Curiosity gets the better of me (again)

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NSNO2021
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Re: Curiosity gets the better of me (again)

Unread post by NSNO2021 »

I was surprised by your "65 year" quote but I know you don't say anything without good reason - I have been aware of class D in audio circles for maybe 15 to 20 years and it's only past 5 years they have started to get more and more positive press. On a personal front I would love to home demo a NAD M23 but that requires me to sell a number of things to have the funds to give one a go.
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Re: Curiosity gets the better of me (again)

Unread post by Geoff.R.G »

NSNO2021 wrote: Wed Feb 01, 2023 10:25 pm I was surprised by your "65 year" quote but I know you don't say anything without good reason - I have been aware of class D in audio circles for maybe 15 to 20 years and it's only past 5 years they have started to get more and more positive press. On a personal front I would love to home demo a NAD M23 but that requires me to sell a number of things to have the funds to give one a go.
Invented by Alec Reeves and first called Class D in 1955 according to Wikipedia. The first commercial amp was in 1964 but MOSFETs only really made them practical in the 1980s. Yes I was surprised to see that too, ic based Class D apparently became available in the 1990s.

My first, knowing, experience of class D was in the Behringer 150W stage monitor about 10 years ago. This is a clever device, looking remarkably like a Mackie Hot Spot, that was then about £150 and a bit bigger than a couple of shoe boxes. I say knowing because it is likely that I had devices using Class D somewhat earlier. High power car amplifiers being ideally suited for Class D, it is difficult to see how one might get four channels at 35W each into a double DIN head unit with class AB. Car audio is a more forgiving environment than home Hi-Fi.

A quick search reveals that Rotel, Cambridge Audio and Kenwood have Class D products available. Not to mention the car audio manufacturers.

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Re: Curiosity gets the better of me (again)

Unread post by Fretless »

Class D - the continuing story ...

Getting to grips with the 'new' desktop installation which has a Cambridge DacMagic Plus (with LPSU) running through the Douk G4 amps and Mission 760 speakers. Hitting yesterday a compatibility problem with the bright Minax speakers shows just how careful component choice is to get a good result from Class D amplification. Through the 'rounded' Mission's the D trademark of crisp detail and pinpoint imaging is evident. These little amps display a clean neutrality with plenty of bass and nice mids. The treble is tamed by the system and is crystalline but not harsh.

Playing Porcupine Tree 'Closure / Continuation' (an album I'm still not sure I like), an awesomely detailed and dynamic listen with the Douk G4's doing an excellent job of presenting it. Switching to harpist Lavinia Meijer's latest 'Are You Still Somewhere?' has her solo instrument beautifully clear in a near-holographic presence on my desk.

For a laugh, I switched the amps over into their 'Sub' mode for a listen. They roll-off at 200 Hz and no doubt have the oomph to drive a serious passive subwoofer, this is the purpose that they are mainly used for - anyhow, it was like listening through mud. In full-range mode and for nearfield use at low volumes they are great little things and do have a sweet and audiophile-satisfying quality in this setup.

It would appear that it is very easy to put a Class D amp into a system that will quite possibly sound rather unpleasant. Their forward and bright character can be very dominant and produce an in-your-face harshness. These cheap n' cheerful ChiFi offerings do allow one to experiment in a fairly painless way and there is another amp that keeps nagging at my attention, the Loxije A10, I just love the look of it!

Image
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slinger (Thu Feb 02, 2023 1:54 pm)

Upstairs:
Vinyl
Pro-Ject 1.2 + Grado Sig Jr + Cambridge Alva Duo
DigiVolumio PC + Kiss DP-500 + Sabaj A20d
NVA: P50sa - Cube2 - SSP - LS6+ Sabaj A10a (x2)
Downstairs:
Vinyl
Logic DM101 + Syrinx LE1 + Grado Sig MCX
DigiDenafrips Ares II + Volumio PC + Cambridge CXC
NVA: P50 - BMU+ Aiyima A07 MAX (x2) + Arcam One
HP: HifiBerry Digi+ PRO + Sabaj A10d
Office:
Allo DigiOne SIG + SMSL M300se + Douk G4 (x2)
Mission 760 + Monolith THX AAA 887
Headphones: German Maestro, Monolith & AQ

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Re: Curiosity gets the better of me (again)

Unread post by karatestu »

Have you put the cubes on the end of them yet ?
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Re: Curiosity gets the better of me (again)

Unread post by Fretless »

The Cube2's are sitting with the Sabaj Class D's and the combination is very impressive. I might well try out the little G4 amps there, and with my MDF-cab Cube3 just to see how they work.

