Digital Amps vs Solid State Amps

Alan, There are just eight allen screws holding that top down. I know he put V caps in some of them, while others just have one Theta. I can tell you, I have had all three versions here, and the Sonicap Platinum is by far the best. It assists the highs in a natural way. All frequencies are even handed. The Theta sounds bland. The V cap is too aggressive.

On wires, Henry is using my SCs, and loves the hell out of them.

Hi Vince,

I don't know what is installed. I am currently using the pair Henry had been using in his system for the last year. He said they are the latest of whatever he stuffs into them. They sound very good.

Alan

Alan,

You may correct in a sense. I would not charactarize the Pass XA.5 bass as punchy or fast. Rather, it conveys a sense of weight and acoustic space, and does not draw attention to itself. It is very natural and realistic, as you say, for classical music. Whether the cello in a quartet, the left hand in a piano concerto, or the double bass section of an orchestra, everything is cohesive.

Aljordan, Can you tell me what bridge caps are in your H2O? I installed Soncap Platinum, and the result is perfect in my system.

Hi Rtn1,

I am sure that I would love the XA160.5 or XA200.5, as I thought the XA100.5 produced a beautiful sound in my system. The midrange and top end of the Pass is wonderful. I like the richness of the bass too, but with the Opus it is a bloomy bass more suited to classical music; it didn't have the micro-dynamics and pitch definition that made for great acoustic jazz bass when mated with the Opus. In my system, I never saw the Pass bias needles moving so I figured power was not the issue.

A friend of mine still owns the XA100.5 and another friend owns the XA160.5. Maybe if I hosted a nice dinner and promised to pay for their hernia surgeries, I might convince them to lug the amps over for a side by side comparison.

Alan

Hi Alan,

While I am glad the H2O are providing a very satisfying sound, I believe you would be please as Punch if you heard the XA160.5 or XA200.5 in your system. I do think the class D amps can provide a more realistically-priced and cool-running alternative to these monsters.

The XA200.5s provide bass that is simply natural and glorious in my system. The Pass bass exceeds a prior amp that had MUCH higher wattage and damping factor, which suggests to me that the topology is important and that Nelson got it right. My search is over, and I am relieved.

Alan - Digital amps most likely don't have higher amount of feedback since analog parameter - time (duty cycle) is more linear than class AB transistors. High damping comes from the fact that speaker is always connected between very low impedance points thru very low resistance Mosfets. Icepower uses full bridge (H-Bridge) of N-Channel Mosfets that keep speaker connected between GND and V+ - only direction changes.

Class AB amps in contrast have often very high gain before feedback is applied reaching 4000. Class A i better in that respect with gains as low as 200 and that's were I would place digital amps.

Hi Dob,

I respectfully disagree that the XA200.5 would control the bass of my speakers better than either the Spectron or the H2O.

I don't think the wattage of the amplifier is what determines its ability to control the low end of the speakers, as much as it is the overall topology of the design. While the higher line of the XA.5 series has more wattage and current available, you will notice that the damping ratio of the XA200.5 is exactly the same as the XA100.5, and I imagine that's due to the overall topology of the amplifier (its low loop feedback).

I've listened to other 100 watt amplifiers in my system, similar in power and current specifications to the Pass XA.5 series, that have controlled the bass far better than the Pass mono-blocks. So I think that if you use an amp designed with low or no negative feedback mated to a speaker with a difficult low frequency impedance load, the result will be comparatively loose bass control, no matter how much wattage the amp pushes out. If my speakers had a more friendly impedance load, I think the Pass would control the woofers to my satisfaction.

In contrast, an amp like such as Spectron or H2O has a much higher amount of loop feedback and a higher damping ratio, and that's probably what allows it to control the woofers of a low impedance bass load.

Alan

Hello Alan,

While I myself own class D amplifiers (Spectron) and enjoy them immensely (with carerfully matched associate equipment) I absolutely diagree with your statement:

"...the Pass amps don't have the control in the low end that class D amps generally exhibit. "

What you observed is simply power matching of amplifier to the speakers it must drive (and control). If you would try Pass XA 200.5 or their more power power amp (if exists) you would write exactly opposite.

Hi,

I've owned the Pass XA 100.5 mono amps for a little over a year, but recently sold them. I've also owned H2O Audio class D amps for a long time, and am currently using H2O mono amps to drive my Avalon speakers. So, I have compared both these amps directly with my speakers and have also listened to both amps extensively with the Magico V2 speakers. The verdict? They are both great when set up within the right system.

