[dBe]

Hey, everyone.  I have a question for all of you that are using one of my BUSSes with an amp with a switching power supply or with digital amps.

What is your experience with them?

I have a gentleman, Giuseppe from Italy, that is interested in a Euro spec UberBUSS and he wants to know about the combination.  Being a tube guy kind of limits my experience, but I know that people have had good results with using them with Gainclones and ICE amps, but would appreciate any infor that you could add here.  It will be good for Giuseppe (I'll link him in) but will also be good for me to know.

I seldom hear anything, but : "Oh, WOW!" which is very good and makes me happy.

Thanks ya'll.

 

Dave

[granosalis]

Thanks Dave, I'll stay tuned 

Regards,
Giuseppe

[satfrat]

I have heard both my UberBuss and that of Bill@LakeGeorge on his Salk HT-3 system that has an Ice Power D-Sonic MAGNUM 2000-5, 525 watts X 3 for the front and 2 X 250 for the surrounds. It was my Uber demo that had Bill order his so I'd say it works darn good on ICE amps. Bill's system is so clean that it takes me a day to reacclimate myself with my system. Bill's Uber system has mighty big balls!    My Uber system has mighty clean not so big balls. 
 
So I guess this would be a 2 Uber endorsement. 
 
Cheers,
Robin

[dvenardos]

Didn't you guys play around with the Virtue amps and battery versus MajikBuss/SMPS at RMAF?

[Danny Richie]

Didn't you guys play around with the Virtue amps and battery versus MajikBuss/SMPS at RMAF?

Yeah, and by far getting them off the grid and onto the batteries and off the switching power supplies makes the biggest improvement. But there was front end components that all ran through a Majik Buss.

You have to treat the AC at a show. It's not good.

[jtwrace]

When I ran the ClassD Audio amp that I built through the Uber it was amazing at the difference.  No brainer! 

It sounded Bella!

[dBe]

Didn't you guys play around with the Virtue amps and battery versus MajikBuss/SMPS at RMAF?

Don, no we didn't.  The guys in another room were having some problems with line noise and not having enough power outlets and I loaned them some Majiks, but we were battery powered for amplification except for the subs through and the Uber and then Gary's Power Supply.

Dave

[granosalis]

Thank you guys for the precious information. 

[jtwrace]

Thank you guys for the precious information. 

So, are you buyin' one?   

[granosalis]

So, are you buyin' one?   

Well, the main doubt was the effectiveness of the BUSS with class D amplifications.
So I think I'll but one, but the decision is not yet taken.

[satfrat]

Well, the main doubt was the effectiveness of the BUSS with class D amplifications.
So I think I'll but one, but the decision is not yet taken.

I asked Bill if he'd care to post his impressions of his UberBuss with his Ice Amps and he replied "Why bother, you've already said it all". 
 
Cheers,
Robin

[granosalis]

Hi guys, thanks to all of you.
Your contributions was decisive. 
Dave was also very kindly answering to ALL of my questions.
At the end I decide to order mine. 

Unfortunately I'm in a galaxy far away away … 

Ciao
Giuseppe

[jdbrian]

Hi Dave

  I am looking at the switching amps using the ICE modules. I have been looking for specific information on your Buss products and don't seem to see any. As far as PF correction- Do the ICE modules have built in PFC. Most switching supplies do have this built in to help with meeting regulatory requirements.
  The power requirements of a class D amp are much less then an equally powerful Class AB amp. This and the fact that the switching supplies can work over a large voltage range should make them less sensitive to poorly regulated power. The unknown of course is how the switching noise from the amp will impact on the incoming power and what this will do to the front end components in the system. It seems to me that the class D amp would require a different solution than conventional amps and that isolation between the amp and the rest of the system/power line would be a critical component of any power treatment.
  I my own situation I am 3 miles from the main road and have a dedicated transformer on the pole at the end of my driveway. It is 250ft to the house and even with a dedicated TX my regulation is poor with the voltage sagging to below 110v in winter when electric heat is in wide use(Canada). I think the classD amps may have an advantage in that the supply can operate down to 90v and still provide rated output.
   What are your thoughts on this and how does the Buss isolate without using any series filter elements?


