Geshelli Archel2 Headphone AMP Review: another champ?

[tomchr]

Also designing opamp using 32nm process etc. Designing audio is easy. I didn't have the scope for years until I finally realize that audio is just something in your heart. I'll be doing 32nm 1V opamp or 0.2nV/sqrthz 200MHz BW 100dB gain amplifier or something like that.

Of course you will. And the first thing you'll do is to make the input stage MOSFETs wide and long so you can get the 1/f noise down and get away from the short channel effects. I hope that once you start typing the channel length in microns in your CAD tool, you'll realize that you're wasting a metric s**ton of money on your 32 nm mask set.

Have you ever designed an opamp at the IC level? I mean... In the industry. Not as part of some class project. I have. I designed the LMP2021. I've designed several opamps used as building blocks in other ICs as well, including the LMK04800 and LMX2581. But I guess I'm not a real engineer, so what do I know...

Tom

 

[scott wurcer]

But I guess I'm not a real engineer, so what do I know...

Tom

Yeah what do I know?

 

[LLL]

It's a headphone 'amplifier'. It drives arguably the easiest, lowest demand, transducer on the planet. A tiny, lightweight, low powered and benign load that is strapped onto the head and makes only a high SPL within a few mm of the ear. Not exactly earth-shattering is it?

Not Earth-Shattering, of course; it's not a nuclear bomb. So why don't you make one and sell one with spec and look that you want, and let's see if the market accepts it?

 

[LLL]

Of course you will. And the first thing you'll do is to make the input stage MOSFETs wide and long so you can get the 1/f noise down and get away from the short channel effects. I hope that once you start typing the channel length in microns in your CAD tool, you'll realize that you're wasting a metric s**ton of money on your 32 nm mask set.

Have you ever designed an opamp at the IC level? I mean... In the industry. Not as part of some class project. I have. I designed the LMP2021. I've designed several opamps used as building blocks in other ICs as well, including the LMK04800 and LMX2581. But I guess I'm not a real engineer, so what do I know...

Tom

Obviously you are not; you are just some hack who have built ICs...and shit.

 

[LLL]

If people are willing ar willing to pay for it, then it worth investing research into it. That includes hifi equipment.

You know its nonsensical comments from people like you that make me want to quit these forums.

This I agree with. I make nonsensical comments all the time, I am not perfect. Just ask my lovely wife, I don't know how she deals with me.

Now, since those "outlandish" researches that you mentioned were paid for by willing parties, they are absolutely worth investing research into it; whether you agree with it or not. And I am glad that you are not the gatekeeper for research funding.

Also, it seems like you aren't quite sure what you were looking for in terms of noise and distortion (zero?), and want deafening level of sound in your ears (5 watts?!). I am not sure why you are here. This is the Audio Science Review forum, isn't it?

 

[Jave]

Theoretically, seeing the channel imbalance here caused by the analog attenuation, would attenuation through a program such as JRiver (64 bit) would be better?

 

[pozz]

Regardless of what's happening in academia, headphone amps are a "solved problem".

It's nice that the Archel 2 has good stats at a low price. But we're talking serious diminishing returns compared to the alternatives if transparency under most common scenarios is the goal.

Do we really think, with an average 50 ohm headphone, and level matched to within 0.1 dB, that the Archell is better / more transparent than any of the top 5 on the SINAD chart?

Or is it just solving the same problem....again...but a bit differently?

Just to add to what was discussed earlier in the thread.

I think what we've seen with the last few excellently-performing pieces is evidence of new product engineering standards. Hopefully, the industry players will soon take the broad view that, to compete, they must first nail transparent production, and then innovate through features, integration and so on.

 

[BYRTT]

Theoretically, seeing the channel imbalance here caused by the analog attenuation, would attenuation through a program such as JRiver (64 bit) would be better?

Works fine for me using Jriver set to "Internal Volume" and using a 32bit deep DAC over ASIO or WASAPI.

 

[JohnYang1997]

24bit volume control is good enough. Because the noise of dac will dominate. As the noise output from dac doesn't decrease as the volume control, you lose bit not because of the volume controller itself but the inherent noise from the dac output.

 

[hfcobra]

I apologize for the terribly nooby post. I have to know how to read this info though!

Can someone explain to me what imbalance vs volume is?

Also what is SMPTE Ratio vs Measured level and how to read the graph?

Distortion vs power? How does the impedance matter?

Lastly, channel imbalance?

So if I want to get the best bang for my buck right now I should get the Topping DX7 Pro DAC passthrough to the Geshelli Labs Archel2?

Will the lack of balanced cables matter at all? I know this is off topic but that does seem to be one shortcoming of the amp. Will it matter?

What sort of RCA cables should I run from the DAC to the amp if I do go with this combo? Do they matter at all? How can I know what I have is quality cabling?

 

[amirm]

Can someone explain to me what imbalance vs volume is?

I rotated the volume control from max to minimum while measuring how different the output is from two channels (show in blue). Ideally this would be zero. If not, it means that the volume may shift toward one channel at times (usually at minimum volume). This impacts IEMs the most since with normal headphones you need more power than that.

 

[amirm]

Distortion vs power? How does the impedance matter?

It does. It determines how much power you get. This is why I run it at 300 and 33 ohm. You can interpolate between them based on headphone impedance you care about.

 

[amirm]

Will the lack of balanced cables matter at all? I know this is off topic but that does seem to be one shortcoming of the amp. Will it matter?

Not at all.

 

[amirm]

What sort of RCA cables should I run from the DAC to the amp if I do go with this combo? Do they matter at all? How can I know what I have is quality cabling?

Don't matter at all from sound point of view. I personally like flexible ones especially given how light these units are.

 

[amirm]

Also what is SMPTE Ratio vs Measured level and how to read the graph?

Sloping down portion indicates how noisy the amp is. The flat to sloping up toward the right determines distortion when you are turning up the unit.

 

[Jave]

Where can I get the required wall adapter for outside the US - a cheap and good one?

 

[solderdude]

You need to ask @Geshelli which DC input plug they use (could be either 2.1mm or 2.5mm barrel plug) and then simply buy a 12V DC adapter locally or from the usual interwebs market places.

Just make sure they are switched mode (or regulated), 12V DC output, have the correct plug with + on the inner pin and are at least 5W.

 

[Wombat]

Where can I get the required wall adapter for outside the US - a cheap and good one?

The Gishelli PS is for 100-240Volt.

Just get a mains adaptor plug for your system to US.

E.g. for UK: https://www.ebay.com.au/itm/US-EU-T...170396&hash=item3b36085420:g:HYoAAOSw0OhdX9vE

 

[Veri]

The PS is for 100-240Volt.

Just get a mains adaptor plug for your system to US.

E.g. for UK: https://www.ebay.com.au/itm/US-EU-T...170396&hash=item3b36085420:g:HYoAAOSw0OhdX9vE

This would be cheapest indeed, most switching supplies accept 200+V, just need the adapter plug

 

[Aap op Sokken]

Where can I get the required wall adapter for outside the US - a cheap and good one?

I mailed the same question to Geshelli yesterday.

The Gishelli PS is for 100-240Volt.

Just get a mains adaptor plug for your system to US.

Confirmed, they said the same thing.