Geshelli Archel2 Headphone AMP Review: another champ?

[Celty]

It is a California, required by Proposition 65, warning label.
https://oehha.ca.gov/proposition-65/about-proposition-65

No one does stupid government excess like California, it is no easy task to beat D.C., but they consistently manage it.

 

[Vovgan]

Ok so I purchased Geshelli Archel2 Pro just for the fun of it and today I had a chance to put it to the test.

My usual headphone amplifier driving Sennheiser HD 6xx's is the Topping DX7 Pro combo, so I put it against Geshelli Archel2 Pro fed by Chord Qutest DAC via Acrolink 6N cables.

Result: Geshelli Archel2 Pro + Chord Qutest win.

These two sets do not sound "completely different", very-very close call indeed, both are super clear and transparent, but Archel2 Pro + Qutest is just slightly more so. Bass is great in both sets, but again slightly tighter in Archel2 Pro + Qutest. Also no hissing of the "s" sounds in the female voices, as for instance in the "Spanish Harlem" by Rebecca Pidgeon, which are heard using Topping.

The more I listen to Archel2 Pro + Qutest, the more I appreciate this small extra bit of effortlessness in listening they deliver, compared to Topping. I haven't been listening to music for more than 10 mins straight for a long while, and I'm already enjoying music for more than an hour with Archel2 Pro + Qutest!

Obviously I can's say whether the difference is due to different headphone amp or DAC, but the point I wanted to make is that if design and functionality wise Archel2 Pro is what you need, it's really fantastic.

(illumination can be turned off)

P.S. I just realised that with Chord Qutest DAC, Geshelli Archel2, Acrolink 6N RCA cables and a custom 16 core OCC headphone cable I might be getting the absolutely best sound out of my Sennheiser 6xx!

 

[Music&space]

Do you think the hifiman he4xx is a good partner to the geshelli archel 2.5 pro? My question is about impedance and the 1/8 rule. In the review archel's impedance was measured to be quite low at 1.2 ohms whereas the manufacturer presents measures of 16ohms - 600ohms. The he4xx's impedance is 35ohms according to the manufacturer. Also, I am not sure if this is relevant, but i am planning to pair the archel 2.5 pro with the enog2 pro which allows for output volume control (does this affect output impedance of the archel 2.5 pro?). I am sorry if some this makes little sense but i am very new to this world and i am just trying to make sense of it.

Edit: i am referring to the archel 2.5 pro which according to geshelli is similar to the archel 2 pro, but more powerful and with balanced inputs.

 

[Veri]

@Music&space he4xx is a planar, most planars have a near flat impedance curve which means the frequency response won't change due to impedance mismatch.

So you don't need to worry about any of that.

 

[headwhacker]

Do you think the hifiman he4xx is a good partner to the geshelli archel 2.5 pro? My question is about impedance and the 1/8 rule. In the review archel's impedance was measured to be quite low at 1.2 ohms whereas the manufacturer presents measures of 16ohms - 600ohms. The he4xx's impedance is 35ohms according to the manufacturer. Also, I am not sure if this is relevant, but i am planning to pair the archel 2.5 pro with the enog2 pro which allows for output volume control (does this affect output impedance of the archel 2.5 pro?). I am sorry if some this makes little sense but i am very new to this world and i am just trying to make sense of it.

Edit: i am referring to the archel 2.5 pro which according to geshelli is similar to the archel 2 pro, but more powerful and with balanced inputs.

The 1/8 rule you mention is the output impedance of the Amplifier against the headphone load impedance. In this case is 1.2ohms of Archel Pro to the 35 Ohms of HE4XXX. The 16 - 600Ohms mentioned by geshelli is the range of headphone loads (in ohms) they are recommending to use with the amp.

In general, this rule only applies to certain types of headphone loads like Dynamic driver-based headphones (e.g. Sennheiser, Beyerdynamic etc) or multi-BA (Balanced Armature) iems. For Planar Magnetic type like the HE4xx it does not matter.

 

[Music&space]

The 1/8 rule you mention is the output impedance of the Amplifier against the headphone load impedance. In this case is 1.2ohms of Archel Pro to the 35 Ohms of HE4XXX. The 16 - 600Ohms mentioned by geshelli is the range of headphone loads (in ohms) they are recommending to use with the amp.

In general, this rule only applies to certain types of headphone loads like Dynamic driver-based headphones (e.g. Sennheiser, Beyerdynamic etc) or multi-BA (Balanced Armature) iems. For Planar Magnetic type like the HE4xx it does not matter.

Many thanks for your explanation! Also, good to know that the rule does not apply to Planars. So, if I understand correctly, there should be no issue since HE4xx's 35 ohms are within the range of 16 - 600 ohms suggested by Geshelli?

 

[Music&space]

@Music&space he4xx is a planar, most planars have a near flat impedance curve which means the frequency response won't change due to impedance mismatch.

So you don't need to worry about any of that.

Thanks for your response! Then I guess I will go with the he4xx. But, just for future reference, do you still consider he4xx's 35 ohms an impedance mismatch with archel's 16 - 600 ohms, or was it more of a general remark? I am asking this just to make sure that I can read these numbers correctly in the future.

 

[Veri]

Thanks for your response! Then I guess I will go with the he4xx. But, just for future reference, do you still consider he4xx's 35 ohms an impedance mismatch with archel's 16 - 600 ohms, or was it more of a general remark? I am asking this just to make sure that I can read these numbers correctly in the future.

The 16-600 ohms is just a number. As mentioned above, if this wasn't a planar headphone you'd look at the 8:1 rule. So for a 35ohm headphone, you'd want the output impedance of the amp to be ~4Ω or lower. The Geshelli totally meets that, and has a high gain mode for when low gain isn't enough (always use low gain when it's loud enough, move to high gain when that doesn't cut it).

