

Apollon?

OK then Mr Boxem. Talk to me.
I'm sure I looked and yours were out of my price range.

I'm using a Topping D90 at one end and Revel M16 at the other. If you've any other options to recommend I'll gladly take a look.

 

[peng]

If I'm honest, this is precisely where I started out. Topping D90 at one end and Revel M16 at t'other is hardly high end, though decent enough, and I question whether or not I need to up things to Purifi. But... having no chance of home demo I'll forever be thinking to myself.... what if?

As bollocks as it has been having dealers peddle their sales targets at everyone who walks through their doors, rather than source the best components for their customers (not ALL shops, I know, but most) this alternative that we're all building on here makes demoes even harder to come by. Not complaining btw, at least now I know that the expensive amp I'm risking testicular castration for is decent and not an absolute donkey. But still the can i appreciate the difference between X and Y via my rig will forever have me looking at possibly unnecessary upgrades.

This is a real problem for people who are not confident with even the most comprehensive bench test results found on ASR, Stereophile, AH, and HTHF. Even if you can find dealers willing to let you compare products in your own home, unless you can do a real apple to apple test, and in DBT or at least SBT, it will be tough to rely on your perceived result to make an informed decision.

One possible solution to this may be for dealers to set up a demo room that is designed for serious shoppers to do a controlled DBT session in which the listener will control the switching between 2 to 3 amps of the listeners choice, pre-wires and level matched to within 0.5 dB. I highly doubt any dealer would be willing to do such a thing, probably not if the listener's choice of amps are in the under $3,000 range. For higher end (based on profit margin) amps, they may consider such a thing if the listener would guarantee purchase of at least one of the amp they compared, regardless of their DBT results.

For people like me who do trust specs and measurements, but not someone else ears, then it is not an issue at all. I would just go with that and may also consider predicted reliability and the physical features, and then price, obviously.

 

[Deleted member 23424]

This is a real problem for people who are not confident with even the most comprehensive bench test results found on ASR, Stereophile, AH, and HTHF. Even if you can find dealers willing to let you compare products in your own home, unless you can do a real apple to apple test, and in DBT or at least SBT, it will be tough to rely on your perceived result to make an informed decision.

One possible solution to this may be for dealers to set up a demo room that is designed for serious shoppers to do a controlled DBT session in which the listener will control the switching between 2 to 3 amps of the listeners choice, pre-wires and level matched to within 0.5 dB. I highly doubt any dealer would be willing to do such a thing, probably not if the listener's choice of amps are in the under $3,000 range. For higher end (based on profit margin) amps, they may consider such a thing if the listener would guarantee purchase of at least one of the amp they compared, regardless of their DBT results.

For people like me who do trust specs and measurements, but not someone else ears, then it is not an issue at all. I would just go with that and may also consider predicted reliability and the physical features, and then price, obviously.

I'm not an electrician, let alone an Audio engineer, so much of the test results whoosh over my head. But I've learnt enough over the years to claw my way around and spot the good from the bad.

My issue is things like the below that someone posted earlier in this thread. Do I read that the Hypex closely matches the Purifi and my ears won't tell the difference? Or do I read that the non linear end brings audible differences that are worth paying the extra for?

Understanding the test results is one thing, placing that into a practical, real world usage scenario is quite another, for me.

I'd love to hear a Purifi next to, say, a Nc502, just to confirm that I can, or can't, discern enough difference to justify doubling the cost. But as that's not likely to happen I'm erring towards the better safe than sorry Purifi.

 

[Phorize]

This is a real problem for people who are not confident with even the most comprehensive bench test results found on ASR, Stereophile, AH, and HTHF. Even if you can find dealers willing to let you compare products in your own home, unless you can do a real apple to apple test, and in DBT or at least SBT, it will be tough to rely on your perceived result to make an informed decision.

One possible solution to this may be for dealers to set up a demo room that is designed for serious shoppers to do a controlled DBT session in which the listener will control the switching between 2 to 3 amps of the listeners choice, pre-wires and level matched to within 0.5 dB. I highly doubt any dealer would be willing to do such a thing, probably not if the listener's choice of amps are in the under $3,000 range. For higher end (based on profit margin) amps, they may consider such a thing if the listener would guarantee purchase of at least one of the amp they compared, regardless of their DBT results.

