300W heat? Any clue how much the X250's chassis can dissipate then?
If I am not wrong X250 is onlyrated for 40W of Class A which means about 160W of Idle dissipation per channel on the 4 quadrant.
If the above is true I don't understand how that case can dissipate that much.
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Well SE output stage is a little too inefficient....
I would like to try Push pull with some serious SE Biasing..
I edited the post you quoted adding something....read it if you can....
Here is the link to the pass with dimension:
https://passlabs.com/products/amplifiers/x.5/x250.5
At 160W per channel the case is then dissipating 320W.
In fact apparently the X250.5 case dissipates 300W but that does not mean it can't do a bit more, maybe 10% more
The 5U 500 case is very similar in size and efficiency to the X250 case
yeah my rough calculation shows 320W on the whole chassis, which would be similar to the 300W.
It seems very strange to me as the heatsink on the 250 are bigger taller.
I don't think you can sqeeze anything more out of the 250.
When it warms up the heatsinks get extremely hot which is the rule of thumb of Nelson that states you can keep your hand there for 5-10 seconds.
It seems very strange to me as the heatsink on the 250 are bigger taller.
I don't think you can sqeeze anything more out of the 250.
When it warms up the heatsinks get extremely hot which is the rule of thumb of Nelson that states you can keep your hand there for 5-10 seconds.
Taller does not equate to much.
Increasing the height does not correspond to a proportional improvement in efficiency.
While increasing the length does indeed significantly improve performance. IE increasing depth of the case and hence the heatsinks, does have a significant effect
Also, Pass Labs are more conservative when biasing on their heatsinks. Not like us FABs
In addition to that, have a look at the fins on the X250, not the most efficient profile
Increasing the height does not correspond to a proportional improvement in efficiency.
While increasing the length does indeed significantly improve performance. IE increasing depth of the case and hence the heatsinks, does have a significant effect
Also, Pass Labs are more conservative when biasing on their heatsinks. Not like us FABs
In addition to that, have a look at the fins on the X250, not the most efficient profile
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yeah they are really spaced apart.
But I would think that Nelson choose a nice efficient heatsink.
At least it is the coolest looking heatsink I have seen so far.
Maybe I could be able to dissipate 350-360W on it.
However if I like to push things as far as possible and be less conservative when it comes to my home project than when I Am designing something for work, I would tend to be conservative with the power amp since it directly interface with my speakers and I don't want it to blow and blow everything around...so I will aim for a stable amp.
But I would think that Nelson choose a nice efficient heatsink.
At least it is the coolest looking heatsink I have seen so far.
Maybe I could be able to dissipate 350-360W on it.
However if I like to push things as far as possible and be less conservative when it comes to my home project than when I Am designing something for work, I would tend to be conservative with the power amp since it directly interface with my speakers and I don't want it to blow and blow everything around...so I will aim for a stable amp.
The heatsink fins on the X250 also run horizontal as opposed to vertical on the 5U 500.
The heatsinks definitely look cool on the X250 and do the job.
The right tool for the job, is the tool that does the job. If they look cool even better.
Yes, they do cost more, but not that much more. Take the Cambridge Audio Azur840W power amp $2000. Then compare it to the Mark Levinson 532H, $8500. In terms of what the parts inside cost, I'd say they are both probably about equal. In no shape or form does the Levinson product justify costing more then 4x the amount.
Lets say we wanted to upgrade the Cabridge Audio part, giving it bigger heat sinks, make it put out 2x the amount of power, giving it another transformer and twice the filter caps. Oh wait, that's like buying two, for $4000 total, still way less then the Levinson and giving you way more for your money. You see where this is going? You could build both for a similar amount of money if done DIY. There's nothing about the Levinson product that makes it need to cost that much.
Then if we want to compare products at the really absurd level, take the Musical Fidelity AMS100 and the MBL 9011. The MF costs $20,000 and the MBL $53,000. They are both huge and probably cost a similar amount to make. You could probably build them both DIY and have spare change from $5000. All things considered,that makes the MF reasonable value for money, but the MBL? Again nothing about it justifies its ridiculous price tag over the MF.
