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ALO The Continental - Page 8

post #106 of 456
Quote:
Originally Posted by Skylab View Post

Tubes are designed to run hot. The bigger issue is whether the components around them can handle the heat they generate.


Actually I thought the issue was the tube not running hot enough in this case?  If it is then I agree preservation is next.

post #107 of 456
The tube running too hot would be an issue if it were running at spec. But it has been theorized that the tube is not running at spec and thus running cooler than it would otherwise.
post #108 of 456
Quote:
Originally Posted by Skylab View Post

The tube running too hot would be an issue if it were running at spec. But it has been theorized that the tube is not running at spec and thus running cooler than it would otherwise.


Right, so the question is what is the tube really putting out.  Isn't there a shot of the board?  Guess not.  We could just look for opamps.

 


Edited by Anaxilus - 8/21/11 at 8:01pm
post #109 of 456

It's weird that Ken is not here to explain, defend or clarify any of this. In the CLAS threads it seemed he was extremely active. Maybe he's on vacation or traveling or just swamped.

 

Anyway, I bet there's just some issue with the numbers listed -- from the reviews so far it seems to be an excellent portable amp, one of the best according to those who've heard it. And I really love my Rx/Mk2 so if it's at the same level of quality, I'm sure it's awesome. :)

post #110 of 456
Quote:
Originally Posted by Anaxilus View Post




Right, so the question is what is the tube really putting out.  Isn't there a shot of the board?  Guess not.  We could just look for opamps.

 


1.jpg

 

post #111 of 456
Quote:
Originally Posted by familiarsounds View Post

Wonder if someone would be fortunate enough to have this side by side with "the continental".

 

http://www.head-fi.org/forum/thread/562045/govibe-porta-tube



+1  ...wonder why not the same fuss about the GoVibe Portatube, which is lacking in specs also, which seems a better competitor than the Mu (price wise, the GoVibe is far more expensive).

 

Is anyone with the Continental on the GoVibe loaner list?

post #112 of 456

No opamps visible in this or the supposed Chinese made 'knockoff'. You can see the pale yellow wrapper on the transfomer, two black capacitors as well as two yellow caps. Some white colored silicone glue/sealant/adhesive? instead of black as in the 'knockoff'. Clearly more smaller components on the PCB in the ALO. The 'knockoff' has more resistors that I do see any of on the ALO Conti.

 

Uncle Erik should go look at the specs on other amps, say the Fiio portables, @300ohms power output is 1/4th or less than @32ohm, just as an example. There was a thread here some time ago attempting to list the various output levels, but someone stated the folly of doing so...let me go find that thread.

 

So has anyone PM'd Ken about this thread?
 

Quote:
Originally Posted by Naim.F.C View Post




1.jpg

 



 

 

post #113 of 456

http://www.head-fi.org/t/550574/paste-and-copy-project-how-much-mw-do-different-amps-or-amps-dacs-have-at-different-ohms-help-if-you-want

Quote:

Ibasso PB1 (Portable Amp)

1400mW into 32Ω

 

Ibasso PB2 (Portable Amp)

Up to 2500mW into 32Ω

 

Ibasso P4 (portable Amp)

Output power: 600mW into 32

 

NFB12 (Desktop Amp/Dac)
3500mW/25 ohm
1800mW/50 ohm
900mW/100 ohm
300mW/300 ohm
150mW/600 ohm

 

Yulong D100 (Desktop Amp/Dac)

900mW at 32Ohm

130mW at 300Ohm

 

E9 (Desktop Amp)

1000mW (16Ω)

 80mW (600Ω)

 

post #114 of 456
Quote:
Originally Posted by MulberryMadness View Post

No opamps visible in this or the supposed Chinese made 'knockoff'. You can see the pale yellow wrapper on the transfomer, two black capacitors as well as two yellow caps. Some white colored silicone glue/sealant/adhesive? instead of black as in the 'knockoff'. Clearly more smaller components on the PCB in the ALO. The 'knockoff' has more resistors that I do see any of on the ALO Conti.

 

Uncle Erik should go look at the specs on other amps, say the Fiio portables, @300ohms power output is 1/4th or less than @32ohm, just as an example. There was a thread here some time ago attempting to list the various output levels, but someone stated the folly of doing so...let me go find that thread.

