Review: CM Labs 914 Amplifier


Category: Amplifiers

Long before Levinson,Krell,Threshold,and others there was CM Labs of Danbury,CT. This little high end company produced some of the most musical solid state power amps.The build quality is robust,and is a total mil-spec amp. The 914 is one of the first,if not the first of the high speed power amps. The power output is 125 Watts RMS into 8 ohms,with less than 0.1 percent THD,at any freqency from 20 to 20,000 Hz. 175 watts RMS into 4 ohm. IM Distortin less than o.1 percent up to rated power.Frequency response +- 0.1 dB from 20 to 20,000 Hz at full power.Damping factor better than 500 at 8 ohms!!Circuitry is fully differential,full complementary common-emitter output.Is built to MIL spec A8625C,Type 2.More important than all the above impressive specs,is the sound quality. This is without doubt one of the finest and most musical power amps I have owned. Clearly in the same league as Threshold,Levinson,and others in the high end spectrum.Seldom seen in for sale or auction. People that have then just dont get rid of them--Thats how good they really are in the real world of high end audio. But if you ever get a chance to acquire one,Grab it fast

Associated gear
Acoustat Speakers,HK T-60 TT,Threshold Preamp

Similar products
Bryston,Adcom,Van Alstine
ferrari
Oh my lord what a amplifier.I just bought the 914a from e-bay for a measley $69.Yes thats right $69.This amplifier sounds oh so very sweet.Has teeth and sweet kisses.I almost feel bad for the $69 purchace but what the heck it was a auction.I was the only bidder. If you would like to get a amplifier that plays like the big boy's and cost like a night out to pizza find a CM LABS 914a. It will knock your socks off!!!!!!!!!!!! 125 watts per side of true handcrafted heaven.
I remember CM Labs. I had a CM Labs stereo receiver. 45 watts per channel. I have never seen one advertised on Audiogon.
Hello!

My name is Rafael Garcia!

I am an owner of a CM Labs 914 Power amp too. I live in Venezuela, and I bought my amp in an similar auction like ebay.com, I spent aproximately 200$ for: Cm Labs 914 Amp, McIntosh C-27, Nakamichi 1000 II Deck, Sansui SE-7 Eq and other thigns. This is my best buy of all my life, I was thiking to buy this amp, but I change my opinion...

Thank you for the information...

If there are other people who can give me pics o more information about this brand, please send me an Email to: Audio_apocrypha@hotmail.com

Rafael Garcia
Congrats to the last respondent of this thread. You have one great amplifier and the rest of you system looks very good as well. I started this review and the above specs listed was all that CM Labs ever released. That were not much on specifications, but decided that the music mattered more than meaningless hype in numbers. Enjoy it is special indeed.
I had a CM Labs amp and pre at one time; my first high end pieces. Pre was a CC-3, I think. Amp was a big monster with dual VU meters. Maybe a 917, not sure. Think it was 150 wpc. It was a rocker, that's for sure and I loved it until a lightening storm took it out and I replaced it with a Moscode 300.
Swampwalker the CM Labs you had was a 912. Extremely rare new and very hard to find today. Only amp they made with VU meters on the amp. Damn - wish I could find one of those thats operational. The 912 was special order only.
I remember CM making a motional feedback subwoofer back in the 1970's, which was way ahead of the times. Never heard any of their products, but they always seemed interesting. Sean
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i own a CM920 amplifier. It is 250 per channel 8 ohms and 400 per channel 4 ohms. I've had it since 1980 and it has operated flawlessly . It has a very smooth and refined sound especially considering its age. I will be keeping mine forever! I do believe i have some brochures on their various amps, preamps, and mixers.
The CM Labs 920 is very rare indeed. Have never seen an actual one, only a brochure on one. Most likely unless damaged will last till the sun goes out, like most of the CM Labs gear. Way overbuilt to a standard hardly found today.
I just came across a CM914 in the storage room where I work. They were going to throw it out. It doesn't seem to power up, but I want to get it fixed.

