Class D = Trash?

madavid0, you can expect at least 600 hours to 1200 hours of break-in before a class D amp reaches peak performance.

Basically, owning a class D amp requires a modicum of patience... These are not instant gratifiers.

Like with any other classes of amps, some class D amps are extremely good, and other ones, hummmm.... Should best be marketed through Home Depot for chasing squirrels and other varmints from attics.

But no, I am not faintly implying that D-Sonic amps are poor... On the contrary. Most of them are based on Pascal power conversion modules, which are extremely good. Amps based on Pascal M-Pro2 and X-Pro2 or X-Pro1 are likely very good performers, if one is patient enough to break them in.

Lastly, feeding any amp with an arbitrary PC whose only claim to fame is its heavy gage may not be the most effective strategy for getting best results from such device, no metter its class of operation.

Saluti, Guido

I fully expect your D-Sonic to sound pretty ragged right now. And you should be prepared to its performance to fluctuate quite a bit for the first few hundred hours... Yes, this means that on occasion it might even sound worse than it does now.... But gradually it will trend for the better, and fluctuations will taper off.

If you have an old FM tuner, feed your amp FM interstation hash whenever you are not using... Even at night that is... THis will accelleate break in.

G.

madavid0, what your amp does now is most likely a break-in artifact... Discount it for the next two weeks or so.

If the behavior persists towards the end of the 3rd week, try switching the left/right inputs of the amp around. If the problem changes channel, there is something amiss in the electronic or wire chain.

G.

Hello madavid0, please let me be the first to extend to you a warm welcome to the wonderful world of class D breakin Purgatory!

For the next few weeks you shall be our guest... Though shall be regaled by the experience of gnashing of teeth, extreme audiophrenic anxieties, buyer's remorse, snarky comments from wife and friends, plunging self-worth, desperation, upset stomach, gastritis, duodenal ulcerations, persistent tremors, and occasional night terrors.

Please do not despair... Know that there is light at the end of this grizly tunnel.... Sorry, we know you can't see it yet... 'Tis around an untold series of nasty bends, dips, collapsing sound stages, intermodulative shrieks, tubby corners, and halls filled with revolting audio mud.

Please find in the left pocket of your seat a 500 count jar of 250 mg generic Valium fast-acting jell caps, a miner's helmet, and a silicon audiophile-approved teeth guard... Please use the teeth guard during rest periods to prevent teeth from shattering from the inevitable gnashing. Always wear the helmet to prevent head injury when hitting the roof during inevitable fits of audiophrenic rage.... And use Valium as needed to reduce anxiety to a bearable level.

Please enjoy your ride!!!

Signed:

Your devoted Class D Break-in Purgatory Administrator (CDBPA)

Very interesting point about switching frequencies… What is the acceptable switching friequency range is targeted by the pundits?

Given that break-in of a class D power amp ranges from 600 hours to approximately 1500, asking a manufacturer to exercise the device for upwards of a couple of months before shipping it to a dealer may be woefully unrealistic… Of course, everything is possible…. For a commensurate list price uplift.

G.

madavid0, my experience with class D amps I had in my system is that two amps based on NCore and three based on ICEpower took about 1K hours. However, my current Rowland M925 monos reached at least 1500 hours before stabilizing.

G.

Aberyclark... Hmmmm.... Really?!

George, funny thing that, trusting my own ears, I really can't hear any artifacts in my gear... SMPS switching at 450 Khz or so. Real heavenly actually.

But I admit that some amps switching at similar frequencies are the ones that should be marketed only as varmint chasers *Grins!*

G.

@ mmrkaic

On the contrary, I enjoy the sound of good class D as much as good class A/B and even some tubes.

My own Rowland M925 amps, for one thing, sport NCore NC1200 modules, and run in class D.

G.

@ jonasandezekiel

If the amps are a recent purchase, they may not be properly broken in. Give them some 1000 hours of break-in... They should have sweetened considerably, and the bass should be rendered OK. However, until now, W4S has not been one of the Class D brands with a house sound that has delighted me at RMAF.

G.

@ retrofunk

I have not heard the Thors yet, but I have tested at length the Merrill Audio Veritas and Teranis... My friend Merril makes wonderful amplifiers indeed, so I am not at all surprised that you are enchanted by the Thors. With 500 hours, your Thors will sound great, but they might continue to bloom further for as many more hours... Feed them some white noise or FM interstation hash at lowish volume whenever you are not listening to them, including night time... That will maximize the break-in speed.

G.

@2channel8There

@2channel8T@2channel8

@2channel8T@2channel8T

There is s nothing unique in class D break-in and re-breakin.... Amps of any type, if sufficiently complex, will take hundreds of hours to break-in.... Even the basic music system in my Toyota Prius took months to sound decent. My class A/B ROwland M625 stereo and M725 monos took about 1000 hours to sound their best. 

