Jeff Rowland

Thanks, Almarg, for confirming what I was seeing. What prompted me to go to the data sheet was the power output inconsistency I read @ the Rowland website, your post & my initial quick perusal of the S-PRO2 data sheet.

agree that the 30A is max implying RMS = 21.2A, as you wrote. Then, in bridged mode if each amp in the stereo module is outputting 13.2Arms that total is 26.4Arms which is greater than the 21.1Arms that the integrated SMPS is capable of supplying!! So, is the amp really able to output 700W into 4 or 8 Ohms in bridged mode (as in the spec sheet)?
In bridged mode, the 13.2Arms must be the total bridged-mode current for *both* amps in the stereo module (700W, 4 Ohm load).
while in Stereo mode the current must be 5.5Arms from each amp (8 Ohm load, 245W/ch).
As you pull the amp out of bridged mode the speaker load doubles to 8 Ohms & the power output drops to 245W/ch.
Or, am i thinking of this incorrectly??

I agree - all these numbers don't jive with each other further adding to the confusion of what the amp is really capable of power output-wise. in such a case, I'd be inclined to take a slightly conservative path & side with the class-D amp module manuf...

03-10-15: Bombaywalla
Then, in bridged mode if each amp in the stereo module is outputting 13.2Arms that total is 26.4Arms which is greater than the 21.1Arms that the integrated SMPS is capable of supplying!! So, is the amp really able to output 700W into 4 or 8 Ohms in bridged mode (as in the spec sheet)?

I'm not 100% certain of this, but I believe the way to look at it is that since in bridged mode the two channels are operated out of phase with each other, and the load is connected between the two + output terminals of the amp, from the perspective of the power supply it is supplying 13.2 amps, not 26.4 amps, when supplying max rated power into 4 ohms in bridged mode.

In other words, the 13.2 amps that is flowing through one channel does not add to the 13.2 amps that is flowing through the other channel, because it is the same 13.2 amps!

While if both channels are driven in stereo mode the power supply would of course have to supply enough current to support the total amount of power being drawn from both channels. Note, though, that all of the output power ratings indicated in the module datasheet for stereo mode are based on only one channel being driven.

... all these numbers don't jive with each other further adding to the confusion of what the amp is really capable of power output-wise. in such a case, I'd be inclined to take a slightly conservative path & side with the class-D amp module manuf...

Agreed (except that strictly speaking I believe it would be "jibe," not "jive" :-)). Perhaps all that can be said with certainty is that this is a very powerful amp, but one which should not be expected to perform well when used in bridged mode with speakers having impedances which drop below 4 ohms at frequencies for which lots of power is likely to be required.

Best regards,
-- Al

Almarg,
I just want to reiterate how much you have helped. Simply moving bass traps solved my problem, that many people would simply blame on the electronics. You have indeed saved me from spending money on another JR 525 or a new preamp. I'm still listening to other DACs to see what improvements can be gained over my PS Audio Directstream DAC. Although I like bass, my priorities have always been what I consider a "natural sound", great spacing, and an open soundstage with good depth.

Glad I was able to help, Ricred, and thanks for the very nice acknowledgment. Enjoy!

Best regards,
-- Al

I moved the bass traps out of the room, put them stacked back in the corner, put two behind the listening position, with two in the front corners and after a whole day of listening decided that one in each front corner and two behind the listening position was best. No bass suckout, but more air and better imaging with two in the front(not stacked) and two in the rear.

Almarg- what is your thought on subs? I called PS Audio and they said I could control a sub through my Directstream DAC's RCA inputs, because my amp is connected via balanced cables. However their own literature says, not to connected both the RCA and balanced cables simultaneously. I want to try a JL F112, but don't want to purchase a preamp.