We used elemental Gallium in high end applications with water cooled microchannel heatsinks. Its melting point is 29.8 degrees C.
Right! The CPU in this PC I am using has Coolaboratory liquid metal between the i7 and the heatsink. It is amusing to take the excess and watch it dissolve aluminum...
I supply a silver loaded thermal transfer compound with my heatsinks, the heat they are removing from amateur radios is more diffuse: 20 W spread over the outlines of two TO-220 cases, compared to a i7 or i9 CPU which can have over 130 W over less area than 2" squared. Also the aluminum issue is a big one...considering my heatsinks are 6063-T6.
Howie
Yeah, I can imagine the applications are limited with aluminum being the most popular material for heatsinks by far. I used the Thermal Grizzly version, I'm sure it's quite similar to the Coollaboratory stuff. I delidded the CPU and applied it between the die and the heatspreader. Depending on the generation of CPU you have they solder the heatspreader to the die, but some have paste.
No output network for a start! Oh sorry Sir you have to buy our magic speaker cable.
Given the heart of Naim amps was a totem pole output stage I am not suprised. I just was driven away by the cult (and the prices and the fact it looked boring).
I was put off suspended chassis turntables just watching people fanatically checking the bounce rate. It just wasn't for me. Having said that I did lust after the Oracle turntable but couldn't afford them. For now I have a suspended wall shelf that seems to isolate well but on my list to diy is an SME model 20 inspired isolation platform, on the assumption I will never be able to justify a minusK.
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The MinusK looks like a pretty high performance isolation solution. I used an optical tensiometer on a TMC passive pneumatic isolator which worked pretty well for such a low-tech design (air bladders with X-Y-Z axis valves). When the company closed I attempted to purchase it, thinking it would make a great TT stand, but was outbid...
So this is a subject which should interest those awaiting an audio topic:
How best to isolate both structure-borne vibration and speaker feedback from impinging on a TT system. I came close to deciding the only real way was to have the TT in another room due to my test findings. The dust cover reduced the HF bleedthrough from acoustic feedback, but had a defined resonance which was higher amplitude than with it taken off. No dust cover gave higher broad-band feedback than with...
How about placing the entire TT system in a vacuum chamber on one of the minusK platforms? I expect the interface between the diamond stylus and vinyl would have higher friction due to the loss of the layer of moisture which coats everything on earth...
One could just listen with headphones...
At home I have had great results with a suspended platform and putting a piece of 3/4" board wrapped in cloth on top of the dust cover to damp it's resonance.
At the radio station I purchased suspension systems for the SP10s to reduce both structure-borne noise and acoustic feedback. Unfortunately the SP10's start torque is so high it sent the stylus skittering across the record when they were remotely started, so I had to eliminate the suspension. At that point in order to reduce feedback I swept the control room while monitoring the TT preamps with the TT spinning in the leadout groove and then eq'ed the monitors to reduce feedback and set max monitor gain below feedback. It may not sound as great as it should, but try keeping college students from cranking the monitors up...
What are others doing?
Howie.
p.s. why doesn't some well-to-do person purchase these as feet for their TT and let us know how it works out? STACIS III piezoelectric active vibration isolation
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Turntable dust covers is an interesting one. For years I always kept the dust cover down when playing then one evening noticed an odd sound with no record on, platter spinning* and cover down. Some investigation led to me finding an odd vibration on the slack portion of the belt. Lift the lid and no amplification of that, close it and you can just hear it from the listening position when all else is silent. Whilst it serves me right for having a TT with a finniky setup it led me to discover that there is as much argument over up/down for dust covers as there is over whether to put jam or cream down first on a scone!
For those with SP10s and remote start putting it an another room does seem a valid approach. RayK did a marvellous damping setup a few decades back. I'll try and dig up the link to that.
*Low torque belt drive so you just leave the platter spinning all the time. I have to say I prefer DD in that sense.
For those with SP10s and remote start putting it an another room does seem a valid approach. RayK did a marvellous damping setup a few decades back. I'll try and dig up the link to that.
*Low torque belt drive so you just leave the platter spinning all the time. I have to say I prefer DD in that sense.
What is the acoustic level in the room of a turntable playing with the stylus in the groove and no lid/lid up ?.
We have listeners arguing about distortions SNR etc but to me the natural acoustic tsss tsss tsss sound of a stylus playing is loud, louder than system distortions when the system is playing at domestic levels.
Is this significant sound source an ignored part of the appeal of vinyl ?.
Dan.
