20.7s

SteveFord · « **Reply #80 on:** 16 Dec 2012, 10:15 pm »

And how did the McIntoshes do with the 20.7s?

mg3720 · « **Reply #81 on:** 19 Dec 2012, 03:34 am »

Quote from: SteveFord on 16 Dec 2012, 10:15 pm

And how did the McIntoshes do with the 20.7s?

At low listening levels they did very well. For this experiment I was using my McIntosh C2300 tube pre amp with the tube power amps in a little under 4200 cubic foot room. The 20.7’s had a smooth, easy going feel to the sound (a “tube” characteristic?). I normally have Krell solid state monoblocks driving the 20.7’s. Even bass passages had some kick to them. At louder or more dynamic levels, I felt the McIntoshes were holding the 20.7’s back. I guess I know what they can do with the Krells. The MG1.7 and McIntosh combination works really well.

TONEPUB · « **Reply #82 on:** 19 Dec 2012, 07:44 am »

Quote from: medium jim on 16 Dec 2012, 05:00 pm

Kevin:

You might be surprised and I would almost bet that you could live with the 20.7's with a mere 150wpc of tube bliss. Off the top of my head, I believe the VAC's have 3db of dynamic headroom, so they can hit 300wpc for short bursts. Then there is the way larger panels will energize the room vs the slightly smaller 3.6's that will compensate nicely.

Jim

Ive just never heard magnepans light up with a tube amp. Even when I had the ARC REF 250's here they were pretty good, but just no where near as immediate and lifelike as a big (or big pair) of solid state amps. There's just an effortlessness even at low volumes that really comes through with a big, high current amplifier and Magnepans. And I've probably tried about 50 different tube amps over the last 30 years with quite a few models. It's just never been all that exciting.

Rclark · « **Reply #83 on:** 19 Dec 2012, 08:05 am »

My experience reflects what you're saying here Tonepub. My finding is that Magnepans like LOTS of power. I have modded MMG's and they eat up nearly 500 watts a side with Ncores, just mmg's, they take power and ask for more. They don't freak out or act like they're about to blow up in any way. 50 watts is enough my ass. They never played like this with my Virtue at 87watts per side. 87 Watts per side they would clip at like 85dB. With Ncores they simply stop getting louder and still take it. And at that point you're got your hands pressed against your ears. They take HUGE power and respond to it.

The extremely high measured performance of these amps, at 1 watt or 480, lends to extremely high fidelity with Magnepans. I feel like I have the ultimate "budget" (speakers plus amps - 5K) rig.

So I've got nearly 500 watts per side, solid state, and the low level is extremely live and engaging. Lit up, as you say.

So I believe what you say about solid state amps and Magnepans. You have a lot more experience than any of us.

SteveFord · « **Reply #84 on:** 19 Dec 2012, 09:29 am »

Magnepan uses either Bryston or Audio Research amps; there's much to be said for both sides.
The Class D amplification appears to be coming into it's own as well. I heard some of the earlier Class D products but not the latest and the greatest; I suspect it's going to be a lot like digital where there's a lot of progress every year.
I like the VTL sound so looking for amplification isn't something I even think about.
Not to totally derail this but does anyone know for sure whatever happened to David Manley?

kevin360 · « **Reply #85 on:** 19 Dec 2012, 01:19 pm »

All I can do is relate my personal experience. I have tried a number of amps with my 3.6s and then my 3.7s. Until I inserted the Bryston 10B Sub crossover into my system, I had no doubt that I absolutely required the power that the Pass X350 had on tap. I systematically pushed that amp as evidenced by the bias meter. With the XO in place, the deflection of that meter diminished greatly.

The door was opened to an amp with less power and I felt the pull towards valves. I replaced that mighty Pass amp with a VAC Phi 300.1 and suffered no loss in dynamics or frequency extension – not a warm, syrupy tube amp. In fact, my initial impression was that the sound was very familiar, but I began noticing subtle benefits. I held on to the Pass amp for several months because I wanted to be sure that the considerable investment in the VAC amp was worth it. A few months after purchasing it, I confirmed the value of the VAC by swapping the X350 back into the system. At that point, I realized that the differences, though initially (and probably still) subtle, were practically indispensable – I had learned where they existed and no longer found them all that subtle.

