C47 Passthru Function
 

I made some changes so my system was down for a while. When I set everything back up I had problems with the Passthru function on my Mcintosh C47 which is connected to a Marantz SR7012. After working on this for most of the morning I finally got it to work. Passthru came on amplifiers came on but no audio. Finally got it to work by setting the Output 1 to unswitched. But now if I turn on the AVR first everything comes on but no audio. If I turn the C47 on first and then the AVR it works. It seams the Output 1 doesn't come on when I turn the AVR first. Don't remember if this is how it worked before or not. :puzzled-2:

I’ve got a SR7012 connected to a C2700. I use a harmony remote but I’m pretty sure anytime the av receiver come on the c2700 is activated to passthru. I can’t check it at the moment because I’m in our condo in Maine.

For some reason Output 1 doesn't activate when the AVR is powered on first. Trying to find out if there is a setting to correct this.

I believe passthru is the same for the C52 & C47. See if this helps

Passthru

When the C52 is part of a Home Theater or Mul*tichannel Audio System the Right and Left Front Channels from an Audio/Video Processor or Surround Decoder can “Passthru” the C52 and onto its associ*ated Power Amplifier(s). The Setup Mode allows selection of the specified C52 Input to be used for the Right and Left Front Channels. In the example below, the Right and Left Front Channels from the Audio/ Video Processsor will be connected to the BALanced 3 Input Connectors on the C52. Refer to pages 8 and 9 for additional connection information.

Note: The Phono and Digital Inputs are not assign*able as a Passthru Input.
Press and hold in the INPUT Control to enter the SETUP MODE. Refer to figure 2 on page 13.
Rotate the INPUT Control until “SETUP: Passth*ru, Off” appears on the Information Display. Refer to figure 39.

Rotate the VOLUME (ADJUST) Control to select
“BAL 3” Input. Refer to figure 40.

Figure 40
Exit the SETUP Mode by several presses of the INPUT Control

I used it before I did some remodeling and thought that all I had to do was plug everything back in. But when it didn't work (probably didn't notice there was no output light on) I did a factory reset and started the setup from scratch. After following those instructions it still didn't work until I set Output 1 to UNSWITCHED and it only works when the C47 pre is turned on first. When I turn the AVR on first everything turns on (amps, preamp) but no audio since the Output doesn't activate. If I have the preamp on first the Output is already active so when I turn on the AVR it works.

Can you use the Main output instead of Output 1 ?

Care to explain. I have tried setting Trigger1 to main if that is what you mean and it didn't help.

This will be a ‘nevermind’.

I see that the C47 has two outputs and both are switched. All the McIntosh preamps I have owned had a ‘main’ output that was always on. Thus the thought to use the main output.
Tom

I've been trying different settings and for some reason it now works when I put Output 1 back on SWITCHED :puzzled-2:

UPDATE: I heard from McIntosh support and apparently this is a know issue and they have an firmware update to fix the issue. Just in case anyone else is experiencing this problem.