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4 amps in 2 weeks


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I have been lucky enough to hear 4 different power amps in my system over the last 2 weeks. These were:

- my Cary CAD-211AE, 110Wx2 Class A. RRP$22,000

- Cary Cinema 2 (see seperate review), 200Wx2 Class A/B. RRP$4500

- a very old AudioAnalyse amp, 70Wx2 Class A. RRP (in the 1980's) about $20,000

- Jeff Rowland's baby power amp, 150Wx2 Class A. RRP around $9,000 (unsure of this)

The guys were around today and we got to compare the CAD-211AE to the AudioAnalyse and the Jeff Rowland. I am sure the others will post their listening impressions eventually, but here are mine. All listening was done unblinded with "approximate" volume matching. It was enough to hear the differences:

Cary CAD-211AE - mids and top end were richer than the other two, with a more extended top end. Control of the woofer was vague and lacking, sometimes resulting in a "boom" where there should have been a "bang". Both the other amps had enough oomph to make the woofer hit its xmax - not the Cary. Soundstage was wider than the AudioAnalyse but image localisation not as precise. Amp had enough power to drive the speaker to uncomfortable SPL's.

AudioAnalyse - a very unusual older amp with massive heatsinks radiating from the transistor which sits proud of the amp in a little metal box. Had an obviously dryer presentation compared to the other two amps. The mids and highs were thinner without the same ease as the Cary. Soundstage was a little narrower, but image localisation within was more precise. Also less forward than the other amps. Having gotten used to the sound of the AA, I also find it a tiny bit more dynamic than the Cary's. Noise floor is obviously lower.

Jeff Rowland - Pulse-R summed it up best - "it just sounds nice". Having been to Luckydog's a few times now and gotten used to the remarkable ease and relaxing sound of his system, I was wondering how much of it was due to the speaker and how much from the upstream electronics. I'm not sure if LD would agree, but the sound from the Rowland today made me think that suddenly I have a lot of the ease of LD's system in my own system. I wasn't sure what to expect when the sound first came on. This is definitely not an amp that sounds big, brutish, and powerful (Krells come to mind). Instead, the sound was relaxed, dainty, and full of charm. The Rowland has a relaxed presentation, with a midrange which is different to the Cary, but just as appealing. Where the Cary was warm, the Rowland was sweet. Obviously a difference in the harmonic structure. The Rowland's woofer control had it all over the Cary - it just had a much better grip on those recalcitrant bass drivers.

If there was another thing that I realized recently - 70W of solid state power is enough to make the woofers max out. The midrange horn and tweeter sound like they have a lot more to give - they continue to sound clean while the woofer box is distorting like crazy. Makes me think I should get rid of the drivers in the woofer box, and pronto.

In any case, I ended up liking the Rowland a LOT. Thanks for bringing them over, LD. Now would you like to hear your speakers with a pair of 110W triodes? :unsure:

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Thanks for having me over today Keith, the hospitality as always is first rate.

As we discussed I think with some work done to improve your lower registers and lower midrange and you will have an outstanding setup (its still great by the way, just wanted to make that clear).

My brief thoughts. (remember this is my own seat of the pants opinion.... no proper testing was conducted)

Cary CAD-211AE - Sounded the best with simple music. I felt with more complex music it lost a bit too much control. I also personally found that it added a bit of warmth to the sound. Personal taste will dictate if thats a good thing or not. I felt that it lacked the dynamics of the other amps. When we listened to Stumbling Block from Foggy Highway by Paul Kelly & the Stormwater Boys this was by far my preferred setup. The imaging was very precise. I was paying very close attention to the where Paul was standing on the sound stage and it was dead smack in the middle and only slightly in front of the speakers. Sounded very good.

AudioAnalyse - The first track that JA played on it showed that it was more dynamic than the Cary amps. I actually preferred this amp for that song over the Cary. But then when we played the Paul Kelly song the imaging was shot. Paul was now almost sitting on my lap and shouting at me, which was not very pleasant.

