Wondering if someone can help me...I have a McIntosh MC2105 amp, C28 pre-amp and MR78 Tuner, Bose ser IV EQ, with a set of 901's...I feel like everything is hooked up right but maybe I've made a mistake somewhere....when I turn the knobs on the C28 they're not doing anything...the only way to change the vol level is through the left and right gains...any advice?
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McIntosh MC2105 and C28 with MR78 Tuner
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Blue Shadow
Waiting for Vintage Gear from this century
Tuner into C28 Tuner input
EQ Amplifier Connections: C28 Tape Output 1 to EQ Amp Connections Input
EQ Amplifier Connections: C28 Tape 1 High Level Input to EQ Amp connections Output
C28 Main Outputs, use L and R top row or bottom row, your choice. To the 2105 inputs.
Set the Amp gain levels to halfway to start. Then turn on the tuner, eq plugged into a switched outlet on the C28 and turn on C28. 11.7 seconds later turn on the 2105
Bose hooked up to the amplifier, speakers ON on the amp
C28 volume all the way down
Select Tuner input
Select Tape Monitor 1
slowly increase volume on the C28 and see if you get some sound.
Set the 2105 gain controls so that the volume is very loud with C28 at 1:00 or a bit more and this will give some control at lower volume levels.
How did you have it hooked up?
EQ Amplifier Connections: C28 Tape Output 1 to EQ Amp Connections Input
EQ Amplifier Connections: C28 Tape 1 High Level Input to EQ Amp connections Output
C28 Main Outputs, use L and R top row or bottom row, your choice. To the 2105 inputs.
Set the Amp gain levels to halfway to start. Then turn on the tuner, eq plugged into a switched outlet on the C28 and turn on C28. 11.7 seconds later turn on the 2105
Bose hooked up to the amplifier, speakers ON on the amp
C28 volume all the way down
Select Tuner input
Select Tape Monitor 1
slowly increase volume on the C28 and see if you get some sound.
Set the 2105 gain controls so that the volume is very loud with C28 at 1:00 or a bit more and this will give some control at lower volume levels.
How did you have it hooked up?
Since you mention volume,here's a point that may be of interest in case your unaware.
If you want to use the pre amp to control volume of the tuner plug the interconnects into the rca jacks on the tuner labeled "fixed". If you want to control volume of the tuner using the volume knob on the tuner,plug the interconnects into the rca jacks labeled "front panel".
If you want to use the pre amp to control volume of the tuner plug the interconnects into the rca jacks on the tuner labeled "fixed". If you want to control volume of the tuner using the volume knob on the tuner,plug the interconnects into the rca jacks labeled "front panel".
Thank you. Think I want the C28 to control all volume...
I disconnected the EQ completely from C28 and 2105 and followed your recs so not sure where the issue lied....
twiiii
Lunatic Member
I had almost the same set up using 2100's in stead of a 2105 to bi-amp my speakers using a Bozak electronic crossover. You need a MC 2300 to really make those 901's bark. Please use someone else's program equalizer for a smoother more accurate and pleasing sound. We sold a lot of 901's and the Bose EQ was a week link for sure. Don't let your 2105 clip as they will damage the Bose drivers prematurely.
Any recommendations on the EQ advice?
damacman
Resident Psycho
Whichever tape loop you have the Bose EQ connected to must be engaged for the EQ to affect the program.
Blue Shadow
Waiting for Vintage Gear from this century
Bose 901s sound like schitt without the EQ. All midrange no highs or lows
Do the speakers work without the eq and not work with the eq?
Do the speakers work without the eq and not work with the eq?
Not sure if anyone on this will catch this old thread but I'll try...The help y'all gave me back in 2024 worked great...no issues since then...About 2 weeks ago I turned the system on and nothing...For the record:
I have an MR78 and a DAC (runs from a laptop tied to my NAS to the DAC and DAC to C28 High Level Input) hooked into the C28 High Level Inputs
It was the DAC I assumed failed so I picked up a new one. Same issue.
I double checked all buttons on front of C28 and all where they should be, nothing changed.
So now I'm assuming C28 or MC2105
I tested the C28 by running the MR 78 straight to the AMP and got sound
Next tested DAC same way but I got nothing...Not sure what that meant as I assumed it would play (turned Gains full little minute bit of static would come and go)
Next tested the Phono by taking it straight in and if I turn the gains full I hear music (assuming not much volume because I have Bose 901's that are hooked into the Bose EQ???)
So is there another test I should do? I kind of assume it's in the C28....How do you test the MC2105 if needed since the speakers can't get wired into the C28
Any recs are greatly appreciated... Thx and have a Blessed Day!
I have an MR78 and a DAC (runs from a laptop tied to my NAS to the DAC and DAC to C28 High Level Input) hooked into the C28 High Level Inputs
It was the DAC I assumed failed so I picked up a new one. Same issue.
I double checked all buttons on front of C28 and all where they should be, nothing changed.
So now I'm assuming C28 or MC2105
I tested the C28 by running the MR 78 straight to the AMP and got sound
Next tested DAC same way but I got nothing...Not sure what that meant as I assumed it would play (turned Gains full little minute bit of static would come and go)
Next tested the Phono by taking it straight in and if I turn the gains full I hear music (assuming not much volume because I have Bose 901's that are hooked into the Bose EQ???)
So is there another test I should do? I kind of assume it's in the C28....How do you test the MC2105 if needed since the speakers can't get wired into the C28
Any recs are greatly appreciated... Thx and have a Blessed Day!
According to Google's AI (so take with a grain of salt), the C28 has a built-in headphone amplifier. If you can, it might make sense to see whether there is any sound to headphones. If there is no sound from headphones, then I think you will have proved that the C28 is the culprit.
The headphone amp is separate amp inside the C 28 so whether it works or not should have nothing to do with your preamp. The TT is low output so it has to run through a phono input to give tha amp enough of a signal to play normally. So I would think there is an issue in the preamp. Also I'll move this to the McIntosh Forum as you might get more answers there. Good luck with the system.
Mike
Mike
Thanks Mike. I was thinking sorta the same thing after that. Cause even if it works it's coming through the h phones. Still doesn't supply sound through the speakers...
Start cycling switches.
Sorry, Jeff? Not familiar with cycling??
What he is hoping is that the selector switch or the tape switches are dirty and the signal is not getting through. Cycling would just be turning or pressing over and over a bunch of times so that the connection would be cleaned simply by the action of switching over and over and then try again.
As far as the Bose EQ goes, I would put it straight between the output of the C-28 and the amp. Using tape one is a great way to loop in an EQ if you want to be able to add or remove it from the chain easily, but the Bose EQ is made to be always in line with the Bose speakers and should always be in the chain IMHO.
It sounds like the amp is working from your description. The low output of the turntable would be normal without a phono section like the C-28 provides when you are plugged into the phono jacks. If the Tuner was playing at a pretty normal volume then the amp is fine.
Gotcha...Thx Refugee for that, appreciate it!!