Upstairs:
Vinyl
Pro-Ject 1.2 + Grado Sig Jr + Cambridge Alva Duo
DigiVolumio PC + Kiss DP-500 + Sabaj A20d
NVA: P50sa - Cube2 - SSP - LS6+ Sabaj A10a (x2)
Downstairs:
Vinyl
Logic DM101 + Syrinx LE1 + Grado Sig MCX
DigiDenafrips Ares II + Volumio PC + Cambridge CXC
NVA: P50 - BMU+ Aiyima A07 MAX (x2) + Arcam One
HP: HifiBerry Digi+ PRO + Sabaj A10d
Office:
Allo DigiOne SIG + SMSL M300se + Douk G4 (x2)
Mission 760 + Monolith THX AAA 887
Headphones: German Maestro, Monolith & AQ

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Re: Curiosity gets the better of me (again)

Unread post by Fretless »

Compatibility:

The Douk Audio 14AWG OFC cable was tried with the little G4 mono-amps but sounded dull and veiled, putting the NVA LS5 in brought this setup up to a satisfyingly sparkling performance, The Douk cable went in with the Kenwood amp and Minax speakers and works absolutely fine there with the soft-sounding amp and cable balancing nicely with the bright tweeters.

Everybody happy!

Again Class D amps show that they are very dependent on component combination and music choice, as complex / loud music can get a bit muddy and confused. But electronic and acoustic albums are incredibly clear and well-defined.
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slinger (Mon Feb 06, 2023 2:43 pm) • karatestu (Mon Feb 06, 2023 4:49 pm) • CN211276 (Mon Feb 06, 2023 6:07 pm)

Upstairs:
Vinyl
Pro-Ject 1.2 + Grado Sig Jr + Cambridge Alva Duo
DigiVolumio PC + Kiss DP-500 + Sabaj A20d
NVA: P50sa - Cube2 - SSP - LS6+ Sabaj A10a (x2)
Downstairs:
Vinyl
Logic DM101 + Syrinx LE1 + Grado Sig MCX
DigiDenafrips Ares II + Volumio PC + Cambridge CXC
NVA: P50 - BMU+ Aiyima A07 MAX (x2) + Arcam One
HP: HifiBerry Digi+ PRO + Sabaj A10d
Office:
Allo DigiOne SIG + SMSL M300se + Douk G4 (x2)
Mission 760 + Monolith THX AAA 887
Headphones: German Maestro, Monolith & AQ

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Re: Curiosity gets the better of me (again)

Unread post by Fretless »

Image

For mainly cosmetic reasons I have shifted the power amps to sit underneath the matching Sabaj DAC - looks rather smart.

The sharp-eyed will spot an odd pair of reflected lights on the top of the CD/DVD transport, they reveal the Schiit Wyrd USB regen that is tucked away there.

Next experiment is to hook DAC and monoblocks directly via XLR. Should happen sometime this week

These amps, by the way, are absolutely great (had I said that already?).

:mrgreen:
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slinger (Sun Mar 05, 2023 3:19 pm) • antonio66 (Sun Mar 05, 2023 11:16 pm)

Upstairs:
Vinyl
Pro-Ject 1.2 + Grado Sig Jr + Cambridge Alva Duo
DigiVolumio PC + Kiss DP-500 + Sabaj A20d
NVA: P50sa - Cube2 - SSP - LS6+ Sabaj A10a (x2)
Downstairs:
Vinyl
Logic DM101 + Syrinx LE1 + Grado Sig MCX
DigiDenafrips Ares II + Volumio PC + Cambridge CXC
NVA: P50 - BMU+ Aiyima A07 MAX (x2) + Arcam One
HP: HifiBerry Digi+ PRO + Sabaj A10d
Office:
Allo DigiOne SIG + SMSL M300se + Douk G4 (x2)
Mission 760 + Monolith THX AAA 887
Headphones: German Maestro, Monolith & AQ

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Re: Curiosity gets the better of me (again)

Unread post by Fretless »

Update time: XLR cables now in the Sabaj setup, running directly from DAC to amps rather than RCA links via P50sa preamp. The balanced XLR connection is recommended by Sabaj themselves and is very impressive.

