A-B-C comparison, Chipamp, MyRef C and Anthem Integrated 225
A few months ago I got interested in the whole 'chipamp' idea. I needed a modest amplifier to power some modest room speakers and I decided to try building rather than buying, just for interests sake.
I have built a fair number of electronic projects over the years since it is related to what I do for a living. I bought a simple ChipAmp system from chipamp.com (NI3886-KIT-ST) and a Standard MyRef C(E) kit (standard components). I put these together without incident and after testing I put them in some metal cases. The only odd thing that I did was build a separate +/-24V DC power supply. I did this because I hate messing with transformers, fuses, switches and the like and so I made a single power supply that could be used with either amp. I cannot see anyway that powering the amplifiers with DC rather than AC makes them 'worse' than supplying AC. And yes, I did use big smoothing capacitors so the power supply is NOT current starved. Remember, the amplifiers own smoothing was still in place.
Either amp is adequate for my original needs, however, I wanted to compare the units with a good commercial amplifier to see how good they really were. I chose a friends system for two reasons: 1) his listening room is very discriminating 2) it was easy to get two opinions from the testing.
Details. CD player (Ah! Njoe Tjoeb) into an Anthem Integrated 225 amplifier into custom built speakers. To make the test as fair as possible, the preamp from the Anthem was used to power each power-amp in turn. The preamp also fed the sub-woofer each time. In this way, the system was IDENTICAL (wires and all) except for the power amp stage. We normalized the volume as best we could and set it so that neither of my amps was at more than 70% of max volume.
None of the amplifiers was objectionable in any way.
1) The ChipAmp sounded 'flat' and the soundstage was limited to the speakers (i.e. oh, there is sound from one speaker, oh, and there is sound from the other). It made music sound dull, like piped music in a high class elevator.
2) The MyRef sounded less flat and had some soundstage, but the music seemed to lack punch at the lower end. When the music became complex, the amplifier seemed to be 'working' to keep up (i.e. separating the music from vocals). All things considered it was not too bad and if I had paid $200 for a commercial unit of that sound quality I might not have been bitching. The snag is that all components and shipping considered, I paid only a little less to build the unit myself.
3) The Anthem had way more punch in the lower midrange (remember the subwoofer was the same in each case) and it sounded as though the bands were in the room. It was musical and effortless.
All in all, there was no comparison, the Anthem was by far the best.
I wondered if it is fair to compare the Anthem (expensive) to the home built units (cheap components, more with the hardware and box). I think it probably is for the following reason. The Anthem retails for ~$1500, so it must leave the factory costing $750. Factor in $120 to assemble, $20 for the remote, $10 for the box and manual, $80 for the transformer, $100 for the heatsinks, case and switches, $50 for the motorized volume control and $25 for the rear terminals etc. That leaves $345 for the amplifier boards, R&D and profit. I therefore suggest that the total value of the amplifier boards and components (excluding hardware) is probably not too dissimilar between my home built units and an expensive commercial unit. It appears, however, that you get something for your money.
My two cents.
1) A Lighter Note LDR-based passive attenuator.
2) A pre-amp or buffer like the Pass B1.
3) Film/foil input coupling caps like Mundorf, Sonicap, Audyn, etc.
4) More extensive use of Black Gates at several locations.
5) R-core power transformer.
6) LF01 hybrid/discrete opamp.
7) Improved shunt regulators for the opamp.
A parts optimized My_Ref has a wide and deep soundstage and don't lacks puch.
Particularly if loudspeakers have low sensitivity.
Well i did compared the Myref at my friend's house.He's using BW CM7 floorstander with
Rotel RB-1070 poweramp.Standing next to a 130W amp the Ref looked like a toy.I also was worried about the ability to drive the low impedance of the BW.
So we connected everything and hit play.The room exploded with massive soundstage
and bass depth we didn't hear with the rotel.Dynamics were also more noticeable.There was more detail right from the start.My friend said it sounds ''Too dynamic''.Well it is compared to the flat,lifeless rotel sound.
The myref was basic TP kit but with Mundorf input cap and 500VA 2x22V toroid.
For the record i use different diy amp now but i might consider building another 'upgraded' version of the Myref.
I suspect the Power Amplifier cost including the transformer and heatsinks is quite a bit less than your final $345 shown for R+D+power amp.