 

So has anyone PM'd Ken about this thread?
 



 

 



Thus far no statement from anyone from ALO. I'm hoping all this is just a mix up and the specs were a simple typo. I was saving up to get some gear from ALO hopefully all this can be explained away if it can't I'll just have to take my money elsewhere. Once my trust in a merchant is lost it's a hard thing to get back.

post #115 of 456
logwed, the 6.25mW is relevant because it is the only power spec listed for this amp. Yes, it will vary at other outputs but we don't know what those are.

You also must ask why this particular stat was listed if you assume the rest to be better. It's weird. It'd be like McDonald's advertising a Big Mac by showing you a corner of the wrapper with a couple of sesame seeds on it. If they're trying to sell a burger, then show the burger.

Stranger yet when the ad copy and the 6moons "review" (where a review is presented by someone who doesn't even have a review sample) advertise this as being a desktop equivalent capable of running AKGs, planars and other difficult headphones. If an amp has the power to drive the heavy hitters, figures are proudly presented. Go ask Ray Samuels, Craig Uthus, Donald North, Kevin Gilmore, AMB, Pete Millett, or Jack Woo about their amps. They're not going to pretend you didn't ask the question. You will get numbers and probably learn a lot about how they design.

Heat is very relevant to the discussion. The 6111 likes to throw off a lot of heat when you get it linear and producing a lot of power. If the 6111 is producing a lot of power it'd produce a lot of heat. There's no active cooling or heatsinks in there. Now, if you don't give it much power, it won't generate hardly anything to drive headphones and it'll go totally non-linear. All tubes are like that. Give a 6SN7 30V on B+ and it'll be a sloppy mess that won't drive anything. Give it 275V and it's a different story, albeit one where you'll get first degree burns if you try to carry it around in your hand.

So my guess is ths the 6111 isn't being driven at all here, let alone enough to power the toughest headphones. If, somehow, it is being driven hard enough to power a planar while remaining cool and extendin the lifespan from 1,000 hours to 100,000 hours, that is quite a trick. One that I would very much like to have explained.

Another very interesting thing is that this is an OTL amp. I don't see any output transformers in there. OTLs are notorious for having a high output impedance. If you have an output impedance above the headphone impedance, there's no damping factor and you lose control of the bass. Yet the claim is that this drives low impedance headphones. Again, that would be amazing if it were somehow pulled off.

So to sum up, we have:

1. Enough power to run the toughest headphones, though the only offered power spec is 6.25mW.
2. An amp that runs slightly warm to the touch while supposedly generating huge amounts of power.
3. An OTL with high output impedance masterfully driving low impedance headphones.
4. A new method of driving a tube that generates huge power while extending the lifespan from 1,000 hours to 100,000 hours.
5. All of this powered from a battery.

It doesn't add up.

If there is an explanation, it is time to tell everyone.
post #116 of 456
Quote:
Originally Posted by Uncle Erik View Post

logwed, the 6.25mW is relevant because it is the only power spec listed for this amp. Yes, it will vary at other outputs but we don't know what those are.

You also must ask why this particular stat was listed if you assume the rest to be better. It's weird. It'd be like McDonald's advertising a Big Mac by showing you a corner of the wrapper with a couple of sesame seeds on it. If they're trying to sell a burger, then show the burger.

Stranger yet when the ad copy and the 6moons "review" (where a review is presented by someone who doesn't even have a review sample) advertise this as being a desktop equivalent capable of running AKGs, planars and other difficult headphones. If an amp has the power to drive the heavy hitters, figures are proudly presented. Go ask Ray Samuels, Craig Uthus, Donald North, Kevin Gilmore, AMB, Pete Millett, or Jack Woo about their amps. They're not going to pretend you didn't ask the question. You will get numbers and probably learn a lot about how they design.

Heat is very relevant to the discussion. The 6111 likes to throw off a lot of heat when you get it linear and producing a lot of power. If the 6111 is producing a lot of power it'd produce a lot of heat. There's no active cooling or heatsinks in there. Now, if you don't give it much power, it won't generate hardly anything to drive headphones and it'll go totally non-linear. All tubes are like that. Give a 6SN7 30V on B+ and it'll be a sloppy mess that won't drive anything. Give it 275V and it's a different story, albeit one where you'll get first degree burns if you try to carry it around in your hand.

