A New Wave of Class D Integrated Amplifiers

[Kal Rubinson]

Kal - If I use the REW software with a calibrated mic (either the one you suggest or the Drayton one that comes in ML's PBK kit), would you suggest that the mic is pointed towards the speakers or upwards towards the ceiling?

I ask because the Dirac instructions say point upwards, but my results were poor, probably as there's a pendant light above some measurment positions. This causes the left speaker to play louder when the filter is engaged. I hope you'll say it's usually best to point towards the space midway between the speakers. Thanks. Peter

The problem with pointing them towards the speaker is the significance of the speaker's radiation pattern, aiming accuracy and specific goals. The three are interactive.
1. If your goal is purely to fix low frequencies and modal-range EQ, it does not matter how you aim the microphone since LF radiation of most speakers (not panels or dipoles) approaches omnidirectionality as does the directional response of the microphone.
2. If your goal is to extend the EQ above that range (i.e., above the Schroeder or critical frequency), you can aim the mic directly at the speaker with REW and take measurements from one speaker at a time, although the mic is likely to be more directional than your ear(s).
3. With Dirac and many other EQ systems which sweep both/all speakers from each mic position, aiming the speaker upwards provides equal treatment for all the speakers above the critical frequency and is also suitable for all the speakers below the critical frequency.
4. Pointing the mic to the mid-way point between the speakers is possible but I'd suggest you consult John Mulcahy at REW. I've done it to characterize a pair of speakers but not for EQ purposes.

 

[Hear Here]

The problem with pointing them towards the speaker is the significance of the speaker's radiation pattern, aiming accuracy and specific goals. The three are interactive.
1. If your goal is purely to fix low frequencies and modal-range EQ, it does not matter how you aim the microphone since LF radiation of most speakers (not panels or dipoles) approaches omnidirectionality as does the directional response of the microphone.
2. If your goal is to extend the EQ above that range (i.e., above the Schroeder or critical frequency), you can aim the mic directly at the speaker with REW and take measurements from one speaker at a time, although the mic is likely to be more directional than your ear(s).
3. With Dirac and many other EQ systems which sweep both/all speakers from each mic position, aiming the speaker upwards provides equal treatment for all the speakers above the critical frequency and is also suitable for all the speakers below the critical frequency.
4. Pointing the mic to the mid-way point between the speakers is possible but I'd suggest you consult John Mulcahy at REW. I've done it to characterize a pair of speakers but not for EQ purposes.

Thanks Kal - all very helpful and logical.

In fact I have 2 EQ options in my present system. Dirac Live in my NAD 33 amp and Avantgarde XD in my Duo speakers.

The former measures the response and provides a visual display of each speaker's performance. It scans the full range but only allows for adjustment below 500 Hz as I haven't bought the full-range upgrade.

The latter doesn't include the response scanning facility but does allow comprehensive adjustments to each active bass speaker's response curve (and crossover type (but I'll stickwith Butterworth 24dB) - so below about 200 Hz. All adjustments have to be judged by one's ears so starting points are difficult to assess.

It's only the bass I'm able to adjust by either system, so your opinion that pointing the mic towards the speakers for bass-only measurement suits me. Thanks for that.

My initial Dirac filter (produced by pointing the NAD-supplied mic upwards as recommended) resulted in poor sound. The obvious problem was the left speaker has become louder - presumably as there's a light fitting above the left side measurements points, possibly affecting 4 of the 9 single-chair readings. Also the bass became rather lightweight, so perhaps it was set on the speakers a bit high.

I've been hesitant in doing more measurements, but perhaps I'll raid the PBK for its calibrated Drayton mic and re-do Dirac, but pointing the mic forward. The resultant response graphs will allow me to make adjustments to the XD speakers and this may avoid the need to engage the Dirac filter altogether - but I'd still have this as an option if it improves the sound.

Many thanks again. Peter

 

[Kal Rubinson]

PBK for its calibrated Drayton mic

? Can you access and use the calibration file in DL? I tend to use the Umik-1, OmniMic2 or GoldLine mics rather than the device-provided mics.

BTW, DL up to 500Hz should do it but you might want to pay attention to the choice of target curve.

 

[Hear Here]

? Can you access and use the calibration file in DL? I tend to use the Umik-1, OmniMic2 or GoldLine mics rather than the device-provided mics.

BTW, DL up to 500Hz should do it but you might want to pay attention to the choice of target curve.

Not sure but I'll check about importing the calibrations. Thanks again. Peter

 

[Kal Rubinson]

Not sure but I'll check about importing the calibrations. Thanks again. Peter

If you can't import the calibration curve, you can't transfer the "calibrated" mic to the other device.

 

[KyoichiOda]

Hello everyone, I listened Technics SU-R1000 with following system:
Speakers: Focal Kanta N2
Analog source: Acoustic Arts Player 1 (as CD player)
Digital source: io-data fidata HFAS1-H40 (NAS as music server)

As you know, SU-R1000 works as full digital amplifier for digital input,
with direct conversion from PCM or DSD to PWM.

It sounds very clean, clear and smooth like nice breeze in summer mountain with high resolution.
However mid and bass are thin and light. I recalled the sound of Magnepan.

Digital input from fidata sounds better than analog input, as its resolution and tonality.
In my view it is the best except phono input I didn't listen this time.

 

[Addicted to hifi]

Hello everyone, I listened Technics SU-R1000 with following system:
Speakers: Focal Kanta N2
Analog source: Acoustic Arts Player 1 (as CD player)
Digital source: io-data fidata HFAS1-H40 (NAS as music server)

As you know, SU-R1000 works as full digital amplifier for digital input,
with direct conversion from PCM or DSD to PWM.

