High-End Audio is all about synergy. Glad you found an amp that works well for you in your system.
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Helpful and thorough review. Thanks. Just for the record, Pandora (the free version) is 128 kbps, roughly 10% of the bit depth of CDs. IMHO, the similarities you heard across different recordings could come from your source gear or your speakers. That's not necessarily a bad thing, but I highly doubt that a bunch of recording engineers have agreed on standard microphone placement. That's hifi sci-fi talk!
I did upgrade my Pandora to 'Pandora One' for about $4/month. This increases the streaming audio to 192 kbps. I did notice an improvement in fidelity which I can best describe as "CD like performance". Point well taken on standardized mic placements by recording engineers. Your explanation is much more likely but I am enjoying the presentation.
You're probably right, many class D makers do describe their amps as having ss bass with tube midrange and treble. But Tom at CDA knew I had a tube preamp. He described the sound I should expect in combination with my existing components very well. They're not lying if it's true, taking your other components into consideration. But, as Rx8man stated "tube preamp in front of class D amps= great sound". Amen, brother. But ss preamp in front of class D amp= I'm not sure, since I never heard it, but my guess would be neutral and accurate sound.
I think, in my limited experience with class D amps, that their overall sound is non existent. They will reflect whatever is inputted into it without coloration, just as a good amp should. If you like that sound, just pair it with with a neutral and accurate preamp and sources and you're all set. If you like a little more warmth and body, use some tubes in the preamp or sources. Simple, which is unusual for high-end audio.
I know I am much more confident that I could detect subtle changes in sound of various power cords, speaker cables and ic sustitutions with this amp than I ever was with my Aragon. Class D has too many advantages not to be the wave of the future. It's affordable, accurate, efficiently powerful, low impedance capable and green, to boot.
Class D amps utilizing Hypex modules will probably be the next step in this transition away from classA, A/B, hybrid and possibly tube amps.
I agree with Rxman that an excellent tubed pre such as his TRL Dude and the correct Class D is heavenly. I use an Ayon CD5s in front of mine with great results. Hpex modules can sound good but power supply, vibration control, electronic isolation, and mass loading are also important. Don't count out other designs. Many besides Hypex are rapidly evolving in the class D area.
I just checked out your system and it looks really nice. It's simple but has excellent, well chosen components. It must be a real treat to listen to music in that beautiful room and setting. It sounds like Rxman (the pharmicist?), you and I all arrived at combining tubes with class D amplification on our own separate musical quests.
I've read about the importance of class D modules (including Hypex modules) needing isolation from vibration. I notice you have some vibration control under your Nuforce amps. Can you tell me what these are and if they're effective? I'd like to address this next since my amp is sitting on a vibration prone glass rack. I'm only using the stock footers right now for vibration control. Do you use anything to isolate your Ayon?
After reading your excellent review, I was curious enough to check out Class D Audio. Their website is amazingly bad--subliterate and almost bereft of specs, info, etc.--it's almost unfathomable that they're an American company. It may very well be that they're quality people making quality products, but they'd be well-served to hire a college kid (or at least someone with a GED) to help 'em with their presentation.
I have the Maggie on wall(4)and centre speaker in a separate HT system.
I get very good results using an Emotiva 5 channel amp that was around $350.00 new.
Granted this is HT,but I can't fault the amp's sonics nor find any noise,tech issues with it.
It's a good match for the small Maggies, and who knows maybe a bargain when using Maggies that need bi-amping.
I actually was considering the Emotiva 3-channel class A/B amp that was recently on sale for $499 on Amazon. I was going to use it to power my front L-C-R Magnepans. I didn't go this route for a few reasons:
1. The XPA-3 puts out 200 watts/ch@8 ohms and 300 watts@4 ohms. I was concerned that the amp's power supply lacked the robustness required for an amp to double wattage from an 8 to a 4 ohm load. Sacrifices may have been made to the power supply to save costs. My old Aragon 4004 put out 400 watts @ 4 ohms and the CDA that I bought puts out 220 watts@8 and doubles to 440 watts @4 ohms.
2. The Aragon amp I was replacing drove my inefficient (87db/1 watt) and low impedance (4 ohm) spkrs effortlessly with no signs of struggling. The Emotiva's 300 watts probably would have been sufficient but I was a little concerned with its ability to sound effortless and still have enough headroom.
3. The Emotiva and Aragon are both class A/B amps and I reasoned they'd probably sound similar. The class D amp, however, is a much newer topology and I thought I had a much better chance of upgrading performance through introducing a newer technology to my system than staying with the class A/B amps. Also, I had read so many great reviews and forum threads on the benefits and sound quality of class D, that I was very anxious to try it.
After having this amp in my system for about 3 weeks, I am amazed that CDA can offer this much performance for so little money. It has completely exceeded my already high expectations. I'm glad you're pleased with your Emotiva,too.
System Update in regards to the similarity in soundstage perspective, even with different recordings and artists, that I had noticed in my original post on this thread:
I replaced the 4 tubes in my preamp with fresh NOS Mullards a couple weeks ago and this seems to have solved this issue. Each recording now has a unique soundstage perspective and my system sounds even better than I originally reported.
