No distortion heard here, and honestly, when not hearing it through headphones, it’s pretty unlikely distortion in the master but most likely in the path to your speakers. Any involved component in that path is suspect…
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Thanks Marin. Guess I’m looking at new speakers then.
Wonder why any time I do hear this distortion it’s always on tracks with rhythmic electric guitar though, and not jazz, acoustic, electro etc
Not so fast, young Padawan…
Rather have an amp with too much power on tap than an underpowered one.
On another note, is the offending sound evident only from a certain loudness on, or over a wide range?
You could switch speaker cables to see whether that clipping guitar in the left channel does the same in the right…
Even try replugging all associated cables to maybe identify a semi optimal contact…
Another idea would be putting your ear as close as possible to the individual drivers, to see if it’s recognizable over all of them, or just one.
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What’s your signal chain before the amp, maybe some overload on the line level side of things?
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1% THD is fairly typical for many Amps at rated power output - it’s an indication of the amp starting to clip.
The amp is rated at 400W into 2 ohms, so it’s good for just a shade over 14amps output current.
Power cord won’t make any difference. I can’t tell if you’re in the UK/Europe or the other side of the pond.
If you’re in the UK, at the maximum output, you’re pulling about 4 Amps off the mains. If you’re in the US/Canada, you’re pulling about 8 Amps. That won’t tax even the thinnest of mains leads. Kettle lead was mentioned - a typical kettle in the UK is about 2.2kW, a “fast-boil” kettle is nearer 3kW.
A typical IEC kettle lead is 1.0mm2 - not up to the rating of a kettle continuously (a kettle boils in about 3 minutes, so there’s quite a safety margin) but will handle 10Amp continuously without overheating.
As Marin mentioned, it’s better to use an amplifier that can overdrive your speakers - your speakers will ‘pop’ as you hit the driver excursion limits if your ears can take the noise level.
If you use an amplifier which isn’t powerful enough and run it to clipping, you risk blowing your tweeters. A clipped amp generates a square wave, so the power distribution changes to higher frequencies ( a square wave is basically a fundamental sine wave, plus 1/n amplitude nth harmonics).
If you’re experiencing audible distortion, then it could be something in the signal chain that’s clipping, or it could be a fault with the amp. It looks like your speakers have plenty of headroom and your amp is in no way lacking unless your listening room is the size of a concert hall.
EDIT: I just noticed the query about “dual mono” - it’s probably stated this way because the amplifier has a dual mono topology, i.e. it’s built like two monoblocs in a single chassis often utilising separate power supplies to each channel, whereas many integrated amps and lesser power amps often share the power supply and voltage & current gain stages for both channels are on the same board.
EDIT 2: Yes, it is a dual mono. Internal photos show two distinct class D amplifier modules:
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Having just read John Atkinson’s measurements section of Stereophile’s review of the Amp+, it seems Mytek is a little, ahem, generous with their specs. Into 2 ohms, the amp went into protection mode at 103.7 W, so it seems output current is limited to about 7 Amps RMS rather than the 14 or so indicated by the specs.
If you’re playing music really loudly, you might hear distortion where the speaker’s impedance is at it’s minimum of 3 ohm, but I honestly doubt that you’re pushing things that hard as you’d be at ear-splitting volume levels.
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Thanks for your input and replies guys. I’ll respond tomorrow once I’ve digested it all and tried a few things.
I’ll address your points individually Marin
The offending sound is worse when louder I think. , although I don’t ever play all that loud really.
I tried switching cables, no difference
Ive unplugged all the cables
I put my ears to the drivers and strangely with the offending song that you also listened to it didn’t sound as bad close up.
Hi Graeme, On your comment about blowing the tweeters - i presume if a tweeter is blown it is effectively useless and no sound is produced, or could it just underperform and produce fauty sound on occasion like I am experiencing?
As regards volume of listening, I’m not playing music really loudly as it would disturb family and neighbours (I’m in semi detached house with thin walls)
… meaning, it’s still occurring in the same speaker, or did the offending sound move to the other speaker?
If staying with the one speaker, then something’s faulty with that speaker.
If moving over to the other speaker, something upstream is the culprit and needs further investigation, like changing channels to the amp, i.e.
Did you activate Roon’s clipping indicator as advised, any red flashing to be seen?
And putting your ears to the drivers, do you hear something offending from all drivers, rather indicating something upstream, or just one driver, likely indicating a deformed voice coil scratching in the magnet gap.
