Unpacking / unboxing
And some smps which fits it.
ZK-MT21 TPA3116
And some smps which fits it.
Attachments
This amp zk mt21 works now in a similar setup like this:
https://www.diyaudio.com/community/...ription-subwoofer-gallery.207217/post-7494416
And it sounds correct with 22volt 2.5 ampere smps.
No hum, noise or popping sounds.
Good quality sound not limiting the good loudspeakers I use.
They must be crazy selling this quality at this price. Or you can say the new small D amp chips offer crazy quality.
https://www.diyaudio.com/community/...ription-subwoofer-gallery.207217/post-7494416
And it sounds correct with 22volt 2.5 ampere smps.
No hum, noise or popping sounds.
Good quality sound not limiting the good loudspeakers I use.
They must be crazy selling this quality at this price. Or you can say the new small D amp chips offer crazy quality.
ZK mt21 sounds not much different than zk tb21 with the same speakers (in a different room). Absolute quality of sound is good enough for me.
Wondered myself because zk tb21 has some inductors on the output. It's a bit bigger and has 6800 microfarad on the power supply input. Zk mt21 a bit less with 4700 microfarad.
https://www.diyaudio.com/community/threads/unboxing-zk-tb21-tpa3116.403912/#post-7501883
Wondered myself because zk tb21 has some inductors on the output. It's a bit bigger and has 6800 microfarad on the power supply input. Zk mt21 a bit less with 4700 microfarad.
https://www.diyaudio.com/community/threads/unboxing-zk-tb21-tpa3116.403912/#post-7501883
In comparison with a TDA2003 chip amp it's better working right out of the box.
With the tda chip amp however you can change it to current drive and get other sonic benefits with loudspeakers which have no copper Faraday ring on the pole piece. 99% of all loudspeakers in the world have no distortion reducing Faraday rings.
https://www.diyaudio.com/community/threads/corner-horn-meets-open-baffle-cfa.398842/
Chip amp modded to basic current drive a la Esa Merilainen
https://www.diyaudio.com/community/...fication-to-current-drive.389985/post-7500357
With the tda chip amp however you can change it to current drive and get other sonic benefits with loudspeakers which have no copper Faraday ring on the pole piece. 99% of all loudspeakers in the world have no distortion reducing Faraday rings.
https://www.diyaudio.com/community/threads/corner-horn-meets-open-baffle-cfa.398842/
Chip amp modded to basic current drive a la Esa Merilainen
https://www.diyaudio.com/community/...fication-to-current-drive.389985/post-7500357
I have both in use zk tb 21 and zk Mt 21 both are dead quiet and sound perfect. And they can play loud and undistorted.
I guess I have good smps one 24v 3a and the other 22v 2.5a.
Maybe you have low wattage bad/noisy power supplies?
I am really content with my 3116 amps
Got them cheap from Aliexpress as initial offer, each for 10/12 euro
I guess I have good smps one 24v 3a and the other 22v 2.5a.
Maybe you have low wattage bad/noisy power supplies?
I am really content with my 3116 amps
Got them cheap from Aliexpress as initial offer, each for 10/12 euro
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Could someone with an oscillator confirm this as if this is true, we then have true budget gems on our hands ? And how is the frequency response ?
No idea. I am in Egypt and do not know the language. Would have to find someone into electronics for an oscilloscope.
For little money you can buy and test them yourself.
My speakers are high end and I hear no lack of frequencies. My sub is corner loaded and I can hear Dark Side from Floyd with correct 30hz bass. And I can turn it pretty loud and did not try to reach clipping.
The small 8cm paper cone drivers have a Faraday ring and are sandwiched with aluminum foil. They reach in original state with nearly no faults from 70 hz to 18khz (measured them years ago). They have a 6db 340 uF filter and a well damped box with a controlled loss due to damped reflex canal with foam. Placed against the back wall to eliminate baffle step. The sub is adjusted by ear.
For little money you can buy and test them yourself.
My speakers are high end and I hear no lack of frequencies. My sub is corner loaded and I can hear Dark Side from Floyd with correct 30hz bass. And I can turn it pretty loud and did not try to reach clipping.
