I was curious if anyone has tried a Purifi-based amp. I was thinking about trying one out with electrostatics or inefficient monitors. i have a Nad C298 coming today as I was oh so curious and will report back. 60-day return policy so no risk. Was thinking about going direct from my Lumin X1 via XLR into the amp and use Leedh volume processing. Also curious if my Lampi would soften up the sound. Would appreciate others’ experiences with Purifi.
Any love for Purifi?
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Not exactly Purifi, but I'm also curious about Mola Mola, especially the Tambaqui briefly discussed here in a DAC thread. No experience with Purifi myself but there are a number of very positive reviews for Purifi-equipped NADs on other audiophile forums ('Shark, Aficionado, etc)
I've been using a pair of DIY Purifi monoblocks for the past few weeks and have been very pleased with them. I spent a while yesterday comparing them to my Parasound JC5, and I think they are comparable. The JC5 is slightly warmer sounding and a tiny bit smoother in the midrange. The Purifi amps have a bit wider sound stage, and a little more energy in the mid-bass. Overall, I could live happily with either.
My amps are a bit different than your typical class D amps in that I have a large linear power supply (1500VA transformer, ~200,000uF of filter caps). I'm currently using the Neurochrome input buffer, but I have a pair of VTV triode buffer boards with Weiss discrete op-amps that I am planning to install next weekend (waiting for a couple of connectors).
I had a pair of Nord NC500 monoblocks in 2019 (tried both Sparkos and Sonic Imagery input buffers) and I was never quite happy with them. They were very clean and detailed, but were not engaging. I never felt like listening to them for more than a short time. My system has changed a lot since then, so I don't know if it's the Purifi modules vs Hypex, different power supply, different input buffers, or other changes to my system.
My amps are a bit different than your typical class D amps in that I have a large linear power supply (1500VA transformer, ~200,000uF of filter caps). I'm currently using the Neurochrome input buffer, but I have a pair of VTV triode buffer boards with Weiss discrete op-amps that I am planning to install next weekend (waiting for a couple of connectors).
I had a pair of Nord NC500 monoblocks in 2019 (tried both Sparkos and Sonic Imagery input buffers) and I was never quite happy with them. They were very clean and detailed, but were not engaging. I never felt like listening to them for more than a short time. My system has changed a lot since then, so I don't know if it's the Purifi modules vs Hypex, different power supply, different input buffers, or other changes to my system.
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Thank you for telling us about Purifi. https://purifi-audio.com/eigentakt/
I noted that the management team has some serious heavy hitters in this field.
Did you buy all of the components from Purifi and put the amplifier together yourself (like old-style Heathkits), or did you buy just the amplifier modules and you fabricated or sourced the beautiful case work and related components?
I noted that the management team has some serious heavy hitters in this field.
Did you buy all of the components from Purifi and put the amplifier together yourself (like old-style Heathkits), or did you buy just the amplifier modules and you fabricated or sourced the beautiful case work and related components?
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I'm an NAD dealer, so take this as you will but have A/Bd the M27 and M28 multichannel amps. Both use the Hypex modules, the 28 is the new iteration of the amp with Purifi. While both exhibit the traditional NAD 'liquid neutrality', the 28 with Purifi adds a greater sense of drive and ease/speed. It's a clear improvement and an excellent amp IMO. The M33 two channel integrated w/Purifi is also excellent.
Hi Jaytor,
Many thanks for sharing!
Transformers from Toroidy are excellent.
May we know more about the linear powersupply and from where they are sourced from?
Also very eager to know your audition comments about the Weiss discrete opamps.
Thanks again!
The Toroidy transformer has 2x45V (15.6A each), and 3x15V (2A each) secondaries. This is a custom Audio Supreme model.
For the high voltage rails, I used two Universal Power Supply boards from DIYAudioStore.com. These are stacked with the first feeding the second. Both of these boards have the resistor bank populated, so the supply acts as a CRCRC: 13,600uF -> 0.5ohm -> 33,600uF --> 0.05ohm -> 20,000uF. This is for each of the two rails. On my house mains, these deliver just under +/- 70V rails.
For the low voltage voltage rails, I used two PCBs I bought from Jim's Audio. These are also stacked and daisy-chained. Since these boards aren't set up as a CRC supply, I used a resistor in between the two boards to connect the output of one to the input of the other, so these have 13,600uF -> 1.5ohm -> 13,600uF for each rail. These +/- 20V rails feed a linear regulator on the buffer board.
For the gate drive (15V referenced to the negative high voltage rail), I used an Omega11 discrete regulated power supply board purchased from AMB Labs.
All the components for all these boards were purchased from Mouser.
These supplies power a single channel monoblock, so this is replicated for each channel.
