Is it the component? Is it the system? Is it how they interact?

[JonMarsh]

Great read here on Stereophile, from the head engineer of a German company, MBL, about his learning experience when he was just getting started 30 years ago...

http://www.audiostream.com/content/open-and-tolerant-mbls-juergen-reis-listening-measurements-and-uncertainty#beLo414yb86ogXAt.97

For those of you who know my background a bit, I'm sure you can see many reasons I might relate to this guy. The story he tells is a classic case of, "if you measure the right things the right way, you can develop correlation between what you measure and what you hear" - but it requires moving beyond the obvious (in one sense) in a thoughtful way as to how you approach the problem... Cutting the Gordian knot, as it were.

It's also the classic story of why just designing equipment for the "normal" test bench environment will only take you so far- but looking at the total system behavior, and the interface between components and the real world, can be quite rewarding.

A must read, in my opinion... :T

Right now I'm working on a several design problems, one for work, and couple for returning to my interest in amplifiers, and I can say that being completely successful in these circumstances, (if one measures success by achieving the highest level of system performance) requires some special thought and more care in the interface between functional systems...

We'll be looking at more of these issues in the future "On the Bench".

[---k---]

Interesting read.

Since that story is 35-years-old, just curious, his example of flipping the phase on the power chord is all? / most? modern gear designed with high common mode rejection to prevent this scenario?

[JonMarsh]

The start of the story is 35 years ago- but he's been applying these ideas and looking for solutions ever since, including products like recent DACS.

My answer to you Ryan is that SOME gear is designed very carefully that way these days- such as my Alpha USB to AES/EBE and S/PDIF interface. An average HT receiver or a $500 DAC? Probably not so much, but as nest as they can.

This is why my friend in Munich runs his whole front end from battery power and Paul Hynes regulators- to break the common mode interaction loop. There's a lot more that could be said on this topic, but I'm still on the clock.

[csmielke]

Guys,
I am interested in your thoughts, experiences and processes for periodic system tune-ups. I bring it up after spending some time this weekend with my own system. First up was a re-biasing my McCormack DNA125 power amp. The guys at SMC were very helpful and sent me their guide with preferred bias settings. Their write up made the process pretty easy. I would never have thought that adjusting the bias down 3-4mv across the right and left channels would make a dramatic difference but, it did. There was additional clarity and focus bringing forward musical information I had not noticed before. Next up was new low noise RAM (brand name) tubes in my Music Reference preamp. Again a positive change in clarity and what I will call smoothness. A little weekend work that added value and made me like my system again, keeping me from spending money on new stuff. I am thinking of tackling the cleaning of all contact terminals next.
My question to you is if you can share your regiments and whether the triggers are time or sound based? It would seem that sound based would be hard as many of the component changes occur slowly over time. It would be any interesting exercise to have done component measurements pre and post tune up but, in the end it's how it sounds that counts. I tried to post this as a new thread in this section but, it would not let me even though it said I had authority?
Thanks for any input and advice,
Chris

[JonMarsh]

Would you like me to start a thread on the topic of system tune ups? And the possibility of pre and post measurement?

No problem to do so, it's a good topic...

[csmielke]

Jon,
If you think there would be some interest and people could gain some useful/helpful knowledge. Perhaps we could start with my initial email and see what response we get. Your thoughts on how to move it forward?
Chris

[wkhanna]

i like it! :T

[Finleyville]

i like it! :T

+1

[csmielke]

New Tweak

Guys,
Thought I would try to keep the discussion on tweaks going with an update. The digital section of my system features an M2Tech EVO DAC and HiFace Evo USB/SPDIF converter. The latter replacing a Musical Fidelity VLink 192 which provided an improvement in my opinion. The HiFace Evo converter has been reviewed favorably in Computer Audiophile/6Moons mentioned in the same articles with the Berkeley Audio USB converter, good company indeed. To start out I used the wallwart power supplies and later substituted cheap PE regulated PS which provided some improvement. I began looking for a PS that would take it to the next level and settled on the AMB Labs Sigma 11 a high performance single rail PS with low noise, high current excellent line load regulation etc. I found an assembled Chinese knockoff to use and matched it with a transformer with twice the current capability needed. I spent the last couple of weeks packaging it up and testing. A couple of days ago I inserted into the system and was really happy with the outcome. The first redbook file I listened to was the deluxe edition of Clapton's Unplugged and overall clarity improved as well as the sound stage which began extending beyond the speakers. On the track Walkin Blues I noticed the F and B sounds more clearly and natural. On the track Old Love, Chuck Leavell's piano solo, his individual keystrokes were sharp, defined with a natural sustain. I also listened to Holy Cole's Temptation file and it has never sounded better on my system. Net take away is if you are still using the old wallwarts get rid of them and implement a pretty cost effective solution for improved sound.
I hope this helps keep the discussion going,
Chris

