soongsc said:
This is what I am looking for and I am a bit puzzled why I am not hearing differences. In theory it should but so far I don't. I also listen to jazz, classical music(my favorite) and modern music like Dire Straits(they have very nice recordings).
I really take time listening to different kinds of music and look for detail,space=3D, warmth of the voice.
My speakers are Monitor Audio Silver RS8 which are quite massive and have no mercy for bad recordings.
This is the sad truth about instantaneous A/B switching tests and amplifiers. Take a good class AB amplifier module and include it in the test too and you may not notice anything either.
All amplifiers having reasonably flat frequency response, reasonably low output impedance and reasonably low distortion sound very similar. When it's anybody else who flips the A/B switch, they are similar enough to prevent you from telling which one is which more accurately than you can predict the flip of a coin.
Fortunately speakers are a much more complex matter.
All amplifiers having reasonably flat frequency response, reasonably low output impedance and reasonably low distortion sound very similar. When it's anybody else who flips the A/B switch, they are similar enough to prevent you from telling which one is which more accurately than you can predict the flip of a coin.
Fortunately speakers are a much more complex matter.
Thanks Bgt,
That's interesting & I have heard this before - that at a certain level of amplification quality, the differences between amplifiers is negligible if not on-existent.
So, Soongsc, I guess that means the MCD wouldn't be as good as the Hafler either?
I guess I haven't reached these levels of perfection yet as I still hear differences between my amps
Edit: Oh, just wanted to ask Bgt, are the UCD modules the full tricked out HG versions? These seem to be better than the standard version from other reports!
Eva, I agree with you that A/B testing sometimes are not revealing. One reason possibly is that we get too analytical in this kind of listening environment.
Technically, the wider the bandwidth, the better the linearity. But if the test is done using single tone sweep, then lots of things will not be shown. Additionally most amp measurements are based on resistive loads, which is really not even close to how most speakers behave. To make things even more complicated, the effeciency of class D amps would probably interact more with the power supply, so power supply design probably would be even more critical. Even with chip amps power supply is very critical. I recently just used a few little black switching PSU module for an LM3886, and the results were good such that another designer started using them on large speakers, and were driving them better than his original power amp.
I think most of the time the speaker itself is masking lots of differences, so differences upstream of the signal may not be obviouse to a point that we know for sure it's an improvement. One thing I have discovered, is that if a speaker sounds clean, but still reveals very good detail, then these will make improvements more obvious even if the frequency response may not be perfect (most speaker aren't anyway).
One thing I was worried about is whether the speaker protection circuit of the MCD has any contacts in series with the output or not. I always try to get rid of those even if it means losing protection. From the pictures I've seen, they seem of have a relay, but it's not clear how the relay is used. I like the way NCD does it's protection circuit.
Technically, the wider the bandwidth, the better the linearity. But if the test is done using single tone sweep, then lots of things will not be shown. Additionally most amp measurements are based on resistive loads, which is really not even close to how most speakers behave. To make things even more complicated, the effeciency of class D amps would probably interact more with the power supply, so power supply design probably would be even more critical. Even with chip amps power supply is very critical. I recently just used a few little black switching PSU module for an LM3886, and the results were good such that another designer started using them on large speakers, and were driving them better than his original power amp.
I think most of the time the speaker itself is masking lots of differences, so differences upstream of the signal may not be obviouse to a point that we know for sure it's an improvement. One thing I have discovered, is that if a speaker sounds clean, but still reveals very good detail, then these will make improvements more obvious even if the frequency response may not be perfect (most speaker aren't anyway).
One thing I was worried about is whether the speaker protection circuit of the MCD has any contacts in series with the output or not. I always try to get rid of those even if it means losing protection. From the pictures I've seen, they seem of have a relay, but it's not clear how the relay is used. I like the way NCD does it's protection circuit.
Eva said:
Despite what "subjectivists" would say, if you can't tell the difference between two (xxx -- amps, cables, CD players, take your pick) on a random double-blind test, you can't say that there's a perceptible difference.
It's well established that if you know what you're listening to the results are biased according to your expectations. This has been proved by telling people they were comparing two different things -- usually a cheaper one and a more expensive one -- and after they decide they prefer the more expensive one revealing that actually they were listening to the same thing all the time...
Guess why double-blind testing is rarely done on amplifiers and CD players and *never* done on cables?
Ian
P.S. Some people with "golden ears" are more able to detect small differences in sound than others, but I think I'm correct in saying that no double-blind test on cables has *ever* successfully shown a difference (unless there's something fundamentally bad about one cable like very high resistance).
I'm really not sure because listening tests are really more personalized, and speaker loading also effects amp performance. Since the speakers I use are my own designs, I make sure to get the impedance as flat and smooth as possible throughout the audio range. So I know I'm driving a pretty well behaved load. So I'm still trying to get a feeling how the MCD might sound and how the possibilities of better performance is.jkeny said:
I plan to get the NCD back and listen a bit more since there have been significant improvement in the driver I'm using. But I can say that Chip Amps are really not bad either. The LM3886 performance actually prompted me to look into changing my old BSC design to get rid of the inductor and cap I had to really compare on an amp to amp with eactly the same load.
jkeny, the UCD modules are just modded ones. No HG versions.
soongsc, I always use a protection relay in the speaker lines.
Cannot hear the difference with/without them.
