ST now makes a TDA7294S. This 'S' version can be run in parallel like the TDA7293V, but runs at a lower voltage.
In a previous thread on the TDA7293V I made mention of posting my results in a parallel-bridged amp. I've had some problems, so I'll stick my results here in case they may be of use to someone.
The initial goal was to build 2 monoblocks amplifiers using 4 heat sinks providing over 300W into 8 ohm loads and capable of driving a 2 ohm load. Previous tests using 2 devices in parallel with a +/-36V supply gave 85W/8ohms, 150W/4ohms, 230W/2ohms, and 210W/1.6ohms, so 4 in parallel bridged with 4 more should handle a 2 ohm load. On each heat sink are 4 devices (TDA7293V): one master and 3 parallel slaves. The power supply is +/-42V. Each heat sink module generated just over 100 W into 8 ohms.
I next configured each heat sink section into a bridged monoblock amp. I cannot test balanced bridged amps on my test bench and before taking them to a friend, I did some listening. (DC offset was around 1 mV in each amp.)
First, I ran both monoblocks for 3 continuous days powering my speakers (using FM radio) without mishap. That weekend, I decided to do the comparative listenings tests. What I heard was a very nicely detailed amplifier with a more forward sound than the balanced bridged STK4048XI amp (described in a different thread). The STK amp was definitely better than my Rowland model 10 amp, which is based on 6 LM3886 devices run in parallel (I since sold the Rowland, that's how good the STK amp is). Anyhow, the TDA7293V is very good but not so refined as the STK.
As I was swapping amps, which are driving a pair of Quad 988, one monoblock blew the power supply fuses. I popped some new ones in and continued listening/comparing tests. On the next swap, the fuses repeatedly blew again in that channel. The heat sinks were never hot (barely warm). Both amps are constructed the same and played for over 3 days without a problem, so it made no sense that one should break and not the other. On examination, all devices in that monoblock were destroyed (8 of them).
The only thing I could think of was that I did not use (per data sheets) a series inductor/resistor on the output. The speakers are electrostatic and may have created a terminal oscillation in the amp. This weekend, I desoldered the dead devices and re-installed new ones--all tested fine and powered up OK. I also added the inductor/resistor filter to each output section (after the resistor/capacitor filter). On connection to the speaker, fuses blew again in that same amp.
I now have both monoblocks at my friends house and I'll test them on the bench later this week. I so far have no idea what the problem is.