The Audio-gd Compass (Was: Designing an alternative to the Zero DAC/amp)
Mar 19, 2009 at 7:00 AM Post #4,276 of 7,725
Quote:

Originally Posted by dBs /img/forum/go_quote.gif
59 Hours of burn in so far and the bass has DEFINITELY toned down. It is sounding more neutral and balanced in weight (despite being Soft 2). Only a little bit of bass emphasis still lingering, right where I would like it to be honestly. Now the goal is to replicate the sound at this point in time I would say, as far as the bass is concerned.

I tested the gain settings. Up until today, I had only used the lower gain setting on both of my phones. I switched to high today, no sound difference as far as I can tell, only volume. Think I want to keep it on the low gain setting then as it will allow me greater adjust ability within my preferred listening volumes.

I have to question the legitimacy of what Im about to say but it honestly seems like the Compass isnt running as hot anymore. The first two days I could see why some were concerned about the sort of heat the Compass put out, but now it doesnt seem as hot as it was. It may be possible that the heat sink compound is balancing itself out just like you can overclock a processor a tiny bit higher a couple days after first getting it, but I doubt that. Only commenting on what Ive noticed, cant claim legitimacy to the findings though, lol.



Hey,
What do you think about the idea that if there is Burn in of all the components that this could effect thermal load, and that as things "Burn in" there is less heat produced?

.
 
Mar 19, 2009 at 7:11 AM Post #4,277 of 7,725
Quote:

Originally Posted by les_garten /img/forum/go_quote.gif
Hey,
What do you think about the idea that if there is Burn in of all the components that this could effect thermal load, and that as things "Burn in" there is less heat produced?

.



I honestly wouldnt think very likely. The main reason being that heat produced is a factor of two players: electricity and resistance. The electricity shouldnt fluctuate much pre or post burn in. Resistance is more likely to fluctuate but even that is extremely minimally. Also resistance has a factor of heat involved in its levels. Temperature goes up, electrons vibrate faster and allow the continuation of electrons easier, so less heat. Eventually things balance out, though thats at very high temperatures-based upon material. Its probably just me thinking its cooler now than then is all. I dont think its much more than that achems razor.
 
Mar 19, 2009 at 7:12 AM Post #4,278 of 7,725
Quote:

Originally Posted by Drosera /img/forum/go_quote.gif
Now look at this, wonderful:


Oh that did come out nicely!

I had been wondering about that!

It's funny actually, I hadn't intended for the box indicating OPA padding to be printed, but I forgot to mention it. Hope it lines up just right and gives the assemblers an easier task of just sticking the tape over that box, otherwise it will be funny to have it misaligned with the padding! I had really just put it there for Kingwa's and my reference
biggrin.gif


Now that it's there though I like it, if you take the tape off but ever need to reapply it for shipping and no residue is left behind by the original tape you don't have to worry about lining it up.
 
Mar 19, 2009 at 7:15 AM Post #4,279 of 7,725
Quote:

Originally Posted by dBs /img/forum/go_quote.gif
I honestly wouldnt think very likely. The main reason being that head produced is a factor of two players: electricity and resistance. The electricity shouldnt fluctuate much pre or post burn in. Resistance is more likely to fluctuate but even that is extremely minimally. Also resistance has a factor of heat involved in its levels. Temperature goes up, electrons vibrate faster and allow the continuation of electrons easier, so less heat. Eventually things balance out, though thats at very high temperatures-based upon material. Its probably just me thinking its cooler now than then is all. I dont think its much more than that achems razor.


Hi,
I was thinking if the efficiency of the caps improves a lot that it may effect it. Not too many times you get to pose this stuff to an EE!

.
 
Mar 19, 2009 at 7:17 AM Post #4,280 of 7,725
Quote:

Originally Posted by csroc /img/forum/go_quote.gif
Oh that did come out nicely!

I had been wondering about that!

It's funny actually, I hadn't intended for the box indicating OPA padding to be printed, but I forgot to mention it. Hope it lines up just right and gives the assemblers an easier task of just sticking the tape over that box, otherwise it will be funny to have it misaligned with the padding! I had really just put it there for Kingwa's and my reference
biggrin.gif


Now that it's there though I like it, if you take the tape off but ever need to reapply it for shipping and no residue is left behind by the original tape you don't have to worry about lining it up.



