Hacking Schiit

So the Skoll brings in some SMPS noise on the left channel since the input is so close to the power input. I “fixed” it by using a steel plate (aka razor blade….all I had at this time) and taped it up there and also ran a ground wire to it. Bam! Noise mostly gone.



I need a steel L bracket that I can screw to the chassis and make that turn. @schiit Is there a way you can put a small metal piece there? It would solve all the noise issues with these.

 

So I finally got some time to mess with Asgard's MB card. Here're the freshly installed OPA2156 from last evening which made me arrive late to work this morning since I stayed awake for a while enjoying the new sound. It's a great difference as already described by many audio friends here, and I think I'll keep this setup for a long while



I cleaned the Asgard's main PCB (since the top holes help to accumulate some dust inside) and I checked few of the IC's. The other two OpAmps (U101 & U201) are TI OP07C. I don't know what's their purpose in the circuitry, the pinout is different from AD8512 and OPA2156, so I won't be messing around them. Maybe someone here is experienced with them and could share more insight.




In the future I plan to replace the AD8512 on my Modi MB OG (connected to the speaker setup) with OPA1656 and see how those sound as well.

 

I suspect those would be for zeroing DC offset. Very slow, very low bandwidth, very stable. The slightest hint of instability there would be pretty awful for performance. Probably not a good idea to mess with them.

 

Big thanks (again) to @Ksorota for f'ing around and making a Piety^2. I like it better than MJ3 and made my own. A few small differences between mine and his: different layout to keep input wiring away from AC, transformer snubbers (the small blue caps and resistors at the PCB power input), paralleled trx secondaries for double the current, grounded input all the way to the PCB. Dead quiet and wonderful. May be my SS forever amp.

 

Great idea on the new layout and input power. I am looking forward to getting mine in a new case that looks a bit nicer...like what you have going on.

Only a few more stops on the loaner for mine...be happy to hear it again!

 

Dammmmmmmmit. I have two Pieties that I wanted to offload but given the terrible resale market I'm tempted to try this. I wanted to be done...

 

I've come to the conclusion that making a halfway decent case is an awful terrible endeavor. Do yourself a favor and spend the money on something prefab.

 

You can half-ass it without making any modifications to the Pietys themselves to see if you like it. If not, sell em.

 

if interested i can send you my initial test setup.

Just the cables, or cables and Valis.

 

Just an fyi, imo a better 10K pot and new transformers make a big difference. But the half-ass version gives you a good clue.

 

So here is my piece of metal I cut up and shaped to cure the noise from the AC power input and PSU of the Skoll. Probably thicker than needs to be, but it was leftover scrap.



Now just to clean it up, cut a hole for a mounting screw, mount, and ground it to the post.

 

Alright, the Skoll left channel input noise is fixed for now. I’m probably going to redo this one even better with a thinner piece of sheet metal that is easier to bend into shape. I also realize I need a smaller screw and nut because it’s so close to the power switch. But man, it is quiet now.

 

What's the purpose of the wire? The bolt you're using to mount to the chassis already grounds the shield.

 

Yes, I likely do not need it. It is redundant. I guess my other temp fix did not connect to the chassis, but this one does. I guess of one glued a shield in, then you would need to connected it to the ground/chassis.

 

This is great! I have a slight hum in the left channel and after trying everything it didn't go away. Thanks for posting this. Looking forward to the cleaner version

 

Has anyone hacked the Modi Multibit 2 yet?

 

I think it is already using the newer TI opamps. I'm not sure though because I do not own one. I don't see why they wouldn't because they use them extensively in other products already. Outside of the opamps, I'm not sure what kind of gains could be made. I imagine that the voltage regulators are adequately cooled as well.

Do you have any pics of the board? The opamps in question are probably on the bottom side unless the design has changed.

 

Schiit has one on the product page as always, no? https://www.schiit.com/products/modi-multibit-2

But also here's one I snapped from when I was worried I might have fried something by accident (forgetting that 120V wall warts do not like 220V mains)

 

Would it be possible to swap them for some crazy discrete Sparkos or Burson OpAmps?

 

You are asking a person whose only project with a soldering iron within the last five years was repairing a mechanical keyboard; I am *far* from being informed in any great capacity about the nitty gritty details of amplifier design, I just have fun chatting about measurements, how they might be correlated to what's audible, and sharing my impressions of gear I've heard. Right off the top of my head, @Azimuth , @Armaegis , @Beefy may be better informed by far because they're not idiots like me