Amp for tweeters only on dsp/active 3 way

[MAB]

Definitely not a placebo. In fact, said listening fatigue is what pushed me to fully treat my room, I assumed it must be from reflections, and I was wrong. I spent ages in REW and even made posts here about it, nothing worked until I switched to AB. In fact, even my older crappy AB receiver that I had before I got the D amps did not cause this issue, despite sounding much worse.

Since switching to the B200s with everything else exactly the same, no issue. I bought them from amazon specifically so that I could return them as I assumed slim chance it will fix the problem, and it did.

My hypothesis is that it's similar to older LED lighting where the color temperature and lumens would measure just fine, but people would get inexplicable headaches due to the speed of the flashes of the diodes. This has been resolved with modern LEDs of course, but those people were not imagining that despite it not being immediately obvious what was going on.

I can listen to a good quality class D and in the first few minutes think it's awesome, hence why I bought them as when I listened to others I thought they were great. But I didn't sit and listen for a long time, so I had no idea that this was even a thing.

You should test this, blind and controlled. Or realize the belief that amps have sound is has been tested exhaustively. Or even more specious, that the sound of amps has yet to be characterized.
Likely find it is your perception of certain amp types, not the sound. Less likely is you find you have a hearing malady irrespective of the amp type. Zero likelihood that your amp induces fatigue.

This perception is pushing you to do things and spend money on unuseful audio activities. Kind of the opposite of the purpose of the formum.
Switching amps doesn't solve listening fatigue, unless you have a really horrible amp, which you don't seem to own. And randomly buying and returning is a waste of your and the vendor's time and money.

 

[Waveform Fidelity]

You should test this, blind and controlled. Or realize the belief that amps have sound is has been tested exhaustively. Or even more specious, that the sound of amps has yet to be characterized.
Likely find it is your perception of certain amp types, not the sound. Less likely is you find you have a hearing malady irrespective of the amp type. Zero likelihood that your amp induces fatigue.

This perception is pushing you to do things and spend money on unuseful audio activities. Kind of the opposite of the purpose of the formum.
Switching amps doesn't solve listening fatigue, unless you have a really horrible amp, which you don't seem to own. And randomly buying and returning is a waste of your and the vendor's time and money.

Room reflections are a known source of inducing listener fatigue, so I would recommend re-visiting that problem with an RT60 or C50 Clarity measurement. In my opinion, money spent on that problem bring large improvements in sound quality.

 

[NJ coffee roaster]

You should test this, blind and controlled. Or realize the belief that amps have sound is has been tested exhaustively. Or even more specious, that the sound of amps has yet to be characterized.
Likely find it is your perception of certain amp types, not the sound. Less likely is you find you have a hearing malady irrespective of the amp type. Zero likelihood that your amp induces fatigue.

This perception is pushing you to do things and spend money on unuseful audio activities. Kind of the opposite of the purpose of the formum.
Switching amps doesn't solve listening fatigue, unless you have a really horrible amp, which you don't seem to own. And randomly buying and returning is a waste of your and the vendor's time and money.

I did not start this thread to debate this, but in this case you are wrong. As I said, I got those amps because I fully trusted this forum and was totally blindsided when I started to get fatigue, I had no idea what was going on, and assumed it must be from room reflections. Again, I ended up fully treating my room (serious 4 inch panels, no BS) even the windows and assumed it would work as this must just be from reflections, and while the sound was improved the fatigue was the same. Tried many different eq curves using REW and my minidsp, nope.

When I switched to the B200s I really didn't think it would do much, I specifically got them on amazon instead of apos so that I could return them easier expecting to return them, and here they are in my system as it solved my issue instantly.