Jeff Rowland - I think this was the favourite combination of the day. Apart from the Paul Kelly song I felt that this gave the most enjoyable sound all round. Didn't really put a foot wrong. Just a great sonic performance.

Thanks again for having me and the others over today Keith, greatly appreciated.

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You are always welcome, Drizt :unsure: You are quite right that the Cary adds warmth to the sound. This was a choice I deliberately made in the beginning although I am now starting to hanker for something a little more neutral. It's annoying when our tastes change, isn't it :) I will start experimenting with different valves first, and if that doesn't give me the sound I am after I might go look for something else.

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You are always welcome, Drizt :unsure: You are quite right that the Cary adds warmth to the sound. This was a choice I deliberately made in the beginning although I am now starting to hanker for something a little more neutral. It's annoying when our tastes change, isn't it :) I will start experimenting with different valves first, and if that doesn't give me the sound I am after I might go look for something else.[/b]

Yeah, tastes seem to change frequently which makes things harder. Happy playing/hunting.

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[

- a very old AudioAnalyse amp, 70Wx2 Class A. RRP (in the 1980's) about $20,000

Interested was that the list price back then or in todays terms? if list price what is that equivalent to today $100,000? in a new amp today?

Any ideas on what accounts for the diffrence - for a non tech head like myself

I have tried the same thing with switching much cheaper amps on myy system and do notcie differces but alwasy unsure if it is set up (most are intergrated amps) which I presume affects diret comparions.

Would have been great to hear - any pictures Keith - would love to see some shots of the amps in situ! :clap:

Cheers

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Thanks again Keith for putting on such a great spread for us yesterday. The tucker again was first rate.

As for the amps, well as I said, in my opinion high sensitivity speakers, like yours are inevitably going to sound best with quality valve amps and I feel your Cary amps were the nicer of the three we had available yesterday. They sounded richer. I too thought the Rowland held up very well indeed and I felt it was a very enjoyable listen. The AudioAnalyse seemed fine on the bass but was lacking everywhere else. The Paul Kelly track played by Drizt brought a bit of a honk to the vocal. It also lacked the same bite that the Cary had when reproducing the horns from whatever classical track we listened to. The Rowland was also a little behind the Cary in this regard, but by a smaller margin. Hehehe, typing that feels funny, like I am critiquing one of my kids :biggrin:

If I had been listening at home to the same tracks at the same (loud) volume, my amp would have been quite a bit warmer than what it was yesterday, which tells me (remembering I am just another silly enthusiast with no technical nous) it was working well within it's current drawing capability, so I interpret that as you not needing such an amp for two parts of your speaker, being the mid driver & tweeter, where the valve jobies shine. Further consideration to maybe making some changes for the bass driver, to hopefully meet your very lofty expectations, because lets face it, what you already have is very bloody good.

With your speakers, I believe they demand quality valve amplification and I do think the path you are wanting to take with your bass driver, with SGR is making more sense. JA has been telling you for ages to bi-amp. This too is making more sense to me.

In response to your question posted above, yes I would like to hear what your valve amps would sound like in my system. I'm sure I could arrange a short term entry permit into Philovision, as long as they don't over-stay their welcome :biggrin: I will need to devise a way to hide the annoying glow though.

I had a great day, thanks for the invite and I always enjoy sitting in front of your system. Thanks.

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I have been lucky enough to hear 4 different power amps in my system over the last 2 weeks. These were:

- my Cary CAD-211AE, 110Wx2 Class A. RRP$22,000

- Cary Cinema 2 (see seperate review), 200Wx2 Class A/B. RRP$4500

- a very old AudioAnalyse amp, 70Wx2 Class A. RRP (in the 1980's) about $20,000

- Jeff Rowland's baby power amp, 150Wx2 Class A. RRP around $9,000 (unsure of this)

The guys were around today and we got to compare the CAD-211AE to the AudioAnalyse and the Jeff Rowland. I am sure the others will post their listening impressions eventually, but here are mine. All listening was done unblinded with "approximate" volume matching. It was enough to hear the differences:

Cary CAD-211AE - mids and top end were richer than the other two, with a more extended top end. Control of the woofer was vague and lacking, sometimes resulting in a "boom" where there should have been a "bang". Both the other amps had enough oomph to make the woofer hit its xmax - not the Cary. Soundstage was wider than the AudioAnalyse but image localisation not as precise. Amp had enough power to drive the speaker to uncomfortable SPL's.