It sounds very clean, clear and smooth like nice breeze in summer mountain with high resolution.
However mid and bass are thin and light. I recalled the sound of Magnepan.

Digital input from fidata sounds better than analog input, as its resolution and tonality.
In my view it is the best except phono input I didn't listen this time.

That’s a very nice system you have there.

 

[CKKeung]

Purifi launches a new and higher class D amp module :

 

[CKKeung]

Output Power: 950W(2?), 500W(4?), 250(8W?)
Output Current: ~40A
THD+N: <0.00035% @ 200W, 4?, 1kHz
Dynamic Range: ~129 dB(A)
Output Noise: ~14µV(A)
Gain: 13dB
Output Impedance: <13µ? @ 1kHz
Efficiency: 94% @ 500W, 4?, 1kHz
Idle losses (outpt stage): 2.8 W

 

[CKKeung]

 

[CKKeung]

 

[The Knife]

Ive got the Technics SU-R1000 the other week. In black. Fantastic combo with a pair of MLs 11.

Technics SU-R1000 Integrated Amplifier - The Absolute Sound

Technics SU-R1000 Integrated Amplifier - This new and innovative integrated from lives up to all the claims that Technics makes for it, earning a top recommendation from Tony Cordesman.

www.theabsolutesound.com

A review with decent praise...

 

[The Knife]

Trying out a new Wireworld Silver Electra on the Technics. 2 hours of burn in so far. Long way to go, but I think it sounds pretty amazing already.

 

[Ric Schultz]

If you raise all your cables off the floor you will have much better imaging and space.

 

[Addicted to hifi]

If you raise all your cables off the floor you will have much better imaging and space.

Yes it definitely improves the sound when you raise your cables off the floor.

 

[CKKeung]

AGD Tempo di GaN Stereo Amplifier :
https://agdproduction.com/tempo/

Review :
http://www.enjoythemusic.com/magazine/equipment/1221/AGD_Tempo_di_GaN_Stereo_Amplifier_Review.htm

 

[Cellcbern]

Still haven't heard a Class 'D' device that sounded musically natural enough to own except when partnered with a tube preamp. The least Class D-sounding, and most musical Class 'D" amps I've ever heard are the AGD GaN Tube monoblocks (Gran Vivace and Audion) which I listened to earlier this month at Capital Audiofest. Used with the AGD Andante analogue solid state preamp/DAC/streamer/phono stage combo most but not all of the characteristic Class D electronic overlay ("haze", "fog", ....?) was banished. As good as these amps sounded at CAF they would have to be paired with a top shelf tube preamp to be in the same league as my modified Pathos TT RR.

 

[Cellcbern]

AGD Tempo di GaN Stereo Amplifier :
https://agdproduction.com/tempo/

Review :
http://www.enjoythemusic.com/magazine/equipment/1221/AGD_Tempo_di_GaN_Stereo_Amplifier_Review.htm

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Saw this one at Capital Audiofest but only got to listen to the two monoblock models.

 

[The Knife]

Saw this one at Capital Audiofest but only got to listen to the two monoblock models.

Still haven't heard a Class 'D' device that sounded musically natural enough to own except when partnered with a tube preamp. The least Class D-sounding, and most musical Class 'D" amps I've ever heard are the AGD GaN Tube monoblocks (Gran Vivace and Audion) which I listened to earlier this month at Capital Audiofest. Used with the AGD Andante analogue solid state preamp/DAC/streamer/phono stage combo most but not all of the characteristic Class D electronic overlay ("haze", "fog", ....?) was banished. As good as these amps sounded at CAF they would have to be paired with a top shelf tube preamp to be in the same league as my modified Pathos TT RR.

Have you had the chance to listen to the Su-R1000?

" The new Technics SU-R1000 integrated amplifier is one of the most innovative and best-sounding pieces of electronics I’ve had the opportunity to audition in recent years. "

Anthony Cordesman, The Absolute sound

You realize he means this regardless of construction or price?

I have listed to this "little"23kg box now for two weeks straight and I can not here anything digital about it. In fact, it sounds more natural and acoustic then basically everything else I have ever listened to. The Apurna PRÉLUDE might beaten the SU-R1000 in sheer "weight" and "punch", but does not reach the same "shimmer". The Apurna is 60k USD ca, so that is ok, even if it would. Of course I understand what is true for me might not be true to you, but that does not worry me to much.

 

[Cellcbern]

No I haven't, but I will when I have the opportunity because I am curious.

Here's an excerpt from a Twittering Machines review of it (link below):

"....I’ve been listening to Fassbaender’s Winterreise since its release in 1990 so we know each other well and the Technics driving the DeVore’s with the Auralic G1 converting the ripped CD’s bits to analog, I was treated with a rich and rewarding rendering. That said, I have heard more saturation from the Line Magnetic Audio LM-845iA Integrated Amplifier (review) making for a greater emotional connection to this emotional music but at the expense of the Technic’s cooler control and greater sense of clarity....."

That's about what I would expect from Class D, and my listening biases are such that I would take the greater tonal saturation and emotional connection to the music of the Line Magnetic tube integrated, over the greater control and clarity but cooler sonic signature of the Technics every day of the week. A similar finding is in the Absolute Sound review that you excerpted, if you read the whole thing. It describes the Technics amp as extremely neutral and lacking in colorations - always code words in my experience for a cool sonic signature, whether in an amp, cable, cartridge, etc. Doesn't mean the Technics is not a good amp or that you wouldn't love it.

Review: Technics Stereo Integrated Amplifier SU-R1000 - Twittering Machines

Michael Lavorgna's Twittering Machines: HiFi with a twist

twitteringmachines.com