what are you listening to?

I thought the clipping shutdown sounded unusual, now thermal shutdown, done it a hundred times over the decades.

I keep reading good things about those amps.
 
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Well since I had a disc tray loaded, I swapped amps and fired up that Underworld-Beaucoup Fish I have been waiting to hear…then turned up the volume after it got started…twice.
Followed by Ultravox-Quartet, U2-Zooropa and Tina Brooks-True Blue.

Rig is without the subs, DQ-10s and amp is now the McCormack DNA-1 and the system was sounding good. Noticed more bottom end vs the 45-yr old 80wpc recapped except the big-uns Luxman M12. The Lux is dual mono using a pair of dual caps for the two power supply rails. These cans could probably stand being restuffed. But I’ll recap the other M12 and see how it sounds first before adding this project to the list, for both amps.
 
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Hexis22 said:
I recommend running one amp per speaker to start, but don’t know enough about the rest of his system or crossover options.
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His Revels are 4 ohm nominal, not sure about the floorstanding Sonus Fabers. He's worried about pushing the monoblock AHBs too hard into a 2-ohm - or less - load at volume. He's thinking bi-amping vertically as an experiment as well; I'm about to send him the links to the crossover thread and the extreme slope thread that Lee started for a little light reading.

HIs system is an LA-4, he's been running a JC-2 Parasound amp but he's trying the AHB2 in its place. We used the Revels all night Saturday and they are rated at 4 ohms. I think he has an RME DAC; couldn't see too well, the lights were down some and my eye doc appointment isn't until Tuesday. He's streaming TIDAL. Everything is balanced except the phono.

He texted me at 6:45 this morning and we got into the active crossover discussion; he's at least considering it. If I know him, there will be plenty of research behind his decision. He's the Dean of our College of Business.
 
As Carroll said: "There's no replacement for displacement." so if you're driving a difficult load, you need a big amp (or several).

Although one SA-220 can drive my speakers just fine, having two was next-level. No louder, just better. It's a staggering difference.
 
Bob Boyer said:
His Revels are 4 ohm nominal, not sure about the floorstanding Sonus Fabers. He's worried about pushing the monoblock AHBs too hard into a 2-ohm - or less - load at volume. He's thinking bi-amping vertically as an experiment as well; I'm about to send him the links to the crossover thread and the extreme slope thread that Lee started for a little light reading.

HIs system is an LA-4, he's been running a JC-2 Parasound amp but he's trying the AHB2 in its place. We used the Revels all night Saturday and they are rated at 4 ohms. I think he has an RME DAC; couldn't see too well, the lights were down some and my eye doc appointment isn't until Tuesday. He's streaming TIDAL. Everything is balanced except the phono.

He texted me at 6:45 this morning and we got into the active crossover discussion; he's at least considering it. If I know him, there will be plenty of research behind his decision. He's the Dean of our College of Business.
Click to expand...
 
Bob,

Thank you for posting this. Thought I would join the fun. Hello to everyone, new to the forum. Really enjoyed hanging with Bob the other night for a good listening session.

A couple of updates, corrections. It was the Sonus Fabers we were listening to. The are fairly efficient at 90db but are 4 ohms that dip into 2 ohm territory. The single AHB2 struggled on the Cars album at high volume shutting down due to heat. I don't listen that loud usually but do on occasion.

I have ordered a second AHB2 to experiment with bridged mode and vertical bi-amping. I am concerned that bridge mode might not be optimal. The AHB2 manual says not to bridge into under 6 ohms, although they have a white paper on the website about driving 4 ohm speakers in bridge mode.

I like the sound of the AHB2, but wonder if I should be considering other amps. Previous amp, which I still have, is an A21+. It never struggles for power but is not as good sounding as the AHB2. Have considered some Pass amps and the JC5.

Glad to meet folks.
 
Older class A Krell amps have enough horsepower to drive low efficiency speakers.

Levinson as well, but the early ones need full rebuilds at this point.

I love the counterpoints but they do color the sound a bit and are slightly fragile. No ballast resistors on the output devices so when one goes, they all go. Very tighly matched at elevated temperature When built new.
 
Bob, I would call Benchmark directly to discuss your setup and recommendations based on the AHB2 capability.

They have been very responsive and clarified all my questions with excellent level of detail.

I now run a full Benchmark stack based on my experience with this US based engineering driven company.
 
So, spoke with Benchmark. They thought the thermal shutdown was from playing the amp for 3 hours or better at that volume level. Said no problems with the 4 0hm speakers. It is stable at all impedance levels. I told them once the amp cooled, we played at the same volume level for another hour with no issue. They said if it happened again let them know and I might need to send it in for a go over as a bit unusual. The album we were playing at the time should have had no impact on the amp's heat.

Second AHB2 on the way.
 
Good Question, what am I listening to??? A construction site boom box............ I'm setting up my WOPL (but not the turntable) in the laundry room till I get the Family room squared away. If I am making dust, I'll either cover it till the coast is clear, or I'll pull it apart for a good vacuuming or both. hell, the wall between the laundry and family room is open partway anyway and I have a big green volume knob. My second WOPL is almost finished, can't wait. I bought a handful of new albums waiting for the day. I was in home depot early the other day and they had the stereo playing and I said, shit, I aint heard that song since I lost my stereo/CD's/Albums in a divorce in 97 so I found the album, still sealed from 1985..... The Hooters!!!! All you Zombies off the Nervous Night Album.... It's bad ass even on the boom box.......
 
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