That came out really sharp.. I saw it earlier today. I don't always hit the site, so thought it had been up a while.

.
 
Mar 19, 2009 at 7:26 AM Post #4,281 of 7,725
Quote:

Originally Posted by les_garten /img/forum/go_quote.gif
Hi,
I was thinking if the efficiency of the caps improves a lot that it may effect it. Not too many times you get to pose this stuff to an EE!

.



Its not usually capacitors that put of heat really. Theres resistance to them but more than anything else they simply store potential and dont allow voltage to rapidly change. Think of a capacitor as a bucket of water with a hose to it and a hole in its bottom. They have temperature thresholds printed on them in case their environment becomes too hot so they dont explode =X

BJTs and FETs are where the majority of your heat comes from. Oh and toroids, they put off a lot of heat as well but thats mostly the resistance in all those windings.

As far as the EE...thats really more a technicality at this point XD I passed the FE exam (HUZZAH!) but still have 58 days left until I graduate. And apparently no ones willing to hire me either right now so that doesnt exactly help, lol.
 
Mar 19, 2009 at 7:36 AM Post #4,282 of 7,725
Quote:

Originally Posted by csroc /img/forum/go_quote.gif
Quite the pricey cartridge.

Anyway, are you talking about connecting your turntable directly to the Compass? If so the results will be less than desirable, you want to have the RIAA equalization to restore correct tonal balance among other things. A phono preamp is a must then in my opinion.

Since you sound like you're connecting through your receiver you'll want to make sure the phono input on your receiver (if it has one) actually employs RIAA equalization. Although Peete is willing to bet that it does I would not be surprised at all if it doesn't as many receivers do not carry that any more but I didn't catch what receiver you have so I couldn't say. If your receiver does have one it may have an in-built phono preamp which is just fine. If not (or if you want to upgrade phono preamps) there are plenty of options. If it doesn't have one then in my opinion you need one.

I do something similar to what you two talked about using the tape monitor connection. My NAD integrated doesn't have spare preamp outputs but I can and do use the tape monitor output to listen to my CD player or record player on my Starving Student headphone amp. My connection is similar to what you'd need if you don't have a phono preamp in your receiver. My turntable is connected to my phono preamp which is in turn connected to the input on my amplifier.



Dude, yes it was a bit pricey (the cartridge). But as far as wanting to hook up the Compass to my turntable so I can use my headphones, yes I would like to do that and am trying to learn what my different options are. I currently can't do it at all with the receiver that it's currently hooked up to because my receiver doesn't have a headphone out. However it does have a phono input. It really is a nice and powerful (200 watts rms x 7 @ 8 ohms) all purpose receiver for being one unit rather then separates. However if I knew then what I knew now, I would have probably gone with separates, maybe down the road. Either way I don't regret the purchase at all.

Sorry, I tend to ramble often, very often.
tongue_smile.gif
Anyway after reading some other peoples posts about my Compass setup, the phono "preamp" came into question. Well I don't have one and never thought about it since my receiver has the phono input and ground. The only thing it says in my receivers manual about attacking a turntable is to make sure it's either an MM or and high output MC. And as far as outputs like a preamp output, it has a few different ones though they call them just "stereo" outputs. I've never used them so I'm not sure. They do say that they are a fixed output though, so I suppose it would need it's own volume control. Some more stuff I'm not too familiar with.
frown.gif


It doesn't mention the quality of the phono input source and whether or not is has the RIAA equalization like you mentioned. This stuff is very new to me since I've never researched it before, nor was I asked about it when I purchased my turntable. After reading up more this week about phono preamps and the specs of my cartridge, I got VERY curious, then confused. However it was also helpful but actually made me start questioning my the sound quality of my turntable running directly through my receiver. My vinyl will run VERY bass heavy, not to mention I have to turn up the volume control quite a bit more compared to any other input. I just assumed this was do to the nature of being analog. And it might be, I'm not sure. After I make some adjustments it sounds great, but it still got me thinking after reading what a phono preamp is intended to do.

The reason this is important to me and related to the Compass is because I own more vinyl then I do any other source. And the Compass is what I will actually need to be able to use my headphones, plus I want the best possible sound out of my vinyl of coarse. Basically during my research about how to hook up the Compass to my receiver to accomplish this I started to second guess my setup for sound quality. And being new to standalone phono preamps I just became over whelmed with my options and even questioned what my options are due to the type of cartridge I have.

