toroidal power supply

[novisnick]

Are they back?
I noticed many amps with switching power supplies are getting the axe! Could their be a rebirth of the toroidal power supply in Emotiva’s future? Our future? Heavy iron sells pretty good IMHO but what do I know? 

[AudioHTIT]

Jun 18, 2019 11:55:55 GMT -5 novisnick said:

Are they back?
I noticed many amps with switching power supplies are getting the axe! Could their be a rebirth of the toroidal power supply in Emotiva’s future? Our future? Heavy iron sells pretty good IMHO but what do I know? 

Are you referring to the “Closeout” badge on many products on the refurbished page? I noticed the PA-1 also had a Closeout badge which surprised me. I have no idea if it’s related to SMPS, but would doubt it.

[novisnick]

Jun 18, 2019 12:02:58 GMT -5 AudioHTIT said:

Jun 18, 2019 11:55:55 GMT -5 novisnick said:

Are they back?
I noticed many amps with switching power supplies are getting the axe! Could their be a rebirth of the toroidal power supply in Emotiva’s future? Our future? Heavy iron sells pretty good IMHO but what do I know? 

Are you referring to the “Closeout” badge on many products on the refurbished page? I noticed the PA-1 also had a Closeout badge which surprised me. I have no idea if it’s related to SMPS, but would doubt it.

Yep! Of course I haven’t a clue as to Emotivas plans but I too thought the PA-1 would have been a winner! Perhaps they found something they could improve upon, OR are they back to toroidals.

[KeithL]

We're "blowing out" a bunch of factory renewed units... and, apparently, "CloseOut" is the closest flag that our shopping cart software offers.

We are NOT discontinuing the PA-1 ... it's actually proven to be quite popular.

And we most certainly are NOT "going back to toroidal power supplies"... or discontinuing models with SMPS...

Let me clarify a few things....

The PA-1 is a Class D amplifier with an SMPS.

The amplifier and power supply sections are included on the same circuit board - the ICEpower module.

Our XPA and XPA-DR amps are Class H (Class A/B) amplifiers with SMPS.

(And you can also have a Class D amp with a toroidal power supply).

We do NOT consider either type of power supply to specifically sound better than the other.

However, from an engineering perspective, each has certain benefits and drawbacks, which may be different at different power levels and price points.

At the price point and power level of our XPA and XPA-DR amps the SMPS has the edge.

It's fully regulated, which is a major benefit, both because it provides extremely stable rail voltages, and because it's quieter.

Compared to a design with a toroidal transformer, the SMPS is also lighter, so the new amps are less likely to be damaged in shipping.

The amps themselves are also a lot lighter and easier to handle.

The SMPS is a more complex design, which adds to the cost, but it doesn't need that toroidal transformer, which is big, heavy, and expensive.

And, as it turns out, the SMPS have proven to be more reliable.

At the price and power levels of our BasX components the toroidal power supply currently has the edge.

It is simpler, and uses fewer components, so costs less to build.

And, at those power levels, the cost and weight of the smaller toroidal transformer simply aren't major issues.

We are very pleased with the performance and reliability of the SMPS we use in our big amps and have no plans to discontinue using it.

Of course, we may upgrade it to a newer version someday, and we'll continue to use toroidal power supplies in situations where they make the most sense.

[tchaik]

Jun 18, 2019 13:13:57 GMT -5 novisnick said:

Jun 18, 2019 12:02:58 GMT -5 AudioHTIT said:

Are you referring to the “Closeout” badge on many products on the refurbished page? I noticed the PA-1 also had a Closeout badge which surprised me. I have no idea if it’s related to SMPS, but would doubt it.

Yep! Of course I haven’t a clue as to Emotivas plans but I too thought the PA-1 would have been a winner! Perhaps they found something they could improve upon, OR are they back to toroidals.

actually, look closer. there are links to the regular priced amps and also the same "factory refurbished amps" at about a 15% discount. no, it does not look like a closeout. Emotiva does this every now and then to get rid of B stock (those returned within 30 days) and amps that needed repair. they are all called 'factory refurbished'. the confusion is the use of the term 'closeout' on the fac refurb vs the A-stock.

oops.... I just noticed Kieth's reply after I posted this.

[garbulky]

The SMPS is more reliable? I hope so. What kind of metric are you using? Because I've used a good few old emo amps that are working just fine. I expect my amps to easily last ten years, and possibly decades without issues due to their torroid. I know my UPA-2 did and afaik it's still going strong. My XDA-1 is still going strong. The switching supply has simply not been around long enough to prove itself like the older torroidal units.