That's all you need to follow. easy

 

[Music&space]

The 16-600 ohms is just a number. As mentioned above, if this wasn't a planar headphone you'd look at the 8:1 rule. So for a 35ohm headphone, you'd want the output impedance of the amp to be ~4Ω or lower. The Geshelli totally meets that, and has a high gain mode for when low gain isn't enough (always use low gain when it's loud enough, move to high gain when that doesn't cut it).

That's all you need to follow. easy

Great! Thanks again!

 

[trl]

My question is about impedance and the 1/8 rule. In the review archel's impedance was measured to be quite low at 1.2 ohms whereas the manufacturer presents measures of 16ohms - 600ohms.

Manufacturer is right: this amp can drive with ease 16-Ohms cans.

I have a headamp with LME49600 in output buffer with 10-Ohms series resistors at the outputs (let's call it A), per TI's schematic & recommendations. I had absolutely zero issues driving 32-Ohms cans, while with 16-Ohms IEM's the bass was incorrectly reproduced. I did many A/B tests with a second headamp having 0.1- Ohms output impedance, let's call it B. After I lowered the output resistors of the first headamp A to about 4-Ohms I was unable to spot this headamp from the headamp B when using 16-Ohms IEM's, hence my conclusion would be that even 1/4 rule seems to do fine, at least for the IEMs I've tested.

In Archel2's case we're speaking about a 1/13.3 report, so you really don't need to worry about. Even with 16-Ohms cans you shouldn't worry, unless you're trying to rich the max. volume, of course.

 

[Music&space]

Manufacturer is right: this amp can drive with ease 16-Ohms cans.

I have a headamp with LME49600 in output buffer with 10-Ohms series resistors at the outputs (let's call it A), per TI's schematic & recommendations. I had absolutely zero issues driving 32-Ohms cans, while with 16-Ohms IEM's the bass was incorrectly reproduced. I did many A/B tests with a second headamp having 0.1- Ohms output impedance, let's call it B. After I lowered the output resistors of the first headamp A to about 4-Ohms I was unable to spot this headamp from the headamp B when using 16-Ohms IEM's, hence my conclusion would be that even 1/4 rule seems to do fine, at least for the IEMs I've tested.

In Archel2's case we're speaking about a 1/13.3 report, so you really don't need to worry about. Even with 16-Ohms cans you shouldn't worry, unless you're trying to rich the max. volume, of course.

Excellent! I have already ordered everything and now I am waiting (im)patiently for them to arrive

 

[EVOLVIST]

I think I'm going to go ahead and order the ARCHEL2.5 PRO Amp and pair it with my Linn KDS/3.

If the amp is everything it's said to be, then I should be getting the unadulterated sounds from the Linn into my HE1000se, yeah?

I've never heard my Linn out of anything other than speakers. It looks like this may be the wire with gain that I'm looking for. Using the Linn as a pre-amp, I imagine I'll just set the volume on the Geshelli and let it fly.

 

[DuxServit]

Been using my Geshelli Archell2 with HD650 off ODAC and Roon. That little box can sure drive the HD650.

 

[jailbird]

I had a 887 THX on order and sadly couldn’t cancel it in time. I’m worndering now if it isn’t worth the RMA fee just to pocket the price difference between that and the 2.5 Pro, especially with these scores! Sure, the 887 still has more power, but I’m not trying to deafen myself.

 

[solderdude]

Unless you need the money or prefer the looks of the Geshelli why not just use the 887 ?

 

[EVOLVIST]

I guess we're kind of assuming that the ARCHEL2.5 PRO Amp measures the same as the one reviewed here?

 

[mkawa]

The circuit is different as well as taking balanced input. The archel2 uses opa1652 and the 2.5 uses 1656. From the datasheets, the 2.5 should be measurably better (which is shocking) and output power may increase somewhat.

i have ordered a 2.5 to get optimal output from the sabaj and i expect that it will measure better than the archel2. The two opas actually cost the same amount, so the difference in sale price probably reflect significant internal upgrades, likely to the power stages, in addition to the balanced input parts.

 

[Evgeniy]

I have a headamp with LME49600 in output buffer with 10-Ohms series resistors at the outputs (let's call it A), per TI's schematic & recommendations. I had absolutely zero issues driving 32-Ohms cans, while with 16-Ohms IEM's the bass was incorrectly reproduced. I did many A/B tests with a second headamp having 0.1- Ohms output impedance, let's call it B. After I lowered the output resistors of the first headamp A to about 4-Ohms I was unable to spot this headamp from the headamp B when using 16-Ohms IEM's, hence my conclusion would be that even 1/4 rule seems to do fine, at least for the IEMs I've tested.

What IEM's you use ?
Dymanic, BA or multi-driver BA ?

 

[trl]

121dB/V Superlux HD381F. I mostly purchased those to test for background noise, so I don't much listen to music with them, but they're also pretty flat sounding, so price/perf. ratio is very good (if you can make a good fit with your ears).

 

[mkawa]

Listening to the 2.5 all day using both the included wall wart and an agilent e3620a. Whereas i think the 2 used a single cui pcn2-s12-d15 to create a bipolar supply for the opa, the 2.5 uses two pdm2-s12-s15s, one for each rail. These dcdcs are rated at 2w but 75mv p-p so there must be some tighter analog regulators in there that i can’t see.

balanced input sounds great and may or may not be audibly cleaner out of the sabaj.

anyway, there definitely seem to be substantial improvements between the 2 and 2.5. Hopefully one will show up for measurement soon!