I think both the Pass and the H2O amps sound wonderful but in different ways, and my preference comes down to system matching. The Pass XA.5 amps have a full, warm sound with a glorious midrange and very smooth high frequencies, and sounded beautiful with the Avalons. However, the Pass amps don't have the control in the low end that class D amps generally exhibit.

The H2O mono amps don't flesh out the midrange as much as the Pass amps do, but they are still wonderfully liquid sounding through the midrange. They can be amazingly good sounding in the right system. I preferred them to the Pass when mated with the Magico V2.

Alan

I'm thinkin' thats the one. My friend built one from a kit.
It was really small......certainly smaller than cigar box size.

The same guy later helped CLOSE Zilog up in Idaho after working there for over a decade. They closed maybe 4 or 5 years ago, tops.
I've worked in semiconductor processing as far back as when Western Digital made its own silicon. The first 'floppy' I ever saw was dinner plate size....8"

Magfan - I remember in late 70's Timex/Sinclair computer with BASIC interpreter and keypad with direct commands. Whole thing was running on Z80 Zilog processor. It had 1kB of RAM but you could extend it with external plug in module. I played fascinating game of table tennis on that thing for many hours.

Is that the same Sinclair who was involved in early computers?
'X-10'.....Hmmmm wasn't that revived by BSR with the home remote thing?
Was Sinclair involved with that TOO?

"It was Hi-Fi amp - it says so on the box (LOL)"

Yep, and instructions enclosed as well.

from SOUND & VISION, issue January 2008
==================================================
"50 Greatest A/V Innovations: The most revolutionary products & technologies of the past 50 years"

- - - - - - - - - - - - -
"Digital Amplifiers:

Going back to the Infinity SWAMP 1 of the mid-1970s, digital amps have had a checkered history, but they seem finally to have turned the corner in terms of reliability and performance. Highly efficient and cool-running, they promise to play a bigger role in the future."
==================================================
SWAMP was this Infinity amplifier developed by John Ulrick and shown at CES 1974....

Not exactly. FM was proposed first by Edwin Howard Armstrong in 1935 paper: "A Method of Reducing Disturbances in Radio Signaling by a System of Frequency Modulation"

Class D amplifier was proposed first by P.J Baxandal in 1959.

First commercial class D amplifier was designed by Gordon Edge and manufactured by Clive Sinclair in 1964 under name X-10.

www.nvg.ntnu.no/sinclair/audio/gallery/x-10_boxed.jpg
www.nvg.ntnu.no/sinclair/audio/gallery/x-10_ad.jpg

It was Hi-Fi amp - it says so on the box (LOL)

"I believe the digital amp technolody has a ways to go. Linn started the idea in the mid 90's "

Hello Levchappy,

The idea of switching i.e. Pulse Width Modulation, PWD power amplifiers started at about the same time as FM radio

The first commercial hi-fidelity switching amplifier was demonstarted by John Ulrick, cou-founder of Infinity Speakers, in 1974 CES Chicago. Today he is the President of Spectron Audio.

In order to judge audio compenent you really must audition it within your system and may be for some time.

In that regard, Spectron and surely some others have 30-days money back guarantee policy.

Rest is up to you.
Good Luck

I don't think fafafion's opinions are "informed". To me informed connotes a fair amount of experience with a number of different manufacturers and/or products.

In fact they are based on a very limited number of Class D amplifiers.

Nonetheless he is entitled to his opinions based on a relatively small number of products.

Fafafion, I support your right to hold an informed opinion.

Levchappy - I think the new Wyred 4 Sound 1000 watt per channel amps would give your old Levinson some real competition.

Mapman,

I like many different amps from SETs to SS behemoth ala Burmester referance range;but i have not found a class D amp that I like,as much as i tried to.There is something strange about them,they sound quite impressive on short demo but I actually couldn't tolerate most once the 15 minutes marked has been reached.At the moment I feel that class D amp is a compromised design,it is almost like the MP3 playback,popular,yes ,but not good enought.

I currently own a FM acoustics combo in my ref system, Bryston amps in my av system and a brilliant Little known French intergrated amp Call Neodio in my library system.

I might not have audiotioned as many class D amp as Audiofeil but i think i have sampled enought of the usual suspects to be able to have an opinion about them as a group;Spectron amps seems to be the leader of the class D pack IMO

Is this thread a troll? He asks if anyone has compared, suggesting he is genuniely looking for input. Then, after only three replies, he asserts, "I believe the digital amp technolody has a ways to go. Linn started the idea in the mid 90's. Perhaps in 5 to 10 more years of product developement all the questtions of power supplies and perhaps hybrid designs will emerge." Fooey.

Bill, any you would put up against an XA.5, where size and heat (possibly $$$) are not an issue?

