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Amateur OB speaker builder and his ARC based digital system


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Forgot to mention this little fella as being part of the hi-fi.

 

IMG_20190127_171455.thumb.jpg.4efa5bcd6598af7f96c30a4e175a2e69.jpg

 

I'm not sure if anyone else considers a humidifier as part of their hi-fi, but this makes a bigger difference than all the cables combined on a dry day. I mentioned earlier the improvement in the top end when I first put my MSB DAC in, as I usually don't turn this on during regular background music listening, but if it's a dry day and I'm doing serious auditioning, I make sure the humidity is at least 45% if possible.

 

Here's a little bit of hard science to support its use (note this is 30m so the effect at 5m listening distance in my room will be much less):

Figure-1-19.png

 

We used it today during the mscaler audition in my system. To avoid duplicating that review here, I'll link directly to the comment in the mscaler thread:

 

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Have been doing some upscaling experiments. See the below thread:

 

Also these 20A guys arrived. No I don't think they're going to make an audible difference, but look at the size of those contacts! The power amps certainly aren't going to complain, and they were only $20 each. The clipsal plugs alone are usually about $100.

IMG_20190129_134337.thumb.jpg.c99df1ff4491656c0e68236ecd86fd62.jpg

 

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Just now, lusk said:

Good way of doing it, very industrial. Will have to update your sockets now to suit the plugs.

That already happened a page back :) Or do you mean to put the outdoor style screw locks? I don't think that's needed.

Edited by Ittaku
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4 minutes ago, Ittaku said:

That already happened a page back :) Or do you mean to put the outdoor style screw locks? I don't think that's needed.

Yeah they normally go with the screw flip lid socket to get the IP66 rating, not really needed.

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  • 2 weeks later...

Since I've started ripping a few CDs and upscaling them to add to my collection of highres audio, I realised that I have NINE different performances of Beethoven's 9th symphony. If that's not evidence of what my favourite piece of music is, I don't know what is... I'm now creating a playlist of JUST those and will slowly work my way through them :)

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3 hours ago, Ittaku said:

ripping a few CDs and upscaling them to add to my collection of highres audio

Oh dear. That's different from my definition of HiRes.

 

I have a big problem of marketeers selling us "HiRes" that's simply upscaled LoRes.

 

Perhaps in this context it's different, but I think we need to be cautious with terminology.

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12 minutes ago, BioBrian said:

Oh dear. That's different from my definition of HiRes.

 

I have a big problem of marketeers selling us "HiRes" that's simply upscaled LoRes.

 

Perhaps in this context it's different, but I think we need to be cautious with terminology.

No, I have a huge collection of actual highres. I just needed to rip half a dozen CDs and am upscaling them. I don't consider them highres, just heavily filtered upscales. See the software upscaling thread for discussion. I was just saying I was adding them to my collection; NOT that they are highres.

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Oh good. It's the wording in my quote that disturbed me.

 

I've been following the other thread - quite challenging and mysterious!

 

OT, but I'd love to know if you've found a great Beethoven 9 slow movement (especially in HiRes). Most of the recordings I've heard since Solti's have the unfortunately common modern phenomenon of sounding like ring-tones; like the conductor looking at his watch, hoping it'll be over soon.

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37 minutes ago, BioBrian said:

Oh good. It's the wording in my quote that disturbed me.

 

I've been following the other thread - quite challenging and mysterious!

 

OT, but I'd love to know if you've found a great Beethoven 9 slow movement (especially in HiRes). Most of the recordings I've heard since Solti's have the unfortunately common modern phenomenon of sounding like ring-tones; like the conductor looking at his watch, hoping it'll be over soon.