Selecting XLR or RCA input to the amps is done via a tiny little switch on the back. As the upstairs system is mainly digital at the moment then occasionally having to change the input to RCA for vinyl playback is no problem.

Sound is far more clear, direct and transparent. Missing some fullness to the bass - but I think that will come as the cables burn-in. The bass is there but very tightly controlled.

Got these XLR interconnects from Amazon:
https://www.amazon.co.uk/Mogami-2534-Ca ... 7G01Z&th=1

Japanese Mogami cable, a popular choice in professional recording studios and heavily shielded. Assembly with Neutrik plugs is done by a company in Germany

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antonio66 (Tue Mar 07, 2023 10:05 pm)

Upstairs:
Vinyl
Pro-Ject 1.2 + Grado Sig Jr + Cambridge Alva Duo
DigiVolumio PC + Kiss DP-500 + Sabaj A20d
NVA: P50sa - Cube2 - SSP - LS6+ Sabaj A10a (x2)
Downstairs:
Vinyl
Logic DM101 + Syrinx LE1 + Grado Sig MCX
DigiDenafrips Ares II + Volumio PC + Cambridge CXC
NVA: P50 - BMU+ Aiyima A07 MAX (x2) + Arcam One
HP: HifiBerry Digi+ PRO + Sabaj A10d
Office:
Allo DigiOne SIG + SMSL M300se + Douk G4 (x2)
Mission 760 + Monolith THX AAA 887
Headphones: German Maestro, Monolith & AQ

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Re: Curiosity gets the better of me (again)

Unread post by Fretless »

A week further, the XLR links have run-in and the Sabaj A10 DAC/monoblock combi is doing amazing things for an entry-level set. Bass is now rich and deep. Pinpoint imaging and a soundfield that draws you into the recording.

Makes me wonder what the A20d DAC (with MQA) and A20a amps (more power) can do.

I have never had a system that is so capable of the resolution and detail this setup is producing.

:music-listening:



Oh and no Deep Purple at this moment but Johann Johannsson's 'Arrival' soundtrack where I'm picking up on layer upon layer that I've not heard before.
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antonio66 (Tue Mar 14, 2023 6:28 am)

Upstairs:
Vinyl
Pro-Ject 1.2 + Grado Sig Jr + Cambridge Alva Duo
DigiVolumio PC + Kiss DP-500 + Sabaj A20d
NVA: P50sa - Cube2 - SSP - LS6+ Sabaj A10a (x2)
Downstairs:
Vinyl
Logic DM101 + Syrinx LE1 + Grado Sig MCX
DigiDenafrips Ares II + Volumio PC + Cambridge CXC
NVA: P50 - BMU+ Aiyima A07 MAX (x2) + Arcam One
HP: HifiBerry Digi+ PRO + Sabaj A10d
Office:
Allo DigiOne SIG + SMSL M300se + Douk G4 (x2)
Mission 760 + Monolith THX AAA 887
Headphones: German Maestro, Monolith & AQ

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Re: Curiosity gets the better of me (again)

Unread post by Fretless »

Haven't had a rant about my Class D amps for a while (sensitive audiophiles can stop reading now!).

The pair of bridged Sabaj monoblocks are now well-and-truly run-in and the recent addition of the upgraded A20d 2022 DAC along with DH Labs Air Matrix XLR interconnects took the system to a significantly higher plane. It became time to get this installation tidied up and repositioned so that the amps could get a chance to really reveal what they are capable of.

