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I love my little Schiit "Magni" headphone amp and have no basic complaints, but might having bigger transformer offer any performance advantage? It's a sweet circuit design-- a discrete transistor power amp that puts out around 1W into low-Z phones. The manufacturer's transformer is a smallish wall-wart that measures 18.2VAC no-load and the nameplate says is 16VAC.
Follow Ups:
Here is what Jason Stoddard, the Schiit Magni designer, thinks about modifications.
Regards
13DoW
I agree with what bcowen was getting at. A real outboard supply would probably yield an audible improvement just because it would be a superior power supply to any wall wart. You could use high quality, low noise diodes, more capacitance, CLC or CRC filtering, and yes, also a larger transformer (probably the least needed part of what you might want to build or buy, but also worth doing). I'd say, build it from components you select; don't buy a done unit unless you know exactly what is in it and why it is superior to your wall wart.
You'd still be feeding it through the internal diodes, and (probably) regulators inside the headphone amp, since the Shiit is designed to be fed AC, with rectification and filtering done internally.Jedrider stated in his post below, "So, if you feed it clean DC, it doesn't really have to do much to it, i.e. it's filtering will be mostly irrelevant."
I suppose that depends on how one defines "mostly". I was feeding my Graham Slee phono stage +24 VDC from two motorcycle batteries in series. I discovered an internal 7818 regulator, which I eventually replaced with a +18 V Belleson SuperPower to great result, better than any cable upgrade I've ever done, for example.(link below)
Apparently the 7818 was adding its own noise, even when fed from what many believe is the best DC power source, batteries.
A well built outboard DC power supply might indeed improve things. But unless the internal diodes and regulators are bypassed, it's likely going to be a compromise.
"Suddenly, I'm not half the man I used to be. 'Cause now I'm an amputee" J. Lennon
Edits: 07/04/17
Until I read the other post, I did not realize how the Schiit is constructed. In that case I would advocate bypassing the internal supply, as well. For Tweakers, only.
and probably less expensive...but it makes upgrades more difficult when everything, including the power supply is contained on one circuit board.A few years ago I was considering trying a phono stage (not the Shiit) that was getting some positive press. I decided against it for the same reasons we're discussing here, because it was built with an external AC rather than DC supply.
I'd much rather have the option to do as you suggested, Lew, and build a high quality external DC supply, without having to cut traces, solder in jumpers, etc, likely destroying any resale value in the process.
"Suddenly, I'm not half the man I used to be. 'Cause now I'm an amputee" J. Lennon
Edits: 07/04/17
Certainly more savvy than I am with regards to what they are doing. There's probably not that much to be gained by fiddling with the Schiit or the iPhono2, for examples.
"Suddenly, I'm not half the man I used to be. 'Cause now I'm an amputee" J. Lennon
Yeah Lew, you're probably right. Why bother trying to improve equipment. He is probably already using the very best filter caps, like Elna Silmic II or Nichicon muse. I'd bet dollars to donuts he is using soft recovery diodes or Schottky. Probably using metal foil resistors also. The transformer is big enough and the thin wires on it are about as good as you can get on this or any other planet. Maybe even the planet you are from. Or maybe you could be full of Schiit?? Like WTF. Why is there even a tweaker's asylum forum? I was foolish in the past to think it was here for tweakers. Tweekie666
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
requires a sharp analytical mind? Sure, there may be some compromises on parts cost, in order to meet a price point for marketing the item. And if you want to "upgrade" the parts quality, go for it.
You want to cast me in the anti-tweaker role. I won't play that part. I wrote elsewhere that a completely discrete outboard supply would be the no-holds-barred way to go, if one is so inclined. For those who are put off by such notions, because they lack skill, knowledge, or experience, the product probably has been well thought out to begin with, if the company building it is reputable, like Schiit or iFi.
Yo Lew, my sharp analytical mind doesn't understand the relevance of your question. I think swapping in better sounding parts makes things sound better. "The only thing he did was change the transformer. We went from a 100mA transformer to a 10A transformer"exactly the same voltage, the circuit was drawing no more current"and the DIFFERENCE was just STAGGERING. To this day it's one of the biggest differences I've ever heard." I kinda like this quote from the Paul McGowan link posted by 1973shovel. Pure hyperbolicness I guess. Why even bother trying to make one's system sound just a tini wini bit better? T456
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
Edits: 07/07/17
.. in fact it's possible to completely screw up a power supply by fitting expensive high-performance components, in much the same way you can mess up the handling of a car by fitting expensive alloy wheels and low profile tires.
I think his point is a little more subtle, maybe. There has to be a cost/benefit review before undertaking costly improvements, like adding a $100+ power supply to a $50 hock-shop headphone amp. (I don't have a huge junkbox any more that I can pull parts from.)
I have no doubt that an outboard high-current DC power supply would bring a sonic improvement, but the ultimate performance level it can achieve under the best of circumstances is probably not going to be worth the cost.
I think that a **cost-appropriate** level of improvement might be to use nice fat transformer and some nice fat wire, hardwired in, like I was thinking originally.
Those regs are like 40 to $50 each. Diode upgrades with new caps and tranny will be a huge difference even without these hyper expensive regulators. T456
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
They work very well. Finding the right transformer is more difficult though because they're generally expensive. Finding a discarded, formerly decent CD player usually yields a good transformer and parts as well.
