• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

$500 amplifiers to test and review?

andreasmaaan

Master Contributor
Forum Donor
Joined
Jun 19, 2018
Messages
6,652
Likes
9,399
Audiophilestyle recently published a review of three Class D amps from PS Audio, Wyred4Sound and a Swedish company named XTZ (that I haven't heard from them before). The PS Audio and the W4S amps are out of the $500 USD mark, but the XTZ Edge A2-300 costs $495 USD and it is 300W per channel at 4 Ohms.

https://www.xtzsound.com/product/edge-a2-300

  • Dimensions: 7.9 x 2.3 (2.8) x 11.2" (cm: 20 x 5,8 (7) x 28,5),
  • Weight: 5 lbs / 2,3 kg
  • Price: 495 € + shipping direct from XTZ webpages. According to XTZ available worldwide on request, incl. US & Canada
  • Design: ICEpower discret build 300AS1 Class D amplifier with integrated power supply, ICEpower 300A1 Class D board attached, Input stage with adjustable impedance
  • Input: RCA unbalanced inputs
  • Output: 1 pair of Music Conductor copper binding posts per channel
I don't know if anyone have heard this amp? It looks tempting a one of the less expensive amps using the 300AS1 module.

ICE publishes quite comprehensive measurements (scroll down to datasheets and resources) of this unit and it appears to be very good.
 

andreasmaaan

Master Contributor
Forum Donor
Joined
Jun 19, 2018
Messages
6,652
Likes
9,399
Speaking of ICE amps, looks like parts express carries a bunch of their boards now. Many even have built in power supplies. Really curious how these perform.

https://www.parts-express.com/Search.aspx?keyword=ice power&sitesearch=true

There are detailed manufacturer measurements in the data sheets for all these amps on the ICE website. Not aware of any independent measurements of the bare boards, but the commercial products that use some of these boards that have been indecently measured seem to validate the manufacturer specs generally.
 

goodkeys

Member
Joined
Apr 8, 2019
Messages
48
Likes
17
been interested in these brands forever, they're pretty much unknown in the west (and don't seem to gain traction in China either?) but dang if those don't look convincing.
https://item.taobao.com/item.htm?id=22705352409
View attachment 25350
https://item.taobao.com/item.htm?id=19298969816
View attachment 25351

Looks interesting indeed. What I don't quite understand is the price. 960.00 Yen. Is that 960 Yen (=9$), or 960'00 Yen (=860$)? Both can't be right.

It can be bought through Audiophonics, where it costs 289€:

https://www.audiophonics.fr/en/powe...fier-class-a-b-lm317-2x50w-8-ohm-p-13076.html

The specs look good, if they are to be believed. SNR of 105db, THD of 0.0063% (50W RMS 8 Ohms), Frequency Response
10-20kHz (± 0.04 dB). All very good.
 

daftcombo

Major Contributor
Forum Donor
Joined
Feb 5, 2019
Messages
3,687
Likes
4,068
Based solely on specs and measurements, the Klipsch has slightly more power, although that really only equates to a dB or two of output.

The Klipsch has lower distortion in the 50mW to 1W range, though I don't know if that would be audible.
I'm also concerned about noise (shhhh) coming from the speakers at low volume. Any idea if one would be worse?
 

maxxevv

Major Contributor
Joined
Apr 12, 2018
Messages
1,872
Likes
1,964
Looks interesting indeed. What I don't quite understand is the price. 960.00 Yen. Is that 960 Yen (=9$), or 960'00 Yen (=860$)? Both can't be right.

It can be bought through Audiophonics, where it costs 289€:

https://www.audiophonics.fr/en/powe...fier-class-a-b-lm317-2x50w-8-ohm-p-13076.html

The specs look good, if they are to be believed. SNR of 105db, THD of 0.0063% (50W RMS 8 Ohms), Frequency Response
10-20kHz (± 0.04 dB). All very good.

That's Chinese Yuan, not "Japanese Yen". About US$140/-.
 

somebodyelse

Major Contributor
Joined
Dec 5, 2018
Messages
3,682
Likes
2,962
3e Audio do amp boards based on the TI TPA325x series, and have some AP test results in their datasheets. While not exactly comprehensive, they suggest they're matching TI's datasheet performance, unlike the (much cheaper) FX502SPro. It's no nCore, but 0.003% THD+N at 5W into 4R for the 2ch TPA3255 is better than most tested here so far. Boards are ~$80, so probably ~$250 once you've added a PSU, case etc.
 

estuardo4

Active Member
Joined
Mar 29, 2019
Messages
143
Likes
136
Another brand that people rave about on the DIY forums is Akitika. They have a DIY kit or a finished model. The model is the GT-102, it is a traditional A/B design and the power is 50W at 8 Ohm

Here are the measurements: https://www.akitika.com/measurements.html

The DIY kit costs $314 USD
Finished $488 USD

This brand and amp has been mentioned numerous times at ASR, but not on this thread, so maybe other forum members doesn't know the brand.
 