[wkhanna]

Hey, Chris!

great write-up, thanks so much for the effort you put into this!

do you have any photos?

where did you source your Sigma 11 PS from?
was it just a bare board that you assembled or was it already populated?

regarding wall warts......this iPower from iFi is constantly getting high praise for the improvements it is making in even basic systems.

i am building a desktop DAC/server with the Raspberry Pi3 & HiFi Berry Pro DAC & still trying to decide on a PS for the build.

[csmielke]

Bill,
Thanks, I will work up some photos over the weekend. You can purchase the board populated or not but frankly there wasn't that big a difference in price. I chose the former and only needed to add the correct zener diode and resistor to set the voltage which in my case was 9V. Once completed, I left it on for 12 hours without a load to make sure there were no wiring issues on my part and checked voltage readings periodically. It held steady at between 9.18 and 9.2V fluctuating when line voltage went from 120 to 122VAC during that time. I will get the link and add it with the photos. I saw the iPower wall warts but no one had done a comparison against a quality linear PS. Might be an interesting exercise?
Chris

[wkhanna]

Bill,
I saw the iPower wall warts but no one had done a comparison against a quality linear PS. Might be an interesting exercise?
Chris

subjective comparison here:

[JonMarsh]

Guys,
Thought I would try to keep the discussion on tweaks going with an update. The digital section of my system features an M2Tech EVO DAC and HiFace Evo USB/SPDIF converter. The latter replacing a Musical Fidelity VLink 192 which provided an improvement in my opinion. The HiFace Evo converter has been reviewed favorably in Computer Audiophile/6Moons mentioned in the same articles with the Berkeley Audio USB converter, good company indeed. To start out I used the wallwart power supplies and later substituted cheap PE regulated PS which provided some improvement. I began looking for a PS that would take it to the next level and settled on the AMB Labs Sigma 11 a high performance single rail PS with low noise, high current excellent line load regulation etc. I found an assembled Chinese knockoff to use and matched it with a transformer with twice the current capability needed. I spent the last couple of weeks packaging it up and testing. A couple of days ago I inserted into the system and was really happy with the outcome. The first redbook file I listened to was the deluxe edition of Clapton's Unplugged and overall clarity improved as well as the sound stage which began extending beyond the speakers. On the track Walkin Blues I noticed the F and B sounds more clearly and natural. On the track Old Love, Chuck Leavell's piano solo, his individual keystrokes were sharp, defined with a natural sustain. I also listened to Holy Cole's Temptation file and it has never sounded better on my system. Net take away is if you are still using the old wallwarts get rid of them and implement a pretty cost effective solution for improved sound.
I hope this helps keep the discussion going,
Chris

Not at all surprised to hear this- and thanks also for taking the time for the write up.

Another component that repsonds well to PS upgrades is the microRendu- even with the base supply, it's quite good, but now I'm using it with an UltraCAP LPS-1, and in my setup it's worth the $395 cost... of course, that's a relatively judgement, but it's about the best solution I know of not just for regulation but eliminating common mode noise injection, at this power level.

[wkhanna]

wow......that UltraCAP LPS-1 is way cool 8)
but a bit over-budget/performance for my Pi3/HiFi berry project.....:cry:

any recommendations in the <$100 range?

Edit: add link to Stereophile review

[csmielke]

Jon,
Isn't that one of John Swenson's designs? I have the components to build a low noise power supply he offered up for the DIY groups some time ago featuring a choke filter. I went with the AMB Labs design cuz I wanted higher current capabilities. Maybe I was misguided in my thinking that the extra headroom would allow it to cruise along without any stress. So far mine barely gets warm after a couple of hours of use. His design was limited to probably 2amps max and I believe mine is limited by the toroidal power transformer max current of about 3 1/2 amps. I might still build it to compare the two. I have probably $100 in the one I built.
Chris

[csmielke]

Bill,
Still working on pictures of the one I did. On the John Swenson design I referenced in my previous post with the choke filter which I though was unique. He did a 5V and a 9V version if you are interested. You are likely looking at the 5V design.
Chris

