[les_garten]

Quote:

Originally Posted by bobsmith /img/forum/go_quote.gif I would not say "clearly." All we know is that someone reported the unit was hot, and that it was skipping - we do not know which is the cause or the effect. We do not know whether the heat was causing the skipping, or whether the skipping indicated a fault that was resulting in extra heat. We also do not definitively know that the skipping was in any way related to the heat...they very well may be completely independent. For example, the skipping could have been related to the voltage fluctuation issue rather than temperature. All I am saying is that it is not a great idea to draw general conclusions from a single data point...

It wasn't someone it was me! These threads sometimes get out of Kilter quick, so let me clarify a few things I mused before.

For a Class A circuit, I don't think 120F on the heatsinks is hot at all. It feels like a Class A circuit. If 120F bothers you, you might want to avoid anything biased Pure Class A. They only get hotter than 120F, not Cooler. YMMV.

I mentioned the skips, I'm not sure of the Etiology of those skips yet. I'm looking for them to happen again so I can finish troubleshooting. Haven't seen them again. My REF1 has been running solid for about 5-6 weeks. My first idea was that it was my Computer/Source. I rebooted and it was still there. Let's not tar the REF1 with that one yet. I didn't finish the troubleshooting on that one.

Also if the skips are to be attributed to the REF1, it is entirely possible it is related to the Memory issue discussed before where I noted distortion and image shift when the REF1 is run for 7 days or so. May be the same issue manifested differently.

Just as a side note. Because I was interested in this during the development stages, I had asked Kingwa if he could install a TTL Serial Comm port on the DSP for monitoring. I never got that point across to them, they either didn't understand or didn't want me mucking around in the Altera Chip.

But I just noticed a Header on that board that looks like it is a TTL header. I may revisit this. It would be nice to debug the Chip while it does the image shift thing.

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[Tachikoma]

Quote:

Originally Posted by Currawong /img/forum/go_quote.gif The Ref 1 isn't just DAC components, each mono DAC and the input section have comprehensive Class A power filtering, which is why it gets warm. I wouldn't consider half the temperature of boiling water to be "hot" for electronic components. The only issue, which has been resolved, was one with voltage fluctuation on the input stage after many hours switched on, which would cause 24/96 input to drop out.

This "Class A = everything is going to be hot" assumption that people have is a bit of a misconception. But for a start, afaik there's no such thing as "class A" for power regulation - a perfect power supply would apply the correct voltage across whatever it's powering, and supply current when the components demand for it. There is no "biasing" here, like Class A would imply.

Quote:

For a Class A circuit, I don't think 120F on the heatsinks is hot at all. It feels like a Class A circuit. If 120F bothers you, you might want to avoid anything biased Pure Class A. They only get hotter than 120F, not Cooler. YMMV.

What "Class A" means is that no matter how large an input signal gets, the power draw of a component amplifying said signal remains the same, so in theory that means better linearity. To do that, you apply a "bias" current to said component. (Someone correct me if I'm wrong) Because the biasing current isn't being used most of the time, this method ends up generating a lot of heat in the component which is _amplifying_ the signal, not the one that's generating the signal. The generator of the signal on the other hand, would much rather see a lot less heat so that it can do its job, that is converting digital data to analog with as few non-linearities as possible.

In other words, there is nothing wrong in seeing ridiculously high temperatures in things like tube amps, but generally speaking, source components should never be that hot if you want them to operate optimally.

Its not 120F at the heatsinks that bothers me, its 127F on the PCM1704 chip that really bothers me.

Quote:

I would not say "clearly." All we know is that someone reported the unit was hot, and that it was skipping - we do not know which is the cause or the effect. We do not know whether the heat was causing the skipping, or whether the skipping indicated a fault that was resulting in extra heat. We also do not definitively know that the skipping was in any way related to the heat...they very well may be completely independent. For example, the skipping could have been related to the voltage fluctuation issue rather than temperature. All I am saying is that it is not a great idea to draw general conclusions from a single data point...

Fair enough.

 

[Jon L]

Quote:

Originally Posted by Tachikoma /img/forum/go_quote.gif Its not 120F at the heatsinks that bothers me, its 127F on the PCM1704 chip that really bothers me.

