Amplifier Clipping

Laundrew · « **on:** 6 Jun 2010, 02:41 pm »

I am curious if anyone else has experienced their amplifier clipping at home or at an audition

I have only experienced two cases of amplifier clipping and both occurred during auditions. The first one was a couple of years ago with a 14B driving Paradigm Signature S8 speakers playing Rush. The dealer mentioned that the amplifier was clipping - I asked how he knew this and he said that the red LEDs were on.

The second occurrence of clipping were a pair of 28Bs driving JBL 1400 Project Arrays and the music genre was Japanese Drums. I believe that these 28Bs were a pre-modified version as the sides of the faceplate was milled flat and not contoured like the top and bottom of the faceplate . Correct me if I am wrong James as I am not sure on this one, I noticed that the side contours matches the top and bottom contours of my post-modified 28B faceplate - thanks.

Granted in both cases, a huge amount of energy was definitely involved and I could not possibly imagine driving my equipment to these extremes. I am quite happy with the red LEDs on only during power-up.

Be well….

James Tanner · « **Reply #1 on:** 6 Jun 2010, 02:51 pm »

Hi Laundrew,

Correct the latest 28B's have the same contour top/bottom/sides on the faceplate.

I do not think most people realize how much power it takes when a musical transient is required - drums being an excellent example. Our amplifiers monitor both the current and the voltage and are instantaneous in their response to a clipped waveform and the LED will go red if the transient power level is exceeded. If this happens on short term peaks it's a warning to turn things down and usually will not do any longterm damage. If it continues on every beat your going to do serious damage to your speakers.

Many amps are in fact clipping on these types of transients - you just don't know it because few amplifiers have clipping indicators.

james

Laundrew · « **Reply #2 on:** 6 Jun 2010, 03:11 pm »

Thank you James

Be well...

Napalm · « **Reply #3 on:** 6 Jun 2010, 03:25 pm »

Quote from: Laundrew on 6 Jun 2010, 02:41 pm

I am curious if anyone else has experienced their amplifier clipping at home or at an audition

Nope. Not the Bryston although it's just a 4B. But then I don't really like high volume. My audio dealer is amazed that I always audition stuff there at low volume for most of the time. He says it's unusual. Well what do I know. He also says that 70% of his customers are going for "warm" setups and their comments on his Bryston setup is "thin". They like a continuous, permanent rumble. Makes them feel that the setup is "powerful". Interesting.

Nap.

Laundrew · « **Reply #4 on:** 6 Jun 2010, 04:07 pm »

Quote from: Napalm on 6 Jun 2010, 03:25 pm

"....But then I don't really like high volume."
Nap.

I agree, I very seldom listen to music at high power levels. I enjoy the detail, subtle nuances and the delicacy of my music without having to get into higher power settings to bring this out.

Be well...

Phil A · « **Reply #5 on:** 6 Jun 2010, 04:10 pm »

I've gotten amps to the edge of clipping, including an old 4BST driving Thiel 7.2s in a big room. Many moons ago, I've experienced in my own systems and others clipping playing Telarc's 1812 Overture on the cannon blasts. I haven't played the recording out in years.

Mag · « **Reply #6 on:** 6 Jun 2010, 04:42 pm »

I've had my 3B ST clip hooked up to Paradigm Studio 100 v2 & either B&W DM601 S3 or Paradigm Studio 20 v3. I think that's a 4 ohm load if correct. I could not reach my desired volume level before clipping with this amp.

IIRC I had my 2B LP clip hooked to the center channel. I've had the 2B LP left channel shutdown from overheating.

I fried one of my Studio 20's woofer playing a dts recording at high volume and the amp wasn't clipping.

I could easily clip my 3B SST when hooked to graphic equalizer if I wasn't careful with the gain switch.

Since acquiring a 3B SST/2 with the above mentioned 4 ohm load on fronts, 3B SST on surround speaker and 3B ST on center. I have not seen any amp clip, and I have the volume between 95-100 db on a regular basis.

Robert D · « **Reply #7 on:** 6 Jun 2010, 09:54 pm »

Laundrew, I have been playing my Paradigms at 1.30 - 2.00 on the BP 26
My 4b's have not Clipped, I guess the just love the heat !!!!

Robert

vegasdave · « **Reply #8 on:** 6 Jun 2010, 10:21 pm »

My 4BSST has only clipped with the volume all the way up. Actually, I got the LEDs to go to a little bit of orange! This was playing Iron Maiden's 'The Number of the Beast' album at full volume! haha.

Laundrew · « **Reply #9 on:** 6 Jun 2010, 10:25 pm »

Quote from: Robert D on 6 Jun 2010, 09:54 pm

Laundrew, I have been playing my Paradigms at 1.30 - 2.00 on the BP 26
My 4b's have not Clipped, I guess the just love the heat !!!!

Robert

Be well...

Ryanz · « **Reply #10 on:** 7 Jun 2010, 01:19 am »

Please pardon my ignorance, but what makes a speaker so hard to drive? Why can some speakers drive an amp to clip and others won't? I hope this makes sense. Long night last night.

