Switching from A/B to D - Looking for Insights

[2.82 MHz]

Hi Everyone,

For amplification, I am currently running two Cyrus Power in mono, both augmented with separate Cyrus PSX-R Power Supply units. This combination is rated 110 W per channel into 8 Ohms. Below I explain my set-up in more detail. I currently plan to switch to class D, eg, boxem. Reasons: smaller footprint (check), higher energy efficiency (check) - better sound (now that's the big question).

I fully understand that no one has made this exact switch, in this exact set-up, and that is not what I am looking for. I am interested if people have made similar switches from a somewhat solid A/B design to a more recent D design, and if they were all happy campers, or is it all with a grain of salt. As you will see from my set-up below, I am using the Topping D70S DAC also as a pre-amp. In my opinion, I have to crank up the volume quite a bit (eg, to -30 dB), to reach a substantial playback level.

I am mostly listening to classical music, in concert in different venues, and on my stereo - for me that means that I should know, to some extent, how instruments and ensembles sound. And when a stereo is capable to deliver Mahler's 3rd, then there should be no issues with reproducing Metallica to reasonable satisfaction. And I need to say that the Cyrus have my speakers quite well under control to deliver on that.

This is my current set-up:

For physical SACD/Blu-Ray/DVD-A playback:
[Universal Player] Sony UBP-X800M2 (HDMI Audio Out) ► [HDMI Audio De-Embedder/Extractor] Noname (I2S Out) ► [DAC + Pre-Amp] Topping D70S (I2S In - XLR Out)

For CD playback:
[CD Transport] Audiolab 6000CDT (Coax Out) ► [DAC + Pre-Amp] Topping D70S (Coax In - XLR Out)

For Streaming:
Tidal (Hifi/Master) ► [Streamer] Logitech Squeezebox Touch (USB Out) ► [DAC + Pre-Amp] Topping D70S (USB In - XLR Out)

The rest of the chain is
[Amp] Cyrus Power Monoblocs w/ external power supplies (XLR In) ► [Speaker] Audio Physic Yara (1st Edition - nominally rated as 4 Ohm speakers)

Any insight is much appreciated - thank you very much!
Dominik

 

[DVDdoug]

An amplifier isn't supposed to have any particular sound... It's just supposed to amplify and most solid state amps do a good job of that.

Frequency response and distortion are almost always better than human hearing as long as it's not over-driven into clipping. But sometimes there is audible noise. All amplifiers (all analog electronics) generate some noise, and if it's audible or not depends on how close you are to the speakers and how efficient-sensitive your speakers are. The dominant noise is usually hiss or power line hum. Unfortunately, different manufacturers have different measurement standards so you can't compare the published specs. (You can compare the measurements here at ASR or any independent "apples-to-apples" measurements.)

 

[Multicore]

If you're current power amps are sufficient to drive your speakers to the SPL you need, you should not notice much difference. If you want to buy new gear because that's your hobby, go for it.

Btw, I don't think Metallica is a good test. It sounds loud no matter what you play it on. Something with lots of clean low bass is a better test, I think. 2nd m. of Berlioz Fantastic Symphony (kinda concieted title he chose for that, eh?:^), solo piano with low notes, Bill Laswell's dub recordings, or some ECM thing with a lot of Dave Holland.

I upgraded from a good 85 Wpc AB amp to a 250 Wpc Hypex and the improvement I notice is that I can use fairly aggressive room EQ and the bass sounds clean even when it's pretty loud. Nice for music but for watching movies and TV with special effects, this can be a problem since those movies like to use a lot of whispering dialog for extra dramatic effect.

 

[fpitas]

If you want a straight wire with gain sort of amp, the Purifi used in the boXem is awfully close. Your old Cyrus amp wasn't bad at all either, so the sound will be very similar.

 

[Multicore]

Wait a minute, are you currently using vintage English Cyrus "audiophile" amps, bridged and with upgraded power supplies? If so, by all means replace that with something that's been designed and verified to work over a wide range of difficult loads and sufficient power for your needs. The reason: it removes all doubt about the amps messing around with the music. This is the value of transparency: when you know you have it you can stop fussing over gear and spend that attention on music instead.

 

[FeddyLost]

As far as I heard about Cyrus "sound" and seen, unfortunately, rare measurements, you must not lose some "musicality" with exchange to Purifi.
Only power and LF control will rise.
But, as always, there are some chances that "timbres will go wrong", because
1) you are already know that you are changing AB to D
2) this amp have custom input buffer and no independent measures

 

[restorer-john]

higher energy efficiency (check)

Measure the power consumption of your existing amplifier at idle and typical volume settings. You may well be surprised how little class AB amplifiers actually use in real life situations.