As an overall package of remote controlled phono+aux+pre+power, it seems like a rather nice bit of kit, giving good value for your money.
The really nice bit, it suits you and your ears.
on price and value, I think it is a very fair comparison.
When I was in the audio business (sales) we had rule of thumbs regarding product cost. It was that product cost was 1/10 of sales cost. There adding another or better component costing 10$, the sales price would increase with 100$. That's why the producing company will keep the cost as low as possible, even if the additional cost seem small to the DIY'er.
Actually, 8x to 10x is a pretty universal (and not unreasonable) overall markup from parts cost to retail cost in many industries.
- the factory usually take a 100% markup to cover assembly costs, capital outlay, and their own small margin.
- the distributor takes a 100% markup on their cost.
- the retailer gets 100% markup.
So 2 x 2 x 2 and there is your 8x. It all adds up.
Note that the "distributor" can take several different forms - a "manufacturer" may outsource much, if not all, of the actual assembly of the product (eg. most of the electronics and computer industries), in which case effectively becomes the "designer/distributor".
Did you match levels at the speaker outputs with a multimeter? If not, chances are you were hearing variations in gain structure as much as anything else.
How efficient are your speakers and what was the listening difference?
Though overall it's not a huge surprise that a very well designed and made commercial amp with scads of power can beat out a design with more limited output.
I think some people are missing my main point, others are not.
We tried the systems in a room in which music is listened to although it was a known discriminating room. We only balanced the volume by ear, but that apparent volume was set by the quietist amp (My Ref C) so that it was not 'pegged'. The music was normal listening volume. If the amp cannot perform in the room chosen at a volume level that one would want to listen to music, that is inherently a fault with the amp. If that fault is musical, that is one thing, if that is that the amp is not powerful enough that is another. We could repeat the test in a broom cupboard, but that is not how the things will be used.
My main point is that if one has a budget of $70-100 dollars for poweramp boards and components (no hardware) the audio industry has a better way of spending it than the amps I built (that is those amps I had, not the myriad amps I might have built). The snag with commercial units is that one has to buy the hardware/profit/R&D etc. as well!
Slightly off topic, I might add that my friend and I have joked about starting a new audio magazine called "Blind A/B Test". We guess it would last about 3 editions before we were blacklisted by the major manufacturers. It seems to us that above a certain audio quality, the best way to 'improve' the sound is to double the sale price.
We have also discussed using a 24bit digitizer attached to the speaker inputs and normalization and spectral methods to try and quantify what 'better' actually means for a given section of music. What do we mean by better, warmer, musical, punch, soundstage and all those other nebulous terms I (and others) use? For instance, I tend to mention soundstage when comparing components, my friend tends to discuss separation of vocals from the instruments and tonal balance. In the end though we tend to rank components in a similar manner.
ps. one other quick note. My friends Ah! packed up a while ago and so we compared his Oppo BD-93 DVD player in cd player mode to my Ah! to see how good it was. We agreed the Ah! was 'better' for all tracks EXCEPT one, where the Oppo was noticeably 'better'. That was a surprise and a valuable lesson. I repaired the Ah! for him.
Enough of my ramblings.
My 2 cents – For the past few weeks I’ve been doing comparisons on an even narrower group – various flavors of the MyRef/LM3886 family. The words and phrases I might use to describe my impressions are indeed inadequate, but in truth – all we as humans have at our disposal. I recently discovered my ability to hear the full audio spectrum has changed due to the natural ageing process. A poster on the MyRef FE project suggested a standardized set of speakers for the beta builders – which I heartily endorsed – got little to no support. When the various room characteristics are necessarily included in the equation, things get even messier.
We all could add to the list of variables for days so I won’t even try to be definitive. I’m beginning to believe that the book title from the 60s really applies to the audio world – “When you meet the Guru in the middle of the road, run the other way.” That doesn’t diminish or challenge the honesty/validity of ones stated impressions. There just doesn’t appear to be a one size fits all – either sonically or with lab tools - method in an area that in its very nature is at least half artistic.
I think the best we can do is use the terms we have to report what each of us experience/prefer (with as complete a description of limiting elements as is practical), and leave the determination of “Best” to those would enjoy calculating Pi to “Infinity and Beyond”.;) :2c:
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