Audeep Cmoy 1W Amp

Hey all, this is just an impressions/heads up post, I don't have any equipment to do a technical review.

I've been looking for a portable amp that puts out decent power. I found a used Cmoy on ebay a little while back that was labeled as "Audeep 1W Cmoybb" but it ended up being the JDSLabs one, which doesn't put out anywhere close to 1W, so I was pretty disappointed.

I had never heard of Audeep so I looked into them and found their etsy page: https://www.etsy.com/shop/audeep

Curiosity killed the cat, so I ended up ordering one just to see if it really does put out 1W. Well, it arrived today and while I have no equipment to measure it, I do have some T50RP's and with the included power supply, this thing drives them pretty easily. Easier than the Vali 2 for sure, so it at least puts out more than that amp. I don't have any 9V batteries on hand because I wasn't expecting this to arrive so quickly and hadn't ordered them, so I haven't listened to it with the batteries yet. I think it will still drive them just fine even battery powered given that with a power supply it will get them louder than I can stand. Batteries will get here on Saturday, so I will provide an update once I listen with just those powering it.

With music on pause and turning volume from min to max, it is silent, so noise performance is good. It also seems fairly neutral to me, I'm not hearing any colorization. All in all, an impressive little portable amp that was $83 shipped with the power supply. If anyone out there is looking for an affordable but powerful portable amp, this just might fit the bill.

 

Here's his measurements if anyone is interested.

Measurements:
DC Power Output @ 32 Ohm/channel: 700mW
AC Power Output @ 32 Ohm/channel: 1000mW
Bass boost: +5dB @ 30 Hz
Frequency Response: 20Hz-20kHz
THD @ 100 Ohm/500mW: <0.002%
SNR: >100 dB
Channel Separation: >94 dB
Output Impedance: 0.4 Ohm
Run Time on Battery: 7-40 hours

 

Thanks for the reply!

1. I thought the Vali 2 (not +) puts out 650mw @ 50ohm? With the Vali 2 I have to turn the volume to about 3 o'clock on high gain to get the T50RP's playing pretty loud. This little cmoy only needs about 12 o'clock. At 3 o'clock it is much louder than the Vali 2.

2. I do not. Supposedly Gelu (guy in charge of Audeep) is very responsive so I can ask him and get back to you.

3. I will ask him this question as well.

4. He uses 2 OPA552. I'll ask him about the voltage rails as well.

5. I haven't had a chance to listen to them with my Hemps yet but I will listen tomorrow and report back.

Edit: Actually it might be OPA551's. I'll clear that up with him too.

 

Okay, I would love to read a post about gain vs power.

And I'll be sure to let you know what he says about the opamps and power rails.

I've listened a little with the Hemps this morning and on pause, there is a slight hiss once you get to about 50% volume. However, the point where I hear the hiss with the Hemps is louder than I would listen. This gets them to loud levels very quickly and at normal (which can be fairly loud for me) listening volumes I can't hear any noise.

I'm still happy with it. I wanted a portable amp that would work with all of my headphones and this definitely fits the bill. I do think the Vali 2 sounds better after going back and forth but that shouldn't be surprising. But this sounds plenty good for portable use and since I often go and work in coffee shops (when it's not a pandemic) I like the unassuming look.

Anyway, as soon as he answers the questions I will let you know what he says.

Appreciate the feedback!

 

A gain switch would have been handy. I can still use them with the Hemps but I'll just have to be careful with the volume knob.

I do think the bass boost works better on this amp than the JDSLabs one. I had to leave the switch off on that because it just made the low end bloated and muddy and this Audeep actually sounds okay. They both supposedly elevate 30hz by 5db but the JDSLabs seems like it elevates it more than the Audeep. Could just be the quality of the bass that is making it seem that way.

 

I still have a breadboard CMoy that I made and am still proud of it (Batman tin!), but spending $80 on a premade one nowadays doesn't seem like a good value, especially if it is a JDS clone and not an evolution like Marv referenced. Maybe I need to find some 9 volts and re-listen and compare to an OG Fulla I still have.

 

Gain is the height of the bridge. Power is how much bungee cord you have. (oversimplified of course )

 

Yeah it's not a stupendous value I suppose. He charges $60 for it on ebay which is a fair price but he's in Romania so shipping isn't cheap. I thought about buying stuff and relearning how to solder and trying to make one myself. I took some electronics courses back in like 2000/2001 and I soldered my own boards and did a fine job but I've forgotten pretty much everything.

But to buy a decent soldering iron and the stuff I'd need, I'd be out just as much money if not more. Maybe I should have done that since I have some aspirations to start getting into DIY but that isn't going to happen until I have the space for it. I'm just a single dude that has been hopping from apartment to apartment. Would love to save for a house but it's damn near impossible when you live alone with how crazy high rents are. Every time I start building up the savings account something major happens and I gotta pay $3k in car repairs or something. Anyway, that's why I mostly just buy budget audio equipment, can't really afford the high end stuff at this juncture in my life. Overpaying for something this cheap isn't a super big deal since it still does exactly what I need it to.

 

I like your viewpoint here. And I got some replies from Gelu.

"The gain is set at 22dB with the linear setting. Enabling the bass boost raises the gain north of 27dB at around 30Hz."

"The criteria we used to reach the maximum power is the 1% THD threshold that we chose as the maximum harmonics acceptable for an audiophile experience. Of course at a lower gain the THD is a lot lower."

"Opamps are TI OPA551PA"

These are the measurements at 32 ohm load at 24V:

 

He just sent this as well, says it's the voltage swing for the opamp per TI:

 

Sorry, I think he just means the measurements with the supplied 24v power supply, rather than with 2 9V batteries.