Good upgrade amp for my Thiel 3.6s

Justin,
My Thiel CS 3.6's have been driven by the KSA-150 which was not bad at all! Then I bought a KSA-250 and it got even better. After talking to the guys at Krell they recommended finding a second KSA-250 and sending them up for conversion to the MDA-500 mono blocks. I'm done! I could not want any better sound from the 3.6's being driven by the MDA-500's. These are incredibly hard to find but you can get the same performance from the MDA-300's for the price you are looking at. The MDA-300's are KSA-150's converted over to Mono Differential Amps. If you already have the 150 then a second 150 would cost you less than 2000.00 *There is also a pair of MDA-300's for sale here from a gentleman in NY which would mean instant gratification without waiting for your amps to come back from Krell. My cables of choice for this system are the MIT balanced inter-connects and MH-750+ series II speaker cables.

The 3.6's can handle large amounts of power and the more clean power you have the less likely you are to damage them. The KSA-250 will sound better than the KSA-150 does. Not by a lot but it does!

Hi Frogman,

I was following some posts that I'd seen here and elsewhere from other 3.6s owners that said that 3.6s like as much power as they can get. The general concensus was that the soundstage opens up more. The imaging improves. The overall sonic capabilities of 3.6s improve with increased power. One poster I recalled saying that "you need at least a 250wpc amp to really make them shine." Though it's not really clear what that means.

I wouldn't say I'm unhappy with the sound of the Krell. I like the soundstage and bass response I get from it. I'd hate to give that up. But I don't have a lot of experience with the sonic characteristics of other amps out there. I'm new to the high-end market, having bought a good system within the last couple of years. Prior to this I was listening to CDs through a Toshiba DVD player into Technics speakers.

Since then, I've upgraded to:

Linn Ikemi CD player
Adcom GFP-750 preamp
Krell KSA-150 amp
Thiel 3.6 speakers

interconnects are another story. Haven't done much with those.

I was just starting to do some research on it. I wanted to get opinions from others who have owned the 3.6s longer and tried them with different amps. I didn't audition that many amps before going with the Krell. I bought it used about 2 years ago. I like its sonic characteristics, it fit my budget, and I went with the dealer's recommendation on it (over new choices like a McIntosh and Bryston 4B). At the time, I listened to a pair of Pass Labs Aleph 100 watt monoblocks, which I liked a lot. I liked the detail they produced but they were more than I could afford.

The Krell literature I have says that the KSA-150s are conservatively rated at 150wpc, and are more likely 250wpc. I listened to a newer Krell series in a store the other night, the KAV2550 I think. I didn't like it. Sounded thin and I thought the presentation was too bright.

I was getting the impression from just a quick look in local shops that to increase performance/power over my amp would be a huge cost. One store tried to "entice" me into buying a Krell FPB300 for $7500!

But maybe there's a used amp out there that might make a difference.

To Bryhifi:

I did look into bridging the KSA-150s to mono and had a chance to pick up a second KSA-150. I thought Krell didn't do it anymore. I spoke with a rep. there and he said they didn't offer that service on older amps like that.

Was I mislead?

J

I had my amps done just about 2 years ago. As far as being misled, I'm not sure? Like I mentioned mine were done a little while ago (6/00). They may have run out of the parts needed to convert like the new face plates and rear panels. Sorry about that, I didn't know they had stopped. You did see the MDA-300's here for sale by "Fsdizon".

Classe amps seem to be popular with the Thiels but my experience with a CA-200 was not as good as the Krell KSA-150. The CA-200 performed quite well but gave up a little too much resolution around the instruments and also lacked the spatial, pinpointed soundstage that the Krell offered. The Krells seemed to remove the boundries of the walls and opened up several more feet to the outside of the speakers.

If you really like the resolution of the KSA-150 then I'd suggest trying their older mono blocks but make sure you are willing to run dedicated 20 amp service outlets for these amps or they will not rise to their full potential. They are powerful amps but need "homeruns" to the breaker box to supply pure power and not degrade the supply to the front end components. This alone made a huge difference in my KSA-150's performance and would not have even thought about trying the MDA-500's to regular circuit outlets. This would stand true for any mono block setup of real substance!!

Bruce

Justin, what preamp are you using? If I missed it above, sorry. A really good preamp really shines through the Thiels. I'm driving my 3.6's with classe ca200 and cj premier 14 with Mullard tubes - more than enough power. Great soundstage, awesome midrange,good extension on the bottom, the only thing that might be missing with Classe ca series is ultimate extension and energy on the very top. I think you get that with the cam's and 01 series starting with 301... good luck.