This is audiophile component pricing right there for you and it gets even more ridiculous when you start looking at things that aren't power amplifiers or loudspeakers. Both of those do have high costs involved as they require physically large parts, cabinets, heatsinks, drivers, transformers etc, so do somewhat warrant their high prices. But preamps? DACs? Take the Bricasti M1 - $7800. LOL. Nothing about that DAC makes it worth the money. It's basically a dual mono DAC, using AD1955 chips and a SHARC processor that does the digital filtering. It then has several power supplies. But seriously a decent PC built for gaming and costing $2000 is going to have way more in it in terms of raw component cost and is also far more of a challenge for the engineers to design, that it is in terms of development cost.
FR4 is one of the industry standards for PCB materials that is required for fire safety. There's nowt else you get for paying more and you choose the copper thickness based on the application. All high power stuff needs 2oz or 4oz to work properly, regardless of cost, it's necessary.
Good quality connectors are not expensive, as in connectors that provide a good quality termination for the wires and then connectors that interface snugly with one another. Any $1000 product is going to have connectors that are of a quality necessary for good signal transmission. Anything else (WBT etc) is audiophile bling that costs more, looks nice, but doesn't actually do anything.
In terms of a power amp this isn't really the case. Any small signal stuff is going to cost pence per transistor. You're looking at less then $2 of parts for the small signal silicon when the parts are purchased in high quantities. Output and driver transistors are a little more expensive, but we're still only talking say $10 worth of silicon for a stereo amp. Doubling that ain't gonna bump the price of the amplifier up by very much.
Once again cost pence.
Are necessary so that your amplifier doesn't have poor reliability and so that it wont explode. This is regardless of cost. Any power amplifier that has multiple output pairs needs decent transistor matching.
The best connectors are NO connectors.
Electrical connections are the root of all evil
Use cable glands wherever possible, and avoid the connection altogether
This is one thing a manufacturer cannot do
Comments below in red
Yes, they do cost more, but not that much more. Take the Cambridge Audio Azur840W power amp $2000. Then compare it to the Mark Levinson 532H, $8500. In terms of what the parts inside cost, I'd say they are both probably about equal. In no shape or form does the Levinson product justify costing more then 4x the amount.
I agree you pay the name, but again the more expensive product uses higher quality parts. A simple transformer like 1 200VA can be $30, $100 or even $300 depending on desing, features and quality of parts and to your eye they might look the same
Lets say we wanted to upgrade the Cabridge Audio part, giving it bigger heat sinks, make it put out 2x the amount of power, giving it another transformer and twice the filter caps. Oh wait, that's like buying two, for $4000 total, still way less then the Levinson and giving you way more for your money. You see where this is going? You could build both for a similar amount of money if done DIY. There's nothing about the Levinson product that makes it need to cost that much.
No question that doing a DIY will save you money as long as you can exactly copy the same part and get the same parts, However the final bill won't be as little as you think. You tend to forget that metal enclousure costs and lathough you can make whatever because you have access to machines, most of us CAN'T
Then if we want to compare products at the really absurd level, take the Musical Fidelity AMS100 and the MBL 9011. The MF costs $20,000 and the MBL $53,000. They are both huge and probably cost a similar amount to make. You could probably build them both DIY and have spare change from $5000. All things considered,that makes the MF reasonable value for money, but the MBL? Again nothing about it justifies its ridiculous price tag over the MF.
Please don't compare two different brands, it's like compare a sport Mercedes and a sport Toyota, brand comes to a price and usually brings a little better quality but not compared to the price tag; if you want the best you have to be prepared to spend much more for little improvement/COLOR]
This is audiophile component pricing right there for you and it gets even more ridiculous when you start looking at things that aren't power amplifiers or loudspeakers. Both of those do have high costs involved as they require physically large parts, cabinets, heatsinks, drivers, transformers etc, so do somewhat warrant their high prices. But preamps? DACs? Take the Bricasti M1 - $7800. LOL. Nothing about that DAC makes it worth the money. It's basically a dual mono DAC, using AD1955 chips and a SHARC processor that does the digital filtering. It then has several power supplies. But seriously a decent PC built for gaming and costing $2000 is going to have way more in it in terms of raw component cost and is also far more of a challenge for the engineers to design, that it is in terms of development cost.