No I don't only want the Compass connected to the turntable, but also my cd player and PC as well. The turntable research just through me for a loop I wasn't expecting. So anyway, if all the "phono" talk is way off topic then I'll just zip it since the last thing I want to do is derail this thread and upset people. I just need a bit more help outside of the Compass now that I didn't think I needed. So while it's relevant to me, it might not be proper for this thread.

Sorry for the rambling everyone. The "strong" pain meds I take for my back really F's with my memory and makes it very difficult to focus. So instead of just "Spitting it out" and getting to the point, I ramble. Again I apologize to everyone for this because I know people don't like to read a wall of text. Thanks you for your help csroc, sorry if my post is difficult to follow. And anyone, please let me know if this is too off topic please, I will kindly take it somewhere else. Thanks everyone for your help, patience and understanding. I'm quite lucky to find such a killer forum with awesome guys and gals here.
smily_headphones1.gif
 
Mar 19, 2009 at 7:53 AM Post #4,283 of 7,725
Quote:

Originally Posted by dBs /img/forum/go_quote.gif
59 Hours of burn in so far and the bass has DEFINITELY toned down. It is sounding more neutral and balanced in weight (despite being Soft 2). Only a little bit of bass emphasis still lingering, right where I would like it to be honestly. Now the goal is to replicate the sound at this point in time I would say, as far as the bass is concerned.

I tested the gain settings. Up until today, I had only used the lower gain setting on both of my phones. I switched to high today, no sound difference as far as I can tell, only volume. Think I want to keep it on the low gain setting then as it will allow me greater adjust ability within my preferred listening volumes.

I have to question the legitimacy of what Im about to say but it honestly seems like the Compass isnt running as hot anymore. The first two days I could see why some were concerned about the sort of heat the Compass put out, but now it doesnt seem as hot as it was. It may be possible that the heat sink compound is balancing itself out just like you can overclock a processor a tiny bit higher a couple days after first getting it, but I doubt that. Only commenting on what Ive noticed, cant claim legitimacy to the findings though, lol.



I'm happy for you and the results your having with your Compass, that's awesome news! My impatience is starting to grow stronger day by day waiting for mine.

As far as the temp thing, I own a few nice temp guns and check that out once I get mine. Might be something sort of fun to check out. Maybe I'll take readings like every 20 hours or so of use, maybe more frequently for the first 50-100 hours or until it stops changing. That is if it changes which it very possible it is. Just a thought.

May I ask what approach your taking for burn in. Thanks.
smile.gif
 
Mar 19, 2009 at 7:55 AM Post #4,284 of 7,725
Quote:

Originally Posted by Serpentd /img/forum/go_quote.gif
It doesn't mention the quality of the phono input source and whether or not is has the RIAA equalization like you mentioned. This stuff is very new to me since I've never researched it before, nor was I asked about it when I purchased my turntable. After reading up more this week about phono preamps and the specs of my cartridge, I got VERY curious, then confused. However it was also helpful but actually made me start questioning my the sound quality of my turntable running directly through my receiver. My vinyl will run VERY bass heavy, not to mention I have to turn up the volume control quite a bit more compared to any other input. I just assumed this was do to the nature of being analog. And it might be, I'm not sure. After I make some adjustments it sounds great, but it still got me thinking after reading what a phono preamp is intended to do.


Ha, this is getting very off topic, but what the hey. If your phono input sounds bass heavy you can rest assured it's RIAA equalized, however it might be that it's not equalized very well. So in that case, a separate phono amplifier and connecting that to either the receiver or the Compass would help a lot. It could very well be that the phono stage in your receiver is a real bottleneck here.
The fact that it's rather low in volume is partly an aspect of vinyl, but might also have to do with the way the phono stage in that receiver works. Apparently, that phono stage was designed with amplification of the signal of a moving magnet cartridge in mind. However, the Grado cartridges appear to be hybrids between moving coil and moving magnet (called 'moving iron') and the Statement series cartridge has a very low output voltage (0.5 mV). This means that the phono stage in your receiver is probably not giving it sufficient amplification. Either a Grado phono amplifier or (probably) any other kind of phono amplifier suitable for moving coil amplification should remedy this problem. (I think, but those of you with more experience in vinyl than I have: please correct me if I'm wrong.)

