Need help What monoblock power amps for bass?

Hi Shadorne,
I agree with you.Unfortunatelly,i have no acess to data on Q factor of my speaker.I enjoyed reading your post on other thread.
Underdog,
I thought about the idea of the 6 same monos.I was talked out of it.Plus i heard for myself in my system that different amps work pretty good.I think there is a lot of potential in that idea.Only combining amps needs to be careful.
Treble and mid driver will be amped by a tube amp that will be built specifically for Sinfonia.That way i can combine different things.

Hi Atma,

Nice to talk to you again.I know that impendance on each section (speaker is tri-wired) never changes more than +/- 10%.
Also,the whole speaker (if connected to one amp) acts exactly the same.8 ohm stable, +/- 10% maximum.
Seems an easy load for any amp.At least to me.
Alan said that tube amps work great in general (SET designs and Atmasphere OTLs), and also that Pass labs amps are also a great match.
He liked the idea of of 6 monos based on 320 B XLS SET.But i think bass drivers would be better with some other amp than SET.
The problem is that here in Croatia i can not listen to and evaluate a lot of gear.I bought Sinfonia only 3 days after i heard the name "Silverline" for the first time in my life.
And in amps there are many more choices...
So i am learning as much as i can for now.

Thanks a lot for all your kind answers.Dalton,monoblocks are mandatory due to the short speakers cables i own.I already chose this setup along time ago.

Ngjockey,i am still considering what attenuator to use,still i am not clear on this.Your input is very helpfull.But you were right,i was considering the pots.

Ramy,your speakers seems very serious and good.I appreciatte the input.I think power is not very important for Sinfonias,anything above 50 Watt would be ok.

What about shunt-type attenuator?I am thinking about ordering a pair of Endler's attenuators,connected straight into power amp(these already have RCA plug joined with them,so there is no interconnect cable to drive from preamp to power amp).Why not use these,or at least try them,and then build a similar style with Vishay S 102 for example?
Seems to me that having only one resistor in signal path is better than more of them.
Atma,why is active crossover neccesary with bi-amping?What about the passive crossover in speaker?Seems to me that each driver still gets the range it needs.

Thanks a lot Atma.Your knowledge always helps a lot.I think Sinfonia was designed for bi-amplification (actually for tri-amplification).

In the case of the passive crossover allowing for bi-amplification, it does seem to sound better than using an electronic crossover.

I thought this would be the case.
The reason for this is probably that there is one less element in the signal path.I think my speakers will work fine in multi-amp configuration,but i have to try and see.There is simply no other way.But first i need to treat the room.This is the next stage.

Price range - well,it depends.Sinfonia is tri-wired.So SS monos will drive either one 12" woofer only (one connection),either that 12" woofer plus another 12" woofer and one 7" mid-bass (other connection).

If 30 W/ch 320B XLS SET proves good/very good in bass,then i will let it drive tweeter and 2" midrange,along with one 12" and 7".
That way i will not sacrifice anything in midrange.Bass will still be suficcient if i connect a rear 12" woofer to SS amp.This woofer is configured for the deepest bass.
In that setup i will not go above 3-4 000 $ for SS monos (used).This is top,but i could also end up paying even less.For example ,Wired4Sound 250 W/8 Ohm monos seem good enough for that option.Class D shouldn't be a problem there.

But,if SET amp shows only treble and midrange good enough,that i have to go with more expensive SS amp,as it will be powering both connections (7"+12" and 12").
Then i have to spend more....Pass seems a way to go then.

I will know which way to go when the monos are built.But i have a great confidence in a man who will build them for me.
I think they will prove good enough for everything.I think that tweeter and 2" mid and 7" and front 12" will end up powered by these.I have a great respect for the knowledge of Siniša Trlin.I was lucky to meet him,he thought me a lot about audio.
Since there is no limit in $$ for building these,i think they will be able to stand side-by-side (or surpass) any SET amp,regardless of price.I am very curious to hear them.
Patience is a virtue.