I agree with you that there is a speculation on premaps, dacs, cd, cables...more than on power amps, but ultimetly you are not considering the team that works on the design, the many iteration for prototyping...I mean if you have designed something on your own you know that you go through several revision, several waste of parts energy time...etc...etc...don't you count this in? The more refined the design the more cost upfront you had to substain
FR4 is one of the industry standards for PCB materials that is required for fire safety. There's nowt else you get for paying more and you choose the copper thickness based on the application. All high power stuff needs 2oz or 4oz to work properly, regardless of cost, it's necessary.
there is teflon, gold plated and many other features
Good quality connectors are not expensive, as in connectors that provide a good quality termination for the wires and then connectors that interface snugly with one another. Any $1000 product is going to have connectors that are of a quality necessary for good signal transmission. Anything else (WBT etc) is audiophile bling that costs more, looks nice, but doesn't actually do anything.
In terms of a power amp this isn't really the case. Any small signal stuff is going to cost pence per transistor. You're looking at less then $2 of parts for the small signal silicon when the parts are purchased in high quantities. Output and driver transistors are a little more expensive, but we're still only talking say $10 worth of silicon for a stereo amp. Doubling that ain't gonna bump the price of the amplifier up by very much.
Once again cost pence.
Are necessary so that your amplifier doesn't have poor reliability and so that it wont explode. This is regardless of cost. Any power amplifier that has multiple output pairs needs decent transistor matching.
Yes, they do cost more, but not that much more. Take the Cambridge Audio Azur840W power amp $2000. Then compare it to the Mark Levinson 532H, $8500. In terms of what the parts inside cost, I'd say they are both probably about equal. In no shape or form does the Levinson product justify costing more then 4x the amount.
I agree you pay the name, but again the more expensive product uses higher quality parts. A simple transformer like 1 200VA can be $30, $100 or even $300 depending on desing, features and quality of parts and to your eye they might look the same
Lets say we wanted to upgrade the Cabridge Audio part, giving it bigger heat sinks, make it put out 2x the amount of power, giving it another transformer and twice the filter caps. Oh wait, that's like buying two, for $4000 total, still way less then the Levinson and giving you way more for your money. You see where this is going? You could build both for a similar amount of money if done DIY. There's nothing about the Levinson product that makes it need to cost that much.
No question that doing a DIY will save you money as long as you can exactly copy the same part and get the same parts, However the final bill won't be as little as you think. You tend to forget that metal enclousure costs and lathough you can make whatever because you have access to machines, most of us CAN'T
Then if we want to compare products at the really absurd level, take the Musical Fidelity AMS100 and the MBL 9011. The MF costs $20,000 and the MBL $53,000. They are both huge and probably cost a similar amount to make. You could probably build them both DIY and have spare change from $5000. All things considered,that makes the MF reasonable value for money, but the MBL? Again nothing about it justifies its ridiculous price tag over the MF.
Please don't compare two different brands, it's like compare a sport Mercedes and a sport Toyota, brand comes to a price and usually brings a little better quality but not compared to the price tag; if you want the best you have to be prepared to spend much more for little improvement/COLOR]
This is audiophile component pricing right there for you and it gets even more ridiculous when you start looking at things that aren't power amplifiers or loudspeakers. Both of those do have high costs involved as they require physically large parts, cabinets, heatsinks, drivers, transformers etc, so do somewhat warrant their high prices. But preamps? DACs? Take the Bricasti M1 - $7800. LOL. Nothing about that DAC makes it worth the money. It's basically a dual mono DAC, using AD1955 chips and a SHARC processor that does the digital filtering. It then has several power supplies. But seriously a decent PC built for gaming and costing $2000 is going to have way more in it in terms of raw component cost and is also far more of a challenge for the engineers to design, that it is in terms of development cost.