[wkhanna]

Chris,

yup.....5V & 1A

final assy will look similar to this:

[csmielke]

Power Supply follow-up

Bill,
I attached a picture of my finished PS as well as the schematic of the John Swenson choke filtered supply. Because of the combination of the power transformer and choke it likely will not be compact enough for your needs based on the picture you posted. I looked at the link where I purchased my assembled sigma 11 supply and they don't show any available assembled but they have the kit available for $32. I think I paid $38 for the assembled one. You can also go to the AMB Labs site buy the board and source the components yourself. I had $27 delivered for the Triad power transformer and $30 or so for the cabinet. Add an IEC connector, switch and misc. wire etc. and it came in around $100. The John Swenson design is similar in cost even with a lower part count due to the cost of the choke. His really looked interesting from the attached write up. Hope this helps and good luck. I am never sure when I attach images if they are going to work or not - strictly user error
Chris

[wkhanna]

thanks, Chris!

your attachments worked just fine.
i found John Swenson's thread you copied at Audio Asylum.

foot print of the chassis is not limited by a design requirement for me.

[wkhanna]

i found this this to be an interesting article on transformers.....link

[csmielke]

Bill,
Interesting read, thanks. The transformers spec. in the John Swenson design are EI if that now matters to you.
Chris

[wkhanna]

meant to say earlier how V clean & professional looking your build is!

i am sure it is over-kill for a Raspberry Pi3 & HiFi Berry DAC Pro, but i am going to build the JS PS you showed me any ways.
if for no other reason than just to try it & gain some experiance.
thanks for bringing it to my attention!

can i ask where you sourced your box?

[csmielke]

Bill,
DIY Audio, kit area but I got it over year ago so not sure of their current offerings.
Chris

[wkhanna]

:thanku:

[wkhanna]

finally settled on a LPS......

as interesting & useful from a learning/teaching experience building the JS unit would be, i need to get this project in motion....

so i am taking the easy way out by purchasing a kit, albeit one with ET's approval according our Maestro, Jon....
the one thing i liked about this unit even prior to Jon's input was the choke circuit, which, btw, is the key element in the JS LPS....

LINK

[JonMarsh]

I didn't have the spare time to follow this thread earlier, but have to say :T for now!

I might go the exact same route some time soon, or at least accurate the parts, as a secondary experiment. But time is so short between work and GF's issues, coming up with sweat equity right now is difficult. That's a sharp looking build... as I mention elsewhere, the only thing missing is some good common mode filtering.

[csmielke]

Bill,
Very cool find, not enough current for my needs but should be perfect for your project. Keep us posted on your progress.
Chris

[wkhanna]

appreciate any insights or 'opportunities for learning' you find time to provide.

Chris's PS build V nice & clean!

as i said, earlier, the LPS i just ordered will powering Raspberry Pi3 with a HiFi Berry DAC Pro to start with.
it will act as a linix-based server of sorts for a connected portable HD & internet streaming for a system i will use at work.

still trying to decide on amplification.....one of my project requirements is the ability to power not only headphones, but also some V sensitive single-driver trans-lines i have in mind.

ZigmaHornet


yes, i know the drivers are no longer available......but there is an acceptable alternative......more on that later


again, our Maestro, Jon, has proven his ability for unbounded facilitation........the Schiit FREYA is soooooo appealing....!!!!

[JonMarsh]

that it is... multi-function in a well engineered high value proposition flexible configuration..

[wkhanna]

PS build started....LINK

[csmielke]

Bill,
Very cool, I will be following your journey. Can't wait till you guys get to the ladder dac part.
Chris

[wkhanna]

thanks, Chris.
i am excited to see how well the PS measures.

[JonMarsh]

Any updates? I'm still on the 7 day a week program at work, with a new major assignment added to the mix that would be a full time job by itself...

Sill hoping I might find a couple of hours this weekend to play with the Freya and Soekeris this weekend, but no guarantees- we have some house renovation tasks going on too, betting the place ready to eventually sell. At least the "work work" is fairly interesting material, and will allow me to kick over a few hornet's nests at work- really more of an ET thing, when I think about it- I should see if he's interested in picking up the task...

[wkhanna]

Maestro, PS build is completed, but not yet tested.
you can see my progress thus far HERE

[Evil Twin]

Yes, let's see how many microvolts RMS of output noise, and what the PARD looks like (on a 12 bit scope please, non of this low resolution Tektronix equipment).