Take your Ncore amp and put a .1 ohm non inductive power resistor on the inside of the amp right at the binding post (in series with the post). Now the output impedance of the amp is at least .1 ohm.......so, listen to it again. Does it sound exactly like some other amp that has 80 damping factor? Not likely......there are so many factors that are probably part of the sonic equation. The measured damping factor of an amp could be realized by several things....including amount of feedback, amount of output devices, resistance of coils in series (if applicable), etc. I bet every amp with the same measured damping factor will sound different in bass quality. This game is way more complex than most people think. You can bypass the power supply with serious film caps and the bass will tighten, faster electrolytic caps in the power suppy will tighten bass....fi you damp certain things you will tighten the bass....or dry it up (over dampen)....on and on and on into infinity. Over simplification is usually done by those that do not do much actual hands on testing and A/Bing......mostly just guessing...and that includes manufactures, as well. I mean, how much time does anyone have to really research something? High end audio is mostly the blind leading the blind.....he he. In drag racing everyone knows what works......this is why dragsters all look the same, as if one person makes them all. This is because there are only 5 things to consider when making a dragster (performance wise).....horsepower, weight, drag, traction and gearing......and the performance can be measured by a clock. No one really knows why a certain piece of wire put in a certain direction would make a sonic change......and that is just one if the infinite possibilities of sonic change. This is why there are tons of amps, including class D and at every price point and they all sound different (and always will)......and sometimes the cheaper one is better. However, one thing is for sure. If you spend enough time doing serious listening tests than you can figure out a lot of ways to lower audible distortion.
High end Class D amps?
Just an observation and a question. Are there 'high end' Class D amps out there that are just as good as Class A, A/B amps? I realize that's a sensitive question to some and I mean no disrespect---but whenever I see others' hifi systems on social media, all of the amps are A or A/B. There's always Pass, McIntosh, Moon, Luxman, Accuphase, etc. Where are the Class Ds? For folks out there that want more power for less efficient speakers and can't afford the uber expensive Class As, A/Bs, what is there to choose from that's close to those brands? Thanks
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Hey Ric, nice to see you around, 20 years ago I had one of your wonderful modded Dacs. That was my point, how do you account for DF independently. My point too was more about lowish DF vs. the ridiculously high DF in most of the OEM modules, one of the keys to the bad sound of class D IMO, especially with my recent experience with the DS225. I get to this a matching issue, I listen mostly to easy to control 2 -ways. I can say this with confidence, strap 20db of NFB on my DS225, gain match a test into a typical woofer with nothing but bass lines and I am going to be able to tell you when I am listening to to DF of 167 vs a significant multiple of that, and I would not need to hear the normal deterioration of the mids and highs. I would agree, amps sound different for a variety of reasons but extremely low output impedance class D amps share a house sound that to me is similar to way too much NFB in a class A/B design. |
I brought my first proto of the mono IceEdge amps over to a guys house last year and we A/Bed it with his mono IceEdge amps from Mivera Audio. When we were listening to his amp the sound of the bass was rather "tubey" and I told him so. He said he liked that sound. However, when we put my super modded monsters in (same module with the same output stage with the same damping factor).....the bass now was way tighter and better and he remarked as such....he liked it much better with my amps. There were so many things different about the amps.....not just all my mods but different platform and feet. No one ever thought my super modded IceEdge amp was overdamped or dry sounding......espeically once I did the last 7 mods.......which is what I released and what Tweak 1 has. Not saying that it is as liquid as tubes or whatever.......just another perspective. Here is a link to a review by Herb Reichert......about his experience with the Harbeth 30.2.....He found no dry overdamped sound from the Bel-Canto amps Ncore based amps......though he did like the liquidity of tubes best. https://www.stereophile.com/content/harbeth-monitor-302-40th-anniversary-edition-loudspeaker-page-2 However, enter a zero feedback input stage Purifi amp and now Herb thinks the Bel-Canto is dry. https://www.stereophile.com/content/lkv-veros-pwr-power-amplifier-page-2 By the way, the Bel-Canto amps he has are simply stock NC500s with the stock switching supply from Hypex and an op amp for a buffer on the input....very basic...and way overpriced. You can buy a pair of mono blocks from VTV with the same configuration for $1300 delivered......Bel-Canto Ref 600s were $6K!!!!! https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-purifi-1et400a... Scroll down a little and you will see the insides of the ref 600s Both the Bel Canto and the LKV use stock super low output impedance Ncore or Purifi modules. You should hear my modded Purifi modules with air core coils and super caps oriented correctly and modded Wima bypasses.....and with all the other mods too! So many ways to change things. Never ending fun! BTW, I can modifiy Purifi modules in your LKV or whatever amp.....and do other mods, as well. |
When I first received my EVS1200, elements in my system were not worthy of it. In the last 9 months I have upgraded interconnects and speaker cables with WireWorld Eclipse Series 8, I also unplugged the 1200 from the CorePower 1800 PLC, now direct to my 20 amp dedicated line. Speakers updated from Emerald Physics KCIIs with Wire World and clarity cap upgrades to EP 3.4s with upgraded outboard XOs and WW jumpers, but I was still using my Oppo 105 with LPM and EIC mods direct to the amp so that I could flip between red book and SACD/DVDs on the fly. Redbook sounded detailed (but I now realize dry). A week ago I decided to reinstall my Audio Alchemy DDP -1 + PS 5: this was right after Peter Madnick left designing really high end kit (I forget whose), but the AA line was/is a mega-bargain. So no longer able to play SACD/DVD-As without reconnecting the 105 direct to the 1200 BUT... DAMN my jaw drops, re-listening to disks like Jennifer Nettles Playing with Fire, some of the songs are very poorly mixed (3s), now sound like (8s). Is it that the AA is warm,a better impedance match, or just that the dac does a better job playing red book? Perhaps ricrevs will chime in Obviously my 105 could benefit from additional mods (but I would need to send it out), or replaced with a better universal disc player, but in the mean time... I’m a happy camper playing red book hth |
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