New portable amp: Better than O2?
Jul 10, 2013 at 12:01 PM Thread Starter Post #1 of 10

inthere

Headphoneus Supremus
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 Ok, auditioned this amp last night and the creator hasn't even named it yet. It's as powerful as an E12, and has a similar sound signature, but it's warmer and has a much better soundstage. 
 
 This came about after I lost my beloved E12 on a flight. I wound up buying a C5 and while it was a very nice amp, it had a bit less power than I would have liked. Anyway, I posted a pic of my new C5 with my name on it and one of my friends posted that he knew an amp that killed it for a 3rd of the price. He directed me to Andrew Pallison at JBSound in the UK. Andrew also builds Objective 2's, and I ordered one of those from him. 
 
 Andrew came over my house and delivered both amps personally. Of course I opened the Objective 2 first (who wouldn't??) and was extremely pleased. Wasn't too excited when he thrust his new creation in my face, but as a courtesy I opened it and listened to it because he was there. 
 
 It looked exactly like JDS Labs cMoy, but it sounded completely different. This was pure clean power man, and the soundstage was godly. Andrew says it has 75 hours battery life from two Duracells, but it's non rechargeable, so you have to replace the batteries yourself which is a downer. Andrew also says he uses the same capacitors as a famous high end 1980's tube amp. 
 
He's charging £50 UK pounds for it right now. JBSound is basically a 2 man operation and can't really handle high volume, but Andrew says he thinks he can handle it if it happens. 
 
 Andrew doesn't even have a website yet, but he has an eBay account I can link to, he says he'll list the amp tomorrow when he thinks of a name for it:
 
http://www.ebay.co.uk/itm/The-Green-Headphone-Amp-Objective2-o2-New-in-UK-with-Warranty-/161061181401?pt=UK_AudioTVElectronics_HomeAudioHiFi_Amplifiers&hash=item257ffe97d9
 
 

 

 

 

 
Jul 12, 2013 at 2:00 AM Post #3 of 10
The picture is a bit blurry but from what I can tell, it seems to be a typical cmoy implementation with dual 9V, TL2426 rail splitter, Nichicon Fine Gold caps, film caps output, and perhaps a NJM4562 as opamp (can't say for sure because it is too blurry, but it is a JRC opamp for sure).
 
Jul 12, 2013 at 2:03 AM Post #4 of 10
Seems interesting. If it measures like an O2 in the form factor of an Altoids can... We may have a winner for a low cost portable amp.
 
Jul 12, 2013 at 11:14 AM Post #5 of 10
Hey, Marshal.
 
Quote:
Seems interesting. If it measures like an O2 in the form factor of an Altoids can... We may have a winner for a low cost portable amp.

 
ClieOS is correct, this looks like an 18V cMoy variation.
 
There's an AC coupling input cap and three resistors per channel (standard non-inverting "cMoy" topology). The 3-pin chip in the corner is likely a TLE2426 virtual ground, considering there must be a ground and little other circuitry is visible. An extra set of resistors are visible in the bottom corner of the board, so he's done something different. It could be a paralleled resistor divider in the virtual ground, or a low cost and very weak 3-ground setup. Triple electrolytic capacitors are a bit strange. These are probably implemented on the power supply rails, and judging by the size and model, we can guess they're 330-470uF parts. A TLE2426 based cMoy is stable with a single 220uF capacitor with decent ESR; extra electrolytic caps here will not improve measurable or audible performance. Decoupling caps are not present. Those are critical for a high-performance cMoy.
 
That said, cMoys perform nicely with the right headphones. Matching O2's SNR/THD/power is another story.
 
Jul 12, 2013 at 11:31 AM Post #6 of 10
Quote:
Hey, Marshal.
 
 
ClieOS is correct, this looks like an 18V cMoy variation.
 
There's an AC coupling input cap and three resistors per channel (standard non-inverting "cMoy" topology). The 3-pin chip in the corner is likely a TLE2426 virtual ground, considering there must be a ground and little other circuitry is visible. An extra set of resistors are visible in the bottom corner of the board, so he's done something different. It could be a paralleled resistor divider in the virtual ground, or a low cost and very weak 3-ground setup. Triple electrolytic capacitors are a bit strange. These are probably implemented on the power supply rails, and judging by the size and model, we can guess they're 330-470uF parts. A TLE2426 based cMoy is stable with a single 220uF capacitor with decent ESR; extra electrolytic caps here will not improve measurable or audible performance. Decoupling caps are not present. Those are critical for a high-performance cMoy.
 