For the high voltage rails, I used two Universal Power Supply boards from DIYAudioStore.com. These are stacked with the first feeding the second. Both of these boards have the resistor bank populated, so the supply acts as a CRCRC: 13,600uF -> 0.5ohm -> 33,600uF --> 0.05ohm -> 20,000uF. This is for each of the two rails. On my house mains, these deliver just under +/- 70V rails.
For the low voltage voltage rails, I used two PCBs I bought from Jim's Audio. These are also stacked and daisy-chained. Since these boards aren't set up as a CRC supply, I used a resistor in between the two boards to connect the output of one to the input of the other, so these have 13,600uF -> 1.5ohm -> 13,600uF for each rail. These +/- 20V rails feed a linear regulator on the buffer board.
For the gate drive (15V referenced to the negative high voltage rail), I used an Omega11 discrete regulated power supply board purchased from AMB Labs.
All the components for all these boards were purchased from Mouser.
These supplies power a single channel monoblock, so this is replicated for each channel.
I’ve had the Nad C298 with Purifi module for a week now. So far I am very impressed with the clean, crystallized tone. Usually run a Naim 250 DR driven by a Naim 272
preamp. Running the C298 direct from a Lumin X1 DAC via XLR balanced inputs or a Lampi Big 7 via single ended RCA’s using the X1 as a streamer and Leedh volume processing from the Lumin. Speakers are either JM Reynaud Offrande Supreme V2’s or Quad 57’s. Obviously lots of headroom with the Purifi, but the additional power I’m not used to with the Naim or several tube amps I rotate in periodically seems to bring out the most in these speakers. Great bass control and not losing any smoothness in the mids or highs, which I expected to be a bit harsh based on the bad wrap Class D has received over the years. For $2,000, which is comparable to the price charged by the smaller independent Purif amp manufacturers, this amp seems to be a bargain worth trying. The 60-day return policy makes it a no-risk proposition.
preamp. Running the C298 direct from a Lumin X1 DAC via XLR balanced inputs or a Lampi Big 7 via single ended RCA’s using the X1 as a streamer and Leedh volume processing from the Lumin. Speakers are either JM Reynaud Offrande Supreme V2’s or Quad 57’s. Obviously lots of headroom with the Purifi, but the additional power I’m not used to with the Naim or several tube amps I rotate in periodically seems to bring out the most in these speakers. Great bass control and not losing any smoothness in the mids or highs, which I expected to be a bit harsh based on the bad wrap Class D has received over the years. For $2,000, which is comparable to the price charged by the smaller independent Purif amp manufacturers, this amp seems to be a bargain worth trying. The 60-day return policy makes it a no-risk proposition.
This is timely ,
Nice build Jaytor!.
I jumped in with accumulating the parts over the past few weeks for a Purifi Stereo EVAL module. Amp and buffer from Purifi and SMPS from Hypex then chassis - which is really very good- from a Chinese supplier.
It all came together this weekend. Ordinarily, it might take a couple of hours to piece together. I made some mods to the unit as supplied so it took me a little longer. I got turned onto it based on the testing someone in our group did for one of the online magazines.. he was just thrilled with it. One reviewer claims it to be the equal of a pair of $40K Constellation monos?
It is pretty slick, burning it in now and it sounds marvelous thus far. I paired it with a totally nuclear modified Counterpoint pre which I built an outboard tube rectified & shunt power supply for along with a host of other mods including built in silver SUTS.
The PS for the little Counterpoint actulally dwarfs the Purifi. I think Class D and what we think of as SOTA are converging quickly.
Nice build Jaytor!.
I jumped in with accumulating the parts over the past few weeks for a Purifi Stereo EVAL module. Amp and buffer from Purifi and SMPS from Hypex then chassis - which is really very good- from a Chinese supplier.
It all came together this weekend. Ordinarily, it might take a couple of hours to piece together. I made some mods to the unit as supplied so it took me a little longer. I got turned onto it based on the testing someone in our group did for one of the online magazines.. he was just thrilled with it. One reviewer claims it to be the equal of a pair of $40K Constellation monos?
It is pretty slick, burning it in now and it sounds marvelous thus far. I paired it with a totally nuclear modified Counterpoint pre which I built an outboard tube rectified & shunt power supply for along with a host of other mods including built in silver SUTS.
The PS for the little Counterpoint actulally dwarfs the Purifi. I think Class D and what we think of as SOTA are converging quickly.
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I'm pleased you're enjoying your NAD amp. I have the NAD M33 that also features the Purifi module. As an all-in-one it also includes streamer, DAC, preamp and DSP and this also makes it a true bargain in terms of value for money. My Avantgarde Duo XD speakers are asking for nothing more exotic. Peter
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