What amp couldn't drive your Infinity's

7.62

7.62

Infinity nutcase.
I thought it would be fun to share some stories of the Amps you've burned threw trying to power your Infinity Speakers.

For me it's been my Kappa 8's presenting the biggest challenge so far, and these are ones that didn't work for me.

Adcom GFA 555-11
Carver A500-X
B&K ST-202
Iverson Eagle 7A

My biggest disappointment was the Eagle 7A, I shelled out some pretty good coin for that monster. My brother in law and I were out on the back porch having one of our BS sessions on a Saturday night jamming to some Tool when all of a sudden nothing.......no sound.

I only had the amp for about a week, a quick look and both fuses were blown. A quick switch back to the QSC and we were back in business. Over the next few weeks I experimented with different music and the Eagle repeatedly would drop fuses. I think it was needing a service but for the cost I decided to part with it and hold out for an Krell or Mcintosh.

The Kappa 8's had beat down another amp :D !
 
Good thread, I am looking forward to all responses.

1)
My new Onkyo A-9070 integrated pushes clean 140 wpc at 4 Ohms, and is a great match with RS-IIIa's. The speakers sound great, and if needed, I can crank up the volume as high as desired, and the amp does not break a sweat.
http://www.onkyo.ca/Products/model.php?m=A-9070&class=Reference

The impedance in RS-IIIa's drops to around 2.2 Ohm at its lowest, and the sensitivity is 88db.

2)
Now, the same amp hooked up to my current RS-II's is not up to the job. I can certainly listen to music with the current combo, but trying to at higher volumes will cause Onkyo to shutdown. I also suspect / feel that even at lower volumes I could use more headroom to really open up these fantastic speakers.

The impedance in RS-II's drops down to 2 Ohm above 5 kHz and never looks back, and moreover hangs around 3 Ohm around 100-150 Hz (where there is a lot of action when the higher woofer and all midranges cross-over), and then of course the sensitivity is lowly 85.6 db. So it looks like that this double whammy kills my Onkyo, these speakers demand a lot of current due to low impedance, and lot of power due to poor sensitivity (if one wants to rock the house).

So, at the moment I on the market for an upgrade, looking for GFA 555's (or the new 555se), Hafler XL-280 in particular, since they apparently drive RS-II's well on a budget.
 
RS IIs drove my AU-919 into protection once. I unhooked it immediately and never drove those with anything other than Yamaha power amps (M-70, M-80, MX-1) since.
 
If you want a XL280 I have one, its in great shape, it just needs to have the bias checked out....

thats it...

PM me if interested...
 
Pioneer Spec 2 on my woofer towers. Newly refreshed and put out 285w. It'll drive my AR-90s to crazy levels but no love for the woofer towers.
 
My Fisher KX200 integrated tube amp driving a pair of Quantum 2's didn't damage the amp but after listen to one LP it was quite a bit warmer than normal. It did sound good, but volume levels were somewhat limited.
 
You asked for amps but I think this falls into the same category. My Pioneer SX1280 (185 w) couldn't handle my RS-II's. I was a bit surprised.
 
Regarding amps that did not work out with vintage Infinities

With the Betas, Adcom 565 (mono-blocs) performed well at lower volumes, but heated up quickly at higher levels, did not work out. Same with Adcom 555-IIs.
Counterpoint SA-220s & NPS 400s were a great match, even a Solid-2 acquited itself well in the woofer columns. Of course, vintage Thresholds & Krells did fine.

With the Gammas, same as above. Additionally, Onkyo Grand Integra 508s did not mate well, went into protection mode easily. A CJ valve amp drove the upper range with no problem, whatsoever. Interestingly, a Parasound 3500 mated well with the woofers. Never tried the Parasound with the Betas.

With the RS-IIs, the Onkyos, Adcoms & Counterpoints did not work well. But an old Conrad Johnson MF200 sounds great, go figure. Best match to date with the RSIIs have been Thresholds & Old Krells.

Please note that all amps are in plural & I emphasize "old" because I lack the funds to own new Krells.
 
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When I first got my QLS's the only amp I had to run them was a Yamaha M45 (180 wpc @ 4 ohms). Nice amp, but definately didn't have the poop to run the Q's to live levels. I took a pair of Yamaha P2200's vertically biamped with 4 times the power to really get the effortless sound I was looking for.
 
Gas Son of Ampzilla on bass for QLS. At best you'd say it kinda sorta did it. Playing non-demanding music, it'd work. But don't try things like Chemical Brothers or something that is really bass and low percussion heavy. Just too much going on down low for the SOA.
 