That said, cMoys perform nicely with the right headphones. Matching O2's SNR/THD/power is another story.

 
 Hey Jon, yes, it looked exactly like a cMoy to me only with Cinnamon flavor(??) Andrew also builds an Objective 2 and I'm not sure how it compares with yours BUT compared to his O2 this thing was definitely louder and has an extremely wide soundstage. Andrew said he had contact with you, I don't know if he actually spoke with you or you just contacted each other through the internet. 
 
 I begged him to charge more for it but as I understand it he just intended it to be for DJ's use. Also, because it looks exactly like the cMoy, he probably doesn't think anyone will pay more for it. He wanted to call it the "Booth Baby" which I loudly objected to. 
 
Jul 12, 2013 at 11:37 AM Post #7 of 10
Quote:
Hey, Marshal.
 
 
ClieOS is correct, this looks like an 18V cMoy variation.
 
There's an AC coupling input cap and three resistors per channel (standard non-inverting "cMoy" topology). The 3-pin chip in the corner is likely a TLE2426 virtual ground, considering there must be a ground and little other circuitry is visible. An extra set of resistors are visible in the bottom corner of the board, so he's done something different. It could be a paralleled resistor divider in the virtual ground, or a low cost and very weak 3-ground setup. Triple electrolytic capacitors are a bit strange. These are probably implemented on the power supply rails, and judging by the size and model, we can guess they're 330-470uF parts. A TLE2426 based cMoy is stable with a single 220uF capacitor with decent ESR; extra electrolytic caps here will not improve measurable or audible performance. Decoupling caps are not present. Those are critical for a high-performance cMoy.
 
That said, cMoys perform nicely with the right headphones. Matching O2's SNR/THD/power is another story.

 
That's what it looked to me as well, but the way it was described in the OP intrigued me. However I'm just learning about different amps so I'm not  the most knowledgeable on the subject.
 
Jul 12, 2013 at 11:42 AM Post #8 of 10
Quote:
 
 Hey Jon, yes, it looked exactly like a cMoy to me only with Cinnamon flavor(??) Andrew also builds an Objective 2 and I'm not sure how it compares with yours BUT compared to his O2 this thing was definitely louder and has an extremely wide soundstage. Andrew said he had contact with you, I don't know if he actually spoke with you or you just contacted each other through the internet. 
 
 I begged him to charge more for it but as I understand it he just intended it to be for DJ's use. Also, because it looks exactly like the cMoy, he probably doesn't think anyone will pay more for it. He wanted to call it the "Booth Baby" which I loudly objected to. 

 
Interesting, he must have set gain higher. O2's default levels of 2.5/6.5x are plenty for most. That extra gain is definitely useful for you DJ's.
 
Gain could be set higher in O2. Alas, if a high gain cMoy gets the job done at 1/3 the price, that's great!
 
Jul 12, 2013 at 11:49 AM Post #9 of 10
I'm *trying* to get Andrew to give out units to certain Head Fi-ers for review and he seemed open to the idea, so if someone contacts him I'm pretty sure he'll mail out demo units. I can't review it myself because I'm obviously biased, although I LOVE JDS Labs too Jon!!! lol
 
 
  Jon from JDS Labs is awesome and knows his stuff and I'll still refer to him as Maestro when I talk to him. The C5 was sensational and i was extremely happy with it but Andrew came over with that ******* cMoy lookalike and here I am. I will say that that thing is extremely loud (with NO distortion) to dangerous levels if you crank it. I want to say it's even more powerful than an E12 but I lost mine on a flight so I can't compare. 
 
Jul 12, 2013 at 12:08 PM Post #10 of 10
Quote:
 
Interesting, he must have set gain higher. O2's default levels of 2.5/6.5x are plenty for most. That extra gain is definitely useful for you DJ's.
 
Gain could be set higher in O2. Alas, if a high gain cMoy gets the job done at 1/3 the price, that's great!

A few DJ's have asked me about my headphone amps because they say they need more volume in the booth. This puzzled me at 1st because I use Beats Mixr's to DJ (yeah, Beats, I know, yada yada) and a headphone amp combined with those would blow off the top of my head. 
 
 But some of the Traktor and Serato controllers are coming out with very low outputs from what I understand and it's hard to hear stuff in the booth. The reason I didn't know this is because I play with CD's. 
 

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