Class D vs Class A


Valvet 3.5 vs Nuforce ref 9 v3se.
Efficient and powerful vs power hungry and sweet consider pairing with Zen Adagios.Considering switch from Nuforce to Valvet will I miss the power?
128x128george99sa
Hi Jorge,
Thanks for the reply. Dennis's newer series have a great reputation. They will continue to improve, enjoy.
If anyone cares, I purchased Abletec ALC0300-1300, 150 Watt mono boards, they run 150 to 8 and 300 to 4. I couldn't find much on this forum except that DSonic and Marten are using his modules. I went to Italian and German forums where they were more widely discussed, most of those guys said that the 0300 module was the most neutral. It was very affordable and an easy build, so that's why I headed that way. I know that Marten and DSonic both have some flavor of the amp modules above the ones that I purchased.... ALC1000-1300. 550 OR 600 watts to 8 ohms (depending on whose specs) and 1000 watts to 4 ohms and still a very easy build. I believe DSonic uses these modules in the M3-600 mono amps and Marten removed the switching supply and ran this same module on his $45,000 mono amps.... If I get a big enough bug, I'll sell off this amp and buy those....
My amps have been playing since 9am sunday morning, when they get 2 weeks on them, I'll give them a hard listen and report. Until then, I hope the info on these modules is helpful for someone.
Tim
Hi Tim. I was referring to agreeing with you as far as hearing an improvment in the amp's sound over time. by no means do i consider myself tech-savvy. i did not build my own amp and would probably never try to. i will leave that to the pros. i have the d-sonic m3-1200s. and yes, it is still improving with time. an incredible product. i will probably never go back to tubes....probably.
Marqmike...now you're making fun of me and that hurts...however...I think somebody should make a simple rack of tubes that power up but don't actually do anything...just enough juice to make 'em look like they're working, and you could simply hide your boring little Class D amps someplace (really...very little heat so stick the damn things in a drawer or behind other stuff) and gaze at the tubes while listening...a win win, and a handy place to keep your extra tubes.
Hey Wolf. I put those lights under mine that they put under the low riders. Then on top I put an oil lamp with all those psychedelic colors. I also set mine up on bobble head doll springs. That makes the whole thing gently sway with the tunes. And man! It makes me feel fuzzy all over.
Hi Jorge,
By the same experience, I assume that you also bought modules and built your own amp. Which modules are you using?
I listened shortly last evening, I definitely had some minor improvements over the night before.
I think as long as amp designers are listening the the things they build, they should be able to make things sound great built from switching amps or blue cheese. Class D is obviously here to stay and Diavelet, Rogue, Bel Canto, and many others have been raved about...pro sound is all over it, and for me it merely means cold little boxes of juice and it bores me (except in pro audio PA stuff where I don't give a crap as long as it works and sounds clear). I think little moving meters would help...or organic looking art deco vibe design...something...ya gotta give me something...Diavelet stuff seems cool but looks like a steam roller flattened your toaster. Small amps with a switch and a little blue dot just don't warm my heart like glowing tubes packed with retro grease making jazz piano sound like it's right there...why would I want something else?
Tim: I'm having the same experience with mine. mine probably has about 20 hours and man! what a difference 20 hours have made! its fun reading other owners' experiences as their amps evolve. can't wait to hear what mine does.
jorge
I heard many class D amps. Many were average and poor. I also heard many class A amps. Often they were great.
Well, it took a little longer than I suspected, but my Class D amp is up and running.... I don't want to over elaborate right now, the amp has only had a signal on it for 12 ours, but I have to say, I've sat in front of a bunch of amps in my 35 years of being an audiophile. I can't tell yet to just how good this amp is, but I can tell you that class D is no joke. My experience is that you get some improvement after 40 or 50 hours and then again around 300 hours of playing. I'll check back soon,
Tim
Wow. If you must go digital, there are other class d amps that I would get in a heartbeat before the Nuforce. I'm a former Nuforce owner and couldn't get rid of them fast enough. IMO, the Wyred amps are warmer, more transparent, organic and just plain easier to listen to than the Nuforce amps. In my experience, there is nothing "musical" about them at all. There are so many more options within your budget. Sell the amps, and one power cord and get a Wyred or another variation of class d (if you must). I don't always agree with Srajan's opinion on equipment but frankly the Job 225 stereo amp is truly a wonderful amp and a steal at it's price. While input impedance is average, its input voltage sensitivity is a ridiculously low .75 volts and gain is absurdly high 35 db. If you don't have a tube preamp (they tend to have high Zout), then consider the Job and pocket some cash if you can. This post has absolutely nothing to do with the fact that I'm selling my Wyred4Sound STI-500 integrated.
The only thing that I can see to do to the Albetec boards is to do some bypassing on the power supply, replace the input caps with the best that I can make fit and solder all leads directly to the boards (using Litz).... any other suggestions are appreciated.
Tim
Yes. Definitely keep us posted Timlub. I have a rebuilt restored Sumo Nine by Mike Bettinger and love its sound in my systems. I am curious to know your results as you have a modified Sumo Nine as well vs Class D type amps. I've listened to Class D amps but not the most expensive stuff and I've always preferred the Class A type amp in my systems.
I have been using a very nicely modified Sumo Nine for the past several years. It is pure Class A factory rated @ 60 to 8 & 120 to 4. Actual after mods it does 90 to 8 & 165 to 4 never leaving Class A. It is driving 4 ohm speakers. I use a Coda CL Preamp. Yesterday I received Abletec Modules, I need to do some testing and am planning to mod those best that I can, so it will be a month or so, but if there is an interest, I'll report the results.
Tim
I'm getting incredible musicality with a TRL 6SN7 preamp in front of NuForce Ref9 V2SE.
I am very happy now with the Nuforce Hovland combo in front of the Adagios.Eventually I'd like to get Crescendos so my amps should still drive them without a problem.I am in the process of setting up an analog rig,I just picked up a Ultimate upgraded Thorens TD126 mk11 with 103R Denon.That should hold me til I get the big Zens.Will keep listening and posting.
I have Zen Adagio's, powered by Channel Islands D-200 Class D amps, Jolida fusion tube pre-amp on top. I find combo wonderful. I like the dynamic punch of class D amps and combined with the tube pre-amp (beautiful mids) sounds great to me
Jdec, on the contrary, pardon my less than qualified attempt at explaining star grounding.

