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Matching components

Sig.Rossi

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Hello,

I've been reading here for some time. A great forum. Thanks to all members for the helpful information found here.

Unfortunately, I'm still far from understanding all of this.

Could someone help with the following question:

What do you have to consider when putting together components?

Do certain values have to fit together and if so, how?

e.g.
volt
watt
Input impedances
Effectiveness of speakers with amplifiers?

Any other important dates?

Can you use RCA components with balanced ones?

Can you use RCA components and balanced components mixed?

Can you use a power amp straight with any device controlling volume?

Perhaps we could put together a simple summary of which values have to match and how, for people like me who don't yet really understand the technical details behind it.

I would be very happy if someone could help.

Thanks a lot in advance and -not being a native speaker- sorry for my english.
 

Rja4000

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That's an interesting topic.

In HiFi, "audiophiles", as far as I remember, always dissert about components matching.
Indeed, if you believe each component should add its own taste or spice to the meal, that looks like making sense.

The benefit, for HiFi vendors and other self-called "high-end" shops, is that they may each say they found the perfect recipe by spending countless hours... and earn big money from this belief.


What's the good way to approach this, then?

The proper scientific way would be to standardize interface between the components, and then to make sure each component can prove to be transparent with an appropriate set of measurements for those very interface conditions.

That's exactly what we are looking for here.
That's why Amir standardized DAC output measurement at 4V for balanced output or 2V for unbalanced. That's why he's taking the pain yo travel to an AES event to explain his proposal for a standardized methodology to assess DAC performance.
And so on.


So, at our level, what can we do ?

Components should all be at least "good" on measurements.

Type of connection (balanced or not) should match.

Output level and input sensitivity should match, or, at least, a common level should exist where both devices are still transparent (SINAD ideally >110dB, but at least > 99dB at that level for source and destination).

Source's output impedance to be at least 10 times less than destination's input impedance.

For a power amp and speaker, power should allow at least 10dB headroom above your listening level.

Frequency response of source should be flat (+/- 0.2dB) with destinations impedance.


Am I missing something ?
 
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Speedskater

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In olden times, it was mostly about phono cartridges and pre-amp inputs.

Now it's about power amplifiers being happy driving demanding loudspeakers.
Stereophile magazine sometimes comments on this in loudspeaker tests.

Now it's sometimes about power amplifiers driving demanding loudspeakers.
 

Rja4000

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In olden times, it was mostly about phono cartridges and pre-amp inputs.

Now it's about power amplifiers being happy driving demanding loudspeakers.
Stereophile magazine sometimes comments on this in loudspeaker tests.
Transducers (at both ends of the chain) are all but perfect.
So phono (or mic) preamps and power amps have to be adapted for impedance and voltage.
Now, this isn't rocket science either.
 

Timcognito

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Sig.Rossi

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First of all, thank you for your kind answers, which I try to digest.

The link to Elac is very good. A lot of things are explained very simply and clearly there.

I guess this discussion here


concerns my problem. I wish I could understand this completely.

Is the simple result of it that I can basically combine all devices and then control the problems with the volume controls?

Can I also connect a preamplifier to an integrated amplifier or will there a problem?

As far as loudspeakers are concerned: Amplifiers should have more watts available than the specification of the loudspeaker shows. What I don't understand: How does this relate to very low watt amplifiers (e.g. some tube amplifiers; first clean watt theory)?
 

fpitas

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DWPress

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As far as loudspeakers are concerned: Amplifiers should have more watts available than the specification of the loudspeaker shows. What I don't understand: How does this relate to very low watt amplifiers (e.g. some tube amplifiers; first clean watt theory)?

Some speakers like horns with high sensitivity (on spec sheets expressed as: 95.5dB/1m/2.83v) are very easy to drive at lower wattage. Your typical bookshelf and even many floor standers will often come in around the mid 80dBs which will need more power from the amplifier to drive to full SPL.

Also, if you only plan to listen at moderate levels (neighbors/family) you can get by with a lower wattage amp into less sensitive speakers. It won't be as loud as it potentially could with a more powerful amplifier but it will sound just fine until you crank the amp into clipping levels.
 

DVDdoug

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Usually, everything works fine together with line level connections (RCA with regular consumer equipment). Line level is rather vaguely controlled & defined but most consumer equipment has high-enough line-output, and the line inputs usually have enough gain so everything works fine.

Pro line level (usually XLR balanced) is "hotter" and high outputs aren't a problem because they can always be turned down . But if you have an amplifier with XLR inputs and you are feeding it from a regular unbalanced consumer output you might not have enough gain for full-power.

Is the simple result of it that I can basically combine all devices and then control the problems with the volume controls?
Mostly yes. You can always turn the volume down but sometimes you can't turn it up enough.

Can you use RCA components with balanced ones?

Can you use RCA components and balanced components mixed?
Unbalanced outputs can always go into balanced inputs.

The other way around, balanced into-unbalanced inputs, usually works but sometimes it's a problem. I'd avoid it unless the manufacture (of the balanced device) says it's OK.

Can you use a power amp straight with any device controlling volume?
Something should control the volume. ;) With software volume control, sometimes something goes-wrong and you get a full-volume blast that might blow your speakers (or your ears!) or it might just be annoying. A physical knob tends to be more reliable.

Can I also connect a preamplifier to an integrated amplifier or will there a problem?
Yes. Any line-level output to a line-level input is OK. But since an integrated amp already has a preamp, that's rarely necessary.

As far as loudspeakers are concerned: Amplifiers should have more watts available than the specification of the loudspeaker shows.
Not true. A 100W speaker is supposed to be safe with a 100W amplifier that's hitting 100W on the program peaks. too much power into a speaker can damage it!* But it's a "fuzzy" thing because music has short-term peaks with a much lower average, and it's the short-term average that burns-up speakers. And a tweeter can't handle as much power as a woofer. You can burn-up a 100W speaker with continuous 100W test-tones, and high-frequency continuous tones are more dangerous...

When you over-drive an amplifier onto clipping, the peaks don't go up, but the average does so "heating power" increases and you're more likely to burn out the speaker. And the clipping introduces harmonics (higher frequencies) which can go to the tweeter. And with most amplifiers you can get more total power with clipped waves than with clean sine waves. Theoretically, you might get 200W from a 100W amp if you "push" the sine wave such bad clipping that you have a square wave.

volt
watt
Some electronics math:
Ohm's Law (Current = Voltage / Resistance) defines relationship between voltage, resistance, and current. Resistance (and impedance which is also Ohms) is "the resistance to current flow."

Power is calculated as power (Watts) = Voltage x Current. Or along with Ohm's Law, you can derive Power = Voltage Squared/Resistance.

Amplifiers basically put-out a voltage so with 4-Ohm speakers you can often get twice the power as with 8-Ohm speakers. But, the amp has to be capable of putting-out twice the current, and if not the maximum voltage will drop and you'll clip at lower wattage. (It's common for amplifier to put-out slightly less than twice the power with 4-Ohm speakers.) If the speaker impedance is too low, you'll "pull" excess current and the amplifier might shut-down, or it might blow a fuse, or it might burn-up and die.

Input impedances
Input impedances (of amplifiers & preamps) isn't much of a concern, except for microphone and phono inputs which have certain standards/requirements. As somebody said above, you don't "match" impedance.



* There is a myth that over-driven lower-power amplifiers are worse. Although, you can burn-up a speaker with an over-driven "small" amplifier, a higher power amp (driven to its maximum) is even worse!
 
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Sig.Rossi

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Thank you for all the helpful answers and for putting so much effort into this.
 
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