new amp

[steelie]

Hi all,

I picked up a new amp today!!! It's a McIntosh MC202 and I couldn't be happier with its performance (other than hooking it up to a decent pre-amp)

It's absolutely stunning how deep those RF7s will go. I never felt my 7s punch me in my chest before. That's what they do now. The imaging ... well, it was good before but now it's just so much more solidly placed. Anyway, I don't need to sing any praises on this machine. It's all been said.

Now for the bad part.

I picked up a hum in my system that I never knew I had before. I've isolated it far away from the amp so I know it's not the McIntosh.

I can run the amp with everything else turned off and unplugged ... no hum.

I run RCA from the receiver's pre-outs to amp ... no hum.

I run RCA from CD to receiver, play music beautifully ... no hum.

Cutting to the chase, I can hook up every component fine. The hum appears when I hook up the universal DVD player's six analog outputs to the receiver AND the three component video cables to the TV. Both have to be connected for the hum to appear. If I disconnect either one, then I get no hum.

I tried to separate them as much as I could and I even swapped cables, no change.

I'm truly bummed because if I leave the universal player hooked up only through the fiberoptic cable then I can't listen to SACDs.

I was hoping to write to you guys asking for suggestions on a good 2-channel pre-amp to pair up with the McIntosh. I was looking at the C40 and C42. Maybe this will speed up my next upgrade but is there any solution other than leaving things unhooked until then? It could be a while before I find the $$$ for my next toy.

Thanks for the help.

[dougdrake]

Sounds like a ground loop. A fast way to find out is to put a cheater plug (3 prong to 2 prong adapter) on whatever device has the 3-prong plug and see if it goes away. If so, then you either get to chase down the ground loop (possibly coming from your TV connection - the cable, perhaps?) or decide to live with the cheater plug and its attendant risks.

[steelie]

Only thing with a three-prong outlet is the amp and that has its own dedicated isolated ground circuit right now.

The receiver, TV and DVD player - all two-prong devices - are connected to a separated, dedicated isolated ground circuit through a power bar.

[D-MAN]

I have a related problem with a Mc300 amp.

Use a 2-prong adapter on the amp, and you're problem goes away...

DM

[steelie]

Well, right now I've got it working with no hum but that's done by disconnecting the analog external input cables from the DVD and receiver.

Jeez, I love this thing.

Eventually, I'm thinking this rig is going to be hooked up only to a CD player, a turntable and a tape deck. No more video interference, which will be just fine.

So .... C40? C42? Any opinions on either of these two models?

Any suggestions on a great 2-channel pre-amp would be appreciated.

Thanks again

[D-MAN]

I've got a C40 and it's great although I never use the tape out stuff or the equalizer or the compressor/expandor, etc.

But even with all of that, it's still one fine sounding unit! The lesser model with less stuff on it might be a better choice, I don't know. I'm certainly happy with mine.

As an experiment, I A/B it agains a direct connect from cd to amp. The C40 came so close to a direct connect, that it's a wash IMO (I needed the volume control). By far the best and most quiet preamp that I have ever owned.

DM

[steelie]

Alright dougdrake,

you called it a mile away. It was the cable, or rather, the sattelite that was causing the hum.

But I'm kinda confused on what that's telling me exactly.

What does that mean in terms of the amp?

Was the hum absent before because nothing hooked up had a three prong connector? Why? I'm not getting it. The gear is hooked up to separate circuits.

Should I replace the sattelite cable or try to move things around so they're not so close to each other? That hasn't seemed to help so far.

I'm just kinda stumped on this. Everything is on a separate circuit so how is the cable's hum even coming close to the amp? Is it traveling the wrong way on the component video cables and then to the universal player's analog outputs, through the reciever and to the pre-outs?

What a trip.

Since we're talking different circuits here, I just can't see how the power cables can be affecting each other.

Anyway, in the absence of a two prong connector for the MC202, what can I do to eliminate the hum?

If I hook the amp up direclty to the outlet, the hum is unbearable. If I hook the amp up to my PS Audio Ultimate Outlet, the hum is noticeable only up close, with no source compoonent on.

I suppose that's an easy way out but it's not the best solution.

I'd like to do this one right. Any more help out there?

Thanks again.

[dougdrake]

Your equipment is all connected and grounded to each other via the jumper cables - the outer shield is a ground connection. I'm not real good on understanding the "why's" of ground loops, but some folks have success in eliminating them by connecting all components to the SAME circuit, rather than different ones.

Here's more than you ever want to know about this. Maybe it will help:

http://www.smr-home-theatre.org/Ground-Loops/

[steelie]

S Video cable from sattelite receiver to TV ... should have got there faster but the trick is done.

[Q-Man]

A dedicated single circuit is better then separate circuits.

I use quad shielded coax cable for my S-Viveo cable. It takes two coax cables to do this, but they sell spliters for it.

It is a nice amp isn't it?