Essentially, everything gets plugged into a single power source, such as a power strip, sharing a single ground.

As switching amplifier technology progresses we are seeing less and less of the RF and EMI issues that some early designs produced which seemed to pollute the AC line.

If you are using different legs (breakers) of an AC system to power a system simply try using only one leg.
Vicdamone,

excuse my ignorance but, what do you mean with "star grounding"? how do you "experiment" it with switching amplifiers?

Thanks.
My experience with driving NuForce SEs with an updated Audible Illusions Modulus 3A was that the preamplifier simply added far too much of it's own character and noise. Amp, preamp compatibility is most likely at the root of my dissatisfaction so this is not a blanket statement against tube preamps.

Understandably, this could be very desirable. When I substituted the AI with my current Reflection Audio Quantum the presentation opened up dramatically. The NuForce amplifiers are extremely quiet when driven by a battery powered preamplifier.

Also, I suggest experimenting with star grounding when using switching amplifiers.
I understand your rationale but I suspect if given a listen in your system you'd have loved the Valvet.
Regards,
Thanks for the response guys ,I've decided to stick with the Nuforce.Why?Not for the power my room is small 12X14x9 but the sound should marry better with a new Hp 100 pre-amp adding even more sweetness into this mix might be over the top so lets keep some of the best low end control in the business,after all until your into megabuck equipment this hobby is all about striking a pleasant balance is it not?Those chrome fronted Valvets would have looked beautiful under the Hovland but all that heat and power consumption might not end up so practical either.Your input as always was weighed thanks again!
Nuforce with tubed pre can be best of both worlds. Besides power pay attention to bass control and definition, transparency and liquidity
Just looking at the specifications of both speaker and amplifier/s, this pairing may be powering the speakers on their low side. That's not to say it wouldn't be a good match but an in home audition would be a priority for me.

What I liked about my SE's were their ability to power my Eidolons at realistic listening levels without a hint of congestion or fatigue. By comparison I found some linear solid state amplifiers that had slight issues when pushed.

I evolved from the SE's to a pair of Hypex nCore 400 kits which are an interesting refinement in presentation yet still in the highly transparent switching amplifier theme. The nCores are now in my studio and I've gone back to big tube amplifiers in the main system.
I am in the class A camp,solid state and tubes!,the only class d amps I have heard were for subs and home theatre systems,so I really do not know much about class d amps,I would like to know more from this thread!happy listening!
George,
That's a very interesting comparison of two different topologies.For my
taste, I'd go with the Valvet(simple and straight forward class A circuit with
good part quality) but have no idea what your taste or priorities
are.What is the speaker's sensitivity and efficiency,type of music and how
loud do you listen?Let us know your findings.
+1 Jult52 sums it up pretty well. Call me an old-fashioned Catholic. ;)

Sorry George99sa, only you can determine if you will miss the power or not. We don't know how large your room is, how loud you like to listen, etc.
My speakers are about the same measurements as yours, my amp is 100 wpc Class A and there is plenty of gain for my listening levels in my 24 X 15 X 8.5 listening room. In fact, I have been considering trying a 30 wpc 300B tube amp. I believe 30 wpc will be plenty for me.

Remember, power is on a logrithmic scale, so a 500 wpc amp would only play 10 dB louder than a 50 wpc amp.
Protestantism vs Catholicism. I predict Class D will nail 95 These to the wall and Class A will react with a vicious inquisition.