The Article I Didn't Write For Audiophile Style

[Jud]

I have long been the proud owner of a Spectral DMA 150 amp.  This thing was the absolute schizz (as they say) when it first came out in 1996.  It was exceedingly well designed and built, and there was very little at any price that could touch it.

 

I was content for many years, until two things happened.  First, in the past year every so often there would be a mild crackling of static from one channel or other.  It didn't happen often enough to be a real irritant, but the fact that it happened at all made me think I should really send the unit in and have it looked at. Though I didn't know whether it was the quarter century old amp or the even older Spectral preamp, a tune-up for both seemed like a good idea.  But the second thing, the one that really decided me, was hearing a Purifi-based amp at the last (very last) RMAF.  Music sounded fabulously clear and accurate through the system, and I knew the amp at least wasn't detracting from it.  From then on, I wanted to see what an amp like that would do in my system.

 

At last after taking care of other home priorities I had the opportunity to buy the new amp of, if not my dreams, at least my desires.  I consulted with another AS member with expertise in these issues (who shall remain nameless so as not to be pestered - by people other than me, I mean 😉- unless they want to come forward).  I asked whether I should think of DIY or order from one of the several reputable builders of Purifi-based amps.  This member said for the price difference DIY probably wasn't worth it, and of the various manufacturers they liked the layout and parts quality from Apollon.

 

If after reading this you are thinking of ordering from Apollon (which I would encourage if you want a Purifi-based amp - you won't be disappointed), I should mention it is a small shop that concentrates on building its many orders rather than a lot of communication.  I finalized my order on April 15th, received the amp from UPS on June 27th, and had communication with Apollon during that interval on perhaps three or four occasions.  Not only building the amp but shipping and clearing both export (Slovenia) and import (in my case, US) customs are part of that time frame.  Of course I could have talked to them more often (they offer email or a chat feature on their website), but I thought for the most part it was best to let them get down to building amps and not spend time chatting with me. Thus this route is not for those who want instant gratification or a great deal of handholding, but I can say the result is most definitely worthwhile.

 

Once I received the new Apollon amp, I had notions of writing about listening impressions from switching back and forth between it and the Spectral, the old champ vs. the new challenger.  The Spectral featured a 97dB signal to noise ratio, awesome for its day.  The Apollon with its quarter century newer design substantially bettered that at 131dB(!).  But could I come close to hearing this difference in a listening room that, even in a well insulated home far from city or traffic noise, has perhaps 30dB (perhaps a smidgen less) of background noise?  A feature of Purifi based amps is their substantial power, and the Apollon has it at 227 watts into 8 ohms, 425 watts into 4 ohms.  (My speakers average about 6 ohms impedance over their frequency range.)  But the Spectral isn't lacking at 150 watts into 8 ohms, 300 into 4.  And finally, as I've mentioned before here at AS, in a listening test for various forms of distortion conducted at an RMAF seminar, the distortion I was most sensitive to was slew rate limiting.  The Spectral is all about speed, and doesn't have any slew rate limiting I've ever been able to hear.  Could the Apollon do as well?  The stage seemed set for an entertaining championship bout.

 

To minimize variables, I ran my DAC outputs direct to amp, eliminating the preamp.  I wondered whether the DAC (which includes a preamp) would be able to drive the amps, but I needn't have worried.  Direct to the Spectral amp sounded even better than through the very fine Spectral preamp.  Perhaps it's true what they say about the best preamp being no preamp (with suitable caveats, I imagine).  So now it was time to hook up the Apollon in place of the Spectral and compare.

 

...And all thoughts I had of a back-and-forth comparison that I could write about evaporated immediately.  The Apollon just comprehensively kicked the Spectral's ass.  The Spectral presented excellent bass and percussion; with the Apollon they were absolutely physical things. (Bonnie Raitt's Wherever You May Be was the first track I played and a good example of this.)  With the Spectral I couldn't hear distortion; with the Apollon I felt I could clearly hear details in the music - lyrics, background vocal and instrumental lines - that had been hidden.  This was of course a subjective impression, and I make no claims at all to objective certainty.  But I am one happy man.  (The one objective difference I can relate is that turning up the volume with no music playing, with the Spectral I could hear a very slight hiss from the tweeters and a slight hum from the midrange drivers, while with the Apollon there was utter and complete silence.)