My former set of 4 Mullards were left on 24/7 and lasted almost 6 years. Hopefully, this new set will last as long. I now know that sound stage perspective is affected by weakening tube strength levels.The perspective seems to be further away as the tubes weaken.
It was a real pleasure to read such a positive thread with minimal if no carping or cynicism. Thanks, Noble 100! I too have a tube preamp and D-class amp - EAR 868 and Bel Canto 1000M monos and couldn't be happier with the sound.
Do you think I could biamp my SP Tech Revs with the SDS 470 and Bel Cantos?
I have a theory on why so many people enjoy running tube preamps with class D amps. In general, class D amps are very neutral and add nothing to the sound; like the ideal of a straight wire with gain. This allows the tube sound qualities of the preamp to be passed on to the speakers without any hindrance from the amp. The better the preamp the better the sound.
This quality also lets you tune your system to your preference: if you want accurate and neutral, you can use a neutral and accurate preamp ( ss or ARC tubed) and, if you want a touch of warmth and bloom, just insert a tube preamp with a more traditional tube flavor (I know my VTL with nos Mullards gives me this and I think your EAR 868 probably does the same).
Biamping your spkrs using the ClassD Audio SDS 470 and your Bel Cantos 1000Ms might work out very well. I'd call ClassD and see if they'd recommend a single 470 or a pair as monoblocks. I do know, using my less powerful SDS 440, I have never heard an amp drive my Magnepan bass panels so well (with my sub temprarily turned off).
You could also experiment with the Bel Cantos on top and ClassD on the bottom and vice versa. The ClassD are very good amps but I'm not inferring that they're as good as your Bel Cantos. I have not heard the Bel Cantos but have read very good reviews and posts on them. I think ClassD still offers a 21 day trial period, although you'd pay for the return shipping to southern California.
Good luck and let us know if you try this.
"Was it a magical, temporary alignment of cosmic forces? I don't think so because it has sounded just as amazing every day since.
- Was Tom wrong and his amp does need a few days to break-in?
- Was Tom right and my virgin class D ears and brain needed some time to adjust to such a different, distortion free,noise free, clean and natural musical presentation?"
Tom was right-on.
My experience at first with Bel Canto ref1000m Class Ds was exactly like yours with your Class Ds. My "virgin Class D" ears had to break in for sure in that the sound was so totally different than prior just as you describe.
I use an arc sp16 tube pre-amp with mine.
I did get my BCs used so they may have had some time on them already when I first heard, but I do not notice that they necessarily need any warm up time from cold start to sound great.
Just curious if you were able to talk to Tom Ross at CDA before you decided to buy the SDS-470? Did you buy 1 or did you go for monoblocks? I don't think you'll be dissappointed with your choice either way and I'm looking forward to your impressions. I'm dubious, too, on whether the biamping will be a significant improvement but you never know if you don't try. Worst case, you return it or you keep it as a very nice backup amp.
Like Mapman, I don't think class D needs much time to sound good from a cold start, I just leave mine on for convenience since it consumes so little power.
Good luck, Springbok, I admire your sense of adventure. I always want to try out other class D amps in my system but never have.
Sorry, just read this and saw I owed you a response.
I was using the Aragon's one remaining good channel (200 watts@8 ohms) to drive my passive subwoofer. But I used the unused channel on my 100 watt center channel amp to drive the sub and I couldn't hear any degradation in sound. So, I just sold the amp locally on Craig's list for $50. I bought it used for $1,000 around 1992 and that big beast gave me great sound for almost 11 yrs. Sorry if you were interested in buying it.
I stated on an earlier post on this thread that my tubes lasted 6 yrs being on 24/7. But your question made me rethink this. I bought my VTL 2.5 preamp in April of 2006 and replaced the 4 stock Soviet tubes right away with 4 NOS Mullards. Then, in April of 2013, I noticed the sounstage was changing so I replaced them with a new set.
So, to answer your question, the tubes actually lasted 7 yrs being on 24/7. I never tried turning the preamp on and off daily so I have no experience concerning whether leaving them on constantly prolonged their life or not. I knew, from reading forums that many have verified that leaving the tubes on constantly does prolong their tube life. The theory is based on the idea that the tubes experience more wear during powering up and down. Leaving the preamp on avoids this and keeps the tubes at a constant voltage. I think this theory has some merit and I'm very pleased with 7 yrs between retubings.
I've never seen a tube unit burst into flames but my experience with tubes is limited to tubed preamps. I never had a tubed power amp but I would think they are more apt to do this but don't know for certain.
Hi neighbor. Very nice of you to offer the repair but in a way I'm kind of glad my old amp broke down since it caused me to try the CAD amp as a replacement. I love this amp and doubt I would have tried it if I had the Aragon recapped.
I'm only about 15 minutes away from you. I looked at your system and would love to hear it sometime. If you're ever visiting Noblesville, feel free to stop over if you'd like to listen to my little class D amp driving my magnepans. I'll send you a PM with my phone number.