-
Welcome to ASR. 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!
Geshelli Archel2 Headphone AMP Review: another champ?
- Thread starter amirm
- Start date
restorer-john
Grand Contributor
Look at the back and the front. I don't think alignment is a design imperative here.
solderdude
Grand Contributor
It has no output caps so -0.1dB at 10Hz will be at all impedances.
People may start to complain they can hear that 'roll-off'
Looks like it runs on +/- 12V (DCDC converter inside) but perhaps on +/- 15V.
Output current is limited to 140mA so the output opamp can deliver 200mA max.
Judging from the volume control test the '2' version doesn't have the linear potmeter in there any more and looks like regular A-taper.
People may start to complain they can hear that 'roll-off'
Looks like it runs on +/- 12V (DCDC converter inside) but perhaps on +/- 15V.
Output current is limited to 140mA so the output opamp can deliver 200mA max.
Judging from the volume control test the '2' version doesn't have the linear potmeter in there any more and looks like regular A-taper.
watchnerd
Grand Contributor
Well I wish them the best of luck- that APX has to be paid for with a ton of profitable sales...
Clearly, the performance is excellent, but I don't think I've ever seen such an ugly commercial product in my life. Tom's neurochrome looked like jewelry by comparison. But then again, headphone listeners are a funny lot, they seem to have miniature listening spaces, hunched around a computer monitor on a desk, with a stack of disparate mini components, RGB lights and flexiglass covered PCs- all based on the pictures I see here and elsewhere.
Kids these days...
I'd easily pay $100 more for a nice metal enclosure.
solderdude
Grand Contributor
They use a generic (DIY-type) aluminium enclosure but put their own see through front and rear panels in front.
It looks like a deliberate choice to match that of their other see-through offerings.
I think offering Amir one for review is an excellent strategy for generating lots of sales.
It looks like a deliberate choice to match that of their other see-through offerings.
I think offering Amir one for review is an excellent strategy for generating lots of sales.
watchnerd
Grand Contributor
Great stats.
Lots of enthusiasm.
It's like the Atom story, all over again.
Is ASR becoming a FOTM community?
Lots of enthusiasm.
It's like the Atom story, all over again.
Is ASR becoming a FOTM community?
restorer-john
Grand Contributor
Well, it's clearly got input caps, a deliberate rolloff (100% NFB@xHz) or a DC servo set too high.
Why not take it flat to 2Hz? CD players have done that for decades. Amplifiers have too. Preamplifiers also.
With the performance this good, why compromise the lowest octave at all?
OP
- Thread Starter
- #89
Higher gain means more noise and also distortion. Both work together to push THD+N (distortion+noise) higher. Note that we are still talking about very small numbers here so don't hesitate to use it in high gain mode.
Not disagreeing about longevity (although we don't have data on what they chose, we are speculating). At their price point? That hardly seems reasonable; and feel is subjective. I don't know about the lack of noise; data shows that the pot they chose is clearly not hurting the noise performance. If someone wants that, we can all just grab an RK and do some soldering.
I do wonder if my old ears can hear the channel imbalance with this.Regardless, take my money already.
Nango
Major Contributor
Never!! A $5 metal chassis is worth a mark up of maximum $25 !!!
I'd just add...
"I think designing and building an excellent product at a very low price, then offering Amir to quantitatively verify its performance is an excellent...."
digicidal
Major Contributor
What will be interesting (though not surprising to anyone here) will be once many people have them and talk about how good they sound. How can that be possible with so many high-end manufacturer's claiming the distortion their products have is part of the sound? 
With the responses of some manufacturers to less than impressive measurements on ASR... you'd think almost everyone would hate how "clinical" and "sterile" such a clean device sounded... yet @amirm detected none of that. Who knew?
With the responses of some manufacturers to less than impressive measurements on ASR... you'd think almost everyone would hate how "clinical" and "sterile" such a clean device sounded... yet @amirm detected none of that. Who knew?
Nango
Major Contributor
Longevity shouldn't be an issue with a $100 product, I would even renew every 5 yrs just to support the mfr in case it doesn't hold that period, which btw is to be awaited.
Last edited:
maty
Major Contributor
Geshelli Archel Pro Amp Plexi Case
https://geshelli.com/shop?olsPage=products/archel-pro-amp-clear-case
https://geshelli.com/shop?olsPage=products/archel-pro-amp-clear-case
OPA1688?
bidn
Active Member
I am thinking about the 50 mV SNR measurement in general.
It is supposed to be of interest for IEMs (In Ear Monitor), but one of the graphs shows that it is measured with an impedance of 600 ohms, which isn't realistic for an IEM (I would rather take 20 ohms).
But then I can just look for the corresponding power on the 33 ohm graph, 33 ohm being so much more closer to the impedance of an IEM.
So I looked up for 75 uW on the THD+N graph for the 33 ohm impedance, and there I see a THD+N value that actually seems to match the SNR @ 600 ohm, 50 mV.
It is supposed to be of interest for IEMs (In Ear Monitor), but one of the graphs shows that it is measured with an impedance of 600 ohms, which isn't realistic for an IEM (I would rather take 20 ohms).
But then I can just look for the corresponding power on the 33 ohm graph, 33 ohm being so much more closer to the impedance of an IEM.
So I looked up for 75 uW on the THD+N graph for the 33 ohm impedance, and there I see a THD+N value that actually seems to match the SNR @ 600 ohm, 50 mV.
solderdude
Grand Contributor
Perhaps the voltage amp section....
The output stages are most likely single opamps with 200mA current capabilities.
Given the max output voltage swing of 7V it looks like one needs 12V.
The other amp @maty points to, which is not the tested amp, has 15V rails.
Won't be long before the first teardown pictures are shown. Looking at the Pro design it is just 2 well propery decoupled 2-layer PCB design with no fancy circuitery. A C'Moy but well done with properly selected opamps suited for their task (which we cannot say of most C'Moy amps)
That's impressive (the Archel2). Although I don't need one (having the RME ADI-2 PRO fs) I should get one anyway. Supporting a company which can make something perfect for almost no money is a no brainer - and I can have a look inside as well.
Go to checkout to see overseas shipping. https://geshelli.com/shop?olsPage=products
Similar threads
- Poll