Thanks
Brian

[dBe]

Hi Dave

  I am looking at the switching amps using the ICE modules. I have been looking for specific information on your Buss products and don't seem to see any. As far as PF correction- Do the ICE modules have built in PFC. Most switching supplies do have this built in to help with meeting regulatory requirements.
  The power requirements of a class D amp are much less then an equally powerful Class AB amp. This and the fact that the switching supplies can work over a large voltage range should make them less sensitive to poorly regulated power. The unknown of course is how the switching noise from the amp will impact on the incoming power and what this will do to the front end components in the system. It seems to me that the class D amp would require a different solution than conventional amps and that isolation between the amp and the rest of the system/power line would be a critical component of any power treatment.
  I my own situation I am 3 miles from the main road and have a dedicated transformer on the pole at the end of my driveway. It is 250ft to the house and even with a dedicated TX my regulation is poor with the voltage sagging to below 110v in winter when electric heat is in wide use(Canada). I think the classD amps may have an advantage in that the supply can operate down to 90v and still provide rated output.
   What are your thoughts on this and how does the Buss isolate without using any series filter elements?


Thanks
Brian

"Well, let me say this about that" (JFK, in many instances to avoid some direct answers due to not having all of the facts).

I "think" (uh-oh!) that the ICE modules have PFC that is specific to their operation built into the modules.  I'll shoot Gary Dodd and Seth Krinsky a link to this discussion.  They can answer your question better than I.  Most switching supplies do have that PFC to comply with EU type certification.

Switchers are bad for audio, in general, but necessary to meet energy requirements world wide.  One of the things that my BUSSes do is to isolate and sink the noise from these power supplies through some parallel band pass filters to and through the EMI brick in them.  It is a noise sink, if you will. 

The EMI brick is proprietary and I am necessarily not divuldging what it is made of, kind of like the Coca-Cola recipe.  It is a trade secret (legal definition).  My patent application has hit a snag in the research and discovery phase do to pre-existing art from about 80 years ago that 'may' make my units not patentable.  I'm trying to get a ruling on this before I spend any more $$$.  Oh, well... that didn't tell you much did it?

What makes my units different is that there is no series inductance to current limit and, equally as important, not make the noise reduction bandwidth bound to the common |AV| = 1 / √((1 - ω2LC)2 + (ωRC)2) low-pass equation.  Since this absence of inductance does not effect bandwidth, I can play with the capacitance values to hit the desired low-pass attenuation target.  Basically, the EMI brick manages energy states without resorting to inductive reactance and its' attendant limitations.

Often I get asked: "How does it work?" My usual answer is: "Well."   

Electric heaters are notorious for imprinting DC on the lines.  My units don't help with this.  The PS Audio Hunbusters work well.

Dave
 

[jdbrian]

Dave

  I don't need to know specifically how the Buss works. I am just trying to get a feel for what is going on to reduce EMI and isolate.
  So the Buss reduces noise by lowering the power line impedance at the offending frequencies. So there would be no isolation between the outlets but all outlets would have lower noise?
  How much power does the Buss draw when there is no load? 
I have heard transformer buzz caused by small amounts of DC offset. This is a concern with toroids in particular. The Bryston company has schematics of their amps online. If you look at the schematics there is a circuit used that prevents DC offsets using large electrolytic caps and diodes. This is a product that should be commonly available and perhaps included in power treatment solutions. It is not exotic or expensive to implement.

Brian
 

[dBe]

Dave

  I don't need to know specifically how the Buss works. I am just trying to get a feel for what is going on to reduce EMI and isolate.
  So the Buss reduces noise by lowering the power line impedance at the offending frequencies. So there would be no isolation between the outlets but all outlets would have lower noise?
  How much power does the Buss draw when there is no load? 
I have heard transformer buzz caused by small amounts of DC offset. This is a concern with toroids in particular. The Bryston company has schematics of their amps online. If you look at the schematics there is a circuit used that prevents DC offsets using large electrolytic caps and diodes. This is a product that should be commonly available and perhaps included in power treatment solutions. It is not exotic or expensive to implement.

Brian
 

Brian,

The BUSSes work by using the EMI brick as an energy sink for EMI and RFI and circuit to circuit isolation ('A' & 'B') is primarily capacitive in nature to prevent backfeeding grunge back into the separate circuits in the BUSS as well as shunting RF to ground (first order) like most filters.  There is isolation between the circuits at HF - RF frequencies.  That is why there are after filters following the EMI brick.  It does not reduce line noise by lowering target frequency impedance.  That is where energy state management is important.  The BUSS is essentially 11ga wire from input to output.

The BUSS draws about 1 - 1.5A.

DC in an A/C invironment just sucks.  The PS Audio Humbuster works pretty well.  Bryston amps have a great hum circuit.  That is one of the things that made them popular as studio amps.