I’m not @Graeme_Finlayson, but usually a tweeter voice coil melts and opens up when overdriven too hard, yes.
Midranges and bass drivers often get their voice coil deformed from bottoming out, scratching along the tight magnet gap.
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@Marin_Weigel’s spot on. If you blow a tweeter, the voice coil wire melts and goes open circuit, so no sound.
I would try running the amp into one speaker at a time, swap speakers on one amp channel and repeat on the other amp channel. That way you can narrow the issue down to either the amp or the speakers (or neither) and determine if it’s one particular channel or speaker (or none of them).
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Sorry guys I’ve been away most of the day at football. I’ll act on your posts tomorrow ,as I doubt I’ll get a chance tonight. Thanks for your continued support and advice.
Well just to throw a curve ball here.
I had a faulty tweeter on a pair of Wilson’s.
It still worked but produced an underlying almost scratchy sound on certain frequency only.
Drove me crazy for a few hours as you know when something just suddenly changed.
It was definitely the tweeter as I replaced the pair with brand new and back to being righteous again.
So…
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Hi Marin, sorry I may have misinterpreted your suggestion about switching speaker cables.
I eventually swapped the speaker cable at the amp end from left terminals into right terminals and now the distortion in the song I mentioned has moved from left speaker to right speaker.
The distortion is happening with the song whether I play it back on CD, or stream it with Qobuz on Roon so the clipping indicator would not be relevant here?
Hi Graeme, I’m unclear about what you are suggesting here? By running the amp into one speaker are you simply saying just unplug the left speaker and listen to right speaker only, and then do the opposite? And by swapping speakers on one amp channel, is this what I have already done in my reply to Marin in my post above?
… indicating your speakers are fine…
We’re looking at upstream problems now, so what happens when swapping input to amp?
If that’s not it and there’s a preamp in the chain, swap its input from the DAC.
By doing this we could be able to determine the offending component.
If then we’ve established that it’s not the amp or the preamp or the DAC by swapping channels, we might be looking at
EDIT
a cold solder job in one of the interconnects.
If it seems to be one of the pieces of kit, the problem might even be some analog signal overload situation due to suboptimal component match, rather than a real damage to it.
Keep us informed on how things progress from here…
Sorry Marin I’m not really following you here,
Are you saying it might be the CD player, or the streamer. And if this is what you mean , what does “the problem might even be some analog signal overload situation due to suboptimal component match” mean, and what should I be checking?
Hi Kevin, yes that’s what I was suggesting and it seems you have already done this.
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It’d be great, if we knew all components in your system and how they’re interconnected - makes it easier to give instructions…
You’re using a CD player’s analog out?
You also got a DAC for Roon?
So are you using a pre amp in the chain?
Have you changed anything else while inserting the new amp?
Give as much detail as possible, please!
That said, start by swapping channels at power amp input - does distortion move with it?
No → problem likely at power amp, needing further investigation there …
Yes → problem likely upstream, go to next component upstream and perform test there… you get the procedure.
As the problem obviously occurred after inserting the new amp, your interconnects may also be suspect - as I wrote, cold solder joint being jerked at due to replugging cables.
So swapping the interconnects left/right per component might shed some light, once you’re done with above testing and getting inconclusive results…
Forget for the moment about me mentioning a possible line level overload problem introduced by swapping in the amp…
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Hi chain is below
Mytek Brooklyn DAC/Pre amp
MCRU LPS for Brooklyn DAC/Pre amp
Mytek Brookline Amp + (power amp) - connected by balanced cables to pre amp
Stack Audio Link II Network Player (streamer) with USB connected to Brooklyn DAC/Pre amp
Stack Audio VOLT (LPS to power the Link II)
CYRUS CD T transport
Rega Planar 6 turntable
Bowers + Wilkins 603 floorstanders
Cambridge Audio Minx 200 subwoofer
CD player is Coax cable output in to DAC
I’ve already did the channel move haven’t I? And the distortion moved as I posted above
I’m using balanced interconnects that I bought at same time as I got the amp so unlikely to be those at fault, and anyway I also tried ordinary RCA interconnects and still distortion.
Have unplugged various parts of the chain but distortion still there on the songs.
It’s funny but I have been discussing this on other forums, and I’ve been phoning dealers to check out potential new speakers if I perhaps go down that route, and the common consensus seems tof many people seems to be that they dont rate these particular speakers in general. Of course the dealers might say that anyway to get me to buy new speakers, but I’ve never heard dealers be particularly dismissive of other products like CD players, or streamers or turntables when I’ve enquired about those products.