I love Solti's but this is my regular listen currently for high-res. Check out the sample to see what you think https://www.prestomusic.com/classical/products/8029549--beethoven-symphony-no-9-in-d-minor-op-125-choral

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One of the things about the active DSP room correction + crossover in my system (the Dspeaker x4) is that sample rates are limited to 96kHz maximum coming out and going to the main output DAC. The nice thing is that unlike miniDSP and other solutions, it will work with the native frequencies it's given of 44/48/88/96, but not beyond that. With the upscaling experiments where we found improvement by pushing beyond this sample rate (but only when associated with more taps!) I thought I'd try some experiments of offloading the DSP to my PC and not using the Dspeaker, and using the subwoofer's crossover for its own roll off and using my DAC full range instead. However, no matter how many times and different ways I tried, it never sounded anywhere as clean as actively rolling off the main speaker woofers and allowing them to breathe and operate better. The advantage of actively crossing over between my mains and subwoofer is more than 10x more sound quality improvement than anything I get from upscaling. The PC solution also has issues with changing the sample rates when doing DSP on the fly so it'd only be practical to upscale everything to the highest 384 which means that sources that are samples of 44 won't be getting single multiple upscales and will be compromised (though with 25 million taps it may not be audible anyway.) I would need to look at ways to cross them over at the PC as well as doing the DSP, and it's all falling into the too hard and convoluted basket. As it stands, the improvement was mostly audible on 44/48 material anyway, and I'm already upscaling that at extreme levels to 88/96 now so I've all but lost interest in pursuing it any further, especially since I can use as many taps as I want for the simple doubling upscale unlike the MScaler.

 

So, back to the waiting game for my freaking baffles before I can complete the darn speakers. ? Which reminds me, it's time for my regular reminder to my mate to give him a subtle prod.

Edited by Ittaku
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On 09/02/2019 at 7:07 PM, BioBrian said:

Perhaps in this context it's different, but I think we need to be cautious with terminology.

Not really ... in ALL contexts the term high res if often very very misleading.   There are many parallels in the world of cameras.

 

 

In short, just because someone recorded audio in a huge depth and rate .... or just because someone recorded it in a low depth and rate, and then converted it to a higher rate ...... neither of those things reliably tell us anything about the audio quality.

 

So the outrate about "upscaling" .... or the desire to acquire the "higher resolution version" (and our measure for that is the rate/depth) .... are both potentially quite misguided (in general).     The industry doesn't generally care to inform people otherwise, they just bend to what the market wants (even if the market is totally misguided).

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  • 3 weeks later...

So CAV contacted me to say they have a pair of fully burnt in Ref 160Ms which I asked them about a while back. These seem to be the new flavour of the month with just about every hi-fi show and speaker demonstration using them for amplification instead of the Ref 250SEs like I have.  As I have WAAAAY too much power for my speakers, and generate way too much heat in my room, I'm going to have a listen to these to see if they're a better match for my system and sound better. The change over cost will be substantial so they really need to be a lot better, as they won't be selling me a second hand pair since they're still so new. Shame the Audio Research trade up program only exists in the USA. Anyone looking for a pair of 250SEs second hand may be in luck in the near future. I'm hoping the 250s sound equally good and I can just hold onto them but the completely revamped topology in the 160Ms sounds desirable. They have literally half the number of KT150s in there, preferring to only use the 6H30s as driver tubes whilst the 250s have the crazy overkill approach of even using KT150s as drivers. They're also lacking the 6550s as voltage regulators which have been a staple in the top ARC power amps for ages. They're also auto-biasing which I have mixed feelings about.

 

http://www.audioresearch.com/en-us/products/power-amplifiers/reference-160m

 

Watch this space...

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New family members, Stax SR-009 headphones and Mjolnir KGST headphone amplifier.

IMG_20190303_205558.thumb.jpg.8f667f6788ac4667056f461a1bd99e57.jpg

 

Bought another Topping DX7S to play with different sample rates so I can do more upsampling experiments using these headphones without any DSP requirements nor sample rate limits, but that'll take a couple of weeks to get here.

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So I've had a really good listen to the Stax now. I'm a little disappointed. They are definitely the best sounding headphones I've ever heard. Amazing detail without a hint of brightness or glare, incredibly balanced sound, great dynamics, extension in both directions. So what's missing? The real factor. I don't expect a stage to be created from them in my head without a binaural recording, but there's just some of that last bit of magic missing which makes you think the instruments are real with actual speakers. This was listening through the rest of my regular system, so the same quality DAC and I tried with and without my own preamp (which is totally unnecessary.) It sounded a little better with my preamp in with just a touch more of the natural life breathed into the sound, but still missing something. I think they're exceptional headphones and the amp is a great match, but it seems they're missing whatever that bit of colour is that turns recordings into real sounding instruments. They certainly make for a great reference pair of headphones but I prefer listening to my speakers. I still need them for my experimentation, as a reference, and for the very rare occasion it's more convenient to listen to headphones so no way will I give them up. Unfortunately, one of the things in the upscaling experiments is the effect on stage and 3D presentation, and I can't honestly feel any stage effects whatsoever when the sound's in my head.

