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Burson FUN Headphone Amp Review

Jimbob54

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#41
You were however complaining about SINAD, which is not a weighted metric of sound quality. It is a metric that past a certain point ceases to be of further value in any balanced metric of perceived sound quality. The amplifier reviewed here has past that point. So long as any device is past that point, any additional SINAD performance does not add to the sound quality.
Assume that point depends on users ears, but what it the generally accepted number beyond which it has no value? (or range)
 

dinglehoser

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#43
Assume that point depends on users ears, but what it the generally accepted number beyond which it has no value? (or range)
This is just me, but I broadly interpret "good enough to not matter" to be around 105dB SINAD for typical 16 bit content. My thinking is that since noise/distortion is additive, and you'll always have a digital->analog step and an amplification step, you want to ensure that the resultant THD+N from the entire chain isn't appreciably adding to the noise already coming off the source material (theoretical maximum dynamic range for dithered 16 bit content is 93dB). Assuming two steps, a SINAD of 105dB at each step results in a theoretical reduction of ~0.5dB. Going above 105 doesn't bring much benefit; however, dropping below 105dB, things get ugly in a hurry.

Example: if both your DAC and your amp have a SINAD of 93dB (to match that of the theoretical DR of Redbook), the resultant SINAD of a system playing back 16 bit content is ~88dB. Assuming both components have 105dB SINAD, you're looking at ~92.5dB. Going the other direction, if both of your components are SOTA (117dB SINAD), the output will have a SINAD of 92.98dB.
 

LTig

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#44
You need a 5 Amp Power Supply for a headphone amp?
It's Class A so it needs a fair bit of current. There seems to be four transistors per channel.
Well 5A at 12V are 60 W. Split over 8 transistors would be some 7W dissipation each. This ain't gonna work without a serious heat sink - and I can't seen any heat sink at all, not even small finger style ones.

The transistors in my DIY class A preamp output are biased to carry 46 mA to feed a 300 Ohm headphone and dissipate 0.7 W each. Even for this a heat sink is required. See here:

pre1-line.jpg


No way the Burson requires 5A, there is nothing in it which hints how those 60W could be dissipated safely. Hey, my RME ADI-2 PRO fs has a 12V 2A power supply and it gets quite warm in use, even when idle. With 60W it would be cooking hot.
 
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amirm

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Thread Starter #45
You need a 5 Amp Power Supply for a headphone amp?
These are OEM laptop chargers so are made in volume and very cheap. The next size down is USB chargers which have much less current and importantly voltage. So it is not a matter of need but what is available in volume and cheap.
 

Labjr

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#46
These are OEM laptop chargers so are made in volume and very cheap. The next size down is USB chargers which have much less current and importantly voltage. So it is not a matter of need but what is available in volume and cheap.
I understood that. I like to point out things that catch my eye. I guess they don't supply the AC adapter.
 
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#47
what it the generally accepted number beyond which it has no value? (or range)
relative to personal human sensitivity. Don't hear it, be happy. Hear it, ASR provided the numbers to confirm.
 
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#48
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#50
Seem pretty straightforward to me. Enough power for most use cases? High enough SINAD to be audibly transparent, or close to it? No unforced engineering errors? Check, check, and check - therefore, recommended.
Straightforward, but some are wildly oblivious to nuance or are simply trying to find faults in everything that is nothing less than perfect. Objectivity to the extreme, I suppose. Or maybe just being an asshat, who knows
 

sam

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#52
Is that 4pin power jack the one used in desktops?
Never seen it used externally before.
 

Jimbob54

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#53
Is that 4pin power jack the one used in desktops?
Never seen it used externally before.
Its built so it can fit into a desktop bay ;-)
 
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#54

Labjr

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#58
This would be a very bad thermal connection, since the screw is the only connection between transistor and heat sink.
It's only a headphone amp. The transistors probably don't require a lot of heat dissipation. The case will work. Most output devices use only one screw, with a little thermal grease.
 
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amirm

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Thread Starter #60
Can you do a 32-tone test under load? Or wideband distortion by frequency.
Sorry no. This has been sent back to its owner.
 
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