[JosephsART]

Quote:

 
After spending 12 years working with thermal analysis teams in the Telecom industry, I can tell you that adding vents (especially on the sides!) makes very little difference.
To increase the cooling effectively, you would need to thermally bond the heatsinks to the case or use some type of forced air cooling.
Adding vents to the sides does little or nothing because hot air flows like molasses.

 
I think the new version had vents designed on the side as to coincide with the introduction of the M-Stage DAC. Question is though, if the devices were stacked on-top of each other (as pictured), which order would the devices stack?
 
I figured running the amplifier on top would allow for heat to disperse from the unit faster, though at the same time, it would conduct heat from the DAC below it (even though the DAC outputs considerably less heat). Having the DAC on top instead could mean it conducts all the heat from the amplifier, and the amplifier would have less ventilation. I'm not sure what the best scenario would be.
 
I suppose alternatively, you could run both devices on their sides, so the heat can escape upwards through the side vents. Doesn't look fancy though.

 

[Guess?]

Quote:

 
And thank you for replying.
I think the M sounds better with the bypass.

  What do you think?
 
But I would not want a new Headphone and M Stage owner to damage their 'phones, so I think it bears repeating, even if most of us are sick of hearing it!

 
I like it better too. It's been a while since I've done the mod, and I'm pretty happy with the sound, some friends with pricier amps are loving my M-stage which is good news, for me at least. With the mod I totally disliked the a-biased LME49710NA sound (so cold), and put the OPA627BP. Before the mod I preferred the LME/s to the 627/s. Now the sound is right for my ears, and right now I'm thinking of maybe HE-400 to join the M-Stage some day... Anyway you're right for pointing out about the DC offset, it's an important thing to avoid. Cheers!

 

[JosephsART]

Quote:

Now the sound is right for my ears, and right now I'm thinking of maybe HE-400 to join the M-Stage some day...

 
I'm considering a pair of these as well, though I noted that the damping factor may be an issue with the M-Stage. Will it make a considerable difference? I suppose the only way to find out is to hear it.

 

[Chris J]

Quote:

 
I think the new version had vents designed on the side as to coincide with the introduction of the M-Stage DAC. Question is though, if the devices were stacked on-top of each other (as pictured), which order would the devices stack?
 
I figured running the amplifier on top would allow for heat to disperse from the unit faster, though at the same time, it would conduct heat from the DAC below it (even though the DAC outputs considerably less heat). Having the DAC on top instead could mean it conducts all the heat from the amplifier, and the amplifier would have less ventilation. I'm not sure what the best scenario would be.
 
I suppose alternatively, you could run both devices on their sides, so the heat can escape upwards through the side vents. Doesn't look fancy though.

 
If ya gotta stack, I would put the hotter box on top!
Obviously, keep a few inches of clearances on the sides and top.
 
Cheers, C.
Quote:

 
I like it better too. It's been a while since I've done the mod, and I'm pretty happy with the sound, some friends with pricier amps are loving my M-stage which is good news, for me at least. With the mod I totally disliked the a-biased LME49710NA sound (so cold), and put the OPA627BP. Before the mod I preferred the LME/s to the 627/s. Now the sound is right for my ears, and right now I'm thinking of maybe HE-400 to join the M-Stage some day... Anyway you're right for pointing out about the DC offset, it's an important thing to avoid. Cheers!

 
I'm an LM4562 fan boy myself.
So far, I've tried the stock Op Amp and Class A and Non Class A OPA627s
Personally, I hear very little difference between Op Amps in the M.
I just think the LM4562 is a bit cleaner and clearer.
I normally use the M with my Q701s.
YMMV.
 
BTW, I've found that rolling in those various Op Amps made no difference to the DC offset at the OUPUT of the M Stage. 

 

[Guess?]

Quote:

 
I'm considering a pair of these as well, though I noted that the damping factor may be an issue with the M-Stage. Will it make a considerable difference? I suppose the only way to find out is to hear it.

 
I think it won't be a problem at all, I have already asked some people - all of them reported a great/good combination between the M-Stage & HE-400. The issue is the money.

 
Thanks for the review of the M-Stage Dac by the way.

 

[Guess?]

Quote:

 
If ya gotta stack, I would put the hotter box on top!
Obviously, keep a few inches of clearances on the sides and top.

        Good point.
 
 
Quote:

I'm an LM4562 fan boy myself.
So far, I've tried the stock Op Amp and Class A and Non Class A OPA627s
Personally, I hear very little difference between Op Amps in the M.
I just think the LM4562 is a bit cleaner and clearer.
I normally use the M with my Q701s.
YMMV.
 
BTW, I've found that rolling in those various Op Amps made no difference to the DC offset at the OUPUT of the M Stage. 

 
Yes, I thought the same, until we did a blind test to see what's really happening. We were using K701 then. So we choose three different songs/genres, each one had to listen to those three songs and write down his impressions. After that we repeated the operation with the other op amps. No one was allowed to read the others writings until we finished the test. Then we read what we have wrote to compare - all three of us noticed the same flaws/negatives in the LME/s, the 627BP sounded more full and complete whereas the LME/s more thin and annoying, on one of the songs the difference was really big. There are also some some fake 627s which do not sound the same as the genuine ones, we've checked mine - they're OK. Before the mod I really liked the sound of the LME better than the 627.

 

[Chris J]

Quote:

 
I'm considering a pair of these as well, though I noted that the damping factor may be an issue with the M-Stage. Will it make a considerable difference? I suppose the only way to find out is to hear it.

The HE-400 has a 35 Ohm impedance,
The M Stage has a 5 Ohm output impedance.
In terms of damping factor that should be OK.
The 1/8 and 1/10 or more impedance rules are really just guidelines.
 
