Sean...About the Carver Pro line of products being unrelated to Bob..yes I heard that. For what it's worth, the amps have a "made in USA" label on them, which makes them sound just a little bit better. This Phoenix Gold outfit confuses the hell out of me, it seems like some kind of umbrella company for several brands. I have some interconnects by them which appear to have all the features of other brands except the price.
6X600 wpc @4ohms...$2500. Some other manufacturers have a lot of catching up to do. |
Dmason...The Carver is not my first adventure into the ProSound waters. I have a QSC amp which I bought for its capability with 2 ohm load, driving subwoofers. In the SW application I reasoned that superlow distortion and the like is not critical. But, I have run this amp full range into MG1.6 and Dynaudio speakers, and it sounds embarrasingly good. Checking the specs, I find that at low power level, typical of home audio, distortion spec is 0.06. Not too shabby!
Maybe in the old days ProSound meant a Bogen PA system, with rotten sound for music. Times have changed. |
Dmason...One mod that I heard described pretty much amounted to bypassing the input signal processing (Level controls, high pass filters, clipping management, amplification configuration, etc) replacing the fan with one that is more quiet, and changing the input and output connectors to a different type.
My thoughts about this are that the fan is a good idea, and the rest of it can wait until I get things sorted out. The input and output terminals are just fine IMHO. I use bare wire clamped into the terminals for output, and converting to RCA plug input is a matter of two gold plated adapter plugs for a grand total of $3.60. At the input there is a 0.47 mfd capacitor in the signal path that might be upgradeable, and running a straight wire around the input circuitry is like chicken soup. However the various features of the circuit are individually bypassable with switches, so we really are talking about the difference between circuit board runs and switch contacts and unbroken copper wire (and that discussion could become long and heated). I don't think that anyone knows enough about the digital power amplification circuitry to justify messing with it. In summary, I think that this amp does not particularly lend itself to useful mods, and I would need to have a detailed description of the mod before I would go for it. The fan change, capacitor, and bypass wire are simple enough to do oneself.
If there is someone out there who can shed more light on the mod details, please chime in. |
Kool39...A "full review" of the amp is something that I am really not qualified to do. Others have evaluated and reported on this amp, and their reviews are the reason I bought it. I could write some glowing praise using all the usual words (tranparency, punchy bass, etc) but these are all subjective things that you really need to hear for yourself. I therefore condense my comments to the statement that "this amp is something special, particularly in view of its cost, and it is worth you while to try it".
If I had to put my finger on one characteristic that is better than my Adcom 5503 (350 wpc) it is that in an orchestral recording, individual instruments of the orchestra seem to be separately distinguishable. (Subjective as hell!). I am unsure of how much credit should go to the amp's sonics, as opposed to the Magneplanar speakers. It could be that the more powerful amp is simply getting more out of the Maggies. Different speakers could give different results. |
Gmood1...Yes those reviews and others like them is what got me all excited. The comment "uncanny ability to unbundle instruments" is exactly what I hear.
Sean...Undoubtedly multiple contacts on a switch or relay is a good idea. Sliprings that we use in the gimbal system of the missile guidance system that I work on have (for each of the many circuits) two brushes each with spherical tips riding in a v groove, so that there are four points of contact. But these are sliding contacts.
The sound of switches (unless the contacts are dirty, and resistance is measurable) is something that I personally don't worry about, but let's not get into that one. As to solder, some day when I have nothing else to do I will use about 20 feet of roll solder as speaker wires and see how it sounds. If 20 feet of solder isn't a total disaster, I will conclude that a few millimeters is OK. |
Kana813...Neutric Speakon connectors certainly look like excellent devices, but I do not need to frequently connect and disconnect speakers, so I think that bare wire clamped into the binding posts is probably best. (Least number of contacts, per sean's rule). |
sean...Get with the program!! :) |
With arrival of the third ZR 1600 I now have the "final" setup with each ZR 1600 driving a MG1.6 with one channel, and a subwoofer system with the other.
It's true that Maggies just get better and better as you increase the power amp, and they ain't bad even with 60 watts. They say that the Carver ZR1600, unlike many conventional amps, gets better when bridged. Hmmm...1600 watts into four ohms. I better not try it. |
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. |
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. |
sean...Yes, noise is a significant characteristic of an Op amp. However, the OP Amp circuit topography is such that an IC which is "junky" in other ways, like distortion (thermal or otherewise) gain tolerance, slew rate tolerance (as long as it is above some value) etc, will work just as well as an OP Amp that is perfect in these regards. Op amps can only be evaluated in context of the performance of the overall circuit in which they are used. They should never be thought of as a linear amp. |
lkosova@yahoo.com...Trust the lawyers to screw things up!
sean...The circuit, which includes the OP Amp is linear, even if the open loop performance of the device is "junky".
An analogy might be the output transformer of a tube amp, where, when tested as a component, out of its circuit, its bandwidth and frequency response is "junky". However, put it in a circuit with appropriate feedback (usually derived from extra windings on the transformer) and the resulting performance can be superb.
Certainly there are different levels of OP amp quality, Noise being the parameter of greatest interest. Also, the type of circuit that the device implements affects the degree to which the "junky" characteristics are suppressed by the circuit. For a unity gain buffer amp, (which is what the OP Amps in the Carver ZR1600 mostly are) quality OP Amps would be of minimal value. (Resistors and Capacitors should be the principal concern). When you try to implement a phono preamp, with high gain and heavy RIAA equalization, it's a different story. Even the "best" Op Amps are not so hot in this application, which has given Op Amps their bad reputation.
I guess this is another case of a myth (Op Amps are always evil) that is based on a kernel of truth. |
sean...I think I will stick with 600X6 for a while (for the fronts). I also have biamped rears (misc amps) to annoy the neighbors.
I find curious the way that speakers, Maggies in particular, respond to very high powered amps. I know that the actual power level is nowhere near the ratings of the amps, but something about them is very helpful...Ed |
I was wishing for the Spectron amp, but the price tag for 6 channels is a bit steep. Three stereo Carvers cost about 1/3 of the cost of the 6-channel Spectron, and having the amps in three units is more convenient for me.
The Carver and the Bel Canto (I have heard) use a basic digital amplification control module made by an outfit called TriPath. (You can get complete technical details from their web site. The Carver amp schematic is also available on the Carver Pro website). The TriPath amplifier has some theoretical advantages over the Spectron design, but these don't necessarily translate into audio quality.
I agree with many others who have tried the Carver that it sounds great. The other digital amps may also sound great, but the Carver is the one that you can afford to try. |