I'm confused, though. This one looks different than in the pictures, and is 300 watts per channel. It's got two dials on the front, and appears to be made for a P.A. rather than for a stereo. It also says Albany, NY instead of Danbury, CT.

Can anyone give me a clue as to what this is? I can't find any other info on it.
The only CM Labs I know of that had power meters was the 912. Dials on the front? Just not sure.

E mail me a pic and I will do some research. Does it actually say 914 on the amp. A very few of these were built for concert hall application, which you may have.
I posted these pics after happening across this forum. They should be of interest to all here:

http://www3.telus.net/roverpics/cm920front.jpg

http://www3.telus.net/roverpics/cm920rear.jpg
Many thanks to pvanrook for posting pic of the CM Labs 920 power amp. Appears to be a higher powered version of the 914C power amp,front panel almost the same. These were used mostly for commercial application such as studios and concert hall application, although work extremely well in a home system.

Many thanks
Does anyone have any schematics for CM labs amplifiers? or for the CM labs preamp? I have the 35D which needs a schematic, and I have the 915 which needs a schematic, and th epreamp too which will need a schemo or a tech. Thanks in advance ! Ed
Hello: I have a schematic for the CM Labs 911 stereo amp. I will email it to you if you want it. I have a CM 911 and I have been using a pair of CM lab amps Model 80MRM for the past 29 years. I believe that the CM Lab amps are some of the best transistor amps that were ever produced. They were expensive when new but I would put them up to any other amp such as Mac Fisher etc. Dan
YES! I would love to get a schematic for it, btw, do you know of anyone reputable that works on CM labs gear? I also have a preamp, and a CM Labs 915, which strangely has an address on it for Alabama (?) . Feel free to email directly at ecoleman@whidbey.net . thanks! Ed
I would also like a copy of the schematic for the CM Labs 911 amp, please. Would you have any other info on it; like how many watts per channel? (maybe an owner's manual?). I totally agree with you on the sound. I was amazed how good it sounds when I first listen to it. Thank you in advance for the info. Tony(cornflakeman@gmail.com)
Is this one of the amplifiers that had cinch-jones connectors on the back for the Acoustron - Erath LWE speakers with "motional feedback" ?

I have a pair of LWE-1s I'm dying to hear hooked up to a compatible amplifier.
The amplifier that is pictured in this review has such rear panel connections, Some of the 914a and 914c have this connection as well. If you can find one of these amps then your set.
I have a CM920 which I'm attempting to repair. If anyone has a service manual or schematic or any hints on things like bias settings, please let me know. I got this amp at an estate sale, partly disassembled with the output devices in a plastic bag. So far I've traced the circuit boards and duplicated them in CAD, since the old amp boards were damaged in a few places and drawn schematics on paper but not on CAD yet.

dangus (at) direct.ca or at triant.com
You might try a post on the www.diyaudio.com site. I have found that site useful in getting hard to find information.
I own a CM Lab 911 for quite a long time. I had tubes amp before that. The CM lab doesn't have all the refinement of the Leak amp I had but it could compete very well with my HK citation II. It was also way better that an old Bryston 4B. I have a review done back then when the amp came out, around 68 or 69... the reviewer was pretty enthusiast about the 911. I also have the company's spec sheet and the electronic schema if this may be of any help to someone...
Yesterdays equipment that are still highly competitive sound wise , Threshold fet 10 preamp , Audionics of Oregon BT-2 preamp and CC-2 Power amp , B and K 140 amplifier , Dalquist DQ10 speakers, Spica TC-50 Speakers , DCM Time Windows and many many more . Dont make the mistake of thinking that just because its an old design it isnt solid sound wise . AAHH...the good old days.
Hi Ferrari,