AudioAnalyse - a very unusual older amp with massive heatsinks radiating from the transistor which sits proud of the amp in a little metal box. Had an obviously dryer presentation compared to the other two amps. The mids and highs were thinner without the same ease as the Cary. Soundstage was a little narrower, but image localisation within was more precise. Also less forward than the other amps. Having gotten used to the sound of the AA, I also find it a tiny bit more dynamic than the Cary's. Noise floor is obviously lower.

Jeff Rowland - Pulse-R summed it up best - "it just sounds nice". Having been to Luckydog's a few times now and gotten used to the remarkable ease and relaxing sound of his system, I was wondering how much of it was due to the speaker and how much from the upstream electronics. I'm not sure if LD would agree, but the sound from the Rowland today made me think that suddenly I have a lot of the ease of LD's system in my own system. I wasn't sure what to expect when the sound first came on. This is definitely not an amp that sounds big, brutish, and powerful (Krells come to mind). Instead, the sound was relaxed, dainty, and full of charm. The Rowland has a relaxed presentation, with a midrange which is different to the Cary, but just as appealing. Where the Cary was warm, the Rowland was sweet. Obviously a difference in the harmonic structure. The Rowland's woofer control had it all over the Cary - it just had a much better grip on those recalcitrant bass drivers.

If there was another thing that I realized recently - 70W of solid state power is enough to make the woofers max out. The midrange horn and tweeter sound like they have a lot more to give - they continue to sound clean while the woofer box is distorting like crazy. Makes me think I should get rid of the drivers in the woofer box, and pronto.

In any case, I ended up liking the Rowland a LOT. Thanks for bringing them over, LD. Now would you like to hear your speakers with a pair of 110W triodes? :)[/b]

Thanks for the review Keith - insightful and thought provoking.

The AudioAnalyse I presume to be the b90 form around 1986. Specs are:

* 2×100 Watt class AB

* 2×20 Watt class A

* 1×350 Watt in bridged mode

* 750 Watt peak

* 32 Ampere peak currrent

* Weigh 10 kg

There is a small video here.

Job well done lads, shame we didn't get some of the catering as well... :unsure:

cheers

2sheds

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Agreed LD ... but what I found was that all 3 amps presented as much detail as each other. None was obviously lacking in this. The same could not be said of the Cary Cinema 2 I had a couple of weeks ago - that amp obviously smeared the top end and gave music a muffled quality.

2sheds - it's not a b90 :unsure: I don't know what the model name is, but the amp does not look like that. I'll go take a picture of it later.

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Agreed LD ... but what I found was that all 3 amps presented as much detail as each other. None was obviously lacking in this. The same could not be said of the Cary Cinema 2 I had a couple of weeks ago - that amp obviously smeared the top end and gave music a muffled quality.

2sheds - it's not a b90 :unsure: I don't know what the model name is, but the amp does not look like that. I'll go take a picture of it later.[/b]

Maybe this one...

a.jpg

c.jpg

cheers

2xsheds

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Looks like an old ME amp with elephantiasis! :biggrin:

Come to think of it, specs are not dissimilar either, apart from a much higher output into class A. Hence the "growth" on the top of the amp, I guess.

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Hello Keith W,

Jeff Rowland is 150 watts class A/B not true class A.

This model will soon be discontinued when the remaining metal work runs out in the states. Now only available in Black.

Good to hear it held its own against higher priced competition.

BTW I previously sold Krell and Jeff Rowland and but for the exception of a few speakers that needed the sheer drive of the Krell I prefered to musicality and its ability not to draw attention to itself over the Krell.

