Why is my Mcintosh MC-2155 slow?

Dear 'Goners,

I have a beautiful Mcintosh Mc2155 that I love. It's signature sound is silky smooth with a great presentation without tyrying my ears. However one thing that I cannot figure out is it's so damn slow. I have listened to other comparable amplifier of similar vintage (ARC, Sansui, Conrad Johnson, Marantz) and they all fail when it compares to sonics but speed wise they blow my MC-2155 out of the water.

Is there something wrong with my amplifier? How do I correct this?

The mid-eighties McIntosh amps are like that generally speaking. They have so much microdynamics that the tempo gets a little lost. You can speed it up a bit by replacing the capacitors since they are 25 years old at this point.

Also part of it is probably due to your speakers. Those older amps don't have much damping factor so they are fairly sensitive to the speaker load when it comes to bass reproduction. What you are hearing is actually slow bass. Back in the day, speakers didn't have the bass they do today - nor did they have such wacky and terrible loads. You could improve the speaker/matching to get even better results.

There are several Agon guys that use those vintage McIntosh amps. Maybe they will chime in here but if not, find them in the member system pages and ask their thoughts on speaker matching.

Everything is a tradeoff. The sonics you love so much about it are partly due to this slower tempo. You like the wealth of microdynamic information but the price you pay for that is the appearance of slower speed. It's all a compromise.

Sorry for being dense, but I'm really sure what you mean by "slow". Your amp sounds great but it sounds slow?

I'm now "house sitting" a semi-inherited McIntosh. It kinda appeared out of the blue, and I had such high expectations for it that I stopped acquiring an Anthem that same day. Got it hooked up and it sounded just fine - and in a way that was a little disappointing but probably because I'd had such unattainable expectations. It took a little while to come back to earth and realize that it was doing exactly what it was supposed to - cleanly amplifying the signal and nothing else. It didn't have any extra edge or boost or pizazz or anything that would make it seem more special and stand out in an audition room.

Maybe that's what you're hearing elsewhere and missing w/ yours? Or maybe there's a better way to define or describe how to hear speed?
McIntosh amplifiers normally sound slower than other solid state amplifiers so there is nothing wrong with your 2155. However, there is way that you can change the way it sounded. The MC 2155 has an input sensitivity switch of 0.75V/2.5V. Set it at 0.75V will reduce the negative feedback and increase the gain of the MC 2155. With higher gain, it will sound more dynamic and forward. You can then use the volume control on the front panel to fine tune the best balance between the smoothness and the transient speed.
Hsindao's advice is excellent. I didn't think of it before but I too have found that amps sound more dynamic when they are running at high gain (i.e. low input sensitivity). I run my MC240 at high gain by using "twin amp" instead of "stereo" - definitely an improvement across the board.

Try 0.75V and let us know what happens! Just be sure you have the volume control down all the way before powering the amp back up.

I will try that asap. Thank everyone for your assistance. What type of speakers would you recommend (small footprint because I have limited space) to match my 2155?

I will let you know if changing the input sensitivity makes a difference.
Before I forget I must mention that my 2155 is hooked up to a pair of dali suite 1.7 mini towers (2 1/2 way design, with 2 5" woofers and a 1" tweeter).

The 1.7's are very forgiving and musical however they are not the most transparent or have the widest soundstage.
You don't want a forgiving speaker with McIntosh IMO. The new DALIs I heard were not all that forgiving (ribbon tweeter) but if your's are, then it is time for a change.

You don't mention your budget so I will guess. If I were you, I would look into using Triangles like the Celius ESw or Altea ESw (the latter is 2.5 way if you like that). These speakers are pace and imaging champs which will compliment the 2155 very well - and can be really sweet deals on Agon.

Other options are JM Labs, which is what I use with my McIntoshes. The older Electra series can be had cheap these days and they sound fantastic. The Chorus lines are cheaper still but shouldn't be overlooked cause their tweeter is best in class IMO. The JM Labs tend to have more bass and bigger soundstaging than the Triangles at the expense of some imaging precision.

Personal preference and taste must play a role for you to be satisfied so do some homework before buying. There are many great options. Anything from Thiel, B&W, Revel, and Paradigm Reference will also work great with your Mc. (I have first-hand experience with all of my recommendations.)

Be sure to post your thoughts about the sensitivity change.

You can also consider Thiel speakers. They are neutral, transparent enough that you likely will keep hearing faults in the chain before it during the first month, and have excellent soundstage if given the space. Given your room size limitation, I would consider those in the 2.* series.

Since Thiel speakers are rather neutral, a McIntosh amp will bring it to the warm side and give them a nice body in the mid-range. MC 2155 should have enough power to drive those under 3.* series. Thiel speakers do not allow bi-wiring, which goes nicely with those narrow McIntosh speaker connection strips. Last but not the least, Thiel has excellent customer supports. Being able to access manufacturer directly instead of importer makes a big difference when you need service.
as far as tempo, an amplifier cannot be slow. that is a speed issue. a cd player or turntable may have speed errors. how can an amlifier affect speed ?

are you perhaps alluding to a frequency response phenomenon or a focus problem. if you are having a problem processing musical information, it may be noise, veiling , blurring or phase that you are alluding to.
as far as tempo, an amplifier cannot be slow. that is a speed issue. a cd player or turntable may have speed errors. how can an amlifier affect speed ?

are you perhaps alluding to a frequency response phenomenon or a focus problem. if you are having a problem processing musical information, it may be noise, veiling , blurring or phase that you are alluding to.
Thanks 'Goners. I adjusted the input sensitivity last night. I am going to listen carefully this weekend regarding the change in the amp's pace.

I am also going to check out some of the speakers Aball and Hsindao recommended. Thank you both!

Recently my source has been listening to pandora.com as well as jazz on cd (Tina Brooks, Back to the Tracks), and Arthur Blythe. I am getting sick of my Cal labs Genesis cd player as it does not play CDR's. Everyone has been talking about the cabridge audio's new line of players however I do not like their build quality as they look cheap and very similar looking to Shanling's lower end players.

Any recommendations for an inexpensive used player under $1k? I was thinking of the Adcom GCD-750 as some people love it however I am worried about reliability.
Sometimes the problem is not the amplifier, but the interconnects and speaker cables. When I switched to Nordost cables in my system, My amp went from a prop plane to the Concord!
I have no experience with Mcintosh gear, but have noticed using silver interconnects and speaker cable especially speeds the proceedings up dramatically. Speakercable 16 solid core silver strands, flat braided makes the sound much more immediate.