AudioSource Amps. (1 Viewer)

[Michael R Price]

The Kit281s are not 92db efficient... it's more like 87db, and it clipped at 103-105db at a little over 2 meters in room with both speakers going. But geez, $92 for the Amp One? That's amazing! I'd go for it.

 

[RobWil]

Some dumbass made a bid on it and wiped out the 'Buy it Now' price of $80 I betcha it goes for minimum $90 up to $110.

 

[Charles J P]

http://www.adireaudio.com/diy_audio/monitors/kit281.htm

Frequency Response VENTED: 39 Hz to 20 kHz, ±3 dB
SEALED: 66 Hz to 20 kHz, ±3 dB
TRANSMISSION LINE: 41 Hz to 20 kHz,±3 dB
Impedance Nominal 4 ohms
Sensitivity 92 dB SPL @ 2.83 Vrms
Power Handling 150W RMS, long-term

Do you have professional measuring devices at home or how did you come by your 87 dB sensativity?

Even the review by Joseph D'Appolito on the Adire site states a measuerd 89.7 dB. 90 vs 92... 2 dB is nothing to scoff at, but it means I would need 50 watts instead of 30 or whatever my original calculation was. As I've mentioned I also plan on using the Amp Three for the mains which Audiosource says will do 250 wpc RMS into 4 ohms.

EDIT: Adire states that the Sealed Kit 81 is 87dB efficient. Perhaps you got them mixed up?

 

[RobWil]

The new Amp One/A does not have the meters on the front which I'm actually not a big fan of.

I think they look rather cool, however I've decided that I don't like them illuminated. I've got one w/ the meters illuminated and one on which they're burned out. I'm kinda looking forward to the other ones burning out! But they are rather useless IMO.

 

[DaleBesh]

I got the Amp One A with no meters. When I let my NAD receiver go I had already been using a hunky 3 channel B&K amplifier for the front speakers.
So I picked up the Audiosource for my 2 surrounds. Very pleased.

 

[Zak Ruck]

Hey CJ, Glad to see you are getting some more opinions over here. Good luck getting your amps. Let me know what you think, and I want to see some pics of the 281's when they are finished.

 

[NickSP]

Since this thread is talking about budget amps, let me add that I have been extremely happy with my AMC amps which are built very tough and run pretty cool to the touch. I have 2 AMC-2100N-3 amps that sounds very good and have never clipped on me once.

 

[RobWil]

I just bought a Marantz 6200, would this do me any good?

Yo Benson...just so you don't feel ignored...I can't find a whole lotta info on this...it looks like Marantz made a model 6200 dvd, a turntable, a stereo console....what is this , a receiver?

 

[Michael R Price]

Charles, the measured sensitivity at 2.83V RMS is 89.7db, but they are 4 ohm speakers. This makes the 2V sensitivity, which represents a power level much closer to 1 watt, 86.7db. I think that since the Amp One is rated at 200 watts bridged into 8 ohms, it means the real power produced into 4 ohms with both channels driven is about 100 watts. With the Amp Three, it's 200 watts. Trust me, it'll be loud enough (at 3 meters in room, peaks of 105db or so).

Besides, 90% of speaker efficiency specifications are wrong anyway... For example, Klipsch over-rates most of its home speakers by 3-4db. And, you might be surprised how loud 95db is, never mind 105db. I love to crank rock music, now that I have an amplifier of unknown but absurd power capability, but by "cranking" I mean 90-95db continuous and 100db or so peaks. Above that, the Kit281s start to have some subtle distortion and don't sound as good... unless you highpass them, then you probably get a few more db of relatively uncompressed output.

Also, Rob, the meters are pretty inaccurate, like... they overestimate power a lot. I agree, though, that they look pretty cool.

 

[Charles J P]

Thank you Michael. You learn something new every day. I didnt even know there were forumlae (sp?) to guestimate wattage by voltage. I always wondered why some sensitivity was quoted in 1 watt at 1 meter and some in volts. What is the scale? That is, is 2 volts always about a watt or does it depend on another variable?

Thanks again.

 

[RichardHOS]

P (power)
V (voltage)
I (current)
R (resistance)

P = V*I
V = I*R --> I = V/R
P = V^2/R [edit: realized I had V*2/R oops]

1 Watt = 2.83V^2/8ohms

Therefore, 1 Watt = 2.0V^2/4ohms

 

[Michael R Price]

Yah, Richard gave the right formulas. To complicate things, the speaker has a varying impedance (resistance) with frequency... the Kit281s have a minimum impedance of around 2.8 ohms at tuning (24-35Hz), and it goes as high as 30 ohms or something unless you put in a zobel network to flatten that out. So if your amplifier has a weak power supply, or noticeable output impedance, it will deliver less power than expected at bass frequencies and other impedance dips... but especially the bass. This is part of the reason why people notice a bigger difference changing amplifiers with "difficult load" speakers like Kit 281s.

