chow@cornell.UUCP (Christopher Chow) (10/10/85)
I've come across something interesting. Carver has a ad for their M500t power amp in the October _Stereo Review_, which has a graph of the maximum power output over time. The graph indicates that the 500t is capable of delivering peak power >900 watts into 4 ohms for about 20 ms. The continious power at clipping into 4 ohms is 350 watts. Hence, it would appear that the dynamic headroom on this amp is 10*log(900/350) which is 4.1 db. _Audio_'s equiptment directory lists specs from the manufacturer, and under the power amp section, on page 159, lists the dynamic headroom of all Carver power amps (except 1.5t) as 0.5 db! Does anyone know why these two figures differ so much. They were both given by Carver Corp! Does Carver measure dynamic headroom in a different manner than the EIA standard, or am I simply confused? BTW, if you had a choice between the Carver M400t or M500t, which would you choose and why? Christopher Chow ...decvax!cornell!chow chow@cornell.uucp chow@cornell.arpa
oleg@birtch.UUCP (Oleg Kiselev x268) (10/16/85)
> > I've come across something interesting. Carver has a ad for their > M500t power amp in the October _Stereo Review_, which has a graph of the > maximum power output over time. The graph indicates that the 500t is > capable of delivering peak power >900 watts into 4 ohms for about 20 ms. > The continious power at clipping into 4 ohms is 350 watts. Hence, it > would appear that the dynamic headroom on this amp is 10*log(900/350) > which is 4.1 db. > > _Audio_'s equiptment directory lists specs from the manufacturer, and under > the power amp section, on page 159, lists the dynamic headroom of all > Carver power amps (except 1.5t) as 0.5 db! > > Does anyone know why these two figures differ so much. They were both > given by Carver Corp! Does Carver measure dynamic headroom in a different > manner than the EIA standard, or am I simply confused? > > BTW, if you had a choice between the Carver M400t or M500t, which would > you choose and why? > Carver's approach is to "borrow" power from one channel and throw it to the other. That works only if there is a peak in one channel and not much happening in the other. I assume _Audio_'s measurements were performed with peaks in *both* channels at the same time, wich will be about 400-450 W. Iff only one channel peaks, it goes up to 800-900 W. It really comes down to the power supply and what it can feed to the power amp. It was my understanding that most higher end amps have separate power supplies for each channel. Apparently Carver's power supply can "leach" power from another channel... M500t has more power. It costs more. It looks better. I could not hear a *significant* difference when I listened to both of them at the local audio dealer. M500t (I think) has more different protection cirquits than M400. M500t seems to be a bit fuller and more defined when listening to a good DDD CD. But the diffrence is striking when M400 is compared to a 100 W/ch amp ( M400 delivers 750+W in peak on 4 Ohm load ). Both M500t and M400 are heavily discounted novadays... But they still cost more than new NAD2200 (?). I have not heared it yet. Older NADs were not anywere near Carver league. -- -----------------------------------+ With deep indifference, "I disbelieve an army of invisible | Oleg Kiselev. mind-flayers!" | DISCLAIMER: "OK. They are *still* not there." | I don't know what I am talking about and -----------------------------------+ therefore am not responsible for any damages to people who take me seriously! ...!trwrb!felix!birtch!oleg ...!{ihnp4|randvax}!ucla-cs!uclapic!oac6!oleg Nothing I ever say reflects the views or opinions of my employers. They knew who they hired though!
speaker@ttidcb.UUCP (Kenneth Speaker) (10/23/85)
I have a pair of Carver 400t's which, in general, I am very pleased with. They sound very good on almost everything I put through them, but then, I am using them in a surround-sound video environment (with Yamaha NS-1000 speakers, a 78" Novabeam projector, and super-beta HiFi/Pioneer digital audio video disk). I do have some complaints: Commutator noise is a buzz, rather than a hiss. Not loud, just different. At the 10 foot distance I am from all of the speakers, I can't hear it, but in a small room it might be audible and disturbing. Check before you buy. The commutator injects noise back into the A/C line! This messes up my BSR X-10 remote control units. I can not dim lights from the console which plugs into the A/C at the same location as the amplifiers, although other consoles work fine. I am currently trying to filter the A/C line (unsuccessfully so far) to remove this noise, otherwise I will have a pair of (slightly) used 400t's for sale, cheap. --Kne