[selind40]

Thanks KeithL for the Information and reassurance the PA-1's aren't going away anytime soon. I'm looking forward to my lunchtime purchase of the PA-1's at the discount price, plus the extra Vet's discount to boot....it was a hard deal to pass up on.

[KeithL]

At this point it's just anecdotal evidence.

In other words, I don't have the specific numbers, but the repair guys tell me we've had VERY few Gen3 amps come back with bad power supplies.)

Transformers themselves, and especially the big toroids we used in our amps, almost never fail.

However, in order to switch between 120 VAC and 230 VAC operation, you have to change the actual wiring to the transformer.

This is done by a little board containing several relays and some circuitry to sense the line voltage.

That seems to be where failures tend to occur when they do occur.

And, especially on the older amps, it can be quite tricky to troubleshoot and repair when it does happen.

On the new power supplies all of the handling of different line voltages is managed in the power supply itself.

Also, because the power supply itself is a single assembly, if they ever do fail, it's much simpler to replace the entire thing.

(Although, as I said, so far this has been a truly rare occurrence.) 

And, again, both during initial shipping, and shipping when units were sold used....

Probably the single most common cause of damage we saw on amps was when the transformer shifted or broke loose when the amp was mishandled or dropped...

And this doesn't happen at all with the new lighter SMPS...

And, since the whole amplifier is lighter, they are in general more tolerant of mishandling and less subject to damage due to poor packing as well.

Jun 18, 2019 13:57:52 GMT -5 garbulky said:

The SMPS is more reliable? I hope so. What kind of metric are you using? Because I've used a good few old emo amps that are working just fine. I expect my amps to easily last ten years, and possibly decades without issues due to their torroid. I know my UPA-2 did and afaik it's still going strong. My XDA-1 is still going strong. The switching supply has simply not been around long enough to prove itself like the older torroidal units.

[pedrocols]

It's all about cost savings folks.

[KeithL]

Absolutely.

From our point of view it's about delivering the best performance for the lowest cost.

And, from the point of view of most customers, it's about getting the best performance for the lowest cost.

(If anyone has too much money they just can't figure out how to get rid of... please PM me immediately so we can discuss disposal options.)

Jun 18, 2019 14:30:23 GMT -5 pedrocols said:

It's all about cost savings folks.

[donh50]

A SMPS (switch-mode power supply) moves all the power supply noise way above the audio band (no more 60/120 Hz hum!) and is much simpler to use as a tracking supply for class-G operation (less wasted power and heat). It is also much smaller and more efficient. Reliability has been an issue but so many amps use them these days that is less an issue -- though (like in a conventional supply) you need to use good quality components.

A toroidal transformer has less radiated energy so is a good choice when space is at a premium. It will not couple as much energy into adjacent circuits in a tightly-packed enclosure. In all other ways they are generally inferior to a standard EI transformer, including usually more sensitivity to DC and core saturation. They are also harder (and thus more expensive) to build. They are a audiophile "must-have" but like many other things it's more due to marketing than technology IMO.

FWIWFM - Don

[AudioHTIT]

Jun 18, 2019 14:30:23 GMT -5 pedrocols said:

It's all about cost savings folks.

I somewhat disagree, while the SMPS should indeed cost less, I think lower weight is the biggest advantage of the new designs.

Yes, less weight means lower shipping costs too, but it also means less shipping damage. I have had big heavy amps sustain shipping damage on more than one occasion -- even though they were well packed in their original double boxes. If they're insured, you might get your repair costs covered, but it will be a big hassle and you'll be without your amp while the issue gets sorted out and fixed.

Then there's the issue of our aging audio / home theatre community, and our ability to move heavy equipment in and out of racks and cabinets. Two qualities of Class D amps that I appreciate are lower power consumption and lower weight. The latest SMPS G3 amps move us in the right direction with both of those qualities, which I like. Maybe one of the reasons more women aren't into audio and HT is because of big, heavy equipment? In the 70's I sold a lot of B&O receivers to women, not only because they looked and sounded good, but because they were manageable and easy to operate. Even though I'm still strong enough to move most of my gear, I really like when I have help (usually my wife), but would prefer not to need it.

Now, I'm avoiding whether a G2 sounds or measures better than a G3, I haven't compared them; but while I very much like my XPA-7 G2, I'd sure appreciate handling the 53 pound G3 over my 98 pound G2. So I have no hang ups about 'big iron', just because it's big and heavy, but I understand preferring it IF it sounds better, measures better, and is more reliable, but if a lighter option sounds as good or better, I'm all over it.