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Infinity IRS Betas - proper amplification

I have read these forums for years and I am finally joining after
buying a system that I think demands more commitment to this hobby than I have had before. I am hoping for a contrustive and thoughtful discussion of what my best/most reasonble ($) choices are going forward. I do ask that people not snip demeaning responses about things they might consider obvious. But solid probing questions are welcome. 

My room is roughly 16x24, with a vaulted ceiling that passes to an upper floor running 8’ high from the 24’ wall where the speakers will point up the vault. (Day 1 -any way) 

My current systems are all varying degrees of vintage. Long story short...divorce...Very early Cornwall’s...upgrade to separates (mac MC2100s bridged) off a Decent Yamaha HT integrated., added a Miller kriesel sub and off I went....as is
great but “Klipsch need tubes...” enter mc240, c20, mr71....(now my bedroom system, its a big room) primarily CDs.....scored a roached set of
JBL Apollo 51s,now redone with an N1200, D130 Bs and the standard horn...enter highly modified mc60 monoblocks run though a sunfire theater grand 1 always in source direct off a decent dedicated music server (nothing special laptop) I
dont hang in a huge audiophile group, but some musicians are in the
mix, aside from the magnolia no holds barred theater room I had never heard
anything that made me smile broader than my stereo playing. Saturday night  was
”One Slip” played at (-5dB) (I live in the woods) It was really special....UNTIL....

Last week a local stereo buff listed his one owner excellent condition 10/10 aersthetially last production run IRS Betas, he asked for half of original retail....I now own them.....

Now I am at the OMG, what have I done....he had an easy 15k into his system not including changes over time. Yes, I am getting to the
obvious

What now! I am going to dust off the 2100s for the low end, the mc60s even into 4
ohms are not enough (he ran a sonic frontiers 2 ($2k if I want it (sovetek kt88))) I don’t think I need to worry about the demand on the 60s (PLEASE CORRECT ME IF THATS WRONG) though I am concerned about the polarity(?) as they are heavily modified with filter tubes replaced with filter caps and a huge capacitor in the signal path to
punch harder (I am not an electronics guy but the techs I have taken them to over the years all say they sound and test tight and clean. (I agree ;)

i have tried to be inclusive and I hope folks will have constructive thoughts to share, obviously this won’t be cheap to pair up and I would prefer to learn before I spend $$$.
 Lastly....I Love most music and see live stuff at least twice a month.I  listen to deep earthy blues, ska, some jazz, but more on the funky side. Smiths/cure/stone roses...very little hardcore outside of live shows (But, Ride On by Bon Scott is
a beautiful thing) I also host about 1 party that usually evolves to dancing.....

Wayyyy more than I planned to write...with my thumbs! 

The typos are....just that😮

respectfully,
Walt
128x128entomologist
crwilli57
10 posts
 
I ran my Betas with a McIntosh MC352 on the subwoofer panels and a Threshold S/100 on the upper panels.   Then replaced the Threshold with a McIntosh MC452.   

Yes, I am sorry, almost $9000 of amplifiers.   

The more power the better.  Any amplifier that ‘doubles down’ would be a good direction to go.  Eg 100wpc at 8 ohms, 200wpc at 4 ohms, 400wpc at 2 ohms or a McIntosh with autoformers.
awahl's avatar
awahl
7 posts
 
On my IRS Betas I used 4 mono Jeff Rowland 7 and was very happy. I still use one pair of Rowland 7 for the Base towers , the top end I run a Pass x250 that works fantastic at low levels the detail and musicality is incredible however when pushing the amp to leave class A , quality deteriorates a little. (compared to some other power amps they just sound very bad when the speaker demands control).
Other Power amps I would consider for a IRS Beta system is
PassLabs 100.5 ,
Jeff Rowland 7 ,
Threshold has some option ,
MBL I always liked but was not convinced ,
AVM 8,2 would like to explore ,
Krell I never explore due to the harsh sound ,
Usher had some amp that looked OK but don't know enough about ,
Mcintosh I love the look and build but the sound never impressed me ,
Some old mark levinson ML 3

PS;
A. The biggest improvement in sound on my IRS Beta set up I got out of my pre-amp the Legend Audio L2 signature (now Von Gaylord Audio) and a DA from them plus interconnect cables. (=>tube for pre-amp!!!)
Tweaking the IRS Beta setup to be very revealing leads to most not perfect recorded music sound terrible , for that reason I have additional setups HHScott with Klipsch Corner-horn and a Legacy speaker with a Jadis amp.
B. While my amps were out for repair I had a workable experience with my old Yamaha MX1000 for the Base only (could not listen to it on the panels).
C. I used a MC250 (SS),MC 75 (tube), MC275 (tube)for the base as well but it sounded very muddy , your MC2100 may work for the base until you get something more serious.
johnabercrombie
2 posts
 
Hello Walt and other Beta owners. Around new year 2019 i payed an advance to buy a Beta system. The sale was cancelt by the seller. the system was a G serie with around a G000850 serie numbers for the bass towers to not be exact. So i wonder how many Beta's are made. I don't find it on the internet. Last time a saw a picture with number G001890 so you can please check your numbers and let me know….
Thx
 
progrockkeys
1 posts
 
For the IRS Beta cheapskates out there, an Adcom GFA555 will drive the woofers, and I even use an old SAE A502 on the panels. You can find each of these for around $500. I originally got some VTL 300 tube amps, used for $2500, but even after spending $800 to upgrade them at the factory, they have been hard to keep going. They sounded a lot better though, driving the panels.  G000865 and G000867 are the woofer serial numbers.
bdp24's avatar
bdp24
9,788 posts
 
A real good amp for woofers is the Electron Kinetics Eagle 2, if you can find one in good working order (they are by now pretty old).
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