what is a chip amp?

[cadbury8]

just what is a chip amp? how much power can you get from one? and what kind of load can it handle? i.e. can it be used with a 2ohm load? 4ohm load? 8 ohm load? can i push 500 watts from one?

[richie00boy]

An amp built around a chip.

No to 2 ohms unless you parallel chips together.

Not a chance to get 500 watts really without a silly amount of messing about. IMO

[Conrad Hoffman]

I think Apex has/had a multi-hundred watt chip, but it was so expensive that one would be better off building a discrete design.

[AndrewT]

Hi,
a chipamp is an integrated circuit solution that produces power into loudspeaker type loads, with very few other components.

The maximum sensible power from an LM3886 (and some other types) is about 60W into EITHER 4ohm or 8ohm. The voltage from the power supply must be scaled to allow the chipamp to meet either duty.

If you want 500W then about 10 chipamps and a lot of resources will need to be thrown at the design project. I reckon it is better just to go discrete.
If you want to exercise your brain then 5*LM3886 in parallel could do about 250W into 2r0 and be safe in the short term (a few tens of milliseconds) into a 1r0 test load.
Bridging these two sets of 5chipamps together would give about 500W into 4r0.

[cadbury8]

so i guess where a chip amp would shine would be an active 2 way system when supplemented by a sub with maybe a plate amp for example.

[AndrewT]

Hi,
If you select your speakers with similar sensitivity and impedance then each will require similar power to reach similar maximum SPL.

Choose 94db/W drivers and 50W amps will give 111db/m at any audio frequency.
You don't need a plate amp unless you choose to mix drivers with very different sensitivities or different impedances.

I recently started a thread over in DIYsubwoofers asking for comment that my sub ticks over on about a quarter of the power being delivered to the mains.

[justblair]

Originally posted by cadbury8
so i guess where a chip amp would shine would be an active 2 way system when supplemented by a sub with maybe a plate amp for example.

Chip amps (well the lm3875 I can comment on) shine because the very low component count and very short signal path make for very musical and detailed amplifiers. The amplifier is also very linear in its response due to the design of the chip.

They make a lot of sense into two way systems as you suggest because low component count = relatively low cost. I run mine passively biamped, and next plan to go to passive tri amp. The low cost of each amp stage make this very worthwhile. The other advantage is even a diyhifi noob like myself can build one quickly and get amazing results. My current setup out performs a musical fidelity E200

Why do you need 500w? your speakers must be pretty inefficient or your neighbours very forgiving if this is for standard speaker configeration.

[cadbury8]

I dont need 500w of power. I was just curious to what a chip amp was and how much power it was able to deliver. I have never seen anything or heard anything about it before coming to this site. It is quite the curiosity. I read some and did a search on google but was not able to find anything that i understood or could compare to a SS amp.

The first thing i thought of when seeing chip amps was that it was a DIY digital amp.

So with what has been explained i came to an assumption that since the amp isnt very powerful then it would be the best used with an active crossover where you could limit it and make it even more efficient. so if a DIY chip amp sounds very good in a passive design where its doing a full bandwidth then it only makes sense that its sound quality would be exceptional in an active crossover design. And the real beauty of it would be the fact that it could be integrated with the active crossover and perhaps even installed in the speaker. Kind of like a plate amp design. Way cool.

I could see myself implementing something to this effect. Especially if it is cheap to build. Its really just another option.

or even picture this if you will. A line array of 8 tweeters and 8 mids each driver powered by a single chip amp. And all with an active crossover. A single dayton rs125s-8 mid has an RMS of 30/45 watts max so a single 60 watt amp would probably be perfect especially since its only used in freq range of 100 - 120hz to about 2000 to 2500hz. And that would even increase the head room i would think. Maybe im on track with this thought maybe im not. But it would still be very cool either way.

[AndrewT]

Hi Cad,
right on.
I have pushed the idea of one amp to one driver for ages and few seem to recognise the advantage.
Avoid 4ohm drivers if you can when using chipamps. They current limit and a low spec version may limit audibly when not driven particulary hard.

[cadbury8]

Originally posted by AndrewT
Hi Cad,
right on.
I have pushed the idea of one amp to one driver for ages and few seem to recognise the advantage.
Avoid 4ohm drivers if you can when using chipamps. They current limit and a low spec version may limit audibly when not driven particulary hard.

Ill keep the 4ohm drivers tip in the back of my mind. thanks.

another idea.

Take apart a window shaker and use it to cool the heat sinks as there would be a lot of them. this way your not heating up the room and can vent the heat out the window, the compressor might not even be neccesary as the heat from the sinks would flash off the coolant. would have to take a serious look into this. I always think of taking DIY to the EXTREME! I like to do things that are not available in stores and are abbynormal. hehehe

the other thing i saw was a little amp done in one of those succrettes (sp) boxes. it was run off of battery. This is cool as this way you could take the line array to the beach. hehehe.