Tube Noob - Setting Up MX151 Pass Through?

[Yamaki]

XLR is analog, right? So does the MX151 actually do any processing to analog inputs signals?

[RaceCarDriver]

Why are you trying to push your 2.0 though the 151? We are telling you what you need to do. And that is build your 2.0 system independent of your home theater pre/pro and send the 151 L&R through your 2.0 preamp.

[W9TR]

Originally Posted by Yamaki

XLR is analog, right? So does the MX151 actually do any processing to analog inputs signals?

Yes - every analog input to the MX 151 is digitized by A/D converters, processed, run through D/A converters and then sent to the analog outputs. There is no analog bypass. The MX 151 is truly a digital device.

[Yamaki]

Originally Posted by RaceCarDriver

Why are you trying to push your 2.0 though the 151? We are telling you what you need to do. And that is build your 2.0 system independent of your home theater pre/pro and send the 151 L&R through your 2.0 preamp.

I am not trying to be argumentative on the subject. I am simply asking questions. I understand what you are saying about how to put a pass through together. However, I am trying to find another way.

There are a few reasons why I am trying to "push" the 2.0 signals through the MX:

1. I don't have room to add a second system. I have to work within the space I have.

2. Doing a true pass through, which does appeal to me, means that the tube pre-amp will be on all all the time the MX is on regardless of the function selected at the MX151. I only want that unit to power up for music.

3. The tube pre I would like to use has no pass through trigger. That makes it difficult to put it between the MX & the amps. I can turn it on and off with the supplied remote but that doesn't work as a pass through trigger.

So what I had thought to do was use the tube pre as another source connected to the MX. My answers to the three items above were:

1. I have room for the tube pre.

2. If I use it as a source vs. using the pass through scheme then I can power it up only when I want to listen to music.

3. I can "trigger" the tube pre remotely. It comes with a remote and I can add that function to my URC programmable remote.

I checked in with Ron C. @ McIntosh and he confirmed my scheme to add the tube pre as another input to the MX151 would work. Ron stated:

"Your connection idea to have the tube preamp as a source to the MX151 will work. You can then select this as a source and put the MX151 in STEREO playback mode.

Yamaki Ed. - When that input is selected it is in STEREO mode. No need to change any of the physical connections or input naming/setup on the MX151.

The Tube preamp does not have a pass through function so it cannot sit between the MX151 and the power amps like a McIntosh integrated amp model.

Yamaki Ed. - With it used as a source it will not reside between them.

MX151 will still have the Room Perfect function in the Stereo playback mode."

Yamaki Ed. - Perfect!


I just need some additional XLR cables and I should be able to give this a go.

I appreciate all the input I've received. I knew I could count on the members here at AA!

[RaceCarDriver]

The idea of putting the Freya between the MX151 and 501 is to take priority to the 2 channel experience. Why are you wanting to add the tube preamp? What will it give you that the 151 won't? Putting the Schiit before the 151 you are adding the 151 in the chain to listen to 2ch music.

Let me put it this way, most of these 2 channel systems out there with tube pre, could they all benefit by adding a random 151 in between the preamp and the amps? No, less is more, adding more items in line adds distortion.

Most of the the home theater systems out there, could they all benefit from taking the home theater processor out of the chain (usually the weakest link) and add a quality 2ch preamp when the system is used for 2ch music? Yes.

It is possible to put the tube preamp between the 151 and 501 amps, just without the "passthru" feature that some McIntosh amps offer, its not simple plug and play.

Putting Freya before the 151 means you have 2 different ways to control volume.
Putting the 151 before the Freya still means 2 different ways to control volume.

You would need the Schiit at 0dB gain like previously mentioned. Unity gain when you have 2 preamplifiers in line with each other is the key. That is essentially what you are doing (no matter which is first) and that is what the McIntosh passthru feature solves for you automatically.

You don't need to build 2 separate systems, you don't need more space, you use the same existing gear you have today, it's how you place that gear in the path to your speakers.

Doing it your way saves on tube life, adds a home theater processor to to the 2 channel experience. It it works for you thats all that matters.