Pass amp vs McCormack with Silver/Gold upgrades...

Hey Jim, good luck, I hope that someone can answer your question. I looked on Ebay and I didn't see any pair of Pass amps listed, are they gone? All I see is a XA 30.5, which is a stero amp for $3680.

I'm curious as to how you've narrowed it down to these two brands. I'm not knocking them, Pass and McCormack are both good amps. I'm just curious as to what you are trying to accomplish. What speakers are you driving? How big is the room? How much power do you think you need? Why brands like Rowland, Classe, Coda, Clayton and others seem to be off your list.

Again, good luck in your quest.

John

Interesting. ProAc's are very nice speakers and your amp and preamp are legendary products. I would think the CJ is more of your problem than the amp though. CJ are known to be very musical and warm, but so are ProAc speakers and your Marantz amp. I think you have found out that too much of a good thing is not good. CJ is generally known to be warmer than the Marantz amp though. I think you'd be better off changing preamps first, but that's just my humble opinion.

I'd look for a VAC or ARC preamp. Both of those brands are much more revealing than a CJ, with perhaps the ARC being the most transparent. I have warm speakers too (Soliloquy 6.3i's) and I'm very happy with my Coda Model 11 amp and VAC Auricle preamp. I had a CJ Premier LS 16 mk II for a while, but found it to be too warm when combined with warm speakers.

Just be careful if you get a Pass or McCormack amp, as they have relatively low input impedences, which means they don't mate well with many tube preamps.

Cheers,
John

Jim,

There seems to be a general rule of thumb here on the boards that a 10:1 ratio of amp to preamp is sufficient. That means that a preamp with a output impedence of 600 ohms should be fine with any amp with an input impedence of 6Kohm or higher. I don't really agree with this, I tend to think that ARC's requirements of 25 or 30:1 as a minimum is a better estimate. Meaning a preamp with an output impedence of 600 ohms should not be mated with a amp that has a input impedence of under 18K ohms. Generally the higher the ratio the better. For example, my preamp has a 600 ohm output impedence and my amp has a 50K input impedence. When you have an impedence mismatch you tend to hear it as rolled off bass and highs.

If I remember correctly, the McCormack and Pass amp have input impedence's in the 10K-20K range, which is relatively low for a power amp. Many tube amps have an input impedence of 100K-200K ohms. Tube preamps have higher output impedences than their solid state brethren. Many solid state preamps have output impedence under 100 ohms. So the danger is when you match a SS amp with a relatively low input impedence with a tube preamp with a high output impedence. I don't know what the output impedence of your CJ preamp is.

IMHO, going from a PV-5 to a PV-11 will not accomplish much, it's still a warm sounding CJ product. You seem to be looking in around the same price range that I am now in, as I paid $1125 each for my Coda Model 11 and my VAC Auricle. I have owned much more expensive gear, but these units can hang with just about any gear. The VAC is a full function preamp, so I don't need an additional phono stage. Also, I like the Coda Model 11 a lot, because after living with tube amps for a few years, I find that Class A solid state makes it the easiest to transition back to solid state gear. The best SS amps I've ever owned, Coda, Clayton Audio and Threshold, were all pure Class A designs.

Another thought is to try a used VAC Avatar Super integrated amp. Those amps are fabulous, you should be able to get one for under $3K and it will be very hard to beat for that $$$. Your speakers are a bit low on the sensitivity side, but are 8 ohm loads and you have a relatively small room, so 80 wpc of tube power should be plenty. The VAC preamp section is much faster and more transparent than a CJ preamp.

Cheers,
John

Really? 100K? I always thought that McCormack's were around 10K and Pass around 20K. If your CJ is 200 ohms, you shouldn't have a problem, even with 10K. However, I think you are looking for something with more resolution than CJ.

I've heard the B&K's, but never owned one. I did own a Aragon 4004 mk II many moons ago, it was a nice amp for the $$$. When considering preamps, CJ and Cary are at one end the the tonal spectrum, the rich, warm vibrant end. ARC and VAC are on the other end of the tonal spectrum, the transparent, high resolution end. Audible Illusions is more in the middle, but leans towards the transparent end.

With the 24K inpedence input you should be alright with any preamp with an output impedence under 1Kohm.

What kind of cables are you using? If you're using warm cables like Cardas with warm preamp like CJ and warm speakers like ProAc, that also could be a mitigating factor. Let me know what you think once you get the B&K hooked up.

John

07-11-12: River251
...the problem with college is you choose a path when you are too young to realize how important money is going to be once you can't call up your parents in an emergency....:-)

Haha, ain't that the truth. I have 3 sons, 2 are out of college and working now, though neither is making as much $$$ as we all expected. The youngest is due to graduate next May. Hopefully the economy will pick up down the road. I worry about my kids future....it's looking pretty bleak.

Swampwalker does have a point, but I understand that you are just curious as to how a solid state amp may sound in your system. I have a feeling that the B&K will be a disappointment, as it is far from the best SS and going back to SS after tubes is not easy to begin with.

As far as speaker cables go, ones that are relatively inexpensive but are lots better than the standard drab are Clearview Helix from Mapleshade. I've only actually used the Double Helix, which I felt beat cables that cost 2-3 times their price, but the Helix will save you even more $$$. You can save even more if you can find a used pair. They don't come up often, but I see them every once in a while.

Cheers,
John

Jim,
I wouldn't say that the Mapleshade are bright, but they do lean toward the transparent side of neutral. I have heard brighter cables though.

John