Monoblocks or upgrade to larger amp?

Good question. Obviously there would be a big benefit to adding another amp and running them as monoblocks. Better staging and refinement, but the 250 is an improvement as well. I am not that familiar with the Contours. Do you feel you need much more power? If so, go the 250. If you are very pleased with the sound and just want to better it sonically, I would probably just go with the second 100.

You can always go with 2 SA 250's! :)

there was another discussion recently that applied to this topic where it was thought that bridging the amps didn't produce all that good of sound. Unless you were to biwire/biamp the system, one channel of each amp for the highs and one for the lows or one amp for the highs and one for the lows, bridging would would be required to use the amps as monoblocks. The biwire idea always gets fairly good results though ususally only one amp or a pair of tru mono blocks is involved. More power is always nice for extra bass control and dynamics. I have tube amps with around 230 per side and am wondering what 450 would be like. I'll probably just keep wondering though. For simplicity i think i'd get the bigger amp

Bi-amping will almost always improve sound quality. Actively bi-amping is almost always the best way to go.
Most people will recommend vertical bi-amping, but horizontal biamping will also provide definite advantages.
I personally am actively horizontally bi-amping. The difference from when I just used one amp is mind boggling.
I will never go back!

Believe me, the SA250 will run the Dynaudios much better than the SA100 (have tried these combinations). As suggested above, if you buy another SA100 then bi-amp, don't bridge. You will also find the SA250 sounds different than the SA100 - and the SA250 Mk3 sounds quite different from the Mk4. Looking at your gear, the SA250 Mk3 will be a very good match and obviously cheaper and more available second-hand.

Remember, moving from 100 to 200 watts is only 3db.

Unless you *know* you need the 3db then the extra power means nothing.

All things being equal and so long as their is no question about the sonic differences amongst the amps, the Dynaudio's will always work best with the most power. If you aren't going to actively bi-amp, i would stear towards whatever gave you the most power per channel WITH the sonics that you were looking for. Sean
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Unless I missed it, no one has yet mentioned the advantage of short speaker cables (with a longer interconnect) that monoblocks offer. I found that to be a major improvement in a fairly controlled experiment: monoblocks in place, 7' and 18" speaker cables, both Stealth UR, compared. With all the other advantages already mentioned, I'd go for monoblocks.

One possiability is to get the 250 and see if does the trick. Before getting rid of the 100 try using it with an active crossover just driving the top end and the 250 on the bottom. It could be the best of both ideas. Chris

The Dynaudio's only have one set of input terminals, so bi-amping isn't possible.

Going from 100 wpc to 250 wpc would be an appr. increase in power by 3.75 db's. In theory, this may not seem like much. In reality with power hungry speakers, it can make a WORLD of a difference.

When i changed amps in one system using "power hungry speakers", i went up 1 db and it made a very noticeable difference. While most would say that 900 wpc would be enough for ANY speaker, i was still able to drive the amps into compression. Replacing the biamped pair with one amp rated for 1200 wpc made a world of difference in terms of "never running out of steam" and the increase in "ease of reproduction" and "liquidity".

Keep in mind that a low sensitivity reading at 1 watt does not necessarily make for a "power hungry speaker". Even though some speakers are not real efficient at low levels, they can play quite loudly with just a bit more power into them. Other speakers may take a boatload of wattage to play at that same level. My findings and experience are that the more complex the crossover is, the more power it will take to "rock the house". Much of the power that the amp is generating is "eaten up" by heat in notch filters, impedance compensation networks, etc...

As such, the Dynaudio speakers use very complex crossovers with a lot of parts in them. Much like the speakers i'm using in my HT system, they will "drink an amp dry" if you give them the chance to. Sean
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I would have a bit more respect for the opinions of the dB freaks if you had actually heard a SA100 and SA250 in a few systems. I don't give a toss which one has the more power, the SA250 is a significantly better power amplifier.

Viridian, you wrote "The difference in power is very negligable, any of you slide rule types out there want to calculate the power difference in db for us?" Somehow I cannot find the point you claim to have made about sound quality being the deciding factor - do I have to try reading it backwards, or have familiarity with the Koran? Or is your point on some other post somewhere and I missed it?

You also wrote "Maybe Redkiwi should actually try to read the posts before responding." Maybe Viridian should actually try to post the point he is claiming to make before claiming others are not reading it.

Viridian: so, does your experience tally with Redkiwi in that the 250 is the better sounding amp?

Excuse my confusion, but your first post just has the one sentence Red reproduced (maybe the rest didn't get posted?) and in the second I can't see your suggestion.

Sorry for me adding more confusion than what already seems to be piling up on this thread. While i have heard the SA-100, i was basing my comments on one SA-100 vs one SA-250 in terms of db comparisons. Sorry for not being too clear on that one.

As to Redkiwi's comments, i too would go with whatever amps sounds best. If the sonics are there but the power isn't, you could always double up on the amps. While this could be quite costly, did you think that you would get away "cheaply" in a hobby like this : ) Sean
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I must have been in a bad mood with my earlier posts - sorry about that. Knowing both these amps, it does not gel with me to consider the SA250 as just being a more powerful SA100. Secondly there is a significant difference between the SA250 Mk3 and the Mk4. I don't mean the Mk4 is significantly better, but it is significantly different.

The word is, by the way, that US buyers are holding out for a Mk4 version of the SA100 and sales have slowed, causing Plinius to consider releasing a MK4 version, even though they have no upgrades planned. Kinda illustrates the false conclusions people jump to about how a family of products is developed.

Another little story - A friend of mine had a SA250 Mk3 and used it with his Dynaudios and found it lacked life - auditioned the Mk4 and found it went in the wrong direction for him, and believe it or not went back to using a McCormack DNA 1.0, because it gave the added edge that the Dynaudios needed. I relay this just to put the relative sound in perspective. I reckon his problem was his other gear which was Meridian 500 and 566-20, with a Sonic Frontiers preamp, and his insistance on using very ordinary cables.

Last point - if I had an SA100 and Dynaudios, I would be craving for more power too. The Dynaudios require a powerhouse amp and the SA250 may do the job, but may also be a little laid-back in this combination. The SA 250 Mk4 and Thiel 3.6 work really well together for me, but the Dynaudio is not the same kind of speaker as the Thiel 3.6, if you know what I mean.

Thanks, everyone. Redkiwi, let your friend know that cables have a major impact on the sound. I've tried JPS Superconductors II, Harmonic Tech. Pro, Silver Hyacinths, Transparent Super and Ultra (highly overrated), Nordost SPM's and NBS Monitor IV's, III's and I's. Each cable had it's own unique characteristic. The NBS Monitor I's interconnects brought out the detail better than the rest. The III's speaker cable complemented the I's very nicely (especially since the I's speaker cable are priced a bit out of my range). Looks like I'll keep an eye out for the 250 Mk IV instead of getting another 100 Mk III. I really appreciate all the feedback. Thanks again and happy listening!

My friend suffers from being an electrician and so discussions about cables are not too meaningful.

So, pls help: final verdict? Two S100 or one 250 (or wait for Mk4?)? A friend's been plaguing me for the answer -- and I don't know the machines AT ALL! He's got Avanti IIIs to drive.

Thanks!
Greg

Looks like the 250 Mk.IV is the choice.

Thanks!