Sansui BA-F1 driving RS 2.5. Even freshly recapped/refurbished including 4 22k Gold Tune filter caps and OnSemi replacements for the original outputs it just wasn't up to driving the Watkins properly. I never tried to push it hard into the 2.5's because even at moderate levels it got pretty warm. Loved it on the P362's and the 2000AXT's before I got the 2.5's. Rotel 990BX really woke up the 2.5's, drives them as loud as I care to.
 
lux man, that counts. I forgot that's what got me started. A pair of RS-II's that were my first set of Infinity Speakers. Smoked a nice Kenwood AVR.
 
Prior to refurbing the crossovers in my Kappa 9's I would regularly be replacing blown fuses in my Threshold S 500s. (thats 1000ws per channel at 4ohms for the pair) Thats right I ran 2 bi-amping the K9s and would still blow fuses. Took awhile to figure out the 15mH chokes where the problem not the amps. Also a choke in the midrange was shorting, Once I replaced them all with significantly better chokes I've never had the issue again. I last ran the K9s with 100w channel Class A Thresholds and was amazed how the bass energy was improved over the other Thresholds I have. Class A-AB)
After a refurbishment and upgrade of the Class A amps the current capabilities were somewhat improved. While the transformmers are the same the capacitance has been quadrupled. Thus providing short term a tested 80+ amps to control the woofers.

That is bass control ladies and gents!
 
I never had a problem driving my infinity's but I thought I'd share this with you guys, way back in the day when I was auditioning the Kappa 8 and kappa 9 I remember listening to the k 8 first and was so impressed that I was ready to buy them but the salesperson/owner of the store kept telling me to go for the k9 because it was a better speaker, trying his best to impress me with the k9 he pushed them a little louder, they sounded great but then all of a sudden both Denon monoblock amps (don't remember the model #) literally went up in a puff of white smoke, the guy ran to turn down the volume but it was too late... the damage was done, both amps fried, it was at that point I said to him... I'll take the k8's Lol
 
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No big surprise- I taxed a Carver MXR-900 pretty hard with my Kappa 9's. Well, at least I know the protection works properly!
 
Seppo said:
Good thread, I am looking forward to all responses.

1)
My new Onkyo A-9070 integrated pushes clean 140 wpc at 4 Ohms, and is a great match with RS-IIIa's. The speakers sound great, and if needed, I can crank up the volume as high as desired, and the amp does not break a sweat.
http://www.onkyo.ca/Products/model.php?m=A-9070&class=Reference

The impedance in RS-IIIa's drops to around 2.2 Ohm at its lowest, and the sensitivity is 88db.

2)
Now, the same amp hooked up to my current RS-II's is not up to the job. I can certainly listen to music with the current combo, but trying to at higher volumes will cause Onkyo to shutdown. I also suspect / feel that even at lower volumes I could use more headroom to really open up these fantastic speakers.

The impedance in RS-II's drops down to 2 Ohm above 5 kHz and never looks back, and moreover hangs around 3 Ohm around 100-150 Hz (where there is a lot of action when the higher woofer and all midranges cross-over), and then of course the sensitivity is lowly 85.6 db. So it looks like that this double whammy kills my Onkyo, these speakers demand a lot of current due to low impedance, and lot of power due to poor sensitivity (if one wants to rock the house).

So, at the moment I on the market for an upgrade, looking for GFA 555's (or the new 555se), Hafler XL-280 in particular, since they apparently drive RS-II's well on a budget.
Click to expand...

Just as an update, I ended up getting new Emotiva SA-250 amp (pushing clean 250 wpc at 8 Ohm, and 400 wpc at 4 Ohm loads), and the RS-II's sing magnificently :music: The bass is definitely much improved over Onkyo 9070 (140 wpc at 4 Ohm) at all volume levels. Now, it is my 1kW load rated APC surge protector that is the weak link in the chain. It has gone to protection a few times when blasting Boston's Third Stage... :)
 
Many years ago, while seeing how loud I could play my K8s (with the extended bass switches in the on position) with my Heathkit AA-1800, I was listening to the James Taylor song "Gaia" on the Hourglass album. About 3 1/2 minutes in (IIRC) there is a really low kick drum note which instantly blew out the fuses on both channels. I still use the combination of these components since this is louder than I'd normally listen, but still exercise care when listening loudly to this song on other systems.
 
try an acurus A 250, it has powered my RSII s since 1997. With no issues what so ever, And the Acurus runs cool & collected. It handles 4 ohm and lesser loads with ease. The power supply is so big, you will hear music from the amp some 40 seconds after you shut off the amp.
 
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