Andre Visser said:
How about a used Pioneer SX-1500 . Seems to work as good as anything else.
john curl said:
That comparison is a little off, as far as I'm concerned. To me it seems more like somebody wants to tell me that wine tastes different if I open it with an expensive cork screw. I am not happy with "acceptable" sound, I just don't think you can improve anything on the amplifier side of things.
Cheers
For anyone who's interested a 16-bit 44k1 PWM DAC requires a 2890137600 Hz clock. Nearly 2.9GHz which is pretty much over the speed available in an FPGA anyway.
w
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schumpe said:
So that one is free from colorations? Passed a Bypass Before/After type test?
/Peter
schumpe said:
Indeed, well said. But, you know, if you use that rare corkscrew you won at the antique auction, the wine is bound to taste better 😉
I know, I know, *you* don't need convincing..
Jan Didden
As I previously said, IF all amps sound the same, then look to your speakers and/or your sources. What is wrong with this?
janneman said:
Well, neither you or I or anyone else is going to convince anyone here.
I'm out, this is not going anywhere for me.
I just felt like posting, haven't posted in a while.
wakibaki said:
Yet another anecdote from the tiresome Peter-Pan.
I have heard a signal looped thru a good soundcard and the same file looped via the soundcard and a LM3886 amp (single chip) working into a complex dummy load at aprox 1W.
I could not detect the amp. I listened blind (yes I have done some of those blind tests).
Then I listened to three other amps tested the same way and those could not pass the signal without coloration.
Class D amps (which I have not tested) seems to have coloration in the topoctave which makes them non-transparent. People seems to like them anyway and I guess that's ok! 🙂
/Peter
wakibaki said:
I've said earlier, if you rate a 3886 as hi-fi, we have different meanings for the word hi-fi, there is so much more.
Don't know where the DAC came into the picture but why must it be PWM?
schumpe said:
If you truly believe that, I'm not sure if I must feel sorry for you or admire you.
André
cuibono said:
You insert the DUT in the playback chain and see if it can pass the signal without being detected. This is done blind and if you can't detect when the DUT is in the chain or not one cold argue it's good enough for that particular set up, those ears and the music/signals used.
Makes more sense than A/B since you don't compare the DUT to something else but against itself sort of.
When testing an power amplifier a complex dummyload is connected to the output of the amp.
It's not the only way but one of the best ways to test transmission links.
You can either listen live or record material looped thru the DUT and listen back later. This way files can be shared over the internet for testing by others.
/Peter
Well, I think we can all agree that the difference between speakers will be greater than the differences between amps. There is NOTHING wrong with that! (I won't comment on sources--I'll leave that for someone else to tackle) However, you bring up a good point: different amps are designed to drive different loads, meaning that changing the speakers/loads will change the behavior of the amplifier.john curl said:
This comes back to the question of why we build different amps, but for some reason we seem to be glossing over that fact: amps capable of driving a similar load within their operating range should sound very similar! There may be a difference in clipping response, or behavior outside of normal operating parameters, which is, IMHO, what makes the difference between "good enough" amps and "really good" amps. The latter handle the extremes without strain, resulting in a qualitatively "better" sound when operating close to or beyond the capabilities of the "good enough" amps.
Therein lies the rub! The "all amps sound the same" argument assumes that we don't approach those limits where the really good amps prove their worth.
Someone made fun of the LTS test earlier.. something about only bats would hear a roll off of a few tenths of a dB at 10kHz.
The following is from a BT I participated in on a LM3886 amp. RMAA measurements.
The roll off is because a slightly to big RF cap is used at the input. The designer liked it that way. I listened blind to the soundcard loopback and compared that to the loop including the dummyloaded LM3886.
This small roll off could easily be heard. Once he changed the input cap to a smaller value I could not differentiate between the soundcard loop and the LM3886 loop.
I used a Echo Audiofire4 with HD600 as monitoring tools. So for me 0.4dB at 10k and 0.8dB at 20k was easily heard.
/Peter
The following is from a BT I participated in on a LM3886 amp. RMAA measurements.
The roll off is because a slightly to big RF cap is used at the input. The designer liked it that way. I listened blind to the soundcard loopback and compared that to the loop including the dummyloaded LM3886.
This small roll off could easily be heard. Once he changed the input cap to a smaller value I could not differentiate between the soundcard loop and the LM3886 loop.
I used a Echo Audiofire4 with HD600 as monitoring tools. So for me 0.4dB at 10k and 0.8dB at 20k was easily heard.
/Peter
john curl said:
Perhaps you must type this in a big font and bold it, the message seems to get lost like the lost musical detail in those systems. 🙂
André
Because, people who have good speakers and good sources can still hear differences in power amps.
Sure, you will need VERY good speakers to make any use of the best amps...nothing is better than its weakest link
A "better" amp wont "help" any avarage speakers, only a different amp may do so
Well, I have already said more than I like to
Good luck🙂
A "better" amp wont "help" any avarage speakers, only a different amp may do so
Well, I have already said more than I like to
Good luck🙂
dfdye said:
That's the way it is and for some types of colorations a low resolution speaker can mask enough to make it inaudible even though it is audible on a high resolution speaker.
Well.. no, not if they are not well designed.
The resolution even at a watt or two differs between most amps.
/Peter
pinkmouse said:
PM,
I think you'll find the current research supports the idea of left/right localisation of brain activity and also identifies specific regions activated by listening to music.
This is a quick trawl of science daily turned up these reports for instance:
http://www.sciencedaily.com/releases/2007/10/071027102409.htm
http://www.sciencedaily.com/releases/2007/08/070801122226.htm
http://www.sciencedaily.com/releases/2007/11/071104191553.htm
http://www.sciencedaily.com/releases/2008/02/080226213431.htm
And for those who argue for influence of price tag on perception of quality, you'll enjoy this article...
http://www.sciencedaily.com/releases/2008/01/080126101053.htm
cheers
Paul
Pan said:
Different loop bandwidth, different impulse. You heard much more than half a dB difference.
Pan said:
Hi Peter,
Could you describe the test setup a bit? I'm assuming there was a pot or attenuator somewhere in the loop to set the gain of the amplifier path to 1. Is that correct? If so, where was this pot located? I'm thinking that if it were at the amp's input, that would reduce the cutoff frequency of the amp's input LPF.
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