Image

Last year's vinyl fixation has now diminished (enormously) and Digital is back to being my main music source. I can only think that after years (decades?) of trying to get my digi-rigs to sound as 'Analogue' as possible, now that the turntables are in place - the streamers and CD can just be themselves without having to try to sound like an LP. Certainly the experience has changed my listening tastes and altered my perspective on digital playback. Apples and Pears, Cheese and Onions - don't compare, simply accept.

Changes:

1) shifting the amps: The phono stage and NVA P50 go underneath and leave room on the middle shelf for the Sabaj kit. A20d DAC in the middle with A10a amps on either side. Room to breathe and less RF/EMF interference from each other.

2) DAC: The A20d 2022 is an exceptional unit, providing a clarity and versatility that competes with designs many time the price.

3) interconnects: DH Labs created the Air Matrix with a special foam surround for the conductors that is 60% air, this reduces capacitance to almost zero and these cables remain the best i/c that I have ever had. Short length (50cm) and their own chunky XLR plugs make these a perfect connection to let the amps shine.

4) USB streaming PC: The Acer PC was just too noisy with whirring disk-drives and a whispering cooling fan. The Frankenstein-PSU Intel i7 PC (far right on photo) from the lounge was swapped in and its silent operation was a big relief. The Acer is now in the lounge and in a spot where it is completely inaudible. Win-win. I'll do a post soon about that setup with the upgraded Denafrips Ares II.

5) USB cables: The one annoying feature of the Sabaj 2022 DACs (A10d & A20d) is that USB input is via a smartphone-sized USB-C socket, this severely limits your options about high-quality audio-grade cables (or you need an adaptor with possible SQ consequences). The only 'good' USB-C-equipped link I could find was the AudioQuest Carbon. Although this version is very different to the thicker and heavier USB-B version. The lesser shielding became evident as the system sounded somewhat dull and subdued - until I spotted that the Carbon USB-C lead was lying across other cabling. Allowing it to run free and clear of other wires put the sparkle back in the sound. Also, running from the PC to the Oehlbach USB Masterclock is a DH Labs Mirage - probably the best USB link that you will find without having to pay silly money for an esoteric, boutique-made example.

Also took the opportunity to generally tidy up the mains cabling and leave the speaker leads free of interference.

I've said it before - but I'll say it again; this setup is stunning, just breathtaking with the right music. The forward and highly-detailed character makes if unforgiving of rougher, edgier recordings though. The new XLR cables bring a space and sweetness to the soundfield that allowed me to switch the DAC's PCM filters to run at the highest frequencies without sounding overly bright.

There is a different perception to the lounge system, with the Denafrips DAC and NVA amps (running pretty well the same cables) being 'rounder' and more forgiving. Which is better? Can't say - won't say. Different, certainly. The Upstairs setup has me hooked at the moment with its astonishing resolution that is revealing so many new layers in favourite albums.

It would seem that Class D amps have matured, certainly with newer generations of processors, and these models from Sabaj prove that high-quality sonics can be had at a modest price.

Rant over - as you were. :handgestures-salute:
These users thanked the author Fretless for the post (total 4):
CN211276 (Fri Apr 28, 2023 12:32 pm) • slinger (Fri Apr 28, 2023 12:42 pm) • antonio66 (Sat Apr 29, 2023 7:01 am) • George Hincapie (Sat Apr 29, 2023 11:29 am)

Upstairs:
Vinyl
Pro-Ject 1.2 + Grado Sig Jr + Cambridge Alva Duo
DigiVolumio PC + Kiss DP-500 + Sabaj A20d
NVA: P50sa - Cube2 - SSP - LS6+ Sabaj A10a (x2)
Downstairs:
Vinyl
Logic DM101 + Syrinx LE1 + Grado Sig MCX
DigiDenafrips Ares II + Volumio PC + Cambridge CXC
NVA: P50 - BMU+ Aiyima A07 MAX (x2) + Arcam One
HP: HifiBerry Digi+ PRO + Sabaj A10d
Office:
Allo DigiOne SIG + SMSL M300se + Douk G4 (x2)
Mission 760 + Monolith THX AAA 887
Headphones: German Maestro, Monolith & AQ

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