Phil A · « **Reply #11 on:** 7 Jun 2010, 01:25 am »

Quote from: Ryanz on 7 Jun 2010, 01:19 am

Please pardon my ignorance, but what makes a speaker so hard to drive? Why can some speakers drive an amp to clip and others won't? I hope this makes sense. Long night last night.

Impedance for one. Lower efficiency could also contribute

95Dyna · « **Reply #12 on:** 7 Jun 2010, 01:40 pm »

I very much surprised myself a month or so ago when my right channel 7BSST2 (new transformer/capacitors) winked red at me. I love acoustic bass solos at higher volumes and was listenening to Diana Krall's arrangement of Tom Waits' song "Temptation" from her CD "The Girl In The Other Room". This song features renowned bassist Christian McBride and begins with a 30 second bass riff that spirals rapidly down ending in a smashing mid 20 Hz or so note. This just happens to be around the area my speakers take a dip to .8 ohms (nasty!). This, combined with the volume pot sitting at near 3:00 or so and the 7B cried uncle but only for an instant in one channel. I've really worked these 7's out over the year I've had them and that is the only time I've seen red.

Napalm · « **Reply #13 on:** 7 Jun 2010, 01:43 pm »

Quote from: 95Dyna on 7 Jun 2010, 01:40 pm

This just happens to be around the area my speakers take a dip to .8 ohms (nasty!).

Which speakers are those?

Nap.

95Dyna · « **Reply #14 on:** 7 Jun 2010, 01:45 pm »

Quote from: Napalm on 7 Jun 2010, 01:43 pm

Which speakers are those?

Nap.

Infinity 9 Kappas.

sfraser · « **Reply #15 on:** 7 Jun 2010, 01:54 pm »

I can clip my 4B very easily with a Stereophile CD featuring a drum solo. Surprisingly i also used to clip a pair of 4B's running as mono blocks while watching the Eagles "Hell Freezes Over" DVD.

95Dyna · « **Reply #16 on:** 7 Jun 2010, 07:06 pm »

Quote from: sfraser on 7 Jun 2010, 01:54 pm

I can clip my 4B very easily with a Stereophile CD featuring a drum solo. Surprisingly i also used to clip a pair of 4B's running as mono blocks while watching the Eagles "Hell Freezes Over" DVD.

Isn't it more likely to clip a stereo amp bridged in mono than when operating in its native mode? Doesn't the bridged amp see a lower impedence than one of the channels in stereo mode? I used to use a pair of stereo amps in bridged mode and had to convert them to stereo and biamp due to frequent 7 amp fuse explosions in the output stage. The problem didn't occur in the biamped configuration.

James Tanner · « **Reply #17 on:** 7 Jun 2010, 07:20 pm »

Quote from: 95Dyna on 7 Jun 2010, 07:06 pm

Isn't it more likely to clip a stereo amp bridged in mono than when operating in its native mode? Doesn't the bridged amp see a lower impedence than one of the channels in stereo mode? I used to use a pair of stereo amps in bridged mode and had to convert them to stereo and biamp due to frequent 7 amp fuse explosions in the output stage. The problem didn't occur in the biamped configuration.

Correct - when you bridge a Stereo amp it 'sees' 1/2 the impedance it does in Stereo. So the current draw is greater and the lower impedance may cause current limiting. The voltage swing is much greater though so a lot will depend on the type of load.

james

Phil A · « **Reply #18 on:** 7 Jun 2010, 08:47 pm »

Quote from: 95Dyna on 7 Jun 2010, 01:40 pm

I very much surprised myself a month or so ago when my right channel 7BSST2 (new transformer/capacitors) winked red at me. I love acoustic bass solos at higher volumes and was listenening to Diana Krall's arrangement of Tom Waits' song "Temptation" from her CD "The Girl In The Other Room". This song features renowned bassist Christian McBride and begins with a 30 second bass riff that spirals rapidly down ending in a smashing mid 20 Hz or so note. This just happens to be around the area my speakers take a dip to .8 ohms (nasty!). This, combined with the volume pot sitting at near 3:00 or so and the 7B cried uncle but only for an instant in one channel. I've really worked these 7's out over the year I've had them and that is the only time I've seen red.

Yes - that piece can that really tax an amp. I love the bass riff though

Elizabeth · « **Reply #19 on:** 7 Jun 2010, 10:02 pm »

I probably will never have clipping. I have Magnepan 3.6's with my Bryston 4B-sst@2 in my apartment and play music softly all the time. The music playing right now is 'A' rated 68dB with Radio Shack meter. I would say my highest dB is mid 80's.
(( i guess I got all the "LOUD" out way back in my thirties.. Back then, open the window, crank up Figaro singing his entrance aria in the opera: "Figaro" and let the entire city neighborhood hear it on a Summer Saturday afternoon, while I plugged my ears... (LOL). Another time the manager though a truck had hit the building! ))
Now I just like to hear music, I do not feel I have to have it vibrate my whole body to enjoy it. So mid 80dB is as loud as i need.