I agree with you that there is a speculation on premaps, dacs, cd, cables...more than on power amps, but ultimetly you are not considering the team that works on the design, the many iteration for prototyping...I mean if you have designed something on your own you know that you go through several revision, several waste of parts energy time...etc...etc...don't you count this in? The more refined the design the more cost upfront you had to substain
FR4 is one of the industry standards for PCB materials that is required for fire safety. There's nowt else you get for paying more and you choose the copper thickness based on the application. All high power stuff needs 2oz or 4oz to work properly, regardless of cost, it's necessary.
there is teflon, gold plated and many other features
Good quality connectors are not expensive, as in connectors that provide a good quality termination for the wires and then connectors that interface snugly with one another. Any $1000 product is going to have connectors that are of a quality necessary for good signal transmission. Anything else (WBT etc) is audiophile bling that costs more, looks nice, but doesn't actually do anything.
In terms of a power amp this isn't really the case. Any small signal stuff is going to cost pence per transistor. You're looking at less then $2 of parts for the small signal silicon when the parts are purchased in high quantities. Output and driver transistors are a little more expensive, but we're still only talking say $10 worth of silicon for a stereo amp. Doubling that ain't gonna bump the price of the amplifier up by very much.
Once again cost pence.
Are necessary so that your amplifier doesn't have poor reliability and so that it wont explode. This is regardless of cost. Any power amplifier that has multiple output pairs needs decent transistor matching.
Continue on my phone had to rush out...
Connectors: on the 800s they are using biwire set of top wbt next gen which are extremely expensive.
Unfortunately most of hi $$ gear use standard connector which is a shame for the price required.
Speaking of difference...ohhh..there is a significant difference between a standard RCA and a wbt next gen in term of sound quality: faster and deeper base, more focus on the soundstage, more micro detail...I mean once again u gave to have the rest supporting this...if ur signal cable has a cheap connector it isn't going to make u notice any difference.
Matched semiconductors:
They are used to improve distortion not to make it reliable!! Also can b more reliable under certain circumstances...however ultimately matching is done to improve performance.
This come to a cost which exponentially goes up as power i.e. number of devices goes up and u might need to buy 300 per type to find 24 good matching ..which means 600 fets for maybe 48 good matching.
This eeck more expensive than what u think.
Now the matching is not going to bring u a huge sonic difference..but here u go...if u want this small increment that is the price u pay for it.
From end and small signal matching..same thing less expensive though...unfortunately the good stuff are not available anymore unless u pay a ton! Manufacturer have a stock of those but still..!!
I think I cover pretty much everything.
Let me know if I missed something.
Best,
Connectors: on the 800s they are using biwire set of top wbt next gen which are extremely expensive.
Unfortunately most of hi $$ gear use standard connector which is a shame for the price required.
Speaking of difference...ohhh..there is a significant difference between a standard RCA and a wbt next gen in term of sound quality: faster and deeper base, more focus on the soundstage, more micro detail...I mean once again u gave to have the rest supporting this...if ur signal cable has a cheap connector it isn't going to make u notice any difference.
Matched semiconductors:
They are used to improve distortion not to make it reliable!! Also can b more reliable under certain circumstances...however ultimately matching is done to improve performance.
This come to a cost which exponentially goes up as power i.e. number of devices goes up and u might need to buy 300 per type to find 24 good matching ..which means 600 fets for maybe 48 good matching.
This eeck more expensive than what u think.
Now the matching is not going to bring u a huge sonic difference..but here u go...if u want this small increment that is the price u pay for it.
From end and small signal matching..same thing less expensive though...unfortunately the good stuff are not available anymore unless u pay a ton! Manufacturer have a stock of those but still..!!
I think I cover pretty much everything.
Let me know if I missed something.
Best,
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