Advice for Schiit on how to improve Magni 3+ power supply

That is A LOT weird.

 

Could you cite which amplifier output parameter(s) will be affected by this change internal to the power supply, and by how much? It would be helpful if you would state specifically which measurements will change and by how much.

 

i am not equipped to do amplifier measurement so I won't be able to figure it out. I can only probe PSU output. However, I have a guess. After modification, I can send it to whoever wanted to measure it.

Here is your measurement on Magni 3+
Magni 3+ square wave 20 Hz 2 Vpp 1 uS / div 300R load - 5 MHz BW


I think the zigzag shapped response is due to LDO resonance.

Heresy is similar but better with larger caps.




BTW, your magni 3's noise measurement also showed spikes near 4.8Khz, which echos with the TNT-audio link I previously provided. That article mentioned that low ESR caps in LM317's output section would cause voltage resonance near 5kHz.



Meanwhile, i just noticed Magni3+ might only used 1 amplifier of opa1678. If so, I wonder how schiit terminated the unused opamp. When I get it I will check upon that too. According to TI, improper termination will cause the unused opamp to saturate and increase heat level.

 

I won't dislike this but instead i will patiently wait for your results, not even because i will understand them ( i wouldn't/won't) but because i want to know if you can practice what you preach. This said, i think that a good debate about different perspectives can be a good/positive thing, only potentially ruined by some arrogant jackass way of talking.
Let's wait for the results.

 

When it comes to technical stuff, please consider me a robot relaying information without emotion, as things have standards for good/bad. Debating skills and manner doesn't make devices perform better/worse.

One thing I particularly dislike here, is that using "We tried" as a defense of choosing a questionable design. I agree people have constraints, but that's not the reason to discredit manufacturers' documentation with something like "datasheets that don't work".

 

kris to put it bluntly - you are an asshole. thread would be interesting withoiut you being a prick

 

So, @schiit says they tried those designs suggested by the datasheet and didn't like the results, so they found something that works better for them, and you say that isn't good enough?

What if they did exactly what the datasheet says, it measured amazingly, but it sounded like crap, so they tweaked it until it sounds good?

The heresy is all about the measurements, the 3+ is about the sound.

 

I actually looked at other Schiit products. On Saga S , Freya S and Vali 2 they actually are following the guidelines to a greater and greater extend. And this doesn't mean you cannot make a device that sounds good and measures good as well.

Vali 2 seems to be doing exactly what I proposed near the lower LM317 on V1.1 board. Cadj uses a aluminum that has higher esr than MLCC, and output smoothing cap is in series with a R10 resistors placed between LDO and the cap itself. I think I am nice enough to not challenge them directly about the design change.

Schiit can say anything they want. Yet when it comes to technical aspects we need to back up the claims on technical background. I am not trying to market my products like Schiit does, so I don't really care if you like my ideas. My purpose is to show you that it can be improved, which I believe was the intention of bringing up the contest.

 

Quick query: would you prefer to own something that measures significantly better but sounds incrementally worse over the reverse?

 

You are making assumptions that those characters are linked. Why don't we just look into MCTH and Vali 2. Quick search on the forum will give an insight into it.

 

What's your background @kris2014?

 

Electrochemist dealing with voltage and mimor current measurements all day.

 

I don't see how my question was in any way implicating a definite link between those characteristics— as far as I'm aware I asked a simple question that you quite casually side-stepped.

The fact of the matter is my background in the social sciences, arts, and marketing leaves me at much of a disadvantage when it comes to understanding the intricacies of design and implementation, and I happily admit ignorance in that because it affords me opportunities to learn. What I meant to lead into with my previous post was that, while I far from speak for the entire forum, I find that there's a contingent of people here and elsewhere that perceive less-superbly measuring gear as sounding preferable to some units that measure very well beyond the limits of superhuman hearing.

It was established that @schiit tried a great many things and did the best he could to get the Magni 3+ to sound as good as possible within the constraints of its target price, and while I think it implausible for him to have tried literally every possible thing insofar as ekeing as much performance out of a budget amp as possible, I have a nagging feeling that there's been a fair bit of ground covered.

Personally, I am curious to learn what your proposed tweaks might do to improve or otherwise influence the amp's performance; for all I know it could blow the current iteration of the Magni 3+ out of the water. That aside though, and I understand this may not necessarily be your intent, you're coming across as punitive and cocksure, which is never a good look.

 

God i love the title "Electrochemist" - what a great thing to throw down at a sunday BBQ.

Secondly, @neomax, don't pander to the crowd. Have you met many specialized engineers or people a touch different on the social spectrum? I know lots of people like @kris2014. I don't think he means to be rude, he just says whatever technical ideas are on his mind. My partner finds it hard to talk to some of my mates because they don't know how to filter and can't read social queues. They're good people though and would help anyone, including her, in a second.

I'd guess that if he's proven wrong, he'll be fine with it and just wants to have a technical discussion. I think @schiit is handling it grace and am pleased that he joined the conversation. No doubt he is a gifted amp designer.

@kris2014 can you tell me more about what you do? How does it relate to circuitry or is that more of a hobby that happens to overlap with your profession. What amps do you think sit at the top of the heap? It would be interesting to know whether your preferences are more in the SBAF zone of "what sounds good" which I generally align with or if you enjoy those that measure better in general.

 

You asked a lot of questions.

My focus area is more linked to studying oxidation/reduction properties of materials, i.e. those used in batteries. But it is less related to engineering aspect of it. In my early days I battled with potentialstats, in order to learn how capacitance and resistance between the electrodes can ruin the measurements, and how to deal with them.

As for amp, I am an low-impedance headphone user after several years of unsucessful pursue in other parts of the market. I am currently using Neurochrome HP-2 as my reference sound, which I found to be on the neutral side.

 

@kris2014 Are you autistic or something? Spec sheets are not reality. The Magni 3 is 100 dollars and sounds good. There are not a lot of headphone amps at that price that sound remotely acceptable for driving high impedance dynamics. The Topping sucks. SMSL sucks. JDS Labs sucks, the THX sucks, Assdrop Cavalli sucks.

Combo dac/amp (one or the other always is much worse than the other) and interfaces headamps almost always suck and are way underpowered except for some choice exceptions : SPL Crimson, Dangerous Music, and the newer Apogees with the Groove built in and those will all measure much much worse and are more colored than the Magni 3.