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So I'm gauging whether I can connect the internal speaker of my Korg piano to my old hi-fi system's amplifier in preparation for buying and using Pianoteq. Since the internal speakers sound fine, I much prefer to use the internal speakers for the aesthetics and budget reasons.

The amplifier is connected to my PC's sound card.

I found that the amplifier has has rated Independence of 6 Ohms whereas the internal speakers show about 8 Ohms of impedance, measured using a multi-meter.

As far as I understood, this shouldn't pose a problem for either the amplifier or the speakers because of the higher resistance on the speakers' side, am I right? Anything else I need to take into account?

Thanks! :-)

Hello,

Does your Korg piano have a line input? If so, you don't need to make the speaker connection.

=> Either route the line output of the sound card into that line input;
=> Or use the tape out of your old hifi amplifier into that line input.

If you do need to make the speaker connection (opening up the piano and creating some makeshift connections, I presume), and the internal speakers are 8 ohm, driving them out of a 6 ohm rated amplifier is just fine.

Notes:
=> Disconnect the internal amplifier, you don't want to inadvertantly feed another amp's output into it. And/or make a double switch if you want to alternate between internal sounds and your PC generated sound.
=> Note that run-of-the-mill soundcards/onboard sound chips are not optimal for VST use, in terms of sound quality. This applies to PCs in particular, less so with Macs I assume.

Cheers and careful connecting,

HZ

PS We all want Independence, but the term here is impedance 😉. As a general rule, as long as a speaker's rated impedance is higher than the minimum that is specified for the amplifier used, you're fine. That is, as long as you don't connected speakers in parallel to the same channel. The other way around is, again generally speaking, not advisable.

There was a topic about hacking an audio input to a Korg C1 or G1.

(At least the "Air" versions with Bluetooth audio input. But the connector might be there anyway even if the BT module is missing.)

http://forum.pianoworld.com/ubbthreads.php/topics/3108625/korg-c1-and-g1-line-in-mod.html

Hello,


Note to @meghdad, this then would be a line input, *not* to be used to drive a speaker level signal into!

Cheers and careful connecting,

HZ

The speaker is detachable, meaning it has normal connector pairs (two pairs) that goes into the amplifier box that's attached externally beneath the piano..

Anyways, so I'll be good regarding the impedance even if I max out the volume on the hi-fi system's amplifier? It's rated 1000 watts P.M.P.O.

Regarding the sound card, I'll give it a test-drive anyways for what it's worth before dishing out for dedicated sound card.

Hello,


I see. That's convenient (detachable).

As said, driving 8 ohm speakers from an amplifier that is allowed down to 6 ohm speakers is fine.

If you would have to max out your volume though, something is utterly wrong. Two of my amplifiers are 58 watt per channel, the third one is 40 watt per channel. And all of that goes *deafeningly* loud should I want to, which I don't of course. You'll probably use 0.5 to 4 or so watts in real life, the other 996 being 'headroom'. That in itself is not a problem, just be careful and responsible every step of the way.

Cheers and happy careful connections,

HZ

This is odd ...I've never see anything approaching "hi-fi" rated with PMPO (peak music power output). Generally only cheap/junk/garbage equipment is rated that way.

Can you provide make and model for your amplifier?

OK thank you. You're right about the max volume, I was asking a hypothetical question. :-)

@MacMacMac Of course it is odd, because I think I misused the term Hi-Fi haha. I'm not sure if it's junk because it sounds real good for listening to classical piano music. I linked to the audio system in OP, here it is again: https://www.manualslib.com/manual/147533/Samsung-Ah68-00935b.html?page=27#manual

It's quite old and out of production.

My daughters each had a similar stereo set. In those days they came with dual cassette and CD changer.

When the girls grew up they left those stereos behind, so I was left with three of them.

I used one of them as amplifier for my piano. It seemed okay ... until I bought a proper, quality amplifier (a Yamaha).
Big difference. I would never go back.

Oh wow you're a father! I always imagined you as a fellow 30 year old guy haha...

Yeah I don't think it's a great amplifier by any means but will serve me well until I can buy a better one, or a new piano altogether.

Who are you and what did you do to the real HZPiano? No "Happy connecting"?

Meghdad, about the Samsung amplifier, I suspect those 40W are inflated to impress the owner (PMPO even more), notice the 10% distortion.

Adding a line input would be better, but I am assuming you do not want to tamper with your Korg to not void the warranty so, if you already owns the stereo and the DP's speakers are dettachable, you have nothing to lose. Please let us know how things worked once you have the chance to test it.

Oops?

😀

HZ

I'm still using this to run my VST's through. Sounds great and no issues.

Yeah I did notice the distortion level. What does it mean in reality though? Would it sound out of proportion at max volume e.g?

And sure I'll report back once the gear is set up.

Cheers!

Hello,


It may not mean much in your real life case, because you'll almost certainly only use the first few watts, the rest being headroom.

For superficial consumers judge everything by their rated wattage--the "higher is better" mindset--mentioning a 10% distortion is a way to list a higher number for the wattage. As "they" don't know how that distortion works anyway, and 10% doesn't look much, all is "nice" commercially.

But in reality this is just silly. Ideally you'd want a distortion well below 1% or even a small fraction of that for really decent gear. Generally speaking, at a normal power usage of just a tiny few watts, the distortion will also be much lower than that 10%.

But if a manufacturer rates their gear at 5 watt at a decently low distortion figure, they won't sell their units.

This is just how messed up our world has become...

Cheers and happy low wattages,

HZ

Thank you. :-)

I might buy a dedicated amp or use that line-in approach in the end. We'll see.

So I finally hooked them up using some makeshift method to see how well it sounds. Not good. Could be because it is makeshift and wires were loose, not enough insulation or something else. Or could it be the ohm mismatch as stated above? Because it sounded very weak and I had to max out the amp to get a decent sound out of the piano's speakers.

Might be more to do with the signal hitting the amp (from your sound card if I recall?)

What happens when you connect that amp to regular hi-fi speakers?