The Amp One had 90% as much bass as my big amp, and was only a little underdamped/boomy; however, there was a significant difference in "liveliness."

 

[RobWil]

Some dumbass made a bid on it and wiped out the 'Buy it Now' price of $80 I betcha it goes for minimum $90 up to $110.

Told ya!
Even higher than I guessed......
This sucker just ended and it ended up going for $120.50!
Somebody coulda had this for $80 stinkin' dollars. I tell ya....if you see one of these for less than $100 at 'Buy it Now', and want one, you should grab it. The seller screwed up by offering it for $80 and ended up smellin' like a rose....sheesh!

 

[Geoff L]

Hi Rob

As figured and you new , the $80.00 AS-I with meters was a good buy. I was sure it would go for around 100.00+ after the moron bid on it...
They usually average ~{depending on condition of course}~, $110.00 to $160.00. Most right around $125.00, less shipping.
I'm very impressed with these little amps. They run cool, take up little space, bridgeable, and will drive almost any speaker load. An excellent entry level amp that will contend with the big boys (in it's power range)...
And what they can be snagged for if patient, well it's a no brainer!

I also think it was you that mentioned the meter lights where a little to BRIGHT for your tastes....?

Anyway, they do dim down a little with time, like years!
I had a friend put a variable pot on them and change the bulbs out for some very Deep Blue ones. Adjusted them down in brightness to where they look balanced with the rest of the system and closed it up.
He is going to do all 3 Amp-II's for me.
He tried Red & Green lights also, but the Deep Blue bulbs/LED's (not sure what he used), looked best. Look very similar to the Blue Power Meter Lighting of the Vintage Marantz stuff.

Much less annoying and much more attractive for sure. They have more of a nice lite glow now instead of looking like a set of off road headlights!

Just an idea if the AS-II's meter lights bug you. Don't ask me what parts he used as I don't know. He said it only took about 30-minutes to do both Amp-II's.
He will do the last one when it arrives.

Regards
Geoff

 

[RobWil]

Hmmmm.....that sounds way cool!
Yeah....I don't know if they actually bug me, but I have three in a rack, one w/ lights and two w/no lights and I think I prefer the 'no lights'. I like the look of the meters...just not all lit-up I think....at least not so bright anyway. But....a subdued blue!....yeah, that might be pretty nice....txs for the suggestion

 

[RobWil]

They usually average ~{depending on condition of course}~, $110.00 to $160.00. Most right around $125.00, less shipping.

Yeah...it's weird how they seem to go in cycles on ebay.
I paid $125 for the first, then they seemed to go down and I paid $75 and $90 for the next two. Now they look like they're back up around $120-$125. I guess it all depends on how many out there are interested in an item at any one point in time. It's like the Onkyo M-501 amp I bought on ebay. My high bid of $128 didn't meet the reserve, but he emails me and offers it for $135. Almost every other one I've seen before and after has gone for more than that....in fact the same guy sold another one of his about 2 weeks later and got $152 and another one the same week went for $168. Another went for $124 but they mistakenly advertised it as a 100wpc amp (it's actually 150wpc).

 

[Geoff L]

Hi Guys

Have a couple questions for the Amp-I and II owners....

Considering I have no manual for any of my AS-AmpII's, (one of the problems buying used, and I am also unable to download it due to being a Web-Tv user) :b !!!

I don't know the input level sensitivity range of the Amps pre-ins and don't want to over drive the inputs.

Can someone tell me what the (RCA pre-ins Min to Max voltage range is) with the AS-AmpII???

What are you guys setting the AS-AmpII "Output R&L Channel" level knobs to???

I am going to call AudioSource Monday and see if I can get a new user manual sent to me. Should not be a problem as it's said that they have very good customer service according to what I've read...

Thanx
Geoff

 

[DaleBesh]

Manual for the Amp One A recommends full gain for the front controls, and use your preamp for level adjustments.

 

[Geoff L]

Thanks Dale

Still just curious to the line-ins max voltage. Will get that information from AS on the phone when requesting a new manual for free hopefully -- or else the necessary $$...

Thanks for your info on the Amp-I and their suggested gain position for the front R&L outs.

Regards
Geoff

 

[RobWil]

I've heard 0V min-2V max.