tuba@ur-tut.UUCP (Jon Krueger) (09/20/85)
I'm looking to buy (upgrade) a receiver in the 150-300 range. I don't need more than 35 watts for my tastes and speakers. But I've heard that buying more power than that may also buy me more headroom for sudden but brief peaks in music. These "transients" may zip up to 100 watts, although not often or for long. I can't seem to find any vendor specs on their product's performance in this area. Can anyone give any pointers to technical writeups or lab test data? This may be of general interest, post or mail me directly as you think best. -- -- Jon Krueger UUCP: ...seismo!rochester!ur-tut!tuba BITNET: TUBA@UORDBV USMAIL: University of Rochester Taylor Hall Rocheseter, NY 14627 (716) 275-2811
hachong@watmath.UUCP (Herb Chong) (09/24/85)
In article <126@ur-tut.UUCP> tuba@ur-tut.UUCP (Jon Krueger) writes: >I'm looking to buy (upgrade) a receiver in the 150-300 range. I >don't need more than 35 watts for my tastes and speakers. But I've >heard that buying more power than that may also buy me more headroom >for sudden but brief peaks in music. These "transients" may zip up >to 100 watts, although not often or for long. I can't seem to find >any vendor specs on their product's performance in this area. Can >anyone give any pointers to technical writeups or lab test data? the IHF dynamic headroom specification is exactly what you are looking for, but it's a secondary specification, which means that a manufacturer is not required to give it. it is given in dB above the rated RMS power for a pulsed signal of a given duty cycle. i seriously question whether in your price range you will find an amplifier that will give the kind of headroom you are looking for, especially in a reciever. that's just over 4.5 dB of dynamic range. in separate amps, the figure is high, but not unheard of. some manufacturers in that price point would have at best about 1 dB of IHF dynamic headroom, but the majority woulf have less than that. it costs too much to build a power supply with the necessary higher voltage components. you also have to be careful what rated load is used for the IHF dynamic headroom specification. most amplifiers have larger headroom into a lower impedance load. Herb Chong... I'm user-friendly -- I don't byte, I nybble.... (will disappear September 30) UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!hachong CSNET: hachong%watmath@waterloo.csnet ARPA: hachong%watmath%waterloo.csnet@csnet-relay.arpa
schley@mmm.UUCP (Steve Schley) (09/24/85)
In article <126@ur-tut.UUCP> tuba@ur-tut.UUCP (Jon Krueger) writes: >I'm looking to buy (upgrade) a receiver in the 150-300 range. I >don't need more than 35 watts for my tastes and speakers. But I've >heard that buying more power than that may also buy me more headroom >for sudden but brief peaks in music. These "transients" may zip up >to 100 watts, although not often or for long. I can't seem to find >any vendor specs on their product's performance in this area. Can >anyone give any pointers to technical writeups or lab test data? You are onto something here, and it's a topic that is generating more interest lately. The accepted terminology is "dynamic headroom", and it indicates (in positive deciBels) how much power an amplifier is capable of putting into a load for brief (~20 milliseconds, I think) musical peaks. Many articles have appeared in the popular press (Stereo Review, Audio), but I can't point you anywhere specifically. Among the manufacturers that were earliest to design in significant dynamic headroom is NAD. Check the latest Stereo Review (October?) for a review of the latest and biggest NAD amplifier. The reader will probably learn something about dynamic headroom from the review as well. Another less common attribute of amplifiers is "output current". This helps when driving real loads like speakers, which often look to the amp like a very complex impedance whose real value can drop very low, and whose imaginary component can be large. Output current drive capability and dynamic headroom often, though not always, are found in the same products. -- Steve Schley ihnp4!mmm!schley
alonso@princeton.UUCP (Rafael Alonso) (09/24/85)
> I'm looking to buy (upgrade) a receiver in the 150-300 range. I > don't need more than 35 watts for my tastes and speakers. But I've > heard that buying more power than that may also buy me more headroom > for sudden but brief peaks in music. These "transients" may zip up > to 100 watts, although not often or for long. I can't seem to find > any vendor specs on their product's performance in this area. Can > anyone give any pointers to technical writeups or lab test data? > This may be of general interest, post or mail me directly as you > think best. > -- > > -- Jon Krueger > UUCP: ...seismo!rochester!ur-tut!tuba > BITNET: TUBA@UORDBV > USMAIL: University of Rochester > Taylor Hall > Rocheseter, NY 14627 > (716) 275-2811 Most audio magazines provide dynamic headroom numbers for the amps they test. You may want to check the NAD 2200 amp (reviewed in this Oct's Stereo Review). It is rated for 100 watts, but actually provides 158. It can provide about 700 watts for 50ms bursts. Lists at $448. Rafael Alonso
joseph@topaz.RUTGERS.EDU (Seymour Joseph) (09/25/85)
I think the specs you want to look at are Dynamic Headroom and peak power. You are looking for an amplifier that has a high current capacity. I have had pretty good luck with the smaller NAD amplifiers. You might want to check them out. Seymour
oleg@birtch.UUCP (Oleg Kiselev x258) (09/30/85)
> > I'm looking to buy (upgrade) a receiver in the 150-300 range. I > > don't need more than 35 watts for my tastes and speakers. But I've > > heard that buying more power than that may also buy me more headroom > > for sudden but brief peaks in music. These "transients" may zip up > > to 100 watts, although not often or for long. I can't seem to find > > any vendor specs on their product's performance in this area. Can > > anyone give any pointers to technical writeups or lab test data? > > This may be of general interest, post or mail me directly as you > > think best. > > -- > > -- Jon Krueger > ..... > You may want to check the NAD 2200 amp (reviewed in this Oct's Stereo > Review). It is rated for 100 watts, but actually provides 158. It can provide > about 700 watts for 50ms bursts. Lists at $448. > Rafael Alonso In LA area audio stores have been discounting Carver M500t amp. It is rated at 251 w/channel and peaks at 600 w/channel if both channels peak or 750 (?) w/channel if only one channel needs the power. The price quoted was $429. Apparently Carver is coming out with a new line of hardware and the audiofile shops are trying to unload their surplus.