Carver Pro ZR1600

Sean, the best answers are to be found at the ongoing threads specifically on the Carver Pro ZR Tripath amps and modification discussion, at audiocircle.com.

The short answer to your question is that from what I am seeing, they are pretty much load-invariant. I sat and listened to a ZR1600 cruise through difficult and highly dynamic material on a pair of Maggie 1.6 which were enjoying that particular combination ALOT. Resistive loads don't seem to worry these amps at all, nor do wildly varying moduli. Further, they run merely warm to the touch. I have twice read that some are buying them for their Apogees, which kinda says it all.

Sean.

All demos of the Carver 1600 unmodded and modded were using Maggie 1.6s.

Regarding mods...After studying the schematics, and reading about Mod activity, I "popped the cover" (a simple matter of sixteen screws) and looked inside. From what I saw I don't think much is practical with a few exceptions.

The fan replacement (with a quieter model) is easy.

Bypassing all the preliminary signal processing stuff with a wire to the amp itself is practical. Connection can be made without great difficulty at a coupling capacitor location.

Input and output terminal hardware can be changed, although what's there looks OK to me.

The inputs are on a small separable assembly which occupies a shielded box about 4X3X6 inches. It connects to the mother board with a plug-in cable. There is lots of room for a completely new input/driver/processor circuit: for example a Marchand electronics crossover module would fit with room to spare. Carver plans to sell various modules to replace the standard input circuit, but they have not yet told us what will be offered.

Now the bad news. The components (including IC OP Amps) are all surface mount which I find almost impossible to remove/install. There are many. The chances of swapping out all the OP Amps without destroying some part of the circuit board is near zero IMHO. With perhaps a few exceptions, the existing circuits cannot be upgraded with better components. You would have to go completely around them with a wire or with completely new circuitry.

If audiophiles think that the ZR1600 would be better without various ProSound features, and with some better capacitors here and there, the obvious course of action is to get Carver to build an "Audiophile" version. Carver would do well to hire some of the better known Mod people as consultants to do the design. I suspect that the audiophile version would cost no more to build, as quite a lot of circuitry would be eliminated.

I have it on good advice that Carver Pro has already tapped Stan Warren as a consultant on the matter of a stripped down audiophile version, doing away with all the ancillary circuitry, such as the junk op amps and clip limiters up front, and some more useable audio jewellery on the back, with a view to producing a great amp that does more, for less, and come in 'under the radar.' This movement is currently under way. Stay tuned.

Dmason...I hear the term "junk OP Amp" used a lot lately. What does this mean?

With the exception of noise, the open loop electrical characteristics of an OP Amp have almost no effect on how it performs in a circuit, especially for a unity gain buffer application. All that is necessary is high open loop gain and slew rate sufficient to handle the highest frequency of interest. These minimal requirements on the active amplification devices is the reason why the OP Amps circuit is so widely used in all kinds of electronic equipment.