Last edited:

dwkdnvr

Senior Member
Joined
Nov 2, 2018
Messages
418
Likes
698
Now that I have a good cheap front end (Khadas Tone Board + JDS Atom), I really should do a run through my amps since I have a selection of cheap units mentioned in this thread. Modulus-86 (as a reference), Dayton APA-150 (which has been tested and was a bit disappointing), BasX A-100, the 3e-audio TPA3255, as well as a Sure Electronics module from Parts Express (forget the specific model), and a Nad T748V2 if I'm willing to pull it out of the living room system. I'm not entirely sure a purely subjective comparison is all that interesting, though.

My rather obvious opinion at this point is that the Modulus-86 is clearly better than the others, but I'm certainly not going to claim that there is much substance behind that conclusion at the moment.
 

brial05

Member
Joined
Jun 1, 2019
Messages
8
Likes
9
Another brand that people rave about on the DIY forums is Akitika. They have a DIY kit or a finished model. The model is the GT-102, it is a traditional A/B design and the power is 50W at 8 Ohm

Here are the measurements: https://www.akitika.com/measurements.html

The DIY kit costs $314 USD
Finished $488 USD

This brand and amp has been mentioned numerous times at ASR, but not on this thread, so maybe other forum members doesn't know the brand.

IMG_1813.jpg


An ASR whose who ... Schiit SYS, Kdhadas Tone Board and a new Akitika GT102.

I believe it is a fantastic piece of equipment ..... it is only days old for me as it only just arrived.
 

Memoryerror

Member
Forum Donor
Joined
Jun 12, 2018
Messages
41
Likes
20
Very good idea! I am also very interested in your own subjective impression, do you think it would be a significant improvement compared to a Topping PA3? Thank you!
I haven't heard the PA3, so I can't do a comparison to that.

But my guess is that it would not measure the greatest. It doesn't sound the cleanest even with not so efficient speakers. It doesn't sound bad. If I were to compare it to headphone amps it sounds closer to the Massdrop CTH than the Massdrop THX.

Oh, but not nearly as noisy as the APPJ EL34+6N4 tube amp I tried once.
 
Last edited:

trl

Major Contributor
King of Mods
Joined
Feb 28, 2018
Messages
1,967
Likes
2,523
Location
Iasi, RO
Another brand that people rave about on the DIY forums is Akitika. They have a DIY kit or a finished model. The model is the GT-102, it is a traditional A/B design and the power is 50W at 8 Ohm

Here are the measurements: https://www.akitika.com/measurements.html

The DIY kit costs $314 USD
Finished $488 USD

This brand and amp has been mentioned numerous times at ASR, but not on this thread, so maybe other forum members doesn't know the brand.

Very interesting documentation, I had some reading today and will read more in the coming days too. However, Stereophile has different figures for the 4-Ohms test: https://www.stereophile.com/content/akitika-gt-102-power-amplifier-measurements. It really seems that under 60Hz @4 Ohms this amp has serious issues, unless that specific device was faulty.

Now this is an amp that needs tested by Amir, to see who's right: manufacturer or Stereophile? :)
 

maty

Major Contributor
Joined
Dec 12, 2017
Messages
4,596
Likes
3,160
Location
Tarragona (Spain)
My two cents.

The chipamp LM3886 works better with 8 Ohm loudspeakers. At least you need two LM3886 by channel to work with 4 Ohms. If 50 Hz or less at -3 dB.

There are other option, one chipamp by channel but bookshelves speakers (4 Ohms) with true 60, 70 or more Hz at -3 dB. Better with one subwoofer, cut at 80 Hz.
 

GGroch

Major Contributor
Forum Donor
Joined
Apr 7, 2018
Messages
1,059
Likes
2,049
Location
Denver, Colorado
I like the aesthetic and concept of the Akitka, and the noise specifications both self reported and measured by Stereophile seem quite good. But. Why would Akitka provide clipping/power ratings based on one channel driven if they were trying to be transparent about its performance. Whether due to thermal shutdown or power supply inadequacies, clipping into real loads both channels driven seems to be a common shortcoming of cheap chip amps. Akitka chose 1% distortion as the clipping indicator. Amirim generally chooses .03%. In this case the power supply seems more than adequate....so limitations of the LM3886 are probably the issue, as maty points out.

In many cases a real 40WPC may be sufficient. But for decades the argument has been made that there are no audible differences between amplifiers with lower than .1% THD and a frequency response flat within .25 dB. 40WPC clipping is too little power for many uses.

I think when Amir measures the "perfect amplifier" that sells for less than $500 (one that measures below .1% THD, .25dB flat in the audible range, and clips at .1% both channels driven at say 150-200WPC, that it will be a chip amp.

Side Note: I think Guntar Smits video on "The Best Amplifier in the World" was interesting on this topic.
UPDATED Link: Best Amplifier in the world in English

He chooses an iraudamp7s as "Best Amp"...but his real point is that any amp that meets the above .1%/.25dB specifications with adequate power qualifies as a best amp. And, that high clipping power (generally 1.5X your speaker's max input rating) is more important than slightly better specifications at lower power ratings. My guess is that there should be amps (perhaps kits) in the $300 range that qualify. Like dwkdnvr I assembled a 3e Audio TPA3255 amp and would like to see how that measures.
 
Last edited:

maty

Major Contributor
Joined
Dec 12, 2017
Messages
4,596
Likes
3,160
Location
Tarragona (Spain)
Last edited:
  • Like
Reactions: trl
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,368
Likes
234,389
Location
Seattle Area
Top Bottom