• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Improving the Geshelli Archel 2 Pro - aka Pimp My Amp

Joined
Dec 22, 2018
Messages
12
Likes
8
Location
NJ
#1
Great performing amp with precise fit and finish, inside and out. The metal case does not look DIY; it has a very attractive finish.

But I didn't like the Frankenstein look of the screws, which do look DIY, so I replaced the front screws with less visually intrusive round head screws. Thought that the volume knob would be better in black but didn't have any black knobs nice enough to match the amp. Didn't like seeing the nut under the volume control knob so I filed off the end of the potentiometer just a wee bit. Don't like the looks of the headphone jack nut, but couldn't find anything to visually improve that.

In case you are wondering what the nut on the bottom of the amp is, its for a ground wire. It's not structural.

Anyone have other ideas for improving the amp?

Geshelli Archel 2 Pro.jpg
 

headwhacker

Active Member
Forum Donor
Joined
Dec 25, 2018
Messages
148
Likes
190
#2
I thought the subject of improving the achel2 is with performance. How it looks is very subjective and not exactly an improvement. I actually like how DIY-ish it looks.
 
Joined
Dec 22, 2018
Messages
12
Likes
8
Location
NJ
#3
Yeah, that was basically the idea behind the post and that's why I didn't say improving performance in the title. Not much to improve on performance.

Channel imbalance has not been a problem at the volume knob settings I have been using. I did find a dual Alps audio taper 100k pot in my parts bin, but that may not be a simple fix and this particular pot probably isn't that well matched anyway.

The push button input selector works great as a muting button (unless you have both inputs active). A functional improvement I hadn't expected, but I didn't download a manual.

Adding VU meters with headphone sensitivity calibration would be a great functional improvement to protect your hearing or if it was really, really accurate, for ABX comparisons. Not much room for meters in that small box.

I don't have high impedance very low impedance or low sensitiity headphones, so I don't need that performance improvement which would be easier resolved by a different amplifier.

As far as performance goes, it's hard to improve upon.

Amirm almost always talks about the looks of the test unit in the first or second paragraph of his reviews, so while subjective, it is that important. He called the Geshelli look industrial. That look would bother some people. I think it looks much less industrial by simply changing the front screws. Yep, it's subjective.
 

headwhacker

Active Member
Forum Donor
Joined
Dec 25, 2018
Messages
148
Likes
190
#4
I can only see channel imbalance the potential problem. I am planning to use volume control upstream(Transport/DAC) and just leave the volume pot to max.
 

restorer-john

Major Contributor
Joined
Mar 1, 2018
Messages
3,689
Likes
7,173
Location
Gold Coast, Queensland, Australia
#5
The really should be ashamed of themselves with those 90 degree tactile PCB switches sticking through the perspex. Taking HiFi to a new low if you ask me.

You should pimp it! Throw away the hideous case, get a polished stainless steel case with birdseye lacquered timber end caps, cobalt blue aluminium front escutcheon with cnc engraved labelling, spun copper cone feet, anodised solid volume pot and proper momentary push buttons and a recessed headphone jack. :)
 

solderdude

Major Contributor
Joined
Jul 21, 2018
Messages
4,093
Likes
7,500
Location
The Neverlands
#7
You should pimp it! Throw away the hideous case, get a polished stainless steel case with birdseye lacquered timber end caps, cobalt blue aluminium front escutcheon with cnc engraved labelling, spun copper cone feet, anodised solid volume pot and proper momentary push buttons and a recessed headphone jack. :)
don't forget the meters.... :cool: add meters....

I agree with @headwacker regarding the title...
 

restorer-john

Major Contributor
Joined
Mar 1, 2018
Messages
3,689
Likes
7,173
Location
Gold Coast, Queensland, Australia
#8
don't forget the meters.... :cool: add meters....
OK. Big meters. And some LED bargraph/dot meters as well.

And some RGB LEDs underneath to put a subtle glow on the shelf.