I've shortcut the relay on the MCD. I don't know the quality of it and it is not a double contact like I use.
The good thing of A/B switching is that you cannot be fooled.
You just switch the speaker lines from 1 amp. output to the other amp. output. With different input opamps you immediately hear the differences.
soongsc, I always use a protection relay in the speaker lines.
Cannot hear the difference with/without them.
I've shortcut the relay on the MCD. I don't know the quality of it and it is not a double contact like I use.
The good thing of A/B switching is that you cannot be fooled.
You just switch the speaker lines from 1 amp. output to the other amp. output. With different input opamps you immediately hear the differences.
I guess the difference with or without the contacts might not be that much difference. Does the current protection mechanism you use rely on series resistor to sense speaker current? If so, what kind of resistor is used.Bgt said:
Hi Bert,
I was also wondering about the output coils, and whether you think changing them will make a difference. I recall you had experimented with some coils some time ago.
I was also wondering about the output coils, and whether you think changing them will make a difference. I recall you had experimented with some coils some time ago.
Soongsc, I use offset sensing for the protection circuitry. No current sensing. I don't care if the amps. blows as long as my speakers stay OK.
Fuses protect the psu(which has a mains fuse also) from the amps.
I did a coil change in the Tripath amps. but thats all.
Fuses protect the psu(which has a mains fuse also) from the amps.
I did a coil change in the Tripath amps. but thats all.
this is the temperature of my diy version
i diy a daul mono stage amp for myself 🙂 to replace my old one at my home. i also like diy amps for my personal .
and i do a test about the temperature
this case is a very good case , 3mm Aluminum botton pannel
5hours running at almose max power.(classcal music 6ohm load, i cant stay at the front of the speaker for a long time, too loud)
just heatsink - air temp <5dgC.
show you a picture
i diy a daul mono stage amp for myself 🙂 to replace my old one at my home. i also like diy amps for my personal .
and i do a test about the temperature
this case is a very good case , 3mm Aluminum botton pannel
5hours running at almose max power.(classcal music 6ohm load, i cant stay at the front of the speaker for a long time, too loud)
just heatsink - air temp <5dgC.
show you a picture
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and about my case
i like this feeling
i like this feeling
An externally hosted image should be here but it was not working when we last tested it.
this is design, i design it myself, pro-E very good tools, just for personal tast
An externally hosted image should be here but it was not working when we last tested it.
Hi every body,
I am new on this forum.
Comming from DIY speakers building I will now build a Class D amp setup.
Would like to ask you all (and Bqt / Bert in particular, since he own's all types I am looking at) wich makes would allow me to work balanced and allow me to use passive volume control (attenuator) with less hassle.
Thank you
I am new on this forum.
Comming from DIY speakers building I will now build a Class D amp setup.
Would like to ask you all (and Bqt / Bert in particular, since he own's all types I am looking at) wich makes would allow me to work balanced and allow me to use passive volume control (attenuator) with less hassle.
Thank you
I got my MCD-255 and transformers about 40 days ago but did not have the time for assembling them until 10 days ago.
I had some little problems, fixed with Fumac's help (the problem was in the setting of the gain. After some little and easy moddings the problem was solved).
The amp is easy to assemble, it stays quite cool (heatsinks are warm even after heavy use).
I own UCD180 and 400 (modded, and good sounding), so I can compare MCD-255 with these other toys:
MCD-255 KILLS after 10 seconds the UCD's!
THIS AMP IS ABSOLUTELY BREATHTAKING! I AM SPEACHLESS...
Powerful, detailed, no trace of harshness, dead quite, the soundstage is HUGE, the ability to drive hard speakers is enormous. And it remains delicate like a 3watt 2a3 tube amplifier!
I own and have before owned every kind of amplifiers (solid state, tube, classD, hybrids), but let me say THIS IS THE BEST AMPLIFIER I EVER LISTENED TO, MO MATTER WHAT THE PRICE IS!
Any more details. just ask. Justa wanted to share this thing because I bought these modules and transformers jus for my curiosity: just have a listen, you know... well, this amp is here to stay, and some 20 times more expensive amps will be taken away from my systems.
Had today some friends to have a listen: their mouths were just falling down...
😱
Pictures coming, anyway.
I had some little problems, fixed with Fumac's help (the problem was in the setting of the gain. After some little and easy moddings the problem was solved).
The amp is easy to assemble, it stays quite cool (heatsinks are warm even after heavy use).
I own UCD180 and 400 (modded, and good sounding), so I can compare MCD-255 with these other toys:
MCD-255 KILLS after 10 seconds the UCD's!
THIS AMP IS ABSOLUTELY BREATHTAKING! I AM SPEACHLESS...
Powerful, detailed, no trace of harshness, dead quite, the soundstage is HUGE, the ability to drive hard speakers is enormous. And it remains delicate like a 3watt 2a3 tube amplifier!
I own and have before owned every kind of amplifiers (solid state, tube, classD, hybrids), but let me say THIS IS THE BEST AMPLIFIER I EVER LISTENED TO, MO MATTER WHAT THE PRICE IS!
Any more details. just ask. Justa wanted to share this thing because I bought these modules and transformers jus for my curiosity: just have a listen, you know... well, this amp is here to stay, and some 20 times more expensive amps will be taken away from my systems.
Had today some friends to have a listen: their mouths were just falling down...
😱
Pictures coming, anyway.
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