We have listeners arguing about distortions SNR etc but to me the natural acoustic tsss tsss tsss sound of a stylus playing is loud, louder than system distortions when the system is playing at domestic levels.
Is this significant sound source an ignored part of the appeal of vinyl ?.
Dan.
I agree Dan, even with the best Japanese heavy vinyl discs or any stylus shape I have used, groove noise is louder than noise from downstream equipment. And distortions due to the LP playback system easily mask almost any equipment distortions. I think this is why a lot of people here always steer towards HD files or other digital media for analyzing downstream stuff.
Cheers,
Howie
Thanks Ed for the backwards compliment !.
I may be seemingly eccentric, or seemingly crazy but that does not mean I am any of those, it's all down to belief systems of those making such judgements about things they have no experience of...like BQP, Goop etc. I ran an experiment last night at a friend's place and all present heard the subjective benefit of Goop on a cheap little Bluetooth/CD shelf audio system. I also demonstrated that placing the streaming Bluetooth connected mobile phone on different surfaces affects/effects the sound of the system across the room. Placing the phone on a nice (Myrtle) wooden kitchen cutting board or 6 inches away on the laminex/MDF kitchen benchtop gave two subtly different sounds. Placing the phone on top of the household WIFi router also caused another (gritty) sound out of the little shelf stereo across the room. Perhaps some physics know it all here has the answer for what is going on ?. Before there is any of the usual ABX BS, four people individually witnessed these subjective differences and individually described the subjective differences similarly. Perhaps a few members here might like to try this experiment for themselves and receive a little enlightenment, BT radio connection should be immutable in theory but in practice I find that it is anything but immutable, ditto WiFi streaming audio connection.
Dan.
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Please quote what I asked in 2015.
Yours (& JC's) isn't hidden as you've acknowledged publicly on 22 Aug. 2018 on "What kind of evidence do you consider as sufficient?" thread of this forum that you are in audio development business.
I remember the psychology terms you posted about me soon after you joined this forum, which were deleted by the mod. Have you forgotten? Yes, those were deleted. Must have gone over the level of offense requiring formal intervention...
This really can't occur, the data is buffered in at least one if not several places before it's even clocked out to the converter. The only remotely plausible explanation is you were affecting the BT link quality and forcing the phone to use a lower bitrate than it would normally use for whatever codec your device supports over A2DP.
I use AirPods every day at work and they sound exactly the same if my phone is on a wood desk or my Qi charging pad.
You should ask Demian, I think he's developed some Bluetooth audio devices.
There are much simpler explanations which bo not involve physics at all. People only hear these effects when Dan is present. No files that he has supplied have supported his claims, but when he plays the tracks for people they hear the effects he describes.
Went out to Richard's house today. Sorry to see him going. The house is full of little and big treasures Richard and Lisa have decided to leave behind for the new owners.
For those more interested in semi-technical details, we did compare the sound of both of our Benchmark DAC-3's, first listening with PCM and then with DSD64.
From the listening comparisons, Richard said two main things to me that I thought most salient: (1) Richard said his DAC-3 sounds better than it did before the recent mods. (I had not listened to his system for some time, so I cannot say one way or another about that.) And, (2) Richard said my DAC-3 sounds better than his DAC-3 (with which I have to agree).
Could be Richard's DAC-3 is an older PCB revision than the one I have, was one possibility we discussed. We do know some DAC-3's had problems with USB spurs, but don't know for sure about either of ours. Essentially, I don't think we have a complete picture of why Richard's DAC-3 sounds better than before the recent modifications, yet still not as good as my DAC-3. Please let's leave it at that, without jumping to conclusions.
After listening, we opened up the modified DAC-3 to see what the mods looked like. A pic attached below shows shielding of cables and of some connectors. Also, there is an EMI absorbent material sprayed (or otherwise painted) over much of the circuitry. What may not be as easy to see in the pic, each of the major chips and each of the clocks has an approximately 1/8" thick piece of EMI absorbent material attached to the top of it, which was apparently applied before the conformal EMI coating.
For those more interested in semi-technical details, we did compare the sound of both of our Benchmark DAC-3's, first listening with PCM and then with DSD64.
From the listening comparisons, Richard said two main things to me that I thought most salient: (1) Richard said his DAC-3 sounds better than it did before the recent mods. (I had not listened to his system for some time, so I cannot say one way or another about that.) And, (2) Richard said my DAC-3 sounds better than his DAC-3 (with which I have to agree).