[steelie]

Nice is understating it but YEAH ... it's a damn nice amp. I'm absolutely hypnotized by music and if that doesn't do it, I can stare at those big blue eyes forever.

You're up the three of these, right Q-man?

I'd follow you on that route, then get a C45 or C46 and run everything through there, but I just can't see myself getting to all those amps before buying a good pre-amp. I think its going to be 2-channel for me. Actually, my original idea was to bridge an MC162 to get 200 watts to the center and getting an MC150 for the surrounds but that's too much time and dinero for me. It took months for me to find this amp and actually get to it in time to buy it. Lots of disappointment on the way.

Now I can say it was well worth it.

[Q-Man]

The MC162 wouldn't sound as good as the MC202. You need the autoformers like the 202, 252,& 352.

No I only have two 202's and one MC206 (six channel amp). I want to replace the 206 with three more 202's one day. I'm shopping for an AV/processor now. I sold my Yamaha RX-3000 that I was using as a pre. I tried to save money and bought the Outlaw 950 AV/processor, but I didn't like the way it sounded and sent it back. Now I may try the Anthem AVM 30.

[steelie]

The MC206 doesn't have the autoformers either, right? I remember giving some serious consideration to that model and the only thing that steered me away was the fact that I really wanted the best stereo amp I could afford. Multichannel is great but not as important for me.

Aside from the fact that the 206 has less power, how would you describe the sound difference the autoformers make?

Just as an aside, since you're no longer using the Yamaha what did you do with the front effects speakers? Are you able to use additional outputs from the 206 to increase the power to other areas of your system? (Not sure how you'd do that but I always wonder)

Thanks

[D-MAN]

About autoformers, I remember back in the 70's that autoformers were considered BAD because they introduced notch distortion to the output amongst other things.

How times have changed...

DM

[Q-Man]

Your right the 206 doesn't use autoformers and is rated at 200 watts per channel at 4 ohms and 120 watts per channel at 8 ohms.

The 202 is 200 watts at 1,2,4,or 8 ohms.

The 206 was or is an improvement in sound over the Yamaha

RX-V3000, but it's not night and day. I would say the 206 is cleaner, more open, or adds more depth to the sound. It's adds more space between the sounds and has tighter bass and more of it.

I used the 206 for six channels, but the Yamaha still powered four of them. I have a total of ten channels. The Yamaha powered the front effects and an extra pair of surrounds. The 206 is probably nicer sounding then any receiver and has what I call the McIntosh sound. This sound is characterized as a warm midrange which is said to be tube like.

I now wanted to see what kind of an improvement ,if any, I would git by going to a pre-pro. To do this I first needed to get four more channels of amplification. That's when and why I got the two 202's stereo amps. I was shocked when I did an A/B comparison between the 202 and 206. This was one of those night and day changes. Powerfull tight bass, much more then the 206. The midrange and highs are crystal clear. The mids are as warm as melting butter, yet still sizzle.

Front effects you ask!

I found a way to still have front effect channels like the Yamaha. I can run the main channel balanced outputs to one of the 202 power amps. Then I can run the main channel un-balanced outputs to a reverb amp for processing and then on to two channels of the 206 amp. You can also use a "Y" splitter from the main outs if you don't have balanced and un-balanced outputs.

I bought three reverbs and narrowed it down to two. When I figure out which one of the remaining two that I like best I'll put the other two on ebay. The front effects sound better doing this then the way they did using the Yamaha. I stumbled onto something good here. I can adjust the sound of them more and they are now full range.

If I could only find an AV/Processor I will be back in business.

[steelie]

Wow. That is one heck of a setup. Ten channels, is that 9.l? I can't think of where you'd place the extra unless you run three surround backs.

I do love my 202 and for me, it was obvious night and day since I went from a Denon receiver amp up to the McIntosh. I still have issues with the Denon that I REALLY don't like but that's another story.

The 202 can only do so much to improve my sound and that's partly why I'm actively looking for a used stereo pre-amp ... likely the C40, C41 or C42 unless I get some other ideas first. (I don't think I have the patience to find two more 202s before getting a multichannel pre-amp so for now, this will be a 2-channel system)

But, if you ever get the inkling to upgrade to the 252 or higher, send me a PM. I'd be glad to keep buying the 202, over and over again.

EDIT: My ground loop hum is back. The S video was no real solution at all. I thought it was working but really, it just reduced the volume even further. I have everything connected to one circuit now and the amp connected to a PS Audio UO. That really cuts down on the hum but not totally. So ... my solution for now is to keep the analog cables from the universal player unhooked. I haven't tried the cheater plug solution. Will that limit the amp in any way or is it simply a safety issue? I guess 2-channel will solve that problem too.

Hmmmm

[Q-Man]

Try the cheater plugs. All my equipment with 3-prong plugs have 2-prong adapters on them. Then they are pluged into a PS-Audio 4.7 power director. The biggest improvement comes from the cheater plugs. I'm dead guiet now. You can also try one of those ground breakers that you put on your TV cable line.