0
\$\begingroup\$

I need some help designing a stereo audio circuit for my speakers.

some info about them: The speakers I want to use and already have are the ones from the Phillips DCM3020/12. They are 4 Ohm speakers with an output power of 60 Watt RMS. Since the amplifier and cd/radio/usb/ipod thing is too big for what I want to build my own amplifier.

The input I use if from my PC or my phone (audio jack cable to RCA).

The problem is that I dont know how to start designing this circuit since I dont have a lot of experience with audio amps.

Im not asking for someone to design the circuit for me, Im just asking how to start (what specifications does the amplifier need to have for these speakers etc. and maybe give me a direction of what audio amp to use).

I see a lot of things about input power, but on the site it only says that output power is 2 x 60 Watt rms. Hopefully it is possible to make this since I dont really want to buy new speakers.

Thanks!

\$\endgroup\$
4
  • 2
    \$\begingroup\$ You probably shouldn't consider the idea of a 2x60 stereo amplifier when you "don't have a lot of experience" with doing this kind of thing. (Unless all you want to do is use some IC, correctly, that does most of the work for you.) Is there a reason you don't start with a more reasonable target for now? You don't have to drive speakers, those that are capable of high power, using high power. You can drive them with less, you know. \$\endgroup\$
    – jonk
    Oct 11, 2017 at 17:11
  • 1
    \$\begingroup\$ I agree with @Jonk. You are jumping in the deep end. You are better and ultimately cheaper to search for and buy a kit or preassembled module. \$\endgroup\$
    – Trevor_G
    Oct 11, 2017 at 17:16
  • \$\begingroup\$ Also confused by your statement "Since the amplifier and cd/radio/usb/ipod thing is too big " Are you saying you don't want to use the 4R speakers on the current amplifier. If so you can always just add in some load resistors to bring the speakers into range of the amp. \$\endgroup\$
    – Trevor_G
    Oct 11, 2017 at 17:20
  • 1
    \$\begingroup\$ @Trevor I dont want to use the current amp since the physical size is too big, i want something that just is an amp with a on/off button that i can hide away :) \$\endgroup\$
    – NoedelSoep
    Oct 11, 2017 at 17:57

1 Answer 1

Reset to default
4
\$\begingroup\$

The largest cost in a DIY amplifier will be the enclosure if you want it to look halfway decent, then the transformer and heat sinks, etc. It also takes a long time to build. In your case I would advise a LM3886 chip amp, but read on...

Considering the speakers you are using, this isn't an audiophile project aiming for 0.00000 whatnot distortion, I'm sure you'd like something practical and decent sounding instead, with a minimum of fuss!

(Note: shopping questions are usually closed, so enjoy it while it lasts).

Get this, and a laptop power brick as a supply.

Rationale: the Chinese steamroller crushes everything in its path. Building your own is only worth it if you want world class audiophile hi-fi for ultra-megabuck speakers. This TI class D chip is known to work pretty well. And considering the price, honestly, why bother to drill a face plate and install connectors... drill & tap the heat sink... Gaaah! This'll work, probably a lot better than you'd expect from the price...

Don't make a fuss about the RMS power, if you put the speakers on the desktop near your PC monitor, you won't exceed a few watts anyway, that should be pretty loud already.

However:

Check the Philips amp that comes with the speakers doesn't use an active crossover! If this is the case then the speakers are married with it and you won't be able to use another amp. A simple way to check is to count the wires in the cable from amp to speakers: 2 wires is passive crossover (OK with any amp), if more wires suspect active crossover.

\$\endgroup\$
3
  • 1
    \$\begingroup\$ Thanks for the info. If its cheaper to just buy a premade one from china then im gonna do that since the speakers aren't that great anyway to make a really high-end audio amp. Its just a + and - wire from the speakers, I checked that before asking the question :) \$\endgroup\$
    – NoedelSoep
    Oct 11, 2017 at 17:56
  • \$\begingroup\$ Good, passive crossover then! You're all set, I guess ;;) \$\endgroup\$
    – bobflux
    Oct 11, 2017 at 18:27
  • \$\begingroup\$ @NoëlVissers - Or (just as an example of what you can get on eBay) ebay.com/itm/… Do a bit of searching. \$\endgroup\$
    – WhatRoughBeast
    Oct 11, 2017 at 19:52

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.