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Odyssey Khartago vs. C. Johnson's 2250A??

Odyssey Khartago amp has received good reviews. At the same time, Conrad Johnson's 2250A though issued in 2002 still gets serious consideration from many audiophiles. Both are solid state amps and approx.120RMS.

Despite CJ's reputation, which amp might sound better with a pair of Acoustic Zen Adagios and a Bel Canto PRe3 line stage pre-amp.... By better I am referring to overall musicality, transparency and bass depth and control. I have read many of the reviews on the CJ 2250A, but am not convinced it will sound better than the Khartago which is a newer design. And I don'want to drop $1000 for the CJ, only to find that it is only average. Thanks, Jim
sunnyjim
zenblaster
504 posts
 
T1s49,
Lower distortion is a good thing so the THD specs for both units speak for themselves.
I never said the CJ was inferior. In my experience with both amps I liked the Odyssey. I would be very happy with the CJ also but given a choice.
I have a CJ PV-10 that I am currently using and I think it is a great sounding preamp. They are a first rate company that has been very helpful anytime I need help with any of their products.
tls49's avatar
tls49
1,351 posts
 
Zen, sorry if I misunderstood your post about the CJ, must have been that “light years” thing, and you are certainly entitled to your opinion about THD. Guess I’m in the camp that as long as it’s reasonably low, differences like the one cited here are just meaningless. It is interesting that some well respected companies don’t list the THD, and others say something like “typically less than 1%”. Also, speakers produce much more distortion than electronics at moderately loud listening levels, but you rarely see any of these specifications published.
almarg's avatar
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almarg
9,670 posts
 
I agree with TLS49. I would go further and say, as someone with an extensive technical background and someone who certainly recognizes the value that specs can provide (especially in identifying combinations of components that are likely to be poor matches with each other), that THD numbers for amplifiers are generally worse than useless.

Extremely low THD numbers are commonly accomplished by heavy-handed application of feedback, which in turn will worsen Transient Intermodulation Distortion (TIM), which is not normally specified, and for which I believe measurement standards have not been defined. And which well respected researchers, starting with Dr. Matti Otala (who is generally credited with first identifying TIM during the 1970s), as well as many respected high end designers, consider to be more relevant to music reproduction than sine wave-based THD measurements.

Also, THD numbers say nothing about the DISTRIBUTION of the distortion among different harmonics. It is well established that extremely small trace amounts of certain odd order harmonic distortion components will be vastly more objectionable than much larger percentages of low order even harmonic distortion components.

Basically, IMO, the only potential usefulness of THD numbers is that they can suggest caution in choosing an amplifier having exceptionally "good" numbers.

Regards,
-- Al
sunnyjim OP
927 posts
 
Thank you again to all who responded. I am curious if the McCormack DNA 125(standard) not upgraded is competitive with the above two amps. SMc upgrades DNA125 to the gold level for approx. $3000, and claims it will compete with amps in the $10,000 range.
zenblaster
504 posts
 
We all agree that words will never adequately describe the synergy between amp and speaker. You have to listen to amps with various speakers to get a taste of what they bring. Speakers can go from majestic to muddy with the switch of an amp.
Nothing will replace getting out and listening to various setups at shows. I have been blessed with going to CES and THE SHOW for the past 8 years and experiencing all types of rooms. What I usually come away with? - how much I have to learn!
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