[ezzieyguywuf]

Hey Community!

So last night I finished building my first CMOY. YAY! I haven't had a chance to enclosure it get but plan on getting than done this weekend. I haven't done any extensive listening tests because since the jacks are dangling I'm constantly afraid that I'm going to rip the wires out of them. Anywho, thought I'd jot down some of my initial impressions.

With my Grado SR-60s I don't hear too much of a difference between just the CMOY and the HP out of my Cowon D2. It can sure enough drive it to ear-splitting volumes though, but I don't want that. I've only tested it with V6 ogg files as that is all I have on my D2 right now.

I listened very briefley with my Denon D2000s last night when I first got it running and I feel like there may have been an increase in SQ, but the last time I hooked up the D2000s to my D2 was over a week ago, so more to come on this guy.

Now, the Livewires have shown me something. First of all, there is a lot of hiss present. I went back to check with the Grados, and the hiss is present when I turn the volume up to about 95%. With the Livewires I hear the hiss at 0%. Oh, and I hear the music too! Woah!

With the Livewires, I definitely feel like the bass is more controlled. Never thought I would hear that kind of difference but I did. I was listening mainly to Mos Def - True Magic and I can really hear and feel the bass: its as if I am sitting right in front of the bass drum and watching the drum-head vibrate. It was pretty magical.

I think this increased bass came at a price though. The highs were a little shy, at least more so than with straight out of the D2. These sonic differences may be characteristic of the Opamp I used (couldn't name it off the top of my head, but its in Tangent's BOM). I will probably experiment with different opamps and see how that goes.

So, overall I am pretty happy with the build so far! I will be far happier once its properly encased. I am somewhat dissapointed at the amount of hiss, and will look into if there are any solutions for it. I'm also dissapointed that I didn't notice much of a difference on the Grado's. I am very pleasantly suprprised with what I got out of the Livewires though.

I will listen to my Grado's strictly through the CMOY for a week or so then go back to bare D2 and see if I can hear a difference.

Thanks for reading!

Update: Pictures!



Here is my board "naked". Looks pretty neat huh? I actually used way too much hookup wire. You'll see what I'm talking about later.



Heres my gear. I also have the Grados and Livewires but didn't want to bore you guys with too many picture.



Here is a close-up of my panel from the outside. Gee I feel like a father when he's showing off his kid for the first time. Isn't she pretty? I mean, I know the components aren't all centered perfectly or evenly spaced, but I think it gives her character :-D






And here you can see what I meant about using too much hookup wire. Ah well, in the end I'm pretty satisfied with the build, specially with it being my first one!!! You can probably see all the electrical tape I used on the pot. Those little legs are finicky! They touch any metal and they're not happy.

Well thats it for picture time. Let me know if you guys want more pictures and I will happily oblige. I will be posting further impressions later tonight

 

[Thermonuclear]

when you have spent cash and time putting the cmoy together, you so want to hear a difference. In your case, you sound a bit under whelmed, I hope your time spent tweaking the cmoy yields good results for you in the end.

 

[ezzieyguywuf]

Quote:

In your case, you sound a bit under whelmed

Lol, well I guess thats a fair assesment. I'm really actually still very optimistic. I just checked the "tweaks" section of Tangent's site and read that:

Quote:

The first step is to determine whether the hiss is being generated in the amp, or is coming from the source. If you unplug the source and the noise goes away, you’ve found your culprit: the source is just noisy.

This is most def. my issue with the noise! So, problem solved, sorta :-D I mean to try it with my computer as a source, through my SoundBlaster Live! 24-Bit External USB soundcard. Not to mention I have a compass on the way that is supposed to have a decent DAC in it.

I'm not completely dissapointed yet, I just don't like to succumb to expectations. I know I was expecting it to sound awesome, but I like to be objective when trying things out, especially if its something I made myself. I'm sorta wierd that way. Don't get it twisted though, I had a blast building it, don't regret spending the money on the parts (as it was a great learning experience) and I look forward to where my opinions will be a week from now. I'll feel better about testing it once I have it enclosured properly.

 

[Pars]

The stock gain of 11 on a Cmoy is a lot. If this is how you built it, this is likely the cause of your hiss. Drop the gain to 2-4 and you should notice that it goes away.

Its not like you spent alot of money on this (<$30), and as an additional bonus, you built it yourself.

 

[ezzieyguywuf]

I'll look into changing the gain. 11 does seem high. I didn't spend much on the CMOY itself but since it was my first DIY project I spent a bunch on other stuff, like tools, hookup wire etc.

 

[ezzieyguywuf]

Hey guys. Added pictures. Bump!

 

[Ashkii21]

I remember building my first cmoy

I know the feeling of building that amp.
I don't know if one of the pictures is distorted but it looks like an electrolytic caps is slightly crushed. If it is crushed, I think it may leak.

 

[ezzieyguywuf]

Quote:

I don't know if one of the pictures is distorted but it looks like an electrolytic caps is slightly crushed. If it is crushed, I think it may leak.

Yea, I noticed that and posted a thread in the DIY forums. I got no response yet. Should I worry about it? Does it need to be replaced? I been listening to it all night and day and haven't had a problem. I really don't want to pull it apart but will if I have to. What happens when a cap leaks? I'm freaking out, but oddly not turning it off. Lol.

 

[Earwax]

Congratulations on completing your amp!

I totally agree with Pars that gain of 11 is too high. 3 to 4 should be much less hissy.

 

[ezzieyguywuf]

I'm considering just building a second one, cuz really it seems like more work than its worth taking this one apart. Now, changing the gain will just change my volume range right? For example, lets say that at gain 11 my volume goes from 0 to 30, and I hear hiss at about 15. When I change the gain to 6, lets say my volume now goes from 0 to 12 (same scale as the original). In this case, I will not hear the hiss but have less volume, albeit greater control over the volume that I do have. I do not currently use even half of the available volume because it gets too loud. I'm waiting till I get my compass and try the line-out before i make a final decision on this though. On my comp and D2 I put the volume all the way up to avoid software volume control.

 

[robjrock]

Heya,
I just finished building my first Cmoy too (well a couple of weeks back...) Which Op Amp are you using? Because I was pretty underwhelmed by the OPA2132, although it sounded 'nice' - once I switched to the OPA2277 I heard some improvement, LM4562 was a big improvement, LME49860 (which I am currently using) is also a big improvement....

I build mine with 3.3k output resistors (R3) instead of the 1k, mostly because I didn't have a volume knob (and also because thats what I had lying around) and the gain is perfect for my 32ohm impedance Phonaks... loud but no hiss and seems stable.