Upgrade audio equipment

chua55 wrote:Oh yeah. Definitely benefits with matching amp. Small little 15Watter Push Pull amp can be quite muscular, depends on where it is used.

Try class A solid state amp too. I am building one. Just 25 Watter, again small.

Oh.. Thanks. Really surprised to hear that.
I have heard of small output amp giving wonderful sound at my friend's place.

Well, to be honest, I know nothing about circuitry.
So, I have to buy from shops.

it depends on what type of amp and what is inside. Some amp will deliver happily 10A into 2 ohm but some cant. For solid state, it is an advantage. For tube amp, it is not difficult too (output trans). Anything lower than 2ohm with phase delay will be a lot of sweat for the amp.

The audition session lasted for hours that day.
Many types of musics being played.
I was really satisfied with the speakers.
So, in the end, I brought them home with a smile on my face.

hi sivaguru , i wrote a lenghty article about the myth of amp wattage ratings at lowyat.net some time back.... lemme try and re-post it here:

....
The next thing would be why certain Amps with high Wattage rating
seem so anaemic and lazy when driving certain loudspeakers. Until
recently, alot of Japanese Amps are guilty of such shortcomings. This
actually has to do with current delivery and the Amp's output Impedance.

Slight
digression .. a Loudspeaker's sensitivity is usually rated in terms of
how much Volts (usually 2.83V for a 8 Ohm speaker) at a distance of 1
meter, will give XX dB of sound level output. aka "Loudspeaker
Sensitivity".

For simplicity , Lets assume we are working with
only real impedances here ... so impedance = resistance. Capacitance
and Inductance are ignored.

Ohms's Law: V = I x R ,
V= volts, I = current (in Amps, A ) R = Resistance ( in Ohms).

Lets
see how we can measure the current needed to "put 2.83V across the
speaker terminals " of a typical 8 Ohm loudspeaker for an Amp that has
a high output impedance compared to an Amp with a low output inpedance.

Case 