I have an adcom 555mk2 that is just sitting around unused. I had tried to use it with the 990, but the input sensitivity was 1.75v to reach full power, and under a load the distortion lights would trigger. Will the 990's replacement have a higher output for such amps or have I missed something? TIA, Brian

P.S. I am also looking at a parasound 2205 wich requires 1.5v to reach full power also, along with Outlaws own 7900 wich needs 1.95v.

Your 990 has a maximum output level of 9 Volts. This is easily enough to drive the Adcom to full power. The Adcom distortion light comes on when the amplifier senses a difference in waveform between the input and output signals. This is usually caused by clipping but could be due to other problems in the amplifier. This amp is getting older and you may have some electrolytic capacitors that have dried out. The problem is not the 990.

Also, into reasonable speakers that amp will blast you out of the room at full power. It's got a fair amount of headroom over the rated 200 WPC into 8 ohms. I know, there's one sitting on a shelf here somewhere (in reserve for side surround if/when I get them)

Manhansm


Nice sytem you have therre. In the mid 80's I like at Kef speakers.

I enjoy it. I bought the Kef 107's new in about 1987. Still not enough bass for me; two LFM EX are on the way.

I recall that Kappa 7's moniker was related to the speakers he owns -- Infinity Kappa 7s, which are notoriously difficult to drive. We sold both the Infinitys and the Adcom line back in the 80s. As powerful as the 555s were (are), the entire Kappa line (7, 8 and 9) could really eat those amps for breakfast if you pushed them hard.

Mahansm also raised an interesting point. I don't know about the 555s, but the 565 monoblocks have a reputation of leaking electrolytic fluid from the capacitors as they age. I'm not sure how old your 555s are, but I'm guessing they may be close to 20 years old (?). If the 565 issues apply, you can test the speaker termminals with a volt meter to see if you're getting any DC offset. I would suggest calling Adcom for more info if you're still interested in using them in your system.

Hey thanks for the help guys. It has actually been a while since I have tried to use the 555mk2 but I did contact adcom at the time and they had mentioned about the dc offset. I did check with a multimeter at the time and was getting some offset on both channels. Adcom said if it was the same on each channel to not really worry about it. I would like to still use my adcom amp in my bedroom, if I open it up will I see leaking fluid?

Videodrome is correct, the kappa line is a difficult load on amps-the kappa 9 dips down below 1ohm! I had the adcom amp paired with an adcom 555mk2 preamp(both are 18yrs old) and the sound was awesome. Once I got into hometheater, the 2 channel setup was removed and replaced with the 990 and the parasound 1206. Again this is a great setup but the kappas need alot of current to do their thing. The 1206 has peak of 35 amps per channel and its bigger brother, the 2205 has a peak of 60. I think the extra current will give the speakers the steam they need. I am always open to others comments and opinions, so please if you have an idea about other amps or info on the adcom let me know. Thanks again, Brian

I think there is a PDF document on Adcom's web site about the 565 leak problem. It has photos that show the stains on the circuit board. You could look at those pics to know exactly what to look for when you pop the top off the 555.

There are a lot of good high current amps out there; starting with the Outlaw of course. Then there's Emotiva and a host of others. If you're looking for a two channel amp, I can personally recommend the McCormack. I've also read great thing about Odyssey.