 

And though I have a photovoltaic system that provides all my electricity, it does feel nice that I'm moving from the Class A electricity-guzzling Spectral (huge transformer, 62 pounds) to the Apollon (much smaller transformer, 20 pounds). The Apollon looks great, with a piano black finish that has a mirror shine (in fact I bought white cotton gloves to handle it).  It also comes in a pearl white, I believe.

 

And one final thing that the geek in me couldn't resist: The Apollon has a 12V trigger input in back to turn it on and off. So for $26 worth of stuff from Amazon (12V power supply, power supply to mono plug adapter, wi-fi plug/receptacle), I can turn my amp on and off from my phone, or just say "Hey Google, turn on amp!"  It's not quite the flying cars we were promised, but it's good geeky fun.

 

I've been listening to music with the new amp for a week and loving it.  And oh, if you happen to think there really isn't a difference between amps and I'm just thinking all of this because I've got a new toy; or if you're into vintage amps - I'm selling the Spectral for a song. ☺️

 

Pictures with Spectral and Apollon follow:

 

 

[Dandou]

No wonder that you are happy with your new amp.

I also passed to class D power amps with two Nuprime mono blocs. 

 

But these Purifi modules seem fantastic. 

I heard very enthusiastic feed back about them from a friend who bought the HPA-S400ET from Audiophonics (which is a good French maker of audio gear). 

Here's a link to the review and the measurements of by Audio Science of this model of double mono power amp. Amir grants it with his strongest recommendation: 

 

https://www.audio “science” review/forum/index.php?threads/audiophonics-hpa-s400et-review-stereo-amplifier.32014/

 

 

[ssh]

Apollon Audio 1ET400A Mini (Purifi based) user here. I am very happy with the amp. Did you upgrade the op-amps?

[Al Jones]

Jud, which Purifi module does your amp use: the Purifi 1ET400A or the more recent Purifi 1ET7040SA?

 

I own the March Audio P451 with 1ET400A and am considering upgrading to their P501 with the new 1ET7040SA?

[Jud]

1 hour ago, Al Jones said:

Jud, which Purifi module does your amp use: the Purifi 1ET400A or the more recent Purifi 1ET7040SA?

 

I own the March Audio P451 with 1ET400A and am considering upgrading to their P501 with the new 1ET7040SA?

As the name of the amp suggests, it uses the 1ET400A. Apollon also builds amps with the 1ET7040SA.

[Jud]

2 hours ago, ssh said:

Apollon Audio 1ET400A Mini (Purifi based) user here. I am very happy with the amp. Did you upgrade the op-amps?

I didn’t. The amp in the system that sounded wonderful at RMAF used the standard Texas Instruments op-amps, so I didn’t feel a need. The AS member I chatted with about this may roll op-amps in the future. If I get reports of a significant positive subjective difference from them, I may consider it. The construction of this amp makes op-amp rolling easy to do if I choose to.

[firedog]

2 hours ago, Jud said:

I didn’t. The amp in the system that sounded wonderful at RMAF used the standard Texas Instruments op-amps, so I didn’t feel a need. The AS member I chatted with about this may roll op-amps in the future. If I get reports of a significant positive subjective difference from them, I may consider it. The construction of this amp makes op-amp rolling easy to do if I choose to.

Can you say a bit more about why you chose the Apollon over the other makers? 

[Jud]

35 minutes ago, firedog said:

Can you say a bit more about why you chose the Apollon over the other makers? 

It really was just as simple as the fact that someone whose knowledge I respect told me that (a) the parts quality, and (b) the internal layout of the Apollon were as good as or (mostly) better than other Purifi-based amps, and that at the price point of the Mini, it represented very good value for money among such amps. (Purifi-based amps being in this person’s opinion “Better than anything else I’ve heard under 5 figures.”)

[Nikhil]

 

Very interesting Jud!  Congratulations on the new amps!

 

I have been intrigued with the possibilities of Class D ever since Jeff Day mentioned that Class D was as revolutionary as the DH-SET movement 40 years ago (Adventures in Real Sound with Shirokazu Yazaki of SPEC).   This was a pretty remarkable statement back then (2015).  It appears that Class D has started to come of age.  The fit and finish of the Apollon gear looks fantastic.  And the MINI appears to be stonking good value given your feedback!

 

 

.

