NAD C 298 Power Amplifier With Purifi Eigentakt Amplification

[JRS]

As far as we know that is the only Purifi Eigentakt amplifier module on the market now, with more to come soon.

I have a post above--may wish to check out this supplier.

 

[mSpot]

EDIT: Hadn't read the entire thread, see that this has been mentioned. Anyhow still curious if anyone has experience with VTV.

VTV has been widely discussed (including several threads specific to VTV). Use the forum search for "vtv purifi".

 

[JRS]

VTV has been widely discussed (including several threads specific to VTV). Use the forum search for "vtv purifi".

Thanks. And ouch--not only do I feel a fool for touting these, it appears to be a can of worms is lurking under the lid such that I gonna have to give this some deeper consideration--so glad you prevented me from an impulse purchase I may have regretted.

 

[aslan7]

I bought the Purifi Eigentakt Eval 1 from VTV and am totally delighted with it. Service and delivery were outstanding. I didn’t opt for the more complex models because no interest in upgrades available for them and wanted to keep everything simple. I use it with an RME DAC and they are a great combination. I can’t believe the high sound quality for the price. Consequently I strongly recommend VTV. It’s also good to have the convenience of an American manufacturer, though Nord and Apollon were very tempting.

 

[aslan7]

I just wanted to add that there were some strongly worded criticisms of VTV lack of quality control posted here a while back. I have had absolutely no such issues—my unit is well made. Prior to buying it I asked the owner about this matter and he reassured me.

 

[Absolute]

I just wanted to add that there were some strongly worded criticisms of VTV lack of quality control posted here a while back. I have had absolutely no such issues—my unit is well made. Prior to buying it I asked the owner about this matter and he reassured me.

He reassured you about what?
"I'm still no electrical engineer and have no clue what I'm doing, but I've listened to random people online about how to do stuffs now so all is good"?

Which ones of these "garage shops" brands actually have any electrical education and proper know-how, and not to speak of instrumentation to actually measure what they are doing? Serious question, I want to know where I will buy from.

 

[aslan7]

The person who found fault with VTV had some very strong criticisms of obvious quality issues that you can read here yourself. The owner assured me I would not have such issues and I didn’t. I wouldn’t characterize the various small companies that produce such units garage shops though some do exist. Some have found fault with major manufacturers like NAD. I can only relate my personal experiences and impressions which in the case of VTV have been quite satisfactory.

 

[Absolute]

Okay, let's call them kitchen-shops then
Point is that some of these brands are a one-man home-assembled side-work kinda thing with no professional experience in the field, and that merits the usage of the word "garage shop" in my world.
Some examples have been shown over the years to be potentially dangerous due to a lack of understanding of electrical safety and some have shown that they sacrifice true performance due to wire lengths and paths compared to the original DIY designs in something like Ghent cabinets.

Since we're supposed to pay somebody for a professionally constructed product as opposed to mounting it ourselves, I'd be really interested to hear which ones of these new kitchen-dealers actually are worthy of the consideration as they're unlikely to kill us or burn down our house to make a quick buck.

I know @Armand from Vera Audio is an actual professional and I suspect @boXem | audio is as well.
What about all the others, even the larger ones like Nord, Apollon, Audiophonics etc? Anyone know?

 

[aslan7]

I am certain you are right but, based on my personal experiences, don’t put VTV in that category. It seems that there was an unfortunate incident in the past that a customer described in detail on this site that has turned off many potential buyers. I surmise that quality problem has been addressed and that VTV should not be judged harshly in light of it. Also, if you don’t like whatever you get just return it in 30 days. Similarly, there was a Nord unit that Amir reviewed that had its wires crossed. Surprising as that was, it doesn’t mean they are a poor company. People used to say NAD stood for Not Always Defective so big manufacturers aren’t immune from errors either. And I certainly don’t want my amplifier to burst into flames while listening to Wagner’s Immolation Scene! Best regards to all.

 

[MaxBuck]

Not to return the discussion to the NAD C298, but holy cow! The more I listen, the more I love my setup, and the C298 is a big part of it. And wonder of wonders, my "mediocre" Bluesound Node doesn't ruin the whole business.

 

[aslan7]

I may get the C298 to replace a Wyred4Sound integrated for the basement system—I never use the preamp part and have given up on LPs so no need for a turntable connection. I never had anything by NAD so this will be an adventure.

 

[atmadams]

I bought the Purifi Eigentakt Eval 1 from VTV and am totally delighted with it. Service and delivery were outstanding. I didn’t opt for the more complex models because no interest in upgrades available for them and wanted to keep everything simple. I use it with an RME DAC and they are a great combination. I can’t believe the high sound quality for the price. Consequently I strongly recommend VTV. It’s also good to have the convenience of an American manufacturer, though Nord and Apollon were very tempting.