I'm going to be repeating some of what I said before, and not debating this anymore hereafter as I feel your mind is already made up. While I do agree the measurements first approach is best, and its a great way to figure out what a good piece of gear is vs just subjective listening, I am quite sure that there are things we have not quite figured out how to measure yet, or simply dont show up with the equipment currently used that contribute to this phenomena. If I had to guess, it probably has something to do with the way class D amps create waveforms by switching so rapidly, and only some listeners are sensitive to this the same way only some people used to get headaches from LEDs because the switching was not yet fast enough like it is today.


I will continue to look at measurements when selecting gear and I will probably never buy anything amir has not reviewed, but if something measures great and the sound bothers me in my system then who cares how it measures? I need to enjoy the sound.

 

[Mark185]

@NJ coffee roaster you do not say how old you are. If you are over 40 and can still hear frequencies above 10-12kHz, then you are a rare individual. Most Class D amplifiers do have rising distortion levels above the 5-8 kHz range but that distortion is still below the hearing threshold of most people.

I seriously doubt that there is a measurement method still to be discovered when it comes to audio signals and acoustics. There are decades of research that have been devoted to this. I say this as a 69 year old electrical engineer, Audio Engineering Society member, and audio fanatic for the last 55 years.

I suspect your hearing fatigue is more likely due to how your brain processes sensory inputs and that is an area this is not nearly as well understood as basic electrical/acoustic engineering. There is probably a wide spread of human capability when it comes to processing sensory inputs and it is very hard to quantify. So, I am not dismissing what you perceive but I do doubt it is something that has yet to be understood in terms of testing and measuring amplifiers.

 

[LTig]

The unconscious part of the brain brain is extremely good in fooling the conscious part. It is possible that just the knowledge of which amp is currently running influences the listening experience. The only way to find this out is if some other person silently switches the power amp without the listener knowing.

This reminds me of the German de.rec.hifi newsgroup meeting in 2003. We met at the house of an audiophile with a quite expensive system. The speakers were in a big room and the rest of the system in a smaller room besides, which made it possible to tamper with his system without him knowing. We fooled our host twice:

• We replaced his DAC (a very expensive Theta, might have been a DS Pro) by my Behringer Ultracurve 2496. Our host didn't notice it. After telling him he acknwoledged that it did sound good and later bought another Behringer (a samplerate converter for other purposes, not to replace the Theta).
• Our host complained about the horrible sound of MP3 (dead, no life, boring, no dynamic, compressed, ...). I played a CD with a live blues concert (Big Al Dupree) and everybody thought it to be very good and lively. Then I revealed that it was a 192 kbps MP2 digital recording of a live concert at the Blues Festival Dresden in 2000, captured from a digital satellite receiver (Astra Digital Radio) broadcast with my semipro Tascam CD recorder. MP2 is even worse than MP3!. Our host didn't believe it, probably to this day.
  I played the same CD at a demo of the very first big Avantgarde Acoustic Classic Trio by Holger Fromme (CEO). Not one of the audiophiles complained about the sound. After I revealed it Holger Fromme said, that with such great music the recording quality is not important. He actually asked for a copy, and got it.

 

[DatSpeakerTho]

Placebo is a hell of a drug

 

[Koifarm]

NJ Coffee, if you do not want to build the amp yourself. I can recommend Topping LA90.
I know it is pricy but the best for your tweeters.

What brand/type are your tweeters?

 

[Mark185]

If you are willing to build your own tweeter amp, you can't do better than this kit designed by Nelson Pass. It is a low power Class A amp perfect for tweeters.

Amp Camp Amp Complete Kit

DIY amplifier kits, amplifier chassis, hard to find transistors and circuit boards

diyaudiostore.com

If you don't know, Nelson Pass is one of a handful of living amplifier designers that is held in the highest regard by audiophiles and average users alike. His designs are something special. He has supported the DIY community for many years. His commercial products are very high end and cost $$$$.

 

[LTig]

If you don't know, Nelson Pass is one of a handful of living amplifier designers that is held in the highest regard by audiophiles and average users alike.

His early designs may be held in high regard by objectivists as well, but not what he did later (starting with his Passlabs brand), where he deliberately designed circuits with higher distortion.