Then compare it to the class D you are considering in the same conditions.

Manufacturers consumption specifications are mostly all over the place and highly innacurate or not representative of your own usage scenarios.

 

[pma]

Measure the power consumption of your existing amplifier at idle and typical volume settings. You may well be surprised how little class AB amplifiers actually use in real life situations.

Then compare it to the class D you are considering in the same conditions.

Manufacturers consumption specifications are mostly all over the place and highly innacurate or not representative of your own usage scenarios.

Yeah, 14W at idle or "normal" listening level, though it has healthy 100mA class AB quiescent current. My NC252MP eats 17W at idle.

 

[Sokel]

Measure the power consumption of your existing amplifier at idle and typical volume settings. You may well be surprised how little class AB amplifiers actually use in real life situations.

Then compare it to the class D you are considering in the same conditions.

Manufacturers consumption specifications are mostly all over the place and highly innacurate or not representative of your own usage scenarios.

My combo (class D) draws 40 watt idle,I have measured it.

 

[restorer-john]

My combo (class D) draws 40 watt idle,I have measured it.

Is that one stereo amplifier or a number? (multichannel).

 

[Sokel]

Is that one stereo amplifier or a number? (multichannel).

2 amps,active stereo,Ice power edge 1200as2+300a2 (hooked up together as 1200 is also the power supply for the 300).

 

[restorer-john]

2 amps,active stereo,Ice power edge 1200as2+300a2 (hooked up together as 1200 is also the power supply for the 300).

That's pretty good.

I have restored vintage receivers where I knocked 15 watts off idle consumption just by changing out incandescent dial/meter/source illumination to LEDs.

It all adds up when gear is left on for many hours at a time, both in heat and wasted energy.

 

[Sokel]

That's pretty good.

I have restored vintage receivers where I knocked 15 watts off idle consumption just by changing out incandescent dial/meter/source illumination to LEDs.

It all adds up when gear is left on for many hours at a time, both in heat and wasted energy.

Good thing is they automatically go stand-by after 13 minutes (that's default,off the factory) and there they only consume 0.5 watt and they fire-up with signal (or trigger,configurable).
I just set them up and forgot they exist since then.

 

[ldarieut]

Something with lots of clean low bass is a better test, I think. 2nd m. of Berlioz Fantastic Symphony (kinda concieted title he chose for that, eh?:^),

Fantastique in french as "Fantasy", not fantastic: bad tanslation.

 

[Multicore]

Fantastique in french as "Fantasy", not fantastic: bad tanslation.

There's a smiley.

In the old days before everything switched to Unicode, this is how we emoted in the BBS and IRC. Now of course people use images like . It feels weird for me to use childish stuff like that because I'm old and it's not my style. It would be like if I used, like, the manners of speech of, like, teenagers. Gross.

In other words, the part in parens was a joke, and I'm sorry this wasn't clear enough.

 

[Redwine]

One of the main difference for me when comparing traditional class A/B and classD is, that with last mentioned I play louder, likely because less noise and better control of speakers. Further better control means I get better insight into details and less “booming” sound.

 

[Galliardist]

I don't see it being a problem here, but do make sure that input impedance and gain is suitable with any replacement power amp as well.

 

[AkodoGilador]

Wait a minute, are you currently using vintage English Cyrus "audiophile" amps, bridged and with upgraded power supplies? If so, by all means replace that with something that's been designed and verified to work over a wide range of difficult loads and sufficient power for your needs. The reason: it removes all doubt about the amps messing around with the music. This is the value of transparency: when you know you have it you can stop fussing over gear and spend that attention on music instead.

This graph is from Sound Stage Network's analysis of Cyrus' (current) top-of-the-range integrated amplifier, the i9-XR:

And this is from Amir's review of the Purifi 1ET400A:

Alex

 

[fpitas]

One of the main difference for me when comparing traditional class A/B and classD is, that with last mentioned I play louder, likely because less noise and better control of speakers. Further better control means I get better insight into details and less “booming” sound.

Unless your speakers are active, any DCR in the woofer lowpass inductor will reduce the DF considerably. Something to consider when looking at the tremendous DF of some amps.

 

[AkodoGilador]

Unless your speakers are active, any DCR in the woofer lowpass inductor will reduce the DF considerably. Something to consider when looking at the tremendous DF of some amps.

DF is Damping Factor, right, but what's DCR?

Alex