Which chip amp can play sweet sound, need your experience

[Bob Richards]

I was all ready to jump into the switch mode power amp world (class D or?), when a good friend of mine who is an expert at switching power supplies mentioned that switch mode power amps are much less able to handle a part malfunction, than linear (class AB or?) amps. When just about any part in a switch mode power amp goes out, fuses or not, there's a pretty good chance the amp will blow up badly, and take the speaker with it... I've been using Hafler DH220's for 30 years because I used to fix them for a living at a sound company in San Francisco. They liked this amp because when it blew up, it did it elegantly. I never heard of one damaging the speakers when it blew. My personal experience is that they have failed 2-3 times in 30 years, and they just shut down, with minimal damage. If you need it to run on batteries, I'd still consider switch mode amps, but otherwise I'm staying with analog. The 3886 analog chip amp has been working real good for me lately.

[bcmbob]

A little of topic, but I have two DH120s , one I've owned for twenty years and am very impressed by their stability and longevity. The only problem I have had was when trying to drive a large sub in mono mode. Even then it just kept blowing fuses and everything else was safe. One has been upgraded with the kit sold on eBay and the other is just a matter of finding the time. They don't have all the high frequency quality of the newer offerings like the MyRef, but they certainly are a fine example from that period.

[redjr]

Originally Posted by bcmbob

Hi All,

Four weeks to ship and a few hours to build and I finally can hear a TDA7294. The kit is quite simple compered to the LM3886 MyRefs I'm used to. However, I am very impressed with the sound it produces. A short description would be warm, powerful (in my build), accurate and a bit relaxed. The bottom is cleaner and better defined at this "stock" level than the standard LM builds I have done, but not as powerful. I can clearly understand why so many like the character of this chip.

So let me do a few "IMHO" comparisons with the MyRefs and in particular thr Fremen Edition. What stands out the most is the difference in headroom. Below a particular volume level the TDA really shines. Anything above that shows a lot of inter-modulation distortion, harshness and strain. The last few versions of the MyRef stay clean all the way to max. I'm sure there is a lot more sophistication in the power supply technology for the MR than what this TDA build has now. It would be interesting to hear this amp with something specifically designed to power it.

Unfortunately, there are no props for the TDA's top end when compared to the MyRefs. Again, that may not be a fair comparison as the kit I built is bare bones from my understanding. The MR FE is silky, smooth, defined, airy and shimmering on all types of music. If you are familiar with it, Ravel's Daphnis & Chloe has a wide range of dynamics, instrument combinations and volume levels. As long as everything is soft to moderate the TDA sounds beautiful. It just doesn't take long/much for louder and higher range portions to get muddy and a touch blaring. Bells and chimes break through brightly during crescendos and loud finales, but just below that it gets pretty mushy. Some of that may be resolved with higher grade components on the build, which I hope to do soon.

What I hear in the dynamics in percussion and general mid-rang regesters is very impressive. Without any specific knowledge or technical background, I would suspect the TDA is simply "faster" than the LM3886. If anyone has that knowledge please pass it along. There is a real element of genuine excitement produced by this chip, particularly with wild classical tracks.

So the few hours I've owned a TDA7294 have been very enjoyable to say the least. I did run several passes of the Isotek burn-in cd that cleaned away some fuzz that was there at first power-up. This kit is capable of a BTL configuration and I am very interested in trying that as well as some of the other dual chip setups Daniel W. has suggested. At $30 for a two board kit with all the necessary do-dads, one can't go wrong and a second set won't break the budget.

Thumbs Up for the TDA7294

And....Happy Holidays Y'all.

Bob - I just completed a little 7294 build myself. You can find it here. Our modules look identical.