Advice on Quad power amps.

[Tryant]

Burn in ist mutually exclusive to active or passive components. Cables regularly demonstrate audible changes throughout the first 100hrs.

The Khozmo is no different. At first things can sound a little tight. Maybe even sharp.

After you've given it a good run, it "relaxes".

Why this happens to any bit of kit is not something I have a definitive answer to

Wow. Tell me this is a wind up, right? The only thing that demonstrably changes in the first 100 hours is your imagination. You have no definitive explanation because there's isn't any. I thought these ludicrous claims were debunked years ago.

[Leeken]

Wow. Tell me this is a wind up, right? The only thing that demonstrably changes in the first 100 hours is your imagination. You have no definitive explanation because there's isn't any. I thought these ludicrous claims were debunked years ago.

I really wish you could have heard my quad qsp for the first few hours,unlistenable!

[Bigman80]

Wow. Tell me this is a wind up, right? The only thing that demonstrably changes in the first 100 hours is your imagination. You have no definitive explanation because there's isn't any. I thought these ludicrous claims were debunked years ago.

Yes. Of course its my imagination. I'd like to see you demonstrate demonstrably.

Same imagination as KLE (and multiple others) who recommend 100hrs on their plugs before evaluation.

A lot of us are delusional.

Feel free to continue your (incorrect) belief.

[Bigman80]

I really wish you could have heard my quad qsp for the first few hours,unlistenable!

It was your imagination. Tyrant said so. He's an authority on the subject apparently.

[Spectral Morn]

Wow. Tell me this is a wind up, right? The only thing that demonstrably changes in the first 100 hours is your imagination. You have no definitive explanation because there's isn't any. I thought these ludicrous claims were debunked years ago.

This is a subjective forum and while objectivists are welcome, views must be expressed in a less dismissive and rude manner. Your experiences/opinions discount such things others don't share your experiences or views.

I suggest strongly you read the site Ethos https://theartofsound.net/forum/show...asics-of-Ethos

[Marco]

Wow. Tell me this is a wind up, right? The only thing that demonstrably changes in the first 100 hours is your imagination. You have no definitive explanation because there's isn't any. I thought these ludicrous claims were debunked years ago.

Erm, excuse me, Jesse, we don't address each other here in such a terse and dismissive manner, so kindly desist from behaving that way in future.

AoS is also staunchly 'ears first', so people's valid subjective experiences will always be given due consideration and shown the respect that they deserve, not rudely dismissed out of hand because they don't appear to fit with someone's scientific belief system.

Marco.

[DSJR]

Wow. Tell me this is a wind up, right? The only thing that demonstrably changes in the first 100 hours is your imagination. You have no definitive explanation because there's isn't any. I thought these ludicrous claims were debunked years ago.

You're a new member, so I can understand your disbelief at these things and most of the time, you'd probably be absolutely right!

However -

For some years I ran a system with three identical power amps (two as bridged stereo pair and the third for headphones) run from the same preamp together. I used two good quality sets of interconnects (no need to say yet again what they were), one admittedly made by myself, although my soldering isn't bad imo. When new, I swore I could hear a slight difference between them, one set having a slightly 'plump' characteristic and observed by others who'd used this cable. The other set sounding possibly slightly 'livelier' to me and just maybe not as 'gracious' in it's music presentation (forgive my description). I regularly swapped these cables from one amp set to the other (amps were stacked) and felt the difference (using headphones) was repeatable - for a while... Both cables carried the same signal at the same volume at any one time.

Some months later, I attempted to do this comparison again and was damned if I could tell any difference between them whatsoever. Now, this is obviously NOT a scientific comparison or feeling and of course physical changes in me and/or my ears could well have played a large part - I NEVER trust my ears as so many here seem to do!

Anyway, the only thing I can say is to keep an open mind to some of these things. The cable I thought had the slight plumpness is often regarded as this, or safe and not as 'clear' as some by many peeps who've tried it. I can see where that observation comes from and I'm damned if I know why these changes happen to installed cables that are left pretty well alone and not messed around with over the course of six months... I've had mine made up for a few years now and just forget it's there, so I'm happy!

I have other cables that don't change their sound at all in any way, like 'em or not...

To be honest, my decades around and about this industry have shown that ancilliaries like wires, plugs and so on are the least thing to bother about if the gear itself isn't matched properly. As for 'grounding boxes,' measurably 'they' appear to make the situation worse and the whole 'grounding' idea is totally mis-understood out there in audiophile-land anyway it would appear as the only 'ground' we have is the planet we live on, not a wooden box full of magic ingredients and a couple of metal plates. Let's see if they're a passing fad or gain credence over the next few years as they become better understood.. So many 'best since sliced bread' fads have come and gone in my time, so we'll see!