I just got my VTV Eval-1 up and running. I was a bit skeptical with the Class D and accounts of VTV issues... but overall very satisfied and impressed with the Eigentakt platform. Night and day upgrade from my Marantz PM6007 which was a bit under-powered for my Focal Chora 826s.

One question for you: I'm getting an audible idle hiss when you get about 6 inches from the tweeter. Have you experienced this with yours?

 

[mSpot]

One question for you: I'm getting an audible idle hiss when you get about 6 inches from the tweeter. Have you experienced this with yours?

What is your source (dac/preamp)? The hiss might be coming from your source rather than generated by the amp. Does the hiss level change with the volume setting?

 

[aslan7]

I have had no such problem—absolutely dead quiet. Hope you solve this issue and enjoy.

 

[atmadams]

What is your source (dac/preamp)? The hiss might be coming from your source rather than generated by the amp. Does the hiss level change with the volume setting?

Unfortunately it happens with no source connected, but it’s very faint. It certainly gets louder when I add in the Schiit Lokius and my CXN V2 streamer. You can’t hear it from the listening position and/or when music is playing.

 

[atmadams]

I have had no such problem—absolutely dead quiet. Hope you solve this issue and enjoy.

I’ll do some more troubleshooting. Thanks.

 

[ebslo]

One question for you: I'm getting an audible idle hiss when you get about 6 inches from the tweeter. Have you experienced this with yours?

This sounds normal. I don't have the numbers for your system, so I'll calculate for mine. FWIW, I hear hiss with my ear directly in front of the tweeter at a distance <= about 4 inches.

Speaker sensitivity = 88.5dB @ 1W re 8Ohm load, 1 meter distance
Amp (C298) SNR = 120dB, A-weighted
Amp max power re 8Ohm load = 185W

SPL of noise @ 1 meter = 88.5dB + 10*log10(185W) - 120dB = -8.8dB
SPL of noise @ 4 inches (assuming +6dB per halving of distance in the near field) = -8.8dB + (6 * log2((100 / 2.54) / 4)) = 11dB

There is some hand waving here WRT measurement bandwidth, so I would expect to actually hear a few dB lower noise than this, but it is unsurprising that the hiss is audible above the ambient noise in my room. While a full-band measurement of ambient noise in my room gives about 35dB, most of that is low frequency and ambient noise level is much lower over the frequency range of the tweeter's response.

 

[atmadams]

This sounds normal. I don't have the numbers for your system, so I'll calculate for mine. FWIW, I hear hiss with my ear directly in front of the tweeter at a distance <= about 4 inches.

Speaker sensitivity = 88.5dB @ 1W re 8Ohm load, 1 meter distance
Amp (C298) SNR = 120dB, A-weighted
Amp max power re 8Ohm load = 185W

SPL of noise @ 1 meter = 88.5dB + 10*log10(185W) - 120dB = -8.8dB
SPL of noise @ 4 inches (assuming +6dB per halving of distance in the near field) = -8.8dB + (6 * log2((100 / 2.54) / 4)) = 11dB

There is some hand waving here WRT measurement bandwidth, so I would expect to actually hear a few dB lower noise than this, but it is unsurprising that the hiss is audible above the ambient noise in my room. While a full-band measurement of ambient noise in my room gives about 35dB, most of that is low frequency and ambient noise level is much lower over the frequency range of the tweeter's response.

Wow thanks for the detailed answer! I assumed it was normal, but this is my first legit speaker/amp set up and wasn't sure what was expected. I love this forum and the number crunching. Now... gotta go find the TI-83 in the basement.

 

[aslan7]

You are certainly going to like the additional power because the Marantz is only 45 watts. Those Focal speakers are supposed to be very good and are even made in France.

 

[atmadams]

This sounds normal. I don't have the numbers for your system, so I'll calculate for mine. FWIW, I hear hiss with my ear directly in front of the tweeter at a distance <= about 4 inches.

Speaker sensitivity = 88.5dB @ 1W re 8Ohm load, 1 meter distance
Amp (C298) SNR = 120dB, A-weighted
Amp max power re 8Ohm load = 185W

SPL of noise @ 1 meter = 88.5dB + 10*log10(185W) - 120dB = -8.8dB
SPL of noise @ 4 inches (assuming +6dB per halving of distance in the near field) = -8.8dB + (6 * log2((100 / 2.54) / 4)) = 11dB

There is some hand waving here WRT measurement bandwidth, so I would expect to actually hear a few dB lower noise than this, but it is unsurprising that the hiss is audible above the ambient noise in my room. While a full-band measurement of ambient noise in my room gives about 35dB, most of that is low frequency and ambient noise level is much lower over the frequency range of the tweeter's response.

I actually just figured this out... totally forgot my Topping A90 has a pre-amp mode (use as my headphone amp in my office). Installed it after the streamer... everything is dead quiet now. I guess the CXN in digital pre-amp mode adds a fair bit of noise to the signal.