Apexorca systems

[Apexorca]

It's no doubt about it.
My system gets significantly better with this bi-amping. Krell 350 MC and 400cx. The first thing I notice is the voices getting more focused and real. Transparency, airiness and clerity are better.
The sound gets better in every point I think, bigger soundstage and more holographic.
The control is amazing.

Though, the fuse in QB8 is not up to the task. 10A fuse is not enough. As I krank up the volymen it releases. So I have to by a QB8 High Current instead.

[Charles]

Carl, beautiful pics. Magnificent system. The "old" Krells can't be matched or beat. The only drawback is heat but I can tell you the amps are extremely rugged and heat resistant. I also remember something if my memory has not failed me.

When I had my MCXRT30 speakers run from my FPB 700 stereo amp (looks identical to your center amp except about twice as long), it had two sets of binding posts. My memory is hazy on this but I believe I ran the subs off one pair and the mids/tweets off the other. They tried there best to sell me 4 MC 1201's but I refused the amps but bought the speakers. The 30's were OK but had to much presence in the mid to suit me.

Anyway, absolute congrats on finding these old amps. Also, I am sure these amps come with their own Krell manufactured power cords. Mr. D'Agostino did not think any cord on the market suitable for his amps so he made his own non detachable cord. My advice to you is to plug the amps each into their own dedicated 20 amp line with no conditioner. It IMO is the correct way to run these amps. Forget the fuse. I ran my FPB 700 this way for maybe about 15 years.

Your amps are the most incredible amps ever built. They have twice the number of transistors as normal amps. The transistors are special made, very different from the usual transistor. There are no large capacitors or capacitor banks in these amps and they run full Class A 100% of the time. No power conditioner is ever needed. The penalty for all this goodness is heat. But again the amps are designed to take the heat.

Best

Charles

[Apexorca]

Originally Posted by Charles

The penalty for all this goodness is heat. But again the amps are designed to take the heat.

Hehe. Were I live heat is very welcome.

Your amps are the most incredible amps ever built. They have twice the number of transistors as normal amps. The transistors are special made, very different from the usual transistor. There are no large capacitors or capacitor banks in these amps and they run full Class A 100% of the time.

Maybe that's why they are so fast.

Anyway, absolute congrats on finding these old amps.

Tank you! Since I laid my hands on FPB 350Mc I'v been thinking of bi-amping and for almost 1 year I'v been looking for FPB 350mc or 450mcx. The are hard to find good and safe units and I also got fooled once during these period of time. Finally I found one FPB400cx in excellent condition. That will do for a while.

I use no Power Conditioner just a very well crafted power distribution unit (Nordost QB8) with absolutely now restrain that I can hear. I'v been trying in these Krell with or without QB8 and it sonds better with the QB8 unit.

[Charles]

Carl, I would use three 20 amp lines straight out of the fuse box if possible. These are one of the few amps ever made designed specifically that way.

I would have no interest in your amps because of the heat. But the dynamics, speed, detail/resolution, smoothness with intensity of presence at the same time, bass grip and deepness of bass, treble extension and beauty, are breath taking. They are quite simply the best amps ever built. I kept mine for 15 years until I went with Mac because of heat. I wish folks could hear your amps. Then they would know what I mean.

Don't forget with double binding posts for each amp you have the equivalent of 6 amps. These amps are designed to run with both binding posts employed if you want. I used this arrangement for many years. No current amps I know of can do this amazing feat.

Best

Charles

[PHC1]

Originally Posted by Charles

Carl, I would use three 20 amp lines straight out of the fuse box if possible. These are one of the few amps ever made designed specifically that way.

I would have no interest in your amps because of the heat. But the dynamics, speed, detail/resolution, smoothness with intensity of presence at the same time, bass grip and deepness of bass, treble extension and beauty, are breath taking. They are quite simply the best amps ever built. I kept mine for 15 years until I went with Mac because of heat. I wish folks could hear your amps. Then they would know what I mean.

Don't forget with double binding posts for each amp you have the equivalent of 6 amps. These amps are designed to run with both binding posts employed if you want. I used this arrangement for many years. No current amps I know of can do this amazing feat.

