MC-2100 gain knob part #090-017

[mghorayeb]

Hi,
I need a gain/volume knob for an MC-2100 amp. NLA at McIntosh.
Looking all over, but no success so far.
Thank in advance.

Mark

 

[SaturationPt]

That looks like the same knob as on my MC75s. I don't know where to get one, but maybe look at other models that could also have them to expand your search.

 

[motorstereo]

Good luck to you. I searched for a long time for originals for one of my mc2500's to no avail. I even inherited a 5 gallon pail full of knobs of all different types years ago and wouldn't you know there was not a single Mcknob in the entire collection.
FWIW universals with a set screw can be made to fit if you don't find an original and you can use a pair for a "custom" look.

 

[Robvolz]

I’m headed to my local repair shop

I’ll do you the favor of looking through his buckets of knobs for yours.....

If you can make an effort to find me some lil old-style aluminum knobs off a MI3

together we can do this.

 

[mghorayeb]

Appreciate that. I actually just ordered a set of vintage style knobs from a place called the Tube Depot. They are the correct 0.25” shaft diameter, have brass cores, a 2mm Allen set screw etc., and they were very reasonable. I will put those on the 2 MC2100s I have until I find the missing original one I am missing. It will turn up eventually I had the same issue with an MC2300, and I got lucky, eventually...Meanwhile, I’ll see what that knob you’re seeking looks like and keep an eye open, though I’m making an effort to stay home these days...

 

[Robvolz]

Well, you just named a website I hadn’t heard of, so staying home and road-tripping on the ol’ information superhighway has its advantages

 

[Robvolz]

These are the little guys as seen on the MI2 and MI3

 

[Way Gone]

I need a gain knob for my 2100 as well. The left one is missing off mine as well. What say we flip a coin and the loser send his knob on to the winner?

 

[Robvolz]

funny, i think i found a box full.

must check with local guy first

 

[mghorayeb]

funny, i think i found a box full.

must check with local guy first

Hi Rob,
That would be amazing...otherwise I may have to flip
“Way Gone” (member above) for one...

 

[mghorayeb]

I need a gain knob for my 2100 as well. The left one is missing off mine as well. What say we flip a coin and the loser send his knob on to the winner?

Let’s see what Rob comes up with first, then we can flip...

 

[jbailey930]

@Robvolz I could use a newer pair if you find that box and have spares. thanks

 

[mghorayeb]

Here are my amps with the temporary knobs from Tube Depot.
They look/work great...but since I’m OCD (like so many Mc owners), I won’t be able to sleep till I have the correct knobs...

 

[Way Gone]

For substitutes, they don't look too bad. As a new 2100 owner, I would like to know what the gain control is used for. Is it simply a volume type adjust meant?

 

[mghorayeb]

For substitutes, they don't look too bad. As a new 2100 owner, I would like to know what the gain control is used for. Is it simply a volume type adjust meant?

It controls the amp’s output, so yes, it controls the volume. If you were using a pre-amp, you would control the volume from the pre-amp (with output dialed in and set once at the amp). If you have no pre-amp, you’d use those amp gain knobs to adjust volume. If no pre-amp, make sure you turn the gain knobs on amp down when you switch it on/off (i.e. push/pull plug from wall).
Either way, amps are always switched on last & off first.

 

[Way Gone]

Thanks. Makes sense now. I'll be cording my pair of the 2100's to a C22 that I recently purchased that is being sent to Audio Classics for a looksie- over. I will be using them one amp per channel. Was hoping to use one amp per set of speakers on the A and B speaker selector switch till I found out the old version C22 ain't got an A/B selector switch. Least I don't think so. I think the newer release c-22's have this capability. With the C-22 do you think I just set the gain on the amps once, or do folks play around with the gain to find various sweet spots?

 

[mghorayeb]

C-22 is the cat’s meow!

Generally, people tweak with the amp gain controls since sources could have varying outputs. Sounds like you’ll be bridging each amp to mono. For that, you need to use the right channel outputs & gain knob (after toggling the stereo/mono switch to the right). This will render the C-22 balance control useless. Have someone tweak the amp gains with a flat consistent source signal, and you direct them from your listening spot...

 

[SaturationPt]

The balance control will still work.

Read the manuals. The official McIntosh setup (from memory) has to do with setting the preamp gain/volume to a set point (can't remember if it's 12:00) and then turning your amps' gain up to the maximum normal listening level. This puts the loudness pot in the correct orientation to use the loudness curve in the preamp, you then don't need to touch the amps' gain knobs again.

 

[chef free]

Ugliest knobs Mac ever used! There must be a better looking knob that would fit!

 

[Robvolz]

I had to make an emergency trip to SF to LA to Vegas to SLC to Durango.

Then I'll report my findings when I get back.