His designs are something special.

Yep, they distort much more than necessary, and you pay extra money for it.

 

[Mark185]

His early designs may be held in high regard by objectivists as well, but not what he did later (starting with his Passlabs brand), where he deliberately designed circuits with higher distortion.

Yep, they distort much more than necessary, and you pay extra money for it.

Understood but I do not think that negates recommending the Amp Camp low power Class A for tweeters. You can adjust the distortion with bias and it is a very simple, easy to understand circuit.

Say what you will but what other noted designer supports the DIY community to this degree? If he is purposely designing Passlabs products with higher distortion, I am sure it is because there is a market for that. He has talked in interviews about designing what sells so he can still pursue what he loves to do.

 

[Mark185]

I think there is an analog (pun intended) in the mobile audio world. Robert Zeff has been highly regarded for at least 30 years as a premier mobile amplifier designer for both Class A/B and Class D amps. I have personally measured several different Zapco and ARC Audio amps that are very highly regarded for sound quality and they have higher distortion levels than other amps. A specific comparison is the Alpine PDX F4 and F6 Class D amplifiers. The F6 was tested by @amirm with excellent results. I own 2 PDX F4 amps. They measure better than the ARC Audio amps in terms of SNR and THD - but the ARC Audio amplifiers are much more highly regarded for SQ. I have listened to all of them in my home systems and cars and any sonic difference is very very minor and hard to discern.

In particular, I noticed with one of ARC Audio's special 20th Anniversary amps that the distortion characteristics changed with power output and actually got better at high power compared to low power. Also of note is the 2nd harmonic was below the 3rd harmonic at low power but the reverse is true at high power. This is clearly a design intent.

 

[LTig]

Understood but I do not think that negates recommending the Amp Camp low power Class A for tweeters. You can adjust the distortion with bias and it is a very simple, easy to understand circuit.

Say what you will but what other noted designer supports the DIY community to this degree?

Douglas Self. Here, no nonsense.

 

[Mark185]

Douglas Self. Here, no nonsense.

This is getting off topic so I won't post on this topic again. I am also an admirer of Douglas Self. I have read his books and studied his work. I also have great respect for Bob Cordell, his writings and his designs. None of this diminishes my respect for Nelson Pass and his work. Will have to agree to disagree.

 

[Plcamp]

I am currently puzzling about a low power amp (I need <1W) to drive a Compression Driver on a 600hz horn.

Then I ran across the Topping Mini300. 15 uVrms noise. Overkill power capability.

Is there some reason that amp would not be advisable as a tweeter amp controlled by dsp?

 

[DatSpeakerTho]

I am currently puzzling about a low power amp (I need <1W) to drive a Compression Driver on a 600hz horn.

Then I ran across the Topping Mini300. 15 uVrms noise. Overkill power capability.

Is there some reason that amp would not be advisable as a tweeter amp controlled by dsp?

Just put a resistor on the CD to pad it down.

 

[Elgrosso]

I am currently puzzling about a low power amp (I need <1W) to drive a Compression Driver on a 600hz horn.

Then I ran across the Topping Mini300. 15 uVrms noise. Overkill power capability.

Is there some reason that amp would not be advisable as a tweeter amp controlled by dsp?

The Topping is probably good, make sure it’s ok to use as a power amp.
For ex I had a problem with the previous PA3 that triggered protection at every start, something related to the volume set at max.
Also check if it pops on or off.

Otherwise the schiit rekkr, absolute best noise level I had, dead silent ears on CD, but only 2W/4W bridged, no pop, no heat, tiny, no issue at all.

 

[Flaesh]

For example B&C

If I'm not mistaken, the second version of the crossover for the 464 doesn't contain light bulbs.
I've been living without protective capacitors for 15 years and haven't burned anything yet. Recently, an audio buddy started making regular 2way speakers for himself (tweeters cost 300-500 euros apiece), which increased my interest in tweeter protection.