 

[John Hughes]

Thats great!  At one time I owned a DMA 150, but have had many amps since.  I am currently rocking a VTV Purifi amp, and it was revelatory that such good quality is available for this price.  Its definitely one of the best amps I've had in my system.  I recently purchased the Atma-Sphere Digital Monoblocks (which us GaN technology).  I am eagerly awaiting their arrival. I'm very enthused to see what a first rate classic tube designer does with Class D. 

[davide256]

On 7/6/2022 at 3:42 PM, John Hughes said:

Thats great!  At one time I owned a DMA 150, but have had many amps since.  I am currently rocking a VTV Purifi amp, and it was revelatory that such good quality is available for this price.  Its definitely one of the best amps I've had in my system.  I recently purchased the Atma-Sphere Digital Monoblocks (which us GaN technology).  I am eagerly awaiting their arrival. I'm very enthused to see what a first rate classic tube designer does with Class D. 

Agree. Tubes are slow but "fattening". If some of that tonal richness could be worked into that fast, articulate class D power it would be a delight.

[Jud]

1 hour ago, davide256 said:

Agree. Tubes are slow but "fattening". If some of that tonal richness could be worked into that fast, articulate class D power it would be a delight.

I’ve not noticed a lack of richness or body from the Apollon at all. In fact the power reserves seem to me subjectively to give great body to vocals, cellos, double bass, acoustic guitar, etc. But on the other hand I don’t know the particular tube sound that appeals to you, so it may not be the sound the Purifi/Apollon presents.

[davide256]

2 hours ago, Jud said:

I’ve not noticed a lack of richness or body from the Apollon at all. In fact the power reserves seem to me subjectively to give great body to vocals, cellos, double bass, acoustic guitar, etc. But on the other hand I don’t know the particular tube sound that appeals to you, so it may not be the sound the Purifi/Apollon presents.

I use either a passive pre or a tubed LTA MZ2 into GaN Orchard Audio mono blocks. While the passive pre is more dynamic,/ detailed/doesn't truncate lowest bass,  its not fluid and easy to live with like the LTA MZ2. In  my "best of all possible worlds" I'd like to see all of the positive attributes above in an amplifier without needing 10,000 BTU's of room cooling

(class A or tubes) fed directly by DAC as volume control.

[Rexp]

2 hours ago, davide256 said:

I use either a passive pre or a tubed LTA MZ2 into GaN Orchard Audio mono blocks. While the passive pre is more dynamic,/ detailed/doesn't truncate lowest bass,  its not fluid and easy to live with like the LTA MZ2. In  my "best of all possible worlds" I'd like to see all of the positive attributes above in an amplifier without needing 10,000 BTU's of room cooling

(class A or tubes) fed directly by DAC as volume control.

Maybe you should try his Project DAC/Pre..

[Jud]

20 minutes ago, Rexp said:

Maybe you should try his Project DAC/Pre..

Well, I’m enjoying it, but I make no particular claims it is anything but a decent relatively inexpensive ESS DAC.

[davide256]

4 minutes ago, Jud said:

Well, I’m enjoying it, but I make no particular claims it is anything but a decent relatively inexpensive ESS DAC.

One of the reasons I've yet to buy a better DAC is that I keep finding what I dislike is mostly the fault of something else in the system 😉

 

[Jud]

3 minutes ago, davide256 said:

One of the reasons I've yet to buy a better DAC is that I keep finding what I dislike is mostly the fault of something else in the system 😉

 

Though that might be quite hard to tell. 🙂

[Rexp]

35 minutes ago, Jud said:

Well, I’m enjoying it, but I make no particular claims it is anything but a decent relatively inexpensive ESS DAC.

You never know, you might have found a unicorn. The pre/power synergy is key.

[Jud]

1 hour ago, Rexp said:

You never know, you might have found a unicorn. The pre/power synergy is key.

Not sure it’s synergy so much as simplification. I removed the Spectral preamp from the system. It’s an outstanding preamp, but it isn’t as good as nothing at all between the DAC’s built-in preamp and the amp. So the DAC’s not screwing things up too badly, and then the amp is being tremendously faithful to what it receives (as the specs would indicate).

[firedog]

13 hours ago, davide256 said:

Agree. Tubes are slow but "fattening". If some of that tonal richness could be worked into that fast, articulate class D power it would be a delight.

I've put tubes in front of Class D. It adds tube flavoring, or whatever you want to call it. 