If you read fafafion's posting history over the last couple years, you'll note he rails on Class D amps consistently.

My money is on the bet that he's had very limited experience with some of the top Class D products introduced to the market over the last 3 years.

Even the most stubborn/stodgy/traditional solid state listeners acknowledge that Class D technology has advanced at an extremely rapid pace. Some of the stuff is scary good.

Dealer disclaimer

Faf,

What amps do you like?

Thiel and IcePower might work fine I think depending on user preference. BC ref1000m2 is not bright at all, in fact it is the least bright of any amp I have used. It is highly damped which might not be optimal for all speakers or for all personal tastes (what is?). A somewhat warmer tube pre-amp and/or digital source might be a useful ingredient to consider for many for a Thiel Icepower combo.

I think the combinations of Thiel and Digital amps is an audio disaster waiting to happen.While the Thiels are amongst the most accurate loudspeakers around,the sound tend to be bright .I have found the old Class A Mark Levinsons to be amongst the best mate for Thiels speakers.

Class D amps are not for me.They are just too mechanical and they tend to strip the music out of its soul.Class D amp is a compromised design,in a big way,and i do not think at the moment ,anyone has figured out how to solve the problems of noise it generates.It is not something that I enjoy listening for a long time,i develop listeners fatigue quite easily with classs D amp.If you must get a class D amp ,gop with Spectron.This is the only class d amp that I could listen for more than a week

This is just a comment related to your current speakers, the 3.6s need alot of power and Class A power cost alot of $$$. From a pure finacial point of view, I think you will find it easier to find good sounding Class D at a lower price, but not sure I would not go A/B if I wasn't going to use Class A SS.

Thanks, Al, I was just getting back to this and you'd covered it.

I think the first 'd' amps were years ago, before SS. So they must have been tube.

Are there class C amps?

Yes, but they are not used in audio:

http://en.wikipedia.org/wiki/Electronic_amplifier#Class_C

Also, re "Digital Amps vs Solid State Amps," I'm not sure it's clear that "solid state" has nothing to do with amplifier class. It means that the amp uses transistors, as opposed to tubes. I don't think there are any Class D amps that are NOT solid state.

Also, a true "digital amp," such as the TacT's, has a digital input and a signal path that is entirely digital until d/a conversion is performed, at a point in the signal path that is very close to the amp's output. See http://www.tactlab.com/Products/MS2150XDM/FutureofAudio.html

Regards,
-- Al

I've compared a W4S amp and integrated to a couple of Pass class A designs and would agree that it comes down to personal preference. In my case I preferred W4S, but not by a wide margin.

"first, 'd' doesn't stand for 'digital'....it was the next letter in order to be used."

Are there class C amps?

Are we talking about the "real" digital as in TacT or just transistor variation of the solid state?

first, 'd' doesn't stand for 'digital'....it was the next letter in order to be used.

My ASP / ICE moduled PSAudio integrated is fast, accurate and plays well with my panels. I wouldn't call it lean OR bloated. I may not have enough background and audition / listening experience, but this amp is totally satisfying and musical.

At pretty loud levels I have used my DVM and only see about 8 volt peaks shoot by. I'm sure by the time I hit 35v peaks, the police would be banging on the door.

What Tvad said. Either can be top notch. Personal preference in sound is a factor. Also make sure the amp is capable of driving the speakers to the max. For many less efficient designs, Cladd D and IcePower in particular will do this more cost effectively meaning you will pay a premium for Class A power so be sure of what you really need to sound not just good but the best your speakers are capable of sounding in your room.

Your tHIELS NEED 250 WATTS

Thanks all for your thoughts;

I believe the digital amp technolody has a ways to go. Linn started the idea in the mid 90's. Perhaps in 5 to 10 more years of product developement all the questtions of power supplies and perhaps hybrid designs will emerge.

I just hope Harmon International does not become the Benchmark of new product design where cost reduction in in quality and transfer of facilities to India becomes the reality.

"We have a Levinson 333.5. "

Then simplest thing of all is to buy or audition Levinson No 53 - fully class D amplifier monoblocks and compare...

Can't do that - then call to manufacturer (Madrigal Labs, I believe) and discuss why they built their newest flagship as class D amp...

Please report to us.

I own Pass's class A amps and a Red Wine Audio Signatue 30.2 (Tripath chip based). I use the RWA in the summer months in my home office and enjoy it a lot. If I didn't, I would just crank the air conditioning and keep the Pass's running. Might not be enough power for your Thiels if you like it loud.

"Out" perform the Lev's? Who knows. Probably not. Depends on what you value in your listening experience. I think you would gain some areas, lose in others.