Cheers Tony C.

Good on you LD for dragging your gear around Victoria.

S.A Members I had the Jeff Rowland in my bedroom at Tony M's plage at the GTG.

Next time you'lll hear it.

Cheers Tony C

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Hi andythiing,

Any ideas on what accounts for the diffrence - for a non tech head like myself[/b]

Much of the difference in sound retrieval can be attributed to a characteristic of amps called PSRR or power supply rejection. A design that is poor in this regard will pick up and amplify all the half wave harmonics generated by the (Class AB or :( output stage and superimposed on the power supply impedance. These blur images and raise the noise floor and generally contaminate the sound. :angry:

Designers can either improve the PSRR (if they know how) or use regulated power supplies or run Class A which eliminates these artefacts. The last two are expensive methods both of which require bigger power supplies transformers and heatsinks, so you end up with these monster amps. In my 40 odd years of designing amps I have seen a lot of naive, blinkered design from iconic makers.

The first method is the elegant one as it desensitises the amp so it ignores artefacts on it's power supply. If this PSRR can be finessed, there is no need for Class A or regulated supplies or indeed the inflated size weight or $$$ price tags. But it's knowing how. I published an article in Wireless World (UK) "Distorting Power Supplies" back in Dec 1990 that describes the mechanism in detail. If you feel like wading through the maths / diagrams I can send a copy. Of course this is one of my primary design aspects with my current designs.

Greg

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Kieth and others, thanks for posting your thoughts on the amps, always an interesting read, especially for those of us who don't get to play with gear of that prowess on a regular basis.

The Simaudio Moon amps are one bit of gear I'd love to hear. Reviewers regularly comment on their mix of musicality and valve like smoothness (the best of both worlds).

Again, not a product for the financially challenged. :blush:

Cheers

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Thanks Curly, but I was not listening to a SimAudio Moon :angry: We had Luckydog's Jeff Rowland power amp.

Greg B, what you have said sounds fascinating. Would love to hear a bit more about PSRR and distorting power supplies.

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Hi andythiing,

Much of the difference in sound retrieval can be attributed to a characteristic of amps called PSRR or power supply rejection. A design that is poor in this regard will pick up and amplify all the half wave harmonics generated by the (Class AB or :( output stage and superimposed on the power supply impedance. These blur images and raise the noise floor and generally contaminate the sound. :angry:

Designers can either improve the PSRR (if they know how) or use regulated power supplies or run Class A which eliminates these artefacts. The last two are expensive methods both of which require bigger power supplies transformers and heatsinks, so you end up with these monster amps. In my 40 odd years of designing amps I have seen a lot of naive, blinkered design from iconic makers.

The first method is the elegant one as it desensitises the amp so it ignores artefacts on it's power supply. If this PSRR can be finessed, there is no need for Class A or regulated supplies or indeed the inflated size weight or $$$ price tags. But it's knowing how. I published an article in Wireless World (UK) "Distorting Power Supplies" back in Dec 1990 that describes the mechanism in detail. If you feel like wading through the maths / diagrams I can send a copy. Of course this is one of my primary design aspects with my current designs.

Greg[/b]

Thanks for the answer that gives me a good appreciation and was simply explained - I can't claim to fully understand it but at least I have a better aappreciation. Also appreciate the offer to access the paper but my limited technical skills/knowledge may preclude me from getting a lot out of it. I think I will try and build my knowledge base up slowly to start with - by letting some of the higher level issues saok in a bit.

Your response is very much appreciated :clap:

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Hi Keith W,

I have reworked the article into a bite by byte forum thread here -

http://ska-audio.com/Forum/YaBB.pl?num=1177359205/0#0

so it's a little more readable as the original was written for a tech mag.

Hi andythiing,

Your response is very much appreciated[/b]

What it means is that a great sounding (SS) amplifier doesn't need to be big and $$$ and Class A, just well designed. :) The monster amps only really excel when it comes to driving 1 ohm loads and nails!

Greg

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