It's fine if that's what you want. 

Can't say it's "better" - it's different; it does reduce somewhat the advantages of good Class D - that clean and very clear sound. Sounds "dirty" in comparison. But it's still good sound, it's just a matter of what flavor you like. 

[DuckToller]

@Jud

Congratulations for your choice!!!  Happy you like it and you enjoy what you hear !!!

I have heard the Purified Class D in Munich 2019 and Paris 2019, and I was really feeling, if ever there will be new amps, these would be the high road to audiophile nirvana. I was very happy that the amplification and the PuRiFi speaker were passing the exam of the expert review by @mitchco, confirming my own positive impressions

It’s about two years,  I had exchanged mails with Pavel from OKTO Research about doing a feature about “European Excellence”, contemplating pairing the DAC stereo with the Apollon Mini amp and perhaps some speaker from French or Danish manufacturer …
however, with all the troubles and limitations that came with these malevolent Covidean times, this was left to be an exciting idea, only .

Thus, I am very happy that one of the most  trustful members here get the things done and prove this idea wasn’t that bad at all ;-) BRAVO !

Personally, I have now acquired the OKTO Pro DAC for my recent active speaker project, however, the purified amplification is one of the planned upgrades, but not integral part of the project due to limitations in spending. Priorities are on the speaker assembly, the multichannel DAC  plus DSP / DRC for getting the project kicked off after the summer break. Next week will show if the woodwork will be finished before the summer break.

When the funds will be available, a pair of Audiophonics Mono blocks for the low end (<250hz) and the Apollon Mini for the low-mid/highs  might be the final selection, as their Monos are at half the price compared to the Apollon mono blocs, tax included.  This would mean to double the available current compared to the Mini alone, perhaps a premium in sq?

Actually, as you have mentioned in the OP,  you almost can’t beat these on costs at 749 €/$ with DIY efforts when doing i.E. a GHENT based Purifi mono amp with SMPS400 PS. (around 600 Euro/$ without gain switching board and assembly).

Which DAC you are using? Still the iFi micro DSD? How do you control the volume?
Any thoughts about improving the excellent sound with a different DAC design ?

Thank you for reporting to us your positive experience, stay safe and healthy.

Tom

[Jud]

Thanks so much, @DuckToller, for your very kind comments. Although the iFi micro iDSD does have a preamp/volume control, I replaced it with a Pro-Ject Pre Box S2 a couple of years ago. It also has a preamp/volume control, plus a remote control. As you can tell from the review I am very much enjoying the sound. While I don’t think of this as my ultimate DAC (I’d look for something that has balanced outputs and leaves DSD sent from my player software untouched), a replacement is unlikely to happen any time soon.

[Jud]

On 7/16/2022 at 8:38 PM, Jud said:

I removed the Spectral preamp from the system.

 

Or rather, I removed it from the chain where the DAC is the source. Happily the Apollon has both balanced and single ended inputs, so if I want to listen to my turntable or tuner I can switch to the single ended inputs coming from the Spectral. (My present DAC has only single ended outputs, but I use single ended to balanced cables with it. Of course this doesn’t give me balanced output, but it does allow the convenience of running the DAC direct to the amp.)

[jhopki]

Hi Jud, I have previously followed your insights and experiences with the EtherRegen (which were spot on), so when I saw you made the switch to a Purifi based amp I was very interested. I too am at a bit of an ‘amp crossroads’, having a vintage restored SS amp I love, but with a new set of speakers needing a little more power. The Purifi reviews I have read have been glowing, with only one reservation of occasional note: An alleged lack of low level detail that may render the decay of certain notes and instruments somewhat truncated. For example, the strike of a drum or cymbal; the decay is there, it slowly fades, but then it is somehow shortened or “abbreviated”, at least compared to classic AB amplifiers. Have you on occasion noticed this characteristic? I’m ready to pull the trigger on this technology, probably with one of the smaller companies such as Apollon or VTV, but since I listen largely to classical and jazz, this issue is of obvious concern. Decay and ambience are so important in these genres! Thanks, John 

[ssh]

I bought a Purifi-based Apollon 1ET400A MINI amp with the Sparko SS2590 Pro op amps,

 

I have had it for just over one year. I feed a Bricasti M3 direct to the amp. Since received, every day I am amazed at what I would describe as a visceral clarity.

 

It's a strength and finesse thing.