I have a hum eliminator in the works.  Coming soon.

Dave

[jdbrian]

Hi Dave

  Glad to hear there is a hum solution in the works. I traced my hum problem to a toaster oven of all things. It appeared to use a half wave rectified heating element that caused only a small DC offset in the AC as measured with a Fluke 189 true rms meter. But this was enough to cause audible hum from all the toroids in my Rotel electronics. Disposed of that problem real fast.
  A short story about generic power conditioners. I have a monster conditioner power strip. It is the 2000model with the High Current unswitched outlets for amplifiers. I recently replaced the switching supply in my DAC with a linear one. In order to cut heat in the regulator I had included a series resistor in the rectifier circuit of the +5v logic supply. There still seemed to be plenty of headroom for the regulator. When I powered the DAC up everything was fine. The DAC was plugged into one of the monster isolated low current outlets. When I turned on the power amp, a rotel 990 with 60,000uf and a large toroid, the DAC reset indicating that the power supply had fallen far enough for the supply to loose regulation. It seemed the high current outlets still had considerable voltage drop. I let the amp sit for a few minutes than plugged it directly into the same duplex outlet as the monster conditioner. Turning the amp on did not cause the DAC to reset, proving that the voltage drop was in the "High Current" conditioner. I repeated this several times and results were consistent. Since then I have run my amp off a separate circuit and have increased the headroom in the DAC supply. I notice better slam and dynamics since then.
  Sorry for rambling but your point about current limiting is well proven by my experience.

Brian

[dBe]

Hi Dave

  Glad to hear there is a hum solution in the works. I traced my hum problem to a toaster oven of all things. It appeared to use a half wave rectified heating element that caused only a small DC offset in the AC as measured with a Fluke 189 true rms meter. But this was enough to cause audible hum from all the toroids in my Rotel electronics. Disposed of that problem real fast.
  A short story about generic power conditioners. I have a monster conditioner power strip. It is the 2000model with the High Current unswitched outlets for amplifiers. I recently replaced the switching supply in my DAC with a linear one. In order to cut heat in the regulator I had included a series resistor in the rectifier circuit of the +5v logic supply. There still seemed to be plenty of headroom for the regulator. When I powered the DAC up everything was fine. The DAC was plugged into one of the monster isolated low current outlets. When I turned on the power amp, a rotel 990 with 60,000uf and a large toroid, the DAC reset indicating that the power supply had fallen far enough for the supply to loose regulation. It seemed the high current outlets still had considerable voltage drop. I let the amp sit for a few minutes than plugged it directly into the same duplex outlet as the monster conditioner. Turning the amp on did not cause the DAC to reset, proving that the voltage drop was in the "High Current" conditioner. I repeated this several times and results were consistent. Since then I have run my amp off a separate circuit and have increased the headroom in the DAC supply. I notice better slam and dynamics since then.
  Sorry for rambling but your point about current limiting is well proven by my experience.

Brian

Brian,

I don't consider that rambling by any measure.  Everyone can benefit from everyone elses experience and that is all good info especially the part about the toaster oven.  It is that type of thing that most of us never think about.

Here's one:  swimming pool heaters...........

Current limiting through devices, particularly those with isolation transformers is something that will just strangle the life, dynamics and leading edges out of music that requires supply headroom.  I've seen products with MASSIVE wiring, traces on boards  - the whole thing that then funnels the line and neutral down to 16ga wire wrapped around a toroid ferrite core to trap RF.  That is just one of the reasons I started looking at building a better mousetrap. 

RF mice are really tiny, you know?
Dave.

[jtwrace]

Good thing my pool heater is off when I'm listening...other wise I wouldn't be listening. 

Uh oh, the Mrs. could be in there when I'm listening.   

[jdbrian]

It seems to me that an isolation transformer is always going to have some losses and the voltage will sag under load. Even a large one will have a few percent voltage drop when used with a large power amp and can significantly lower the power available. If you don't need to isolate the ground due to noise problems why use one on a power amp?
   Low level devices are a better fit IMO. The current demands are lower and don't vary much with signal level and the supplies are regulated.
   I work in a large laboratory. From 1985 to maybe 2000 it was pretty standard practice for instrument manufacturers to include an OneAC brand line filter/isolation transformer with new instrumentation. These units were very good at preventing EMI from causing glitches in the operation of this instrumentation. Lately every instrument is supplied with a UPS unit which normally filters as well as backs up the power. Newer equipment is much better engineered and we rarely have any power related problems now.
 Oh! I'm rambling again.


Brian