Just to find the "right" piece of vintage stuff to salvage the trafo from...
16vac 100va tranny from Zorro. This could be the ticket.
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
I was more a fan of Sgt. Garcia. Sgt Schultz had the same place in my heart. Thanks... 100VA seems about the right degree of overklill for a 1W amplifier.
Yo Mr.bear. The used transformers I see on ebay seem to all be a lower or maybe equal VA rating. Might be hard to find a used say 100va one. Don't go by what looks like a physically larger one without looking at the VA rating. T456
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
Hey, this should work. BC would love it. I know nothing, nothing!
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
Cisco Kid for me!
nt
Now I get the door bell thing. Your tranny is 21VA (watts) so your 20 watt transformer wouldn't be an upgrade to a larger one. If it were me and I wanted to do this I'd be looking for like a 60-100VA. I'd sure like to get your report on the difference. T456
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
Sure looks like you are correct. It's just a step down transformer. I've never seen that. Maybe find a significantly larger 16v and give it a try and forget the linear power supplies??
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
The only audiophile aftermarket 16VAC (not to be confused with 16VDC) power supply I'm aware of is a Swagman Lab product designed as a Schiit PSU upgrade:http://www.swagmanlab.com/Product_PSU?product_id=670
Here's an eBay listing from a US seller:
Edits: 07/01/17
The unit in the eBay ad looks lovely and I might not be able to build it myself for $80-90 bux, **if** I could find the perfect toroid... so it seems a decent value.
It may be crazy but I can buy the top-o'-the-line doorbell/ annunciator/ thermostat transformerfor $20 bux- the universal voltage for all the world's doorbells being 16 volts, oddly enough. The top of the range is 20 watts on the nameplate. They look like garden-variety E-I type transformers. To save embarrassment I might hide it in an attractive project box behind the rig tho... don't want anybody to mistake my sophisticated HiFi for the furnace! Powered by NuTone, baby!
Isn't the PS you are using now external?? I don't understand the cutting traces thing if you are using a wall wart. There are some PS's under $100 that look good. You could ask if 15v would work and you said the wall wart is putting 18.2v so you have some lee way. T456
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
The rectifier and filter is inside the little amp, SMD's on the board.
That yugeeeee tranny, a BIG FAT ac wire, a filter cap upgrade on the board if needed and a decent plug and you will have a much improved unit,IMHO. A much bigger sound if that is what you would like. Yuggger is yugely better as I always say. Bigly. And maybe some bigy and better diodes. T456
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
Here's a better image of the Swagman Lab product. Looks like it features a rather nice toroidal transformer.
Way back in the 80s I owned a PS Audio IV preamp with phono stage that had an optional large outboard transformer as an upgrade. It sounded way better. The stock one was bigger than a wall wort but this one was from a power amplifier. Lower impedance power supply? Don't know.
And here it is again (Asylum link below). A quote from Paul McGowan in a Stereophile interview, explaining how Stan Warren "discovered" that a more current capable power transformer sounded better.
You nailed it, Barry. McGowan said the improvement was due to the larger transformer's "very low secondary impedance".
I've always tried to build my power supplies with far more than necessary current capability (when possible) because of this. A five amp transformer doesn't cost all that much more than a one amp, in the big scheme of things. Getting it to fit in an enclosure is another matter though.
Inside that Asylum post is a link to the whole Stereophile interview with McGowan, where I got the quote.
"Suddenly, I'm not half the man I used to be. 'Cause now I'm an amputee" J. Lennon
Maybe, just maybe the women have a point.
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
One of the good things about an outboard power supply is that you can put it far away from the circuit so a larger transformer with larger diameter wires wouldn't have any or much of an increased interference problem. Duster has listened to a number of them. Maybe he could recommend one in your price range. I got a very inexpensive Tripp Lite for a dac and it blew away the wall transformer. Night and day. T456
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
A linear power supply would quite likely offer some improvements, but more from eliminating the noise produced by that wal-wart (which is quite likely a switching supply) than from the size of the transformer. As long as the transformer is capable of supplying the max current draw of the amp, going bigger is unlikely to add anything but the potential for more noise and a larger EM field to interfere with other components.
If you're the DIY type, there are several kits available that can get you a very nice linear supply for $200 or less. And there are a number of manufactured supplies as well, some for even less money (check out the Zerozone units on Ebay that Duster has recommended).
You might consider getting a linear power supply with a significantly larger current rating. That should sound way better and also probably have a larger transformer. You can upgrade the filter cap on anything you get. I'm sure others can recommend some PS's for you. T456
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
Edits: 06/30/17
Thanks, but the Schiit-branded wall-wart is just a transformer that sends 16 VAC to the little amp. There's a decent looking rectifier and filter inside the tiny little box already. Maybe there's more harm than good coming from cutting the circuit traces etc. and connecting an external DC supply, but I'll noodle on that idea.
16vac?? Are you sure??
"The Borg is the ultimate user. They're unlike any threat your Federation has ever faced."
- Q, 2365
I don't see any problem with feeding it DC.
16VAC is about 22 volts DC (I think you just multiply it by the square root of 2). So, maybe an 18-24 volt DC would work.
So, if you feed it clean DC, it doesn't really have to do much to it, i.e. it's filtering will be mostly irrelevant.
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