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On 27/02/2019 at 4:08 PM, Ittaku said:

So CAV contacted me to say they have a pair of fully burnt in Ref 160Ms which I asked them about a while back. These seem to be the new flavour of the month with just about every hi-fi show and speaker demonstration using them for amplification instead of the Ref 250SEs like I have.  As I have WAAAAY too much power for my speakers, and generate way too much heat in my room, I'm going to have a listen to these to see if they're a better match for my system and sound better. The change over cost will be substantial so they really need to be a lot better, as they won't be selling me a second hand pair since they're still so new. Shame the Audio Research trade up program only exists in the USA. Anyone looking for a pair of 250SEs second hand may be in luck in the near future. I'm hoping the 250s sound equally good and I can just hold onto them but the completely revamped topology in the 160Ms sounds desirable. They have literally half the number of KT150s in there, preferring to only use the 6H30s as driver tubes whilst the 250s have the crazy overkill approach of even using KT150s as drivers. They're also lacking the 6550s as voltage regulators which have been a staple in the top ARC power amps for ages. They're also auto-biasing which I have mixed feelings about.

 

http://www.audioresearch.com/en-us/products/power-amplifiers/reference-160m

 

Watch this space...

Why bother?

What you have is good. Changeover will cost $.

Simplify your life - lot easier.

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Did a bit of snooping around inside the headphone amplifier.

 

IMG_20190304_221157.jpg

 

These 6R4A tubes are unusual for an audio application. They were designed for vertical hold in TVs. Mjolnir use them because they handle the output directly with no extra stages. I checked them with my IR thermometer and their hottest point they are 120 degrees which is pretty consistent for a power tube. I guess I need to treat them like other power tubes but they're not exactly expensive so I don't mind leaving them on all day for the warmer sound they impart after they've been on for a while, plus longevity is more related to thermal cycling than it is tube hours of runtime. There isn't much scope for tube rolling these which in many ways is a blessing. The previous owner said he tried the 5 or so different NOS types he could get his hands on and found they all sounded the same, which isn't surprising I guess. He was nice enough to give me all of them as well since he had no use for the spare tubes, so I have years if not decades worth of valves for them. I won't bother rolling anything since I need consistent sound for my upscaling experiments.

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20 hours ago, Jventer said:

Why bother?

What you have is good. Changeover will cost $.

Simplify your life - lot easier.

What!? The thought that there is something better out there is always seductive...

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The freq response graphs I can find online on the headphones are interesting

image.png.2adb79bf3597dcc191f5e0ab4b6065e7.png

 

The roll off at higher frequencies is pretty consistent with listening position and regular loudspeakers though bigger than I would have expected, but the drop off below 60Hz is unexpected and explains the relatively lean sound on them. I might try using DSP correction to see if they sound better.

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Bought a couple of new Bach works in 24/96. Always nice when I check them I can see no noise artefacts and true high-res with substantial high frequency extension.

image.thumb.jpeg.2551d21715e0355580d4c42dd9548fe0.jpeg

 

Unfortunately I can't say that about all my recordings with some impressive noise bands in some, and sometimes 24 bit ones for some reason are dithered which makes not much sense, but I guess that means I effectively get 28 bit depth out of them.

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4 hours ago, Ittaku said:

The roll off at higher frequencies is pretty consistent with listening position and regular loudspeakers though bigger than I would have expected

... most people forget to think about directivity / dispersion pattern, when they look at headphone vs speaker measurements.

 

It just goes to show that looking at one frequency response chart .... rather than many spread across various angles of radiation .... doesn't at all tell the whole story.

44 minutes ago, Ittaku said:

 substantial high frequency extension

Where?

At those frequencies, what is there is much too quiet to be audible under any circumstances (even contrived ones).

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