It's difficult to believe PCM1704 chips are truly operated at that temperature. If true, I would definitely do something about it, maybe install a quiet Nexus fan in there around the DAC chip.

Nexus 80 mm Quiet Fan

 

[les_garten]

Quote:

Originally Posted by Jon L /img/forum/go_quote.gif It's difficult to believe PCM1704 chips are truly operated at that temperature. If true, I would definitely do something about it, maybe install a quiet Nexus fan in there around the DAC chip. Nexus 80 mm Quiet Fan

(8) Chips you mean...

I left the lid off for a few hours and looked over the temps. The numbers all dropped about 4-6 degrees with the lid off

The 120 degrees on the heat sink means the Chip most likely is higher because of Heatsink gradient.

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[Pricklely Peete]

You know Tac...this DAC has been in the field for well over a year or more in the form of the DAC8 (95% the same as the RE1). If Kingwa isn't worried about the heat why should I be ? It's not like he does things haphazardly.

The DSP1 has some growing pains that are being looked after. I'm ok with that.

Here's a link to a smaller version of what the RE1's supply is roughly based upon...н¨ÍøÒ³ 1

Pay attention to setup procedure.



This little module produces a fair bit of heat but sounds great with the Jaycar kit amp. Scale that up by 6 and you have the RE1 PSU roughly speaking. The 3 trafos in the RE1 are pulling 160Watts or is it 150W ? (one or the other).....this isn't an ordinary DAC by any means.

I'm no topology expert either so maybe you'd better ask Kingwa directly how he's got his power supplies setup in the RE1.

All I know is it's sounds amazing and produces a fair amount of heat doing it

.

Thanks for the info. It IS appreciated.

Peete.

 

[Tachikoma]

Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif You know Tac...this DAC has been in the field for well over a year or more in the form of the DAC8 (95% the same as the RE1). If Kingwa isn't worried about the heat why should I be ? It's not like he does things haphazardly.

A year or so may not be enough to cause serious problems, but 3-5 years in the future and you might see these DACs needing repairs. I like gear that lasts forever

(All of my gear is at least 10-20 years old, sans the computer related parts)

I think the heat issue is just an oversight on Kingwa's part - all of us do it after all. The heatsink needs to be able to disperse that heat more efficiently, and mounting it on the bottom just didn't make a lot of sense. Dealing with the heat should have been one of his priorities if he was going to use a power supply that inefficient - 150-160W is A LOT of power for a DAC.

Personally I'd use a liquid cooling system to cool it and keep noise levels down, but I doubt that we're going to see a liquid cooled audiophile component any time soon

 

[tim3320070]

Quote:

Originally Posted by les_garten /img/forum/go_quote.gif Did you figure the switch out? .

It is the optical/ coax switch, I just confirmed. I have a CD running from a Pioneer 300 CD changer and the same album (uncompressed) running from my computer and I am A/B ing them- not hearing any difference with my rig. I will try with my speaker setup but I doubt any real difference can be heard. I must say this DAC with over a hundred hours on it now is clearly superior to my V-DAC in about every way (as it should be). What strikes me is the total smoothness of sound, not one bit of harshness anywhere- before things had a "digital" quality to the sound but that is gone. A real delight.

 

[les_garten]

Quote:

Originally Posted by Tachikoma /img/forum/go_quote.gif A year or so may not be enough to cause serious problems, but 3-5 years in the future and you might see these DACs needing repairs. I like gear that lasts forever (All of my gear is at least 10-20 years old, sans the computer related parts) I think the heat issue is just an oversight on Kingwa's part - all of us do it after all. The heatsink needs to be able to disperse that heat more efficiently, and mounting it on the bottom just didn't make a lot of sense. Dealing with the heat should have been one of his priorities if he was going to use a power supply that inefficient - 150-160W is A LOT of power for a DAC. Personally I'd use a liquid cooling system to cool it and keep noise levels down, but I doubt that we're going to see a liquid cooled audiophile component any time soon

Sorry, but I gotta say, this is not HOT for Class A gear, and if it bothers you, don't get Class A Gear. I've had Krell and Threshold, and Kingwa's Gear is Cool in Comparison.