So my guess is ths the 6111 isn't being driven at all here, let alone enough to power the toughest headphones. If, somehow, it is being driven hard enough to power a planar while remaining cool and extendin the lifespan from 1,000 hours to 100,000 hours, that is quite a trick. One that I would very much like to have explained.

Another very interesting thing is that this is an OTL amp. I don't see any output transformers in there. OTLs are notorious for having a high output impedance. If you have an output impedance above the headphone impedance, there's no damping factor and you lose control of the bass. Yet the claim is that this drives low impedance headphones. Again, that would be amazing if it were somehow pulled off.

So to sum up, we have:

1. Enough power to run the toughest headphones, though the only offered power spec is 6.25mW.
2. An amp that runs slightly warm to the touch while supposedly generating huge amounts of power.
3. An OTL with high output impedance masterfully driving low impedance headphones.
4. A new method of driving a tube that generates huge power while extending the lifespan from 1,000 hours to 100,000 hours.
5. All of this powered from a battery.

It doesn't add up.

If there is an explanation, it is time to tell everyone.


Does all that really seem far fetched though? I feel as surprised when I hear similar claims out of products such as the SR-71B. Ray mentioning it can drive ANY headphone with great authority. It's still also a small portable (smaller than the ALO Continental), balanced and running off of a battery. Yet you do hear reports of people using headphones such as the LCD-2's with them and mentioning they sound very good and drive them comfortably. Or is it specifically it's use of a miniature tubes instead of opamps or whatever that's got you doubting it's capabilities?

 

On another note, say Ken has figured out some masterful method of pulling this altogether (I certainly don't have a single complaint so far actually using the product besides perhaps the size and battery life, but it's worth it for the power), essentially a break through in portable tube amp technology, would he really want to spill the beans on exactly how he pulled it off? I'm not entirely sure. Perhaps answer one or two of the questions or confirm facts or figures, but I don't expect him to detail every little thing, though if he does, all credit to him.


Edited by Naim.F.C - 8/22/11 at 1:56am
post #117 of 456

My basic knowledge about electronics tells me that one way to determine the heat output should be comparing the power input to power output. All power lost in the process should be converted in heat. Maybe we could find a similar amplifier design, determine it's efficiency and see how much heat energy should a sized down model be giving out. I think that common sense should be that a purely tube design gives out a lot of heat as Uncle Eric is telling us. If the heat signature is much lower than a sized down tube amp should be giving out then the transistors are to be blamed. Or it's a revolutionary design.

post #118 of 456

     Quote:

Originally Posted by Naim.F.C View Post

Does all that really seem far fetched though? 

 

It really is extremely far fetched Naim.  Take a look at some literature on tube amps (like Morgan Jones' books), and you will see that all of UE's comments and questions are firmly grounded in well established principles of tube amp design.  

 

Solid state devices like the SR-71B are a completely different ball of wax.  For considerably less than $100, it is easy enough to make a portable solid state amp with IC's, low output impedance, and ample current and voltage swing to drive just about anything.  Google up the open source "objective 2" headphone amp if you want to read more on the topic.  (The O2 is also discussed here: http://www.head-fi.org/t/565821/so-the-objective2-headphone-amp-designed-entirely-around-the-measurements-please-read-rules-before-posting/495 )

post #119 of 456

I'd never buy a product from ALO... if any problem arises they will not help you, as was the case with a $500 time I got from them. They are only in it for the bottom line. many people had this problem with them.

 

71B all the way man, I even preferred the 71B to my WA6SE

post #120 of 456
Quote:
Originally Posted by AndrewG View Post

I'd never buy a product from ALO... if any problem arises they will not help you, as was the case with a $500 time I got from them. They are only in it for the bottom line. many people had this problem with them.

 

71B all the way man, I even preferred the 71B to my WA6SE


This thread is about the Alo continental. Please don't detract from the discussion with unsubstantiated claims of Alo service. I have had nothing but good experiences with them.
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