The small 8cm paper cone drivers have a Faraday ring and are sandwiched with aluminum foil. They reach in original state with nearly no faults from 70 hz to 18khz (measured them years ago). They have a 6db 340 uF filter and a well damped box with a controlled loss due to damped reflex canal with foam. Placed against the back wall to eliminate baffle step. The sub is adjusted by ear.
I am listening again to ZK MT21 amplifier which yields the CS 8673 chip.
https://www.diyaudio.com/community/...loudspeaker-sandwich-cone.402917/post-7709960
Converted a pair of Mauhorn 5 to subwoofers, added ten millihenry inductivity and put them in series for 12 ohm operation.
Two four ohm fulrange loudspeakers which are naturally linear close to back wall with aluminium tweak of the paper cone for my televison set. The 8cm JVC fullrange drivers (kapton former, faraday ring on pole piece) come in with an enclosure made for TV sets. With the right damping they go pretty linear with 6db filtering down to 100 Hertz (measured).
The amplifier has a clean, controlled and impulsive sound. Source is a meanwell 6.5 ampere 24 volt Smps.
It certainly is not the best sounding amplifier with a class D chip but does a decent job.
I wonder if the lack of proper output filtering is really a drawback, see post 15 in this thread.
Amplifier works well without causing any strange artefacts.
Technical question:
Isn't it better not to put an inductivity on the output (or only uncritical small dimensioned ones) if these are the weak point in the sound of class D amplifiers in general?
Getting proper inductivities with low distortion is the key to undistorted sound I read several times.
Isn't leaving them out not an option? It seems to work.
ZK MT21 sounds pretty undistorted in the listening test.
I found out that it has a bit less distortion right from the shelf in comparison to TPA3116 only following the data sheet (not measured).
See:
https://www.diyaudio.com/community/threads/difference-between-cs8673-and-tpa3116.405281/
https://www.diyaudio.com/community/...loudspeaker-sandwich-cone.402917/post-7709960
Converted a pair of Mauhorn 5 to subwoofers, added ten millihenry inductivity and put them in series for 12 ohm operation.
Two four ohm fulrange loudspeakers which are naturally linear close to back wall with aluminium tweak of the paper cone for my televison set. The 8cm JVC fullrange drivers (kapton former, faraday ring on pole piece) come in with an enclosure made for TV sets. With the right damping they go pretty linear with 6db filtering down to 100 Hertz (measured).
The amplifier has a clean, controlled and impulsive sound. Source is a meanwell 6.5 ampere 24 volt Smps.
It certainly is not the best sounding amplifier with a class D chip but does a decent job.
I wonder if the lack of proper output filtering is really a drawback, see post 15 in this thread.
Amplifier works well without causing any strange artefacts.
Technical question:
Isn't it better not to put an inductivity on the output (or only uncritical small dimensioned ones) if these are the weak point in the sound of class D amplifiers in general?
Getting proper inductivities with low distortion is the key to undistorted sound I read several times.
Isn't leaving them out not an option? It seems to work.
ZK MT21 sounds pretty undistorted in the listening test.
I found out that it has a bit less distortion right from the shelf in comparison to TPA3116 only following the data sheet (not measured).
See:
https://www.diyaudio.com/community/threads/difference-between-cs8673-and-tpa3116.405281/
Attachments
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In this video is described that proper output filtering of class D amps has an influence on efficiency:
Interesting to learn about it.
Somehow they managed in the filterless (not filterless but reduced filtering with small inductors!) design of ZK MT21 that efficiency does not suffer or distortion behaviour.
The class D amp does not get hotter than its better filtered friends from the same brand.
It puts out the same wattage (for example ZK TB21 with proper filters and TPA3116 chip) - measurements of the ZK MT21 with oscilloscope showed the undistorted signal capacity.
The Class D audio amplifier - Filters (2/3)
Interesting to learn about it.
Somehow they managed in the filterless (not filterless but reduced filtering with small inductors!) design of ZK MT21 that efficiency does not suffer or distortion behaviour.
The class D amp does not get hotter than its better filtered friends from the same brand.
It puts out the same wattage (for example ZK TB21 with proper filters and TPA3116 chip) - measurements of the ZK MT21 with oscilloscope showed the undistorted signal capacity.