Oh by the way, I've done unscientific comparisons with carbon pots, film pots as a genre and stepped attenuators, either ladder type or shunt. The cheapo film pot I know 'feels' nice and bottom of scale variable balance aside, allows atmosphere and reverb effects to come through quite nicely. The old carbon pots in my power amps are slightly dry in sound and seem not quite as clear (yes I know!). Replacement film pots of the same log value I replaced them with on one amp pair seemed to restore this. Stepped attenuators (each step with precise L-pad) obviously have an advantage in precise exact channel matching, but the real 'difference' comes in shunt types and in my opinion, this entirely depends on what they're used with as to whether this works or not (one fixed value in series and different 'shunt' resistors on each step to vary the volume). Some power amps don't mind the source impedance changing with ever volume step and others do. Same goes for the source item, although many modern sources don't seem to mind (apart from cheaper Rega CD players that need to see around 50k all the time apparently).

Don't totally disbelieve some of the things 'we' come out with. Not all of it is bullsh*t I assure you and there are genuinely objective reasons as to why *some things* make a slight objective difference.

[DSJR]

I said it earlier, I like the Dada Quad updates which can be quite comprehensive, yet true to the original design goals I feel.

The main limitation with a 306 is power. 50W isn't much these days with higher dynamic range sources available and with some conventional speakers, it'll become breathless if pushed I think (old Naim 50 Watters hard clipped nastily, but when the listener is a young rocker, this gives a kind of 'frisson' to the music playback experience - is that the right term?).

The one amp I'd be careful of is the 303. Its high output impedance and almost total lack of control at very low bass WILL have an audible effect on any speakers connected to it and this is one reason why the old 33 preamp was *deliberately* rolled off quickly below 35Hz I gather.

[Tryant]

Ooops, sorry fellas. I'll get me hat.

[Bigman80]

You're a new member, so I can understand your disbelief at these things and most of the time, you'd probably be absolutely right!

However -

For some years I ran a system with three identical power amps (two as bridged stereo pair and the third for headphones) run from the same preamp together. I used two good quality sets of interconnects (no need to say yet again what they were), one admittedly made by myself, although my soldering isn't bad imo. When new, I swore I could hear a slight difference between them, one set having a slightly 'plump' characteristic and observed by others who'd used this cable. The other set sounding possibly slightly 'livelier' to me and just maybe not as 'gracious' in it's music presentation (forgive my description). I regularly swapped these cables from one amp set to the other (amps were stacked) and felt the difference (using headphones) was repeatable - for a while... Both cables carried the same signal at the same volume at any one time.

Some months later, I attempted to do this comparison again and was damned if I could tell any difference between them whatsoever. Now, this is obviously NOT a scientific comparison or feeling and of course physical changes in me and/or my ears could well have played a large part - I NEVER trust my ears as so many here seem to do!

Anyway, the only thing I can say is to keep an open mind to some of these things. The cable I thought had the slight plumpness is often regarded as this, or safe and not as 'clear' as some by many peeps who've tried it. I can see where that observation comes from and I'm damned if I know why these changes happen to installed cables that are left pretty well alone and not messed around with over the course of six months... I've had mine made up for a few years now and just forget it's there, so I'm happy!

I have other cables that don't change their sound at all in any way, like 'em or not...

To be honest, my decades around and about this industry have shown that ancilliaries like wires, plugs and so on are the least thing to bother about if the gear itself isn't matched properly. As for 'grounding boxes,' measurably 'they' appear to make the situation worse and the whole 'grounding' idea is totally mis-understood out there in audiophile-land anyway it would appear as the only 'ground' we have is the planet we live on, not a wooden box full of magic ingredients and a couple of metal plates. Let's see if they're a passing fad or gain credence over the next few years as they become better understood.. So many 'best since sliced bread' fads have come and gone in my time, so we'll see!

Oh by the way, I've done unscientific comparisons with carbon pots, film pots as a genre and stepped attenuators, either ladder type or shunt. The cheapo film pot I know 'feels' nice and bottom of scale variable balance aside, allows atmosphere and reverb effects to come through quite nicely. The old carbon pots in my power amps are slightly dry in sound and seem not quite as clear (yes I know!). Replacement film pots of the same log value I replaced them with on one amp pair seemed to restore this. Stepped attenuators (each step with precise L-pad) obviously have an advantage in precise exact channel matching, but the real 'difference' comes in shunt types and in my opinion, this entirely depends on what they're used with as to whether this works or not (one fixed value in series and different 'shunt' resistors on each step to vary the volume). Some power amps don't mind the source impedance changing with ever volume step and others do. Same goes for the source item, although many modern sources don't seem to mind (apart from cheaper Rega CD players that need to see around 50k all the time apparently).

Don't totally disbelieve some of the things 'we' come out with. Not all of it is bullsh*t I assure you and there are genuinely objective reasons as to why *some things* make a slight objective difference.

It's easy to demo the effects here. I have components I KNOW change after time passed. It's happened multiple times.