Oh yeah, don't worry too much about multiple posts. This thread is already at 4200+ posts, a few more won't matter.
biggrin.gif
 
Mar 19, 2009 at 8:04 AM Post #4,285 of 7,725
Quote:

Originally Posted by Serpentd /img/forum/go_quote.gif
May I ask what approach your taking for burn in. Thanks.
smile.gif



I just make sure to have it playing something at all times. Either Im listening to it or its playing pink noise in a continuous loop (pink noise file from here: Burn-in wave files: white noise, pink noise, frequency sweep, channel mix). At night, when I dont have my desktop running (dorm room and its a water cooled, OCed gaming rig so bright and loud), I hook it up to my laptop under my desk (also bright and loud but less so) and have that playing the loop with my headphones in their very sound proofed case.

As far as keeping track of time, I know I hooked it up around 4pm in the afternoon on Monday. If it plays constantly then you can figure out the hours.
 
Mar 19, 2009 at 11:51 AM Post #4,286 of 7,725
I hadn't checked it in a while, but my Compass also seems to be running much cooler than it did at first. Might be my mind playing tricks on me, but that impression of "wow, that's warm" is gone. Could be from removing the padding on the opa.
 
Mar 19, 2009 at 12:05 PM Post #4,287 of 7,725
Quote:

Originally Posted by idunno /img/forum/go_quote.gif
I hadn't checked it in a while, but my Compass also seems to be running much cooler than it did at first. Might be my mind playing tricks on me, but that impression of "wow, that's warm" is gone. Could be from removing the padding on the opa.


This is really intriguing and it made me check the casing temperature of my Compass. What do you know, it's barely above room temperature now. I remember it used to get worryingly warm/hot in the first days I used it.

Now what on earth could be the explanation for this?
 
Mar 19, 2009 at 1:15 PM Post #4,289 of 7,725
"Zero" noise!
But it warms my room for sure.
 
Mar 19, 2009 at 2:04 PM Post #4,290 of 7,725
Quote:

Originally Posted by Drosera /img/forum/go_quote.gif
Ha, this is getting very off topic, but what the hey. If your phono input sounds bass heavy you can rest assured it's RIAA equalized, however it might be that it's not equalized very well. So in that case, a separate phono amplifier and connecting that to either the receiver or the Compass would help a lot. It could very well be that the phono stage in your receiver is a real bottleneck here.
The fact that it's rather low in volume is partly an aspect of vinyl, but might also have to do with the way the phono stage in that receiver works. Apparently, that phono stage was designed with amplification of the signal of a moving magnet cartridge in mind. However, the Grado cartridges appear to be hybrids between moving coil and moving magnet (called 'moving iron') and the Statement series cartridge has a very low output voltage (0.5 mV). This means that the phono stage in your receiver is probably not giving it sufficient amplification. Either a Grado phono amplifier or (probably) any other kind of phono amplifier suitable for moving coil amplification should remedy this problem. (I think, but those of you with more experience in vinyl than I have: please correct me if I'm wrong.)

Oh yeah, don't worry too much about multiple posts. This thread is already at 4200+ posts, a few more won't matter.
biggrin.gif



Drosera dude, thank you very much for your input. I appreciate it very much. Yeah, I suppose your right on me swaying quite a bit off the topic here so I'll drop any more follow up on this subject. It's just nice to hear what others have to say even after days of research. Darn audio stuff. I wish I could borrow any equipment I wanted to try just to confirm suspicion, that way I could give it back if I don't like the result and save $$.
atsmile.gif


My main concern is that darn Grado cartridge of mine with that low input voltage and the whole "moving iron" thing. I'll eventually figure it out. In the mean time I just need to wait for my happy little Compass to get here is all and go from there. Oh yeah, I was trying to find some of those 240 sextett(?) headphones you mentioned but they seem rather rare. Do they pop up on Ebay every now and then?

Anyway, I appreciate your help as always. I wish I had a friend or neighbor like you as well. I guess that's one reason I'm here though, huh? Cool man, thanks again buddy.
smily_headphones1.gif
 

Users who are viewing this thread

Back
Top