For people like me who do trust specs and measurements, but not someone else ears, then it is not an issue at all. I would just go with that and may also consider predicted reliability and the physical features, and then price, obviously.

This would be ideal for the small number of people that would be interested, and I would find it fun. The snag is that the cost per listening room hour would wipe out the seller margin. You’d need to be prepared to pay a lot more for the amp ultimately.

 

[peng]

This would be ideal for the small number of people that would be interested, and I would find it fun. The snag is that the cost per listening room hour would wipe out the seller margin. You’d need to be prepared to pay a lot more for the amp ultimately.

Fully agree, may be charge a fee, say $50/hour per person, 2 hours minimum, with a discount for 2 to 4 people and still sign a contract to purchase at least one amp. That's for dealers. If there are a few individual hobbyists within driving distance, they can share the cost to rig one up too I guess, if they are crazy enough.

 

[Amplifier dude]

I can tell a good Purifi implementation apart from an NC502MP amp blind 10 out of 10 times. In fact a group of buddies and I do this all the time when testing new amps. But you need to feed the Purifi modules direct from a high resolution DAC, bypassing any input buffer. Because most input buffers color the sound.

 

[Rottmannash]

I can tell a good Purifi implementation apart from an NC502MP amp blind 10 out of 10 times. In fact a group of buddies and I do this all the time when testing new amps. But you need to feed the Purifi modules direct from a high resolution DAC, bypassing any input buffer. Because most input buffers color the sound.

Because most will not feed their amp directly from a DAC via bypassing the buffer, not sure what your post contributes.

 

[Amplifier dude]

Because most will not feed their amp directly from a DAC via bypassing the buffer, not sure what your post contributes.

I read some discussions about people comparing the sound. So as this is an audio forum where people discuss subject matter of this type, I thought I’d chime in.

 

[Phorize]

I can tell a good Purifi implementation apart from an NC502MP amp blind 10 out of 10 times. In fact a group of buddies and I do this all the time when testing new amps. But you need to feed the Purifi modules direct from a high resolution DAC, bypassing any input buffer. Because most input buffers color the sound.

You’d be doing the community a service if you shared which buffers aren’t transparent if you support this with evidence. There’s a lot of speculation around on this as only a few have been independently tested in the public domain.

 

[Amplifier dude]

You’d be doing the community a service if you shared which buffers aren’t transparent if you support this with evidence. There’s a lot of speculation around on this as only a few have been independently tested in the public domain.

I haven't tested every buffer implementation ever made. However if you read Amir's review of the stock Eval 1 board it measures better with the buffer bypassed. Sounds way better too. Just need a proper DAC with 9.6v+ output to drive the amps to full power without a buffer.

 

[Phorize]

I haven't tested every buffer implementation ever made. However if you read Amir's review of the stock Eval 1 board it measures better with the buffer bypassed. Sounds way better too. Just need a proper DAC with 9.6v+ output to drive the amps to full power without a buffer.

The eval 1 buffer didn’t colour the sound though, it was still completely transparent from a listener perspective. I have an rme dac which would be fine without a buffer but most dacs will need one, so it’s a feature rather than an bug.

 

[Amplifier dude]

The eval 1 buffer didn’t colour the sound though, it was still completely transparent from a listener perspective. I have an rme dac which would be fine without a buffer but most dacs will need one, so it’s a feature rather than an bug.

Well not to my ears. There's a drastic difference in sound with it in or out. The less gain stages in a system the better. Best bet is to just get an amp that uses the Purifi built buffers. Either the mono or stereo boards. Then you can try yourself, as you just need to remove some jumpers to do so. But the mono boards are actually better than the stereo board. They have better regulation.

 

[peng]

I'm not an electrician, let alone an Audio engineer, so much of the test results whoosh over my head. But I've learnt enough over the years to claw my way around and spot the good from the bad.

My issue is things like the below that someone posted earlier in this thread. Do I read that the Hypex closely matches the Purifi and my ears won't tell the difference? Or do I read that the non linear end brings audible differences that are worth paying the extra for?