.

 

[les_garten]

Quote:

Originally Posted by tim3320070 /img/forum/go_quote.gif It is the optical/ coax switch, I just confirmed. I have a CD running from a Pioneer 300 CD changer and the same album (uncompressed) running from my computer and I am A/B ing them- not hearing any difference with my rig. I will try with my speaker setup but I doubt any real difference can be heard. I must say this DAC with over a hundred hours on it now is clearly superior to my V-DAC in about every way (as it should be). What strikes me is the total smoothness of sound, not one bit of harshness anywhere- before things had a "digital" quality to the sound but that is gone. A real delight.

Hey,
Glad you are hearing the diff! You should hear better resolution of detail without a feeling of harshness. At first that may seem counter-intuitive. I noticed this in complex percussion details. The freq's were relatively high (200hz-1000hz) and the separation of congestion was phenomenal. I also noticed some Voice resolution that had been alluding me that was resolved. Very nice gear!

.

 

[Tachikoma]

Quote:

Sorry, but I gotta say, this is not HOT for Class A gear, and if it bothers you, don't get Class A Gear. I've had Krell and Threshold, and Kingwa's Gear is Cool in Comparison.

Alright, since you're not going to bother reading my posts, suit yourself.

 

[les_garten]

Quote:

Originally Posted by Tachikoma /img/forum/go_quote.gif Alright, since you're not going to bother reading my posts, suit yourself.

Hey,
I read your post, what did I miss? If Class A temps bother you, go elsewhere! Get it!

.

 

[Pricklely Peete]

Quote:

Originally Posted by Tachikoma /img/forum/go_quote.gif A year or so may not be enough to cause serious problems, but 3-5 years in the future and you might see these DACs needing repairs. I like gear that lasts forever (All of my gear is at least 10-20 years old, sans the computer related parts) I think the heat issue is just an oversight on Kingwa's part - all of us do it after all. The heatsink needs to be able to disperse that heat more efficiently, and mounting it on the bottom just didn't make a lot of sense. Dealing with the heat should have been one of his priorities if he was going to use a power supply that inefficient - 150-160W is A LOT of power for a DAC. Personally I'd use a liquid cooling system to cool it and keep noise levels down, but I doubt that we're going to see a liquid cooled audiophile component any time soon

I just have to shrug my shoulders to this...tell you what why don't you email Kingwa and tell him exactly where he's gone wrong...I mean you obviously have the answers on how things SHOULD be built. Go right ahead he's a nice guy and will listen. Maybe in 5 or 6 years when the design is through testing you can buy it. Always a bright side.

Peete.

 

[les_garten]

Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif I just have to shrug my shoulders to this...tell you what why don't you email Kingwa and tell him exactly where he's gone wrong...I mean you obviously have the answers on how things SHOULD be built. Go right ahead he's a nice guy and will listen. Maybe in 5 or 6 years when the design is through testing you can buy it. Always a bright side. Peete.

You're a Slick one!

.

 

[Currawong]

Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif I just have to shrug my shoulders to this...tell you what why don't you email Kingwa and tell him exactly where he's gone wrong...I mean you obviously have the answers on how things SHOULD be built. Go right ahead he's a nice guy and will listen. Maybe in 5 or 6 years when the design is through testing you can buy it. Always a bright side. Peete.

x2.

By the way, the operating temperature for the PCM1704UK is 0°C to 70°C (32°F to 158°F). When I've had gear I was concerned about the cooling of, I would get a 120mm fan, screw on two grills, put it next to the component and connect it to a spare USB port. Not much air needs to be moved around a component to cool it quite well.

 

[les_garten]

Quote:

Originally Posted by Currawong /img/forum/go_quote.gif x2. By the way, the operating temperature for the PCM1704UK is 0°C to 70°C (32°F to 158°F). When I've had gear I was concerned about the cooling of, I would get a 120mm fan, screw on two grills, put it next to the component and connect it to a spare USB port. Not much air needs to be moved around a component to cool it quite well.

Hold it, you can't do the x2 BS, and then the put up some USB FAN Port crap. Pick one! You are being obsequious. You can't have it both ways. Figure out where you're at...

The circuit is functioning correctly or it is not...

.