Could be Richard's DAC-3 is an older PCB revision than the one I have, was one possibility we discussed. We do know some DAC-3's had problems with USB spurs, but don't know for sure about either of ours. Essentially, I don't think we have a complete picture of why Richard's DAC-3 sounds better than before the recent modifications, yet still not as good as my DAC-3. Please let's leave it at that, without jumping to conclusions.
After listening, we opened up the modified DAC-3 to see what the mods looked like. A pic attached below shows shielding of cables and of some connectors. Also, there is an EMI absorbent material sprayed (or otherwise painted) over much of the circuitry. What may not be as easy to see in the pic, each of the major chips and each of the clocks has an approximately 1/8" thick piece of EMI absorbent material attached to the top of it, which was apparently applied before the conformal EMI coating.
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OK mob,
Markw4 was here and we listened and compared and he took pictures. here is my take on it. yep, only shielding analog from digital emi/rfi - wise. Both absorbption and reflective materials used in various places all over.
Military equipment has a paint coating that is absorptive and selected for enemy freq to be max absorption.
It appears to me that a lot of the pcb was coated with similar 'paint'. OK we could hear difference between his BenchMark DAC-3 and mine. But he has not been around for a long time since or before it got emi/rfi proofed. So, hard to say anything about change for better or for worse. However, I did hear and so did Jam improvement in accuracy and clarity, IMO.
My best guess is the digital signals maybe Ok with one another but the near-by analog doesnt handle them so well.
BUT -- the real improvement came when we took digital source out instead of analog out. The digital is clearly {-) superiour in terms of accuracy.
Mr. Mark can describe the sound.
So, JC.... analog is officially done in my home as SOTA in sound accuracy. fer sure. 🙂
THx-RNMarsh
Markw4 was here and we listened and compared and he took pictures. here is my take on it. yep, only shielding analog from digital emi/rfi - wise. Both absorbption and reflective materials used in various places all over.
Military equipment has a paint coating that is absorptive and selected for enemy freq to be max absorption.
It appears to me that a lot of the pcb was coated with similar 'paint'. OK we could hear difference between his BenchMark DAC-3 and mine. But he has not been around for a long time since or before it got emi/rfi proofed. So, hard to say anything about change for better or for worse. However, I did hear and so did Jam improvement in accuracy and clarity, IMO.
My best guess is the digital signals maybe Ok with one another but the near-by analog doesnt handle them so well.
BUT -- the real improvement came when we took digital source out instead of analog out. The digital is clearly {-) superiour in terms of accuracy.
Mr. Mark can describe the sound.
So, JC.... analog is officially done in my home as SOTA in sound accuracy. fer sure. 🙂
THx-RNMarsh
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Don't see how it could be deemed as emi/rf proofed if the white plastic 6 pin molex connector is not shielded.
Thats a spectacular way of messing up a DAC player. Amateurs at their best.
Engineers don't do this type of stuff when designing RF equipment.
Thats a spectacular way of messing up a DAC player. Amateurs at their best.
Engineers don't do this type of stuff when designing RF equipment.
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Please let's try not to be rude. The person who did the mods has has been known to improve the sound of some early 2000's decade consumer equipment (I have on good account), some of which probably came in plastic cases and could reasonably have benefited from some retrofit shielding. Whether or not DAC-3 is equipment of that type is a separate question.
Wasn't being rude at all, just pointing out the engineers at Benchmark would be aware of the principles of pcb layout when mixing digital and analogue circuitry without the need to have goop haphazardly smeared all over the internals.
A good example on how to **** up an otherwise perfectly good engineered DAC-3. What a shameful scam, painting the board all over with some goop and claiming it shields EMI better than a clever designed PCB. And protecting chips with EMI absorbent, how the hell are the space technologies not adopted these “methods” yet. I’m about to bet both the goop and the absorbent have some special quantum properties and both are derived from top secret military research.
But nothing is more shameful than two individuals, driven by a gross lack of knowledge and understanding of the EMI basics, and/or a vested interest, praising this BS squared. If you have any diplomas in EE, you should burn them before somebody finds out and exposes you.
Needless to say, I am beyond disgusted
. And yes, I am rude, and purposefully so. Promoting this crap is an insult to everybody’s intelligence, common sense, education and experience.
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No praise given. Only the facts. As I said before, please don't jump to conclusions.
If you want to hear praise, the M2 speakers themselves are gorgeous sounding. The Crown amps, not so much.
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Facts? Calling yours an Richard’s “sounds better” prose “facts” is yet another insult.
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