View attachment 168336
Understanding the test results is one thing, placing that into a practical, real world usage scenario is quite another, for me.

I'd love to hear a Purifi next to, say, a Nc502, just to confirm that I can, or can't, discern enough difference to justify doubling the cost. But as that's not likely to happen I'm erring towards the better safe than sorry Purifi.

I would say yes, that their measurements look close enough such that if say the noise floor of your room is not lower than 25 dB or so, you won't be able to tell a difference between a few dB difference in SINAD, okay may be up to 20 dB difference if you pick the worst spot on the THD+N vs frequency vs output level graphs with 45 kHz bandwidth. For example, the 6 ch Buckeye NC502MP has about -77 dB, or 0.014%, while the Purifi did about -97, or 0.0014%. So under that condition the Buckeye NC252 appears to have 20X THD+N, but that's measured with a 10 kHz signal and 45 kHz bandwidth that would have included the ultrasonic harmonics and noise.

Can we really hear 0.014% THD+N that included everything up to 45 kHz? I would think that even if limited to the audio range THD+N is still 0.014% (that it isn't), we cannot hear a difference when using the amps for music and movies.

Aside from THD+N, we already know those amps have very high damping factor, SNR, and the FR of the NCore amp is flat to 5 kHz, with roll off by 0.25 dB at 15,000 Hz and 0.5 dB at 20,000 Hz vs the Purifi's FR flat to 20,000 Hz. I am not done comparing the NC502MP to the Purifi Eval1 myself but if I am going to report that I heard a difference I would try very hard to do it in SBT first before making such a claim. I know I am biased so I also plan on having someone younger with less or little hearing loss to take a listen as well, all time permitting..

 

[peng]

I read some discussions about people comparing the sound. So as this is an audio forum where people discuss subject matter of this type, I thought I’d chime in.

Questions:

- Aside from "blind", was it double blind,
- Level matched to with 0.5 dB,
- Compared with very short delay in between switching from AB/BA
- Did the others in the group score 10/10 too, if not, what's their average
- Was the audible difference subtle, or easy to tell
- Did they have a preference, if yes, which amp scored better

Thank you

 

[Amplifier dude]

Questions:

- Aside from "blind", was it double blind,
- Level matched to with 0.5 dB,
- Compared with very short delay in between switching from AB/BA
- Did the others in the group score 10/10 too, if not, what's their average
- Was the audible difference subtle, or easy to tell
- Did they have a preference, if yes, which amp scored better

Thank you

We use no strict rules. I just hook the gear up behind a blanket, and we listen to a bunch of tracks. Let the gear warm up nicely, then move on to the next. Then we repeat this multiple times. 2 of my buddies and I always agree on what's best. When others are involved with less trained ears they sometimes can't hear much difference.

If I don't think a new amp sounds better I don't buy it. Because I use these amps in active speakers. If they cost more money and don't sound better I make less money.

 

[boXem]

Apollon?

Hehe. Won't be cheaper than boXem.

OK then Mr Boxem. Talk to me.
I'm sure I looked and yours were out of my price range.

I didn't realize that March had gone to the bottom end of the market. Not that long ago, our prices were quite close.

I'm using a Topping D90 at one end and Revel M16 at the other. If you've any other options to recommend I'll gladly take a look.

I consider the 4215/E2 to be the best option for your setup. If the pricing is not fitting your budget, I also perfectly understand that you may want to look elsewhere

 

[boXem]

They have better regulation.

How do you know this?

 

[Amplifier dude]

How do you know this?

Have a look at the boards then you tell me.

 

[boXem]

We use no strict rules. I just hook the gear up behind a blanket, and we listen to a bunch of tracks. Let the gear warm up nicely, then move on to the next. Then we repeat this multiple times. 2 of my buddies and I always agree on what's best. When others are involved with less trained ears they sometimes can't hear much difference.

If I don't think a new amp sounds better I don't buy it. Because I use these amps in active speakers. If they cost more money and don't sound better I make less money.

Do you at least level match?

 

[Amplifier dude]

Do you at least level match?

No we listen at all volume levels. In order to know what an amp can do you need to hear it at all levels.