Impedance Mismatch: A.I. M3A, Krell KSA100

Many People Use Tubes with krell amps but just follow this blog and what do you get??????. I never said you can't mix and match nor did I ever say there's a law against it --- my point is just read what is being said -- I just cut through the questions (logic) and technical stuff and what ifs and told the man he should stick with a Krell -- you know keep it simple. But way off base -- no way -- just read the above and tell me what advise is being given --. My advise is buy the krell and fatigue will be the least of your worries --- If Krell is tiresome -- why are so many people always on the KREll forum comparing there experiences with other companies (I know there isn't a law that says you only can talk about krell on the krell forum but....really... they must be doing something right and for a long time...Funny how <> everybody relates to a Krell (everybody guns for the best -- good or bad). Hey I think there is some really fantastic world class Tube preamps and amps out there that yes are on level with Krell (no bad comments). But cut through all the above exchange and buy the krell and don't worry about...I won't repeat what I have already stated....

I don't know what your budget is ..but I would try the Kav-280p (Really nice preamp), KCT (Hard to beat), or even the KRC-HR (lot Older but - hey still will get you up close and personal with anything out there)
I do own a KSA-100S and at the time (1995ish) I used a KRC-2 and it sounded great -- I still use my KCT with it every once and while just to listen to the amp (sounds great).

Arc makes fantastic World Class Stuff -- Bar None -- But they sound the very best with other ARC Components (Hope I wasn't way off on that statement -- even on the Krell forum)

Buy The Krell -- Or sell the krell and buy an ARC

I'am easy!

Scoutdog is waaaay off base. Many people use tube preamps and solid state amps. There is no law against mixing and matching. IMHO, a krell pre and power amp makes for a very fatigueing sound. Just sayin.

Thanks for all the responses.

I'm in a different position since I moved away from big cities, now. I'm 2 hours away from Boston and Nashua, NH. Those being the closest with shops that might carry and lend equipment for trying out.

I once used an A.I. M2 with a KSA50, hence the M3A idea as a way to lower the risk of a bad surprise.

So Scoutdog, just to be clear, I should go with a Krell, right?

Seriously though, I've tried a PAM3, PAM5 but those particular preamps didn't move me at the time. Maybe some of the better ones, but the budget is not high.

Thanks again.

NoLanh,
I hope you figured out by now -- stay away from tube stuff with Krell. You should not have to use your hard earned money and have to guess if this tube amp or preamp or whatever tube at any cost will work with a krell amplifier -- Hell get a krell and finish it.......Go to any tube amp or tube preamp discuss (forum) and that's all you hear..Try this amp with this tube but you have to make sure this is that .. how about plug it in and listen...or if you put this new tube from russia in instead of the factory tube in your $10,00 amp you will blow everything away but first you have to break the tube in for 500 hours to make it sound its best and replace the tube after 1,ooo hours -- HUH. If you have a tube preamp get a tube amplifier, if you have a solid state preamp -- stick with a solid state amp whether its from arc, Krell, mark levison, or whoever. Use your head -- unless you enjoy listening to all the tube technical experts, engineers... and that sweet midrange your hearing is coloration... just throwing it out there......couldn't resist -- this is the KREll Forum -- Arc is over there with the Tubes, coupling, caps, bass roll off, 3.3 what .. cable shorter than 10ft...ratio, have a guy build you a impedence matcher.. really - wow....no really wow...that should cover all the bases... BUY A Krell Plug it in with what ever length cable and sit back and enjoy.....
tube guys I couldn't resist....
I know if I would just take the time to learn how to roll a tube....etc...ok ok I'll stop.. You guys can rip me up now.

When you buy a Krell Amplifier in the manual it states beware if you use a tube component (just pointing that out). I think you can get world class sound from tube components and I'am sure many, many people have had success but .. after listening to the above .. what do you think!
Just saying.......

Nolanh, AI Recommends, when the M3a is connected to an amplifier with a low input impedance, keeping the interconnect cable shorter than 10 feet. Typically, the M3a has 5uf coupling caps so you should encounter no problem. Regards, AI Technical

The output coupling cap value should be large enough as to not roll off the bass. Need to know the value of those caps to help you. If they are over 3.3uf or so you will be fine.

Sonnyyoung: Later Krells tend to have much higher input impedance ratings. The KSA100S has 47K for instance.

Jcus: Could you provide more detail on length and capacitance you are referring to for interconnect cables?

Should be no problem providing you don't run very long, high capacitance interconnect cables. We know of many Krell owners who also own an M3A with excellent results. Regards, AI Technical

I have a Modulus 3A preamp coupled with a Stratos Extreme stereo amp with a 22K input impedence. It is a match made in heaven. I am smitten with the sound and couldn't ask for any better. I would suspect your Krell amp with the 22K input impedence would be a great match as well.

Bob

Romandoc is correct. The value of the output coupling cap in tube preamps can significantly increase the output impedance of a tube preamp in the bass frequencies as compared to the rated output impedance at 1 KHZ. The actual output impedance of the Modulus,is probably significantly higher than 1200 ohms at 20 HZ. I would also suggest that the optimal impedance ratio is better at 20:1 or 30:1.

I have an Audio Horizons preamp matched witha KSA-100S. Match made in heaven.

Yeah, but it depends whether that 1.2K is over the entire audioband. If, say, below 100Hz preamp's output impedance gets higher (I believe Stereophile showed that to be the case for the Aesthetix preamp), then an amp with the input impedance of 22K may not be a good match.
My personal opinion to be taken with a grain of salt is that for an amp with the input impedance of less than 50K the best match in a tube preamp would be one that is transformer coupled. That keeps the output impedance low over the entire audioband and guarantees electrical compatibility.

Based on the usual recommended 10/1 ratio this more than fills the requirement. Should be fine