I ran across your threads on the CM Labs amplifiers and you appear to have knowledge about CM amps. I read the review on the CM914 and it appears to be a great piece of equipment. I recently purchased a CM915 professional power amp and I can't find any info about this amp. It looks very different than the photo you provided of the 914. AUDIO is stamped in lower left corner. My 915 reads CMLabs. I'm assuming the 915 was a later model produced in 1983. It appears certain models were available by custom ordering. I have a photo that I can provide. My ISP or browser sometimes has problems posting to the forum. Any info you can provide would be greatly appreciated. Thanks
The 915 was a pro amplifier designed primairly for musicians and for recording studio use. These were special order only if memory serves me correct. Very ruggedly built. This one is about 150 WRMS per channel and about 250 WRMS into 4 ohms. The 915 can drive very difficult loads. Sholud be fine in a home installation. Peter at Soundsmith is very knowledgeable on the CM Labs units and worked with their designer. Nice amp, very musical and has the muscle when needed.
Thanks Ferrari for the info on the 915. It's a very musical amp with plenty of power. I would like to upload a photo, but I can't seem to find any instructions. Can someone please tell me how to go about this? I use Safari browser and Mac computer.

Ingelsj
Great thread, My name Ray I Live on the west coast of Canada.
I've been searching for a tube amp for months but do to my budget and the size of my power hungry speakers "heco Lab 2 Lautsprecher" I would need to spend far to much.
I was lucky enough to find this thread after seeing a cm labs cm149a in a local pawn shop. It looks like there have been some repairs/upgrades?
So I am now the proud new owner of this amp!!! I would like to Say many thanks to Ferrari!!!!! This thing is awesome, I will take some pictures asap and post them!!
I would like to ask anyone with info on my speakers to email me "sensitivity / biampable?"
Thanks in advance!!!
Just got my CM Labs 914a back after many years apart...I bought this in the late 70's as my Quatre Gain Cell kept breaking down (anyone own one of those?) Then the 914a went to my brother when I went to Levinson and Krell...I've now rebuilt my 2 channel analog audio room after many years of just HT 5.1 and I'm having a great time listening to the 914a...What a strong piece of gear...
Wow, I was looking at resurrecting all of my Vinyl equipment and part of that setup is 2 - CM 914's - Mine don't have the nice handles and wood sides, would be a nice addition. I always knew they sounded really nice and have compared them to many amps in the past. I had them powering a set of custom Infinity 2000a speakers with electrostatic arrays and upgraded quamtum jr 12" bass drivers. Added some heil air motion drivers in place of the mids and they sounded incredible. Unfortunately the bass drivers needed new foam and I have to fix one the ribbons on the heil drivers. fortunately, I have spares except they don't work either. More work. Back to the amp. My only complaint was when turning off the amp there was a pop in the speakers as the current was released. So I thought of adding a soft start circuit to the amp to prevent that. Comments? Should I just leave it? I also was going to replace all of the power transistors and drivers with sets of matched ones that I bought some 25 years ago. Guess I will be looking for some nice handles as well. I think somewhere if I can find it, I actually traced out schematics for this amp some 25 years ago. I will look to see if I can find them.

Glad I finally found some info on it!
I get the chance to buy a CM LABS 912 the one with the VU
power meter. At a very good price. The seller said that
i will need to change some old electronic piece to get
a maximum sound from this old amplifier.

Someone has an experience with a rebuild of a CM LABS 912 power amp or other CM LABS model?

This worth the investment knowing i will need to paid also
for rebuild.

Thank to answer me as i have to make my mind soon...
I finaly choose to buy the CM LABS 912 and i'm very happy
i did. I will made a rebuilt from a pro tech and comment on the result. It will be my part contribution for audiogon forum
who has help me a lot in the progression on my modest system.

I have to said that i have been bless in my system cause this
912 is a pretty rare found and at a very good price... But
same in the bad period i never stop believe in God and today
i reap what i have sow in tears...
FERRARI,

You have experience in CM LABS product so it will be nice if you can explain us the difference between the CM LABS 914
and the 912? I have read some where that the 914 was sold
new $400 and the 912 $800??? But no more info...
I had a 35D for awhile, it was great fun to listen to. Blew a pair of Minimus 7 woofers with it!