I would be more concerned about other owners impressions of the HE-400 and M combo.
Guess? says the HE-400 owners like the combo, so I would go with the reported synergy.

 

[JosephsART]

If ya gotta stack, I would put the hotter box on top!
Obviously, keep a few inches of clearances on the sides and top.

 
Thanks Chris, dunno why Matrix pictured it with the DAC on top. I had it like that originally and it just didn't make sense, so I swapped them around tonight. There's plenty of space around the stack, and I think everything is running cooler
 

The HE-400 has a 35 Ohm impedance,
The M Stage has a 5 Ohm output impedance.
In terms of damping factor that should be OK.
The 1/8 and 1/10 or more impedance rules are really just guidelines.

I think it won't be a problem at all, I have already asked some people - all of them reported a great/good combination between the M-Stage & HE-400. The issue is the money. 

 
Thanks for the review of the M-Stage Dac by the way.

 
If it's any comparison, the HE-400 is 91db/32Ω, HE-500 is 89db/38Ω and the LCD-2 is 91db/60Ω.
 
I read that the HE-500 & LCD-2 shine with >1000mW power, so I hope that (being orthodynamic) the HE-400 is as manageable as everyone suggests with the M-Stage pushing 400mW. I haven't found any requirements for them myself, so I'll presume the reported synergy is desirable.
 
And thanks, it's the curiosity from people here that got me into the M-Stage, and it's awesome to give some feedback

 

[HamilcarBarca]

I received my (M-Stage amp) shipping confirmation from Tam Audio this afternoon. It's been just over 7 days since I ordered.
 
The online status has changed from "Complete" to "Shipped." It's confusing, to me at least, because Amazon uses "Complete" to mean everything in the order has shipped. But that's a minor quibble.
 
Now, I start following the tracking information!

 

[chicolom]

Headfonia has reviewed Matrix's new little amp/dac box.
http://www.headfonia.com/the-320-portable-dacamp-matrix-mini-portable/
 

 

[HamilcarBarca]

Quote:

I received my (M-Stage amp) shipping confirmation from Tam Audio this afternoon. It's been just over 7 days since I ordered.
 
The online status has changed from "Complete" to "Shipped." It's confusing, to me at least, because Amazon uses "Complete" to mean everything in the order has shipped. But that's a minor quibble.
 
Now, I start following the tracking information!

 
UPDATE: When I enter my tracking number into the EMS web page, http://www.ems.com.cn/english.html, I get this helpful response.
 
    无查询邮件信息或邮件超过查询期限.
 
Google says this means
 
    The no query mail messages or e-mail over query period.
 
If EMS can't be bothered to hire an English translator for their "WORLDWIDE EXPRESS MAIL SERVICE", I'm going to avoid ordering from any vendor who uses them. I'd rather shop at Walmart.

 

[chicolom]

Quote:

If EMS can't be bothered to hire an English translator for their "WORLDWIDE EXPRESS MAIL SERVICE", I'm going to avoid ordering from any vendor who uses them. I'd rather shop at Walmart.

 
Good luck finding an M-Stage at Walmart.
 

 

[JosephsART]

Quote:

I received my (M-Stage amp) shipping confirmation from Tam Audio this afternoon. It's been just over 7 days since I ordered.

 
Don't sound surprised. I've been nothing but unhappy with Tam Audio's performance recently. I believe the dude packed up and went on holidays and he's been fairly difficult to work with as of late. Like I said earlier, I received my item with the original box used as the packaging, with a shipping slip strapped to it. My op-amp was also incredibly lightly packed, and he strapped tape on the actual hardware itself! My first order took 2 weeks since payment, my second order, 4 weeks.
 
Quote:

When I enter my tracking number into the EMS web page, http://www.ems.com.cn/english.html, I get this helpful response.
 
    无查询邮件信息或邮件超过查询期限.

 
I've bought Matrix equipment from 3 different sellers, 2 from eBay and Tam Audio. They were all in China and they all used EMS.
 
I had success using this page http://www.ems.com.cn/mailtracking/e_you_jian_cha_xun.html
 
Though sometimes the captcha image doesn't load, or the item can't be found.

 

[HamilcarBarca]

Quote:

Quote:

I received my (M-Stage amp) shipping confirmation from Tam Audio this afternoon. It's been just over 7 days since I ordered. I believe the dude packed up and went on holidays and he's been fairly difficult to work with as of late. Like I said earlier, I received my item with the original box used as the packaging, with a shipping slip strapped to it. My op-amp was also incredibly lightly packed, and he strapped tape on the actual hardware itself! My first order took 2 weeks since payment, my second order, 4 weeks.

 
Don't sound surprised.

 
There were a number of reports of late or non-existent shipping confirmations and of poor packaging. I recognize yours as one of them. I was and am somewhat anxious, but I knew in advance of these potential problems. However, EMS is a "WORLDWIDE EXPRESS MAIL SERVICE" (to quote from their web site) who can't be bothered translate a simple message into English. Tam Audio may be disorganized; EMS' service is unacceptable.
 
When I lived on the (US) east coast, I wouldn't order from any vendor unless I was assured they wouldn't use FedEx who would routinely
 

1. abandon valuable packages on my doorstep or my neighbors' doorsteps; and
2. attach dishonest "attempted delivery -- nobody home" notices to my door even when I was at home.

 
Where I live now, FedEx' service is much better. I still like USPS far more than I like FedEx or UPS. Some people have had different experiences.

 

[JosephsART]

Off topic, I'm still puzzled with this one;
 
Does anyone know how the gain switches work?
 
How does using the gains affect the sound signature and performance?