The 1500 hours I mentioned is the upper limit of my own experience with amps... It did take about that much for my Rowland M925 monoblocks to stabilize.

As for needing to re-break-in, it all depends on how long devices have been off line. If I leave my system offline for several days, a few hours of warm up returns the system to top performance level.. On the other hand, when I moved from TX to SC, my system was in storage for over 6 months... When I finally reconnected and restarted it, it took a couple of weeks for it to return to top performance... Perhaps 300 hours of making music at minimum volume.

G.

All, the aforementioned "red hering" suggestion that upwards of 1000 hours and sometimes more might be required to break in a class D amp, or for what it matters, a class A/B amp, SS or tubed linestage, or CDP comes from me.

Over the years I have broken in a number of pieces. They all eventually stabilized with break-in times largely hovering around the 1K hours mark with some exceptions. Many of them created eventually thir own special kind of magic. Some did not at all, no matter my persistance. Shown below are only the ones which in time delivered real music:

Aragon 4004 (A/B) approx 1K hours

Rowland M312 (D) approx 1K hours

Bel Canto REF1000 Mk.2 (D) Approx 1K hours

Bel Canto REF500 (D) approx 1K hours

Rowland M625 (A/B) approx 1K hours

Rowland M725 (D) approx 1K hours

Rowland M925 (D) More than 1500 hours

Merrill Veritas (D) approx 1100 hours

Merrill (Teranis (D) approx 600 hours

ARC LS2B (linestage hybrid) approx 1K hours

ARC REF3 (Linestage tube) approx 1K hours

Rowland Capri (linestage SS) (approx 1100 hours

Rowland Criterion (linestage SS) approx 1100 hours

Rowland Power Storage Unit approx 200 hours

Rowland Aeris DAC greater than 1500 hours

Esoteric X-01 (CDp SS) approx 1K hours

Esoteric K-01 (SS CDp) approx 1200 hours

GamuT CD-3 (CDp) approx 800 hours

As for warm up from power-on time for a well broken-in piece, I experienced it to vary from about one hour to about one day.

I claim no particular scientific knowledge. I purely rely empirically on my own old ears, which I have used one way or another for listening, studying, and occasionally performing music for some 60 odd years.

Doubtless, other equipment might behave differently. Besides, you might not experience the same long break-in curve as I did. If your quest for sonic nirvana is on a steeper curve, more power to you.... But if you find that after a couple hundred hours of installing a new piece nirvana has not yet reached you, you may want to wait a bit before succumbing once again to Upgraditis Furiosa.... Patience can be Golden!

G.

Good points @sfseay and Geoffkait....

No, I have not sat on my thumbs for thousands of hours, but yes, I typically assess the sound periodically  on a number of CDs, particularly on a test CD containing several key tracks that I compiled in 2005. Yep, still use the same one for consistency, amongst other ones.

I also have developed an automated spreadsheet tracker that I have used for a decade or so to track and annotate progress.

When possible, I drive a music signal or FM instation hash through the system whenever I am not listening to music... Yes, this means also night time.... If not FM radio is available.... Like in my current setup, I play music at low level or a break-in CD containing hash.

If the weather is stormy, I disconnect the entire system from the AC mains.

I am sure that time of day, weather, AC mains load all play a part on any particular data point.... However, if the long term trend looks like a stockastic curve pointing upwards, I venture to guess that things are moving in the right direction.

And you guys are correct..... Do not trust me nor anyelse's ears, no matter their particular metallurgy.... Golden, Silver, Tin, Transuranic, leadden, or otherwise.... Use your own ears as much as you can, and well... Yes... Trust them... It's your musical taste that counts, not mine.  If you do not, you will turn into a paper audiophile.

G.

Hi George, it Seems that when I try to follow the links you just posted, I end up on an image instead of a regular page.... As my screen reading software cannot decipher images, may I ask you to post links to the actual pages, or to post the model of amp you are referring to?

Al, past the 500 hours mark, performance trof should be relatively minor on the Rowland Continuum S2.... Gradually, sound will continue to open up for quite a spell.

Saluti, Guido

Thank you Al, Rowland M102 is the most entry level class D amp that Rowland ever created. The model is almost 10 years old, and is today hardly representative of what can be done with class D and with SMPS. M102 has been discontinued a couple of years ago, and has been replaced by the M125, which sports a much newer ICEpower module, supports bridged mode operations via a toggle switch in the back of the chassis thus delivering 500W per chassis, and contains several other technical updates. According to all 3rd party reports I heard, M125 is an exceptional little amp... Far superior to the original M102.

G.

Hi @stevecham, for a different perspective on class D amp, you might want to read the following thread:

https://forum.audiogon.com/discussions/class-d-is-just-dandy

There is a rapidly growing number of music lovers are adopting class D amplification and are loving it. Having said that, not all class D amps are able to make wonderful music... But isn't this true of all amplifier topologies?!

Regards, G.