PDA

View Full Version : need help with power amp specs translation



neanderthal
12-24-2007, 10:46 PM
I really don't like to come across as being ignorant when looking at amp specs but that's what Iam.What Iam trying to decide is which amp to drive the 2231A's reconed with C8R2235 kits in my 4350A's.I have read the 4350's can handle whatever you throw at them.Looking at specs and trying to understand them is like trying to read and understand a book wrote in Japanese to me.None of it makes any sense at all.Do the specs below look as though it would be a good amp.The crossover I will be using at this point will be a bryston 10B.I would like to listen to a few amps before I decide on which one I want but where do you go,the amps Iam looking at have been discontinued.Any input would be greatly appreciated.


Power output levelContinuous average sine wave power with less than 0.05% THD. 20 Hz - 20kHz. Stereo 8 ohms. 430W +430W. Stereo 4 ohms 700W+ 700W. Mono 8 ohms 1400W.Frequency responseStereo, @ 8 ohms, 1W. 0dB +/- 1.0dB, 10Hz- 50kHz.Power bandwidthStereo, 215W, 8 ohms, 0.1% THD. 10Hz- 100kHz. Stereo, 350W, 4 ohms, 0.1% THD. 10Hz- 100kHz. Mono, 700W, 8 ohms, 0.1% THD. 10Hz- 100kHzTotal harmonic distortionStereo, 215W, 8 ohms, 20 Hz - 20 kHz. Intermodulation distortionStereo, 215W, 8 ohms, 60Hz:7kHz=4:1. Channel separation(ATT MAX input 600 OHM shunt) 215W, 20Hz- 20kHz @ 8 ohms. >/= 80 dB.Damping factor1kHz @ 8 ohms. >/= 300.S/NInput 600 ohms shunt @ 12.7kHz LPF. >/= 105dB. Input 600 ohms shunt @ IHF-A. >/= 110dB.Slew RateStereo, 8 ohms, full swing. +/- 60 V/ mmS. Mono, 8 ohms, full swing. +/-100V/ mmS.Sensitivity400W 8 ohms @ 1kHz. +4dB (1.23V).Input impedanceBalanced/ unbalanced. >/=15k ohms.Maximum voltage gainInput level maximum @ 1kHz. 33.3dBIndicatorsRed clip LED x 2. Illuminates when output distortion from channel exceeds approx 1 %. Green BTL LED x 1. Illuminates when BTL (mono) mode is selected. Red thermal fan LED x 1. Illuminates during high-speed fan operation. Red protection LED x 1 Illuminates during protection or muting circuit operation. Red pilot LED x 1. Illuminates when power on.Protection circuitsMuting. 6 sec (+/-2 sec) after power on. DC sensing. DC +/- 2V output voltage. Thermal. >/=100deg. C heat-sink temperature. PC limiter. RL Cooling fan speed circuitAll temperatures refer to heat-sink temperature. Off.

boputnam
12-25-2007, 12:16 AM
Looks pretty good to me.
- I like the damping factor - should provide a nice tight bass response.
- THD is a bit high, but acceptible (and certainly inaudible).
- channel seperation at only 80dB seems a bit low?
- signal to noise is good at -105dB

But the real question is, how does it sound?

Hoerninger
12-25-2007, 12:54 AM
How does it sound?
It has some power of course.

Please name the brand and type, some will have experience with it.
___________
Peter

neanderthal
12-25-2007, 01:51 AM
The specs are for a Yamaha PC4002M ,Thanks for taking the time to respond ...Iam just trying to decide if the specs look half way decent or if I maybe need to look more at the crown K2 or the bryston 4B or a crest 8001 for the lows.In your opinion do you think a crest 8001 at 750 watts @8ohms would be over kill for the lows on the 4350's.I just do not have any experience playing around with different amps and dreed the idea of buying and selling amps on a semi weekly basis.That's why Iam wanting as much input as I can get to narrow it down because for me to look at specs and understand what Iam looking at I'd just as well be looking at a blank page.:banghead:

Hoerninger
12-25-2007, 05:02 AM
The specs are for a Yamaha PC4002M...
crown K2 or the bryston 4B or a crest 8001 ...
at 750 watts @8ohms would be over kill ...

The specs will not help (unless there are documented deficiencies :blink:.)
Crown has a high reputation, you will find some information in this forum.
I do not think it is an overkill, although it is a lot. (It depends on the efficiency of the speaker too.) It is better to have a stronger than a weaker amp. You have less distortion and more safety for the speaker.
__________
Peter

majick47
12-25-2007, 02:52 PM
Re the Yamaha PC-4002M amp maybe JBLNUT will see this post and comment since he has one also.

boputnam
12-26-2007, 05:27 PM
The specs are for a Yamaha PC4002M ...I personally would not go that route. It must be a Class A, judging by the weight? The Yamaha site doesn't say.

I think you'd be happier with a class AB - I'd also suggest something smaller than what you are considering.

I use the QSC CX502 on my 2245's, and have plenty of power. There are a few on eBay right now - I have no knowledge nor involvement with them - but they are priced damned good. If I needed a 502 I'd hop on one of them.

majick47
12-26-2007, 11:00 PM
The Yamaha PC-4002M is class A/B and just shy of 100lbs. As I said JBLNUT is better informed but it was an expensive pro amp circ 1980s. I have the same amp and it powered a pair of 2235h very nicely and you should have no problem powering four. If your not moving it often the weight shouldn't be an issue.

jblnut
12-27-2007, 08:01 AM
The PC4002M is a class A/B amp. It's pretty close to being two PC2002's stuffed into one chassis. It's unusual in that it has two main power transformers (one for each channel) which is what makes it so heavy. It was a very expensive "cost no object" design that owed a lot to the dollar/yen ratio in 1989. It was a $5k amp back then that found its way into many studios and concert halls. It's still popular in the Japanese high-end market overseas.

How does it sound though ? It's absolutely fabulous for bass. It seems to have a bit more low-end extension than the similar PC2002M which I currently use. It's great full-range too but I seem to have deveoped a taste for tube amps lately.

I would not hesitate to use a PC4002M for any purpose whatsover, except maybe situations requiring moving it around. It's a beast! You'd have a hard time justifying more power than this, and you'll never find another amp of this quality and power for the money. They sell for $400-800 depending on condition, which is a steal imho.


jblnut

boputnam
12-27-2007, 08:58 AM
I think you'd be happier with a class AB...


The PC4002M is a class A/B amp. ... It's absolutely fabulous for bass. Well, I got that part right! :p