I am hoping there is someone with technical expertise who can answer my question.

I have a receiver (Marantz 4400) that has pre-outs but NOT main-in.

I would like to integrate an ICBM for use with ALL source.

My question: would it be economicaly sound to have a tech mod the receiver and add a bank of main-amp in jacks? Is this feasible?

I am assuming the jacks are cheap. Any estimates as to how much labour is involved?

regards Colin

Hmmm . . . are you still under warranty? Don’t think that would be maintained if a mod was done. How ‘married’ are you to the 4400?: Would the cost of paying a qualified tech to make the mod be more or less than selling the 4400 and finding other equipment that would allow you to interpose the ICBM?

Anyway, I have not been ‘inside’ a Marantz 4400 before, but have been inside other models a few times. In general: if the pre/pro section of the receiver feeds the amplifier section with short jumper cables that can be interrupted/replaced with outs/ins, you might be in business. Of course the volume control would have to precede the feeds to the amp section, not follow. Otherwise, as you turned the volume up or down, the subwoofer(s) would not be affected.

If you make this mod, however, and the ICBM was removed from the signal path, external short jumpers would be needed in it’s place. I had an Onkyo receiver manufactured with outs/ins/jumpers so that an external device could be placed in the signal path before the amplifier section. There may be some receivers out there that would allow you to do that without a mod or going to separates – although this is an excellent opportunity to say, “I think it’s time for separates!” I’ve heard about this ‘Outlaw’ company . . .

If the pre/pro section feeds the amplifier section directly on a circuit board, it becomes quite involved to break a potentially tiny conductor on the board and try and connect wires from that point and then back again. The circuit board could be ruined, then where would you be?

bestbang4thebuck's thoughts closely match my own. I did a brief web search for the SR4400, and from what I can tell it has been on the market for just under a year, meaning that there should still be a warranty in place - I would assume that any mod of this type will void the warranty. Since my background is more mechanical than electronic, I don't know how accessible the leads to the amps might be - if ther were wires that could be intercepted pretty cleanly, that would make the mod pretty straightforward (assuming the volume control preceeds that point, but since you are using the receiver's pre-amp outputs to feed the ICBM I would assume that should be the case). Looking at some receivers' innards, though, makes me wonder if the signal path isn't on a circuit board all the way to the amp sections. If it is, the tech doing the mod would need to be very careful. The amp sections will probably have power wires to them and wires going out to the binding post - if you are savvy enough about electronics, you might pop the top off and see whether anything else is obviously wired to the amp sections or not.

The rear panel has a few potential open spots for additional jacks - there's an area near the pre-amp outputs (making the jumpers that bb4tb pointed out conveniently short in the event that the ICBM were removed), but I suspect there's a power supply hiding behind it. There's also an area on the far side near the tuner section that is probably more likely to be unobstructed.

Another thought is cost. The material cost is tiny, but the labor is likely to be higher, especially with the risk involved. Unless you've got somebody who does this sort of stuff on the side and can risk "living on the edge" a bit, you may find yourself paying as much as the replacement cost of the unit so the guy can afford to replace it if he lobotomizes it by accident and you pitch a fit (and even if you agree not to on the front end, he may not want to risk having you change your mind) - at which point an inexpensive power amp might become almost as cost effective. It would cost more (Outlaw's 7100 retails for $900, or $825 for B-stock), but it would leave the Marantz in stock condition (making it much easier to sell later if you choose to do so) and happily under warranty.

Thanks for the great input guys.

I am tending to agree with you.. perhaps buying a used 5 channel amp is my best route.

Thanks again.

Colin

I seem to be missing something. I see a 6.1 channel input section and a 6.1 channel preamp output section, plus a number of two channel inputs. What are you looking to do?

He's looking for a direct amp input - a way to connect straight to the amp channels. That would allow him to go from preamp output to the ICBM for bass management and then to the amp channels.