Conrad Johnson 17LS2 tube problems with Krell amp?


I have a Krell 400cx amp, Esoteric DV-50 universal player, B&W Nautilus 801 speakers, and the older Krell KRC-2 preamp. I'm considering the CJ 17LS2 preamp and wondering if there are any technical compatibility issues to worry about regarding using tubes with the Krell amp. I'm also considering Krell's KCT preamp. Has anybody heard either preamp in similar systems? I've yet to listen to them but intend to soon. I listen to classical music and hard rock music. Thanks for any advice.
liszt458
I have the KCT CAST connected to a 400cx. Before I switched to a Krell based system I had Bryston BP25 running into 7BST monoblocks. At that time I was looking for something with a bit more air and dynamic contrast so I suditioned a cj 17 pre with the 7BSTs and found it to be sweeter but as my wife said, lacking in oomph. So I audioned the KCT with the Bryston amps via balanaced lines and the result was much improved over the BP25 pre. At that point I realized that the KCT was optimized with the CAST into one of Krell's big amp, so decided to go the rest of the way. This was a couple of years ago and I have no desire to change out this combination. It has everything I could want, smoothness, dynanic contrast, extension top and bottom, soundstage that is dictated by the recording. In fact nothing artificial that I can identify. KCT-CAST-400cx, a keeper for life for life.
If you purchase the CJ preamp, remember that it inverts phase so you will have to reverse your speaker wire leads.
No, I don't believe the CJ's have any DC leakage present at the output, however Oldpet's advice is very astute! Most any well designed vacuum tubed preamp should not have any dc present if the power supply is properly designed.That said: most any tubed preamp "can and will" develop dc leakage if one or more of the electrolitics in the power supply decide to fail. It is imperative to have it bench tested to ascertain if their is any DC voltage present on the output regardless if your using a krell or any other SS amp, older units in paricular.
hi
I have Krell 450mx. I used to pair them w/ a First Sound Audio tube preamp and had no problems but it did not have DC leakage.
I recently bought a Krell KCT to see what it sounds like. Personally I prefer the Krell better for one for reason: Cast connection. You will hear increase in details, transparency, dynamics... I also use a Krell 28c cdp so my whole system is connected via cast connection.
Your choice of music will benefit more w/ the Krell. The CJ is sweet and romantic so it is better for vocal and jazz music.
Nick T
Liszt 458

For the past 3 months I've been looking for a suitable tube preamp for my 400cx. The only concern that you MUST lookout for is, DC leakage. DC can leak from tube preamps. It is damaging to Krell amps. You can also move the jumpers on the digital board inside the Krell for protection from DC. Krell will give you the instructions if you contact the service guys. I have elected not to move the jumpers, but find a preamp which doesn't leak DC. A much more challenging situation I must say. Moving the jumpers will change the sound of the Krell. There are several tube Preamps which do not leak DC. However I've never checked into CJ. Good luck. I know how you feel.

pt
Actually I have demo'd these two set ups at the now defunct Celestial Sound of Chicago( great store-Ricardo is a fantastic person to do business with!) I must say that given your preference of music I will recomend with much confidence the preamp not of my choice between the CJ and Krell. As I listen to different music, my preference is for the CJ. But it is not going to inject the energy needed for Rock- it will not get you to where you want to go period. For classical its going to be fantastic. Depending on where you are comming from, the trade off may be accecptable if you mostly listen to classical. Not the other way around though. There is no compatibility problems with the CJ-none.