Eventually, a tube went into run away during a power-up and I temporarily lost my valve amp. Naturally, this occurred within a week of my selling the big Pass amp. So, I moved my Pass X150 down to the spotlight position. It doubles into 4 ohms, which suggests that it should provide more grunt than the tube amp of the same rating (into 8 ohms). That simply is not so – not by a wide margin. At low volumes, it definitely lacks the body I get with the VAC. As I push the volume into the territory of 'loud', the dynamics begin to flatten – something that absolutely does not occur with the valve amp. In fact, I blew the main fuse on the X150 trying to achieve similar (as registered on my RatShack meter) sound pressure levels – and the sound was not only lacking in dynamics, but had also become somewhat shrill.

I have little doubt that big power is required for Magnepans which are being driven full-range. Even in the context of 3.7s that aren't being asked to do much below 60Hz, that appears to be so for solid state, but the right tube amp seems to have no problem. I realize that my experience is very limited, but I don't think that completely invalidates my impressions. I have not tried to drive my 3.7s without the sub XO in the system, but I honestly don't think I need to – memory of how the bias meter on the X350 deflected in that context is enough evidence for me.

YMMV

medium jim · « **Reply #86 on:** 19 Dec 2012, 03:58 pm »

I think enough has been said with regard to SS vs Tubes and will let it ride.

Jim

rollo · « **Reply #87 on:** 19 Dec 2012, 04:12 pm »

Whatever amp you choose must have lots of juice for Maggies. The class "D" hybrid we use gives ya 1000W @ 35 amps, oh my !

charles

SteveFord · « **Reply #88 on:** 19 Dec 2012, 04:33 pm »

That should be enough power.
I found my answer on David Manley:

http://www.gate.net/~vital/www_manl.htm

josh358 · « **Reply #89 on:** 22 Dec 2012, 03:11 am »

Quote from: kevin360 on 19 Dec 2012, 01:19 pm

A few months after purchasing it, I confirmed the value of the VAC by swapping the X350 back into the system. At that point, I realized that the differences, though initially (and probably still) subtle, were practically indispensable – I had learned where they existed and no longer found them all that subtle.

And now you know why it isn't a good idea to try Heroin.

Seriously, I'm not surprised that the VAC has more dynamic headroom than the smaller Pass, you can usually get away with a tube amp of half the nominal size of a transistor amp.

jimdgoulding · « **Reply #90 on:** 22 Dec 2012, 05:25 am »

For my size room, I'm real tempted to buy a pair of 1.7's. Got a pair of Kenwood LO7M's at 150w into 8ohms that ought to drive them. I say ought to cause I don't know.

SteveFord · « **Reply #91 on:** 22 Dec 2012, 10:40 am »

There's only one way to find out.

When I had Carvers with meters I found that most of the time I was using 50WPC or less.
When I'd get carried away I'd see peaks of 150-200 but that was about my limit.

jimdgoulding · « **Reply #92 on:** 22 Dec 2012, 05:32 pm »

Quote from: SteveFord on 22 Dec 2012, 10:40 am

There's only one way to find out.

When I had Carvers with meters I found that most of the time I was using 50WPC or less.
When I'd get carried away I'd see peaks of 150-200 but that was about my limit.

Thanks, Steve.

Question for anybody . . I would only be able to get the 1.7 panels 5' off the rear wall. What could I expect in that case? I shouldn't want to compromise depth of field or the reproduction of a hall, for example, in my 15x12x8' room.

medium jim · « **Reply #93 on:** 22 Dec 2012, 05:55 pm »

Quote from: SteveFord on 22 Dec 2012, 10:40 am

There's only one way to find out.

When I had Carvers with meters I found that most of the time I was using 50WPC or less.
When I'd get carried away I'd see peaks of 150-200 but that was about my limit.

