Fuck it let’s do this. They give you 4 coasters when you order these btw.
So my first attempt ended up in smoke. My tips below will allude to why. I haven’t verified audio comes out but lights come on and there’s no smoke so it’s progress.
The BOM on Schiit’s website has an error. You need 3 10uf 50V 1206 capacitors, not 2. The Designator column has C3,4,12, but Quantity has 2. You’ll need 3.
Surface mount isn’t that bad. You can use tweezers. Putting the surface mount piece on the PCB and melting solder on the ends worked well enough. With through hole components you’re supposed to heat the joint not the solder. With smt, a technique that worked for me was to put the solder on the surface mount and heat the solder. Eventually enough would melt that it would stick to the coaster and the component.
Buy an extra of every cheap surface mount component. When you open the thing they come in and one goes flying across the room you are never going to find it. When you open the thing they come in and one falls and bounces off your workspace and onto the floor or on your clothes you probably won’t find it. You will lose at least one and then have to pay the $8 mouser shipping fee again.
While the surface mount capacitor direction doesn’t matter, the installation direction of the surface mount diodes (D1-4, D102, D202) does matter. With through hole diodes you get a visual reminder direction matters because one lead is longer than the other. You barely get a reminder here. And these are tiny buggers so you’ve got to really pay attention to detail. Or you may get smoke. For the LEDs there’s like a little green marker on one side of the LED. Notice for D102 and D202 there is a half rectangle around the mounts. The markers go on the closed end. you can see it a little better in real life
Also for D1-D4, notice the open ended rectangle. If you look really really hard at the diodes there is a very faint line on one end. The end with the line goes on the closed end of the rectangle. There’s no way I can take a picture to see the line on the diode. You’ll need to use a flashlight to see the line.
Lastly, installing Q1, Q102, and Q202 suck because of their size. If you install all the resistors first, installing these things is much more difficult because of the crowded space. I would install them as soon as you are comfortable with surface mount soldering but after some practice. I would recommend this install order in order to install some resistors that provide good practice and are out of the way of the transistors before tackling the transistors:
- R1 and R3
- R2, R4, R100, R200
- R107 and R207
- Q1, Q201, Q202
- Other surface mount resistors, capacitors, and diodes
- Through hole items from shortest to biggest
Shootout coming with this vs starving student, millett nuhybrid, and an actual vali 2+. Because this hobby should be fun. I mean I can’t believe I made an actual serious detailed post about building this thing.
ok so i have it hooked up to an iphone lighting 3.5mm cable because I don’t have an rca to 3.5 handy and I really can’t wait to plug this up to a real DAC. Turned all the way up my HD6xx’s are louder than I like. I feel like if I comment more about imaging or bass or whatever is gonna take away from the fun of the damn thing. Is it perfect? No. Does Pharoah Sanders still wail playing with Floating Points and the London Symphony Orchestra*? Hell yes. If I start to care how congested the imaging is with this, I’ve missed the point.
*Stop reading this and go listen to Promises with Floating Points, Pharoah Sanders, and the London Symphony Orchestra now.
Congrats. It’s nice to see one of these actually completed.
My question is how well it still functions as a drink coaster. The capacitor forest seems to lift your mug so it’s easy to reach, plus keep it warm too. That’s some prescient Schiit!
So I seriously just bought this on ebay and I’m going to mount the amp in it. I’m going to drill a hole in the back for the power and one in the top for volume. I think the pot will stick out just enough to put a knob on. Looking for ideas on how to pimp it out.
Ah, 1970s Harvest Gold coasters!
For the ultimate pimped eclectic look and massive over-cooling, add a gaming PC RGB lighting setup. “Harvest” a PC fan glow-ring as a surround for the pot.
[Fast forward to the end for the systems in operation]
Maybe use a vegetable shaped knob from a kitchen timer? Tomato, pumpkin, corn, etc. Either round or pointy veggies would work depending on your preference.
The tacky knob idea is gold
You are a freaking role mode!
Love everything about this build.
(But how do you improve on the perfection that is that coaster cozy?)
This is hilarious. I’m really disappointed with how thin the back of this is. Still need a knob. There’s not a lot of space so I could drill the hole a little bigger but I love the design.
Sir! Don’t drink that! You have Schiit on your glass!
I use my amp as a coaster all the time. This is really upping the game though.
We need an update about this and its knob. And photos.
So, knobbage is hard. It doesn’t stick out enough out the top for a normal knob. I could drill a larger hole and have the knob sit further down into the top but I don’t want to. I have tried a few things and this works.
I’ll give some audio impressions after my daughter goes to bed.
The statue says “king of dad jokes.”
That’s a standard issue with electric guitars. As a result, parts firms sell long shaft pots. Another option would be a sleeve or extension.
I will report back soon
I did promise audio impressions. I let it warm for about 2 hours before trying it out.
Mimby → Vali Mini/Vali 2+ → HD6xx/he4xx (because I don’t have a 1/4 to 3.5mm adapter lying around)
I’ll get the bad out of the way.
The tubes are very microphonic. They aren’t as loud as the Korg Nutube in the millet nuhybrid but they ring for longer.
The 3.5mm input is because of space constraints. That may limit what you can use the amp with.
The biggest thing I notice is the detail getting dropped. I couldn’t tell you which details. It’s not as crisp, it’s blurred. I would compare it to like watching a 4:3 ratio 80s-early 00s tv show on a big 4k tv, but it’s not that bad. You get the idea though. I will say this is way way way more obvious on the HD6xx. HE4xx is a better headphone for the amp.
I don’t know if I can generalize based on just the HD6xx and HE4xx, but it has enough power for high impedance headphones but I’m guessing is a better fit for easier to drive, “low gain” sort of headphones. It definitely plays better with the easy to drive planar.
That’s it. That’s all the bad. It’s blurry and could have more power. The blurriness can be a little harsh in the lower end, although it could be the headphones (edit: it’s both, the vali mini does make bass boomy fatigue worse. i wouldn’t say it’s warm, i’d say it’s fatiguing. that said the headphones are 2/3 of the issue, the hd6xx doesn’t give me a bass headache from the vali mini and the he4xx is definitely boomy from the vali 2+). It does a lot of other stuff well. One thing the mimby offers over the first level of sigma-delta DACs is a much larger soundstage and more depth. This Vali Mini let’s this come through.
The Vali Mini is a tube amp and has bloom of a tube amp. It’s a little colored. Competing products are probably the amp part of an ifi can. It’s better than the op amp measurement stuff. Let’s not make jokes about a coaster amp, let’s make jokes about measurements instead.
Look, I’m not gonna tell you that this is gonna beat the Vali 2+. That’s a damn good amp for the price. In the DIY world, the Millet Nuhybrid has more power so it’s gonna win on a lot of fronts. I don’t listen to my coaster amp really ever. I have too many other toys. But it has merit as an amp on it’s own, especially for easier to drive stuff (I’ve never heard a Grado but from what I understand this would work well, entry planars). It doesn’t have the op amp stuff, it’s a full on tube amp. Just not that much power for a tube amp. You can treat this seriously. There is real tube bloom and a touch of warmth but it is transparent of the DAC which is great.
now i need an adapter for the anandas to try them.
and a knob. working on it.