Amp upgrade ?

I have a handful of amps in mind that I would like to upgrade to but I can't decide, #1,pass aleph 1s #2,Krell KSA 250 #3,Bat vk-500 #4,Sim w-5 #5,Mark lev 23.5 my current system is B&W 804 pre is audio research sp 16 cd player sony scd-1 I have heard all of these amps but in different system configurations even though some are much older than the others I think the krell and mark are still good units.
I agree with you, the Krell and ML may be the best of your 5 choices. However, at their age, and as hot as they run, they will probably need their caps changed soon, if they haven't had this done recently. So I would look for ones that have recent (within the last 5 years) service with caps already changed. Otherwise you may as well contact Krell/ML now and find out what it will cost to replace caps, then figure that into your budget.

I if you look at it from one point the krell and mark lev was $5900 in 1990 and that would be equal to a $20000 amp today,and probaly as good as a $5000 amp now, but it is a good idea to call mark lev or krell to find out the cost, but I think it will be less expensive to buy a newer but still can't decide.
I'm running a ML 23.5 now and I'm quite happy BUT I get the loud "pop" when it shuts off. I'm thinking it's cap time and that’s going to make me sad. It weighs as much as I do and Harmon isn’t going to take it easy on me. I am curious what the total will be ... $500, $1000, $1500? As far as heat - I have it in a Salamander rack and have 2-3" clearance all around - it's never got that hot ... I keep a desk fan in the back of the rack just to quietly move air. I would say "warm to quite warm"

I have a Modwright SWL 9.0 Signature pre and it's the best sound I can afford right now. I have tried other amps - even tubes and I just love the ML 23.5. It has a ton of power (no pun). I am running Aerial model 6's so I am not pushing the amp very hard. A larger more demanding speaker set will obviously push the amp harder. The question is what is the breaking point? Room size, volume level, efficiency of the speaker will all play a part. How does this baby behave when it's pushed to it's limit? I'm sure it gets hot - but I cant attest to how it behaves. It can drive the Model 6's to incredible levels with ease and the Paradigm Signature 4's before them. I am considering Aerial Model 9's now ... I imagine this will be a test. I understand it is possible to run the 23.5 mono - maybe I'll pick up two.

Has it crossed my mind to dump it and upgrade? From time to time ... I wanted to try Pass Labs 250.5 but to be honest - I will take the hit and fix it. I think that says a lot. I have been buying and selling for a while but other than speakers - I am locked in now. One possible addition will be a Mac 275 V ... I like the tube sound AND the SS sound. I would like to be able to go back and forth.

I figure if I get difficult speakers to drive - I'll pickup additional amps and run mono. So the ML 23.5 is scaleable – not every amplifier solution has that capability. I think the question is how will it mate up with your speakers? I have heard ML amps with B&W 802, 800's and even the Nautilus. The 800's and ML combo is one of the best sounds I have heard - period. I have heard it with Aerials up to the 20T’s and it was incredible. I have heard them with Maggies but I like the tube sound better.

Hope this helps a little …

agree..the ml or the krell
The Pass and Krell will probably chase you out of the room in the summer. If you can find newer designs from both companies around the same price, I'd shoot for those as they'd last longer and(supposedly)sound better.
What amp do you have now? Based on my recent experience with the ARC SP16, i would start the upgrade path by replacing it. I wanted a tube preamp to use while my VAC Renaissance is in for repair and updates. I brought home an SP16 and it took all of five minutes to decide this was not a good choice, very limited bass, flat two dimensional soundstage, plus the awful stepped volume control. I then took home a Manley Shrimp which comes much closer to the sound of the four times more expensive VAC. It does not match the VAC in bass weight, detail or separation but the overall presentation is one I can live with for awhile. The biggest downside is no remote control but it does have a nice feeling volume control that is not stepped. IMHO, no matter what amp you purchase, your speakers will sound thin and weak in the bass with the SP16 preamp. B&W's need a bit more meat on the bone and just changing the amp won't do it.
For less than half the money, I chose the BAT VK-500 with Batpack option to drive my Thiel CS 6 speakers. I considered the ML and Krell amps, but don't think spending two or three times the money would have resulted in that much better sound. My pre-amp is an ARC SP9 Mk II.
I agree the bat or the sim w-5 lae is still a very good choice both build like a tank and with the bat pack the power reserve is huge, I don't want to change my pre amp I think the sp-16 is still good I run it with a bryston 4 bst it sounds pretty good but not great, my brother has a krell ksa 100 the pure class a and it surprisingly sounds better than my bryston I have his krell right now and he has my bryston I don't want to give it back , anyway any suggestion would help thanks.
I am still breaking in the Modwright SWL 9.0 Signature model (new caps). So far it's incredible, I hooked up the Levinson No. 27 (paid $1400 local) to my Aerial model 6's. I am pulling the 23.5 and have decided to bite the bullet - sending it back to Harmon for caps and anything else it needs.

If there is an amp out there for $700 that equals the No.27 I am all over it. I will check with my local used audio store in Portland (Echo Hi Fi) and see if he has anything from BAT for demo. I thought I saw something up on the shelf the last trip in. I have tried a few Krell amps over the years but not with the Modwright. I may try that for comparison as well. It's nice to have a local guy that lets you demo equipment in your house. I read a post a week or two ago that said there were issues with running a tubed linestage with certain Krell amps (FPB?) and there where jumpered caps that had to be put in-line before you could run a tube linestage. The caps caused a degraded sound. If you didnt run the caps you risked damaging the amp.

Anyone have any info on that?