Were you running them full panel or with subs? Too bad my amps don't have wattage meters on them, but only when I really get crazy do I run out of amp....but I have subs to take the steam of the botton 2 octaves. My Model 9's are moddest at 70watts, feel they're closer to 90 with the right tubes and can peak over 150watts. I hit the upper 90's at the listening position C weighted on my RS meter and when measured for peaks, around 105db without issues...about that it compresses.

Without the subs it would be a no go for anything above 90db in the c weighted range and with no real bass to speak of. Since I would be using subs anyway it is a non sequitor.

Jim

SteveFord · « **Reply #94 on:** 22 Dec 2012, 07:31 pm »

5' will be just fine, tweeters in and don't go nuts with sound deadening materials.

jimdgoulding · « **Reply #95 on:** 22 Dec 2012, 07:43 pm »

Quote from: SteveFord on 22 Dec 2012, 07:31 pm

5' will be just fine, tweeters in and don't go nuts with sound deadening materials.

Understood. Thanx.

SteveFord · « **Reply #96 on:** 24 Dec 2012, 10:56 pm »

Well, I'll be a (fill in the blank).
Sometime back Wendell took me to task over "3.7s on steroids" as I guess that the implication was just more brawn.
I did a little fooling around with the preamp and phono pre earlier tonight and put on "One of These Days" from Pink Floyd's Meddle.
During a slide guitar section I had a moment of panic as I thougt a tube was going haywire.
Nope. It was a slide guitar passage which zipped from the bottom portion of the left speaker over to the bottom portion of the right speaker and then the guitar swirled up the right speaker.
I've heard this album since it was released back in the early 70s and I've never heard that passage before as it was always buried in the mix.
Increased resolution would be the phrase (along with moving a lot more air).
Very impressive.

Back to Meddle. The dog really hates this album, ha, ha.

medium jim · « **Reply #97 on:** 24 Dec 2012, 11:13 pm »

Quote from: SteveFord on 24 Dec 2012, 10:56 pm

Well, I'll be a (fill in the blank).
Sometime back Wendell took me to task over "3.7s on steroids" as I guess that the implication was just more brawn.
I did a little fooling around with the preamp and phono pre earlier tonight and put on "One of These Days" from Pink Floyd's Meddle.
During a slide guitar section I had a moment of panic as I thougt a tube was going haywire.
Nope. It was a slide guitar passage which zipped from the bottom portion of the left speaker over to the bottom portion of the right speaker and then the guitar swirled up the right speaker.
I've heard this album since it was released back in the early 70s and I've never heard that passage before as it was always buried in the mix.
Increased resolution would be the phrase (along with moving a lot more air).
Very impressive.

Back to Meddle. The dog really hates this album, ha, ha.

Funny thing, it was several early Pink Floyd albums/cds that showed me how much I was missing, especially Atom Heart Mother. Come to think of it, there are many albums/cds that I discovered many new things on when I got my 2.5's.

Jim

MGbert · « **Reply #98 on:** 24 Dec 2012, 11:44 pm »

Quote from: medium jim on 24 Dec 2012, 11:13 pm

Funny thing, it was several early Pink Floyd albums/cds that showed me how much I was missing, especially Atom Heart Mother. Come to think of it, there are many albums/cds that I discovered many new things on when I got my 2.5's.

Jim

Well, that tears it. I was looking for an excuse to play Atom Heart Mother; you just gave me one!

On the subject of albums that mix orchestra with Rock Band, the new Keith Emerson Band CD "The Three Fates Project" is well done musically and sonically. At least one thumb up.

MGbert

SteveFord · « **Reply #99 on:** 24 Dec 2012, 11:57 pm »

I'll have to pick up that Keith Emerson - I knew I liked him when I saw a picture of him wearing a Norton tee shirt. How bad could he be?
I gave side 2 of Meddle a listen and you know that one weird piano note that they ran through a wah wah peddle? I never knew it but that note is repeated throughout side two, it's not just in the beginning and the end of it.

I'll give Atom Heart Mother a spin tomorrow, the dog needs a break after side one of Animals.
They must have put something on there that only dogs can appreciate as she went from first one speaker to the other and circled them. Whatever it was I couldn't hear it.