I think we are onto something here... ;)
 

solderdude

Major Contributor
Joined
Jul 21, 2018
Messages
4,093
Likes
7,500
Location
The Neverlands
#11
A spontaneous reaction is to try a better power supply for 12v. Many different suggestions on the market right now..
But.... the 12V feeds an internal (isolated) DCDC converter so what good would another power supply do ?
Nah... colorful LED strips inside ...
 

solderdude

Major Contributor
Joined
Jul 21, 2018
Messages
4,093
Likes
7,500
Location
The Neverlands
#15
All it takes is some extra capacitors (which are in there) and to use opamps with decent PSRR, which also are in there.
The ripple is above the audible range (80kHz) anyway and is measured with 330nF added filter caps so will be lower with the (max. 470uF) caps and proper decoupling around the opamps (100nF X7R).
This may be visible when the FR were to be measured up to 1MHz most likely.
 
Last edited:
Joined
Dec 22, 2018
Messages
12
Likes
8
Location
NJ
#16
Thanks for all the suggestions, especially recessing the headphone jack.

restorer-john, what is wrong with the pushbuttons? Not familiar with any problems there.

I very much like the flat black case as I am going for an unobtrusive look. But, I do like the idea of a polished stainless steel case. With a mother of pearl front. Nice. Make that inlayed - even better than laser engraving. As an alternative to polished stainless steel, why not a chrome case. But then I looked at my chromed Calrad phono preamp and said, nah, too mid twentieth century.

While looking online for a knob (search for guitar knobs, you can find quite a variety, including skull head knobs) to match a mother of pearl front, I found a gorgeous polished brass knob with a mother of pearl button. Stunning with a beautiful gold appearance. Hey, I have some gold leaf. I could gold leaf the box and front and use that knob. Or it might work as part of a mother of pearl inlay design.

Staying with the original case aesthetics, I could get rid of the low gain LED. Why 2 LEDs? If it’s high gain, an LED is on; low gain, the LED is off. Better yet, single LED with low light for low gain and bright light for high gain. I wonder if that can be done in firmware?

And speaking of knobs, it might be nice to have one of the knobs that says “Volume” on the top with numbered skirts. Or, why not have the knob be LED lit internally with a small dot of light escape to show the knob position. I have not found any knobs that do that. Perhaps one with a windowed skirt would work with backlighting thru the front panel.
 

restorer-john

Major Contributor
Joined
Mar 1, 2018
Messages
3,689
Likes
7,173
Location
Gold Coast, Queensland, Australia
#17
Love the ideas!

And speaking of knobs, it might be nice to have one of the knobs that says “Volume” on the top with numbered skirts. Or, why not have the knob be LED lit internally with a small dot of light escape to show the knob position. I have not found any knobs that do that. Perhaps one with a windowed skirt would work with backlighting thru the front panel.
Many illuminated dots on volume knobs are done the easy way. A 2 or 3mm led is fitted to a hole on the inside of the knob, glued in place and a very flexible wire is wound around the centre knob hub and back through a hole under the knob to the circuitry inside. As it only needs to turn 270 degrees or so, you don't need much wire. The best wire to use for that is an old pair of earbuds you may have lying in a drawer. It's extremely flexible litz style and lightweight (and free).

Others illuminated a prism piece of acrylic and others sent light up the centre of the pot shaft and into a prism inside the knob in order to light up the "dot".
 
Last edited:
Joined
Feb 9, 2020
Messages
1
Likes
2
#20
I would upgrade the unit with these specs:
Inputs
  • Balanced stereo 3-pin XLR,
  • Gold plated stereo RCA
Outputs
  • 1/4" (6.35mm) TRS,
  • 3.5mm TRS,
  • 4-pin balanced XLR,
  • Stereo TRS pass-through

I spoke with Sherri from Geshelli Labs about maybe doing a custom version of the Archel2.5 Pro AMP with the above specs. She replied by stating, “We cannot add what you need on the 2.5 but check back in a few months. We're in development of something that will meet your requirements.” So, THAT’S GREAT NEWS!
 
Last edited:
Top Bottom