Best

Charles

Charles, yes I have heard them. More than once. Fantastic amps. Driving a pair of Dunlavy speakers it was quite an unforgettable at that time experience for me. The best ever built? The best never rest and Dan D’Agostino certainly has not rested. You should hear his latest creations if you have not had the chance.

[Apexorca]

Originally Posted by PHC1

Charles, yes I have heard them. More than once. Fantastic amps. Driving a pair of Dunlavy speakers it was quite an unforgettable at that time experience for me. The best ever built? The best never rest and Dan D’Agostino certainly has not rested. You should hear his latest creations if you have not had the chance.

Dan's newer amps are great! I'v heard them in many different systems, different speakers and so on. Always as good as it gets.

[PHC1]

Originally Posted by Apexorca

Dan's newer amps are great! I'v heard them in many different systems, different speakers and so on. Always as good as it gets.

Mr.D’Agostino certainly has many decades of design experience under his belt and he did not let them go to waste.

What blew me away is how he was able to coax so much more tonal density and so much more “meat for the bones” of the musical skeleton without the amplifiers adding any unnecessary coloration of the sound.

With speakers worthy of partnership and Wilson are a perfect example, the images come out fully and tastefully cooked, to perfection and with all the juice and flavor of the recording intact.

How? Sure dynamic contrast is expressed to virtually unmatched degree, the amps have iron grip... but the tonal pallete, the rich and saturated harmonic structure, the fully fleshed out images... Any audiophile’s dream or should be close to it IMHO. How does a kick drum appear so fully fleshed out way outside the speaker boundaries? Anchored to the floor and palpable, just reach out and touch it. It’s almost 3D or virtual reality.

There is so much flavor here, the master chef has whipped up a recipe that is irresistible.

Ok I made myself hungry with that one...


The earlier Krells were often superb, legendary in fact but D’Agostino amps are now pure perfection IMHO. Not sure what else I would ask for?

I was extremely satisfied with my Wilson/D’Agostino system.

[Charles]

I "hear" you all but I'll take the old Krell. One of the reasons for the Relentless is that it is pure Class A to 100 watts. That's why it is so huge. Therefore almost (99% plus if you have even reasonably efficient speakers) all power is pure Class A. Not so with his smaller amps. His new amps also utilize large capacitor banks for current storage and have comparably much smaller power supplies. About 50% the number of output transistors.

Most importantly, the old amps run pure Class A 100% of the time, period. With inefficient speakers they will heat a large room. IMO, best amp in world is the Krell Master Reference. No specs are even supplied and they require 240 volts. Make Relentless look like a puppy.

Best

Charles

[PHC1]

Originally Posted by Charles

I "hear" you all but I'll take the old Krell. One of the reasons for the Relentless is that it is pure Class A to 100 watts. That's why it is so huge. Therefore almost (99% plus if you have even reasonably efficient speakers) all power is pure Class A. Not so with his smaller amps. His new amps also utilize large capacitor banks for current storage and have comparably much smaller power supplies. About 50% the number of output transistors.

Most importantly, the old amps run pure Class A 100% of the time, period. With inefficient speakers they will heat a large room. IMO, best amp in world is the Krell Master Reference. No specs are even supplied and they require 240 volts. Make Relentless look like a puppy.

Best

Charles

I’ve discussed that with Dan one of the times he was presenting his line locally. Let’s just say transistors and capacitors have also changed over time. There is a reason behind everything he does.

[Apexorca]

Originally Posted by PHC1

I’ve discussed that with Dan one of the times he was presenting his line locally. Let’s just say transistors and capacitors have also changed over time. There is a reason behind everything he does.

You are probably both right. It's a matter of taste at this level.
I think it's hard to announce a winner. I know that Dan's new brand is fantastic. Though I have never compared Krell vs Dan d'Agostino in the same system. They have the same basic idea of how to present music. That test would be very fun.
One good thing about used Krell in very good condition is that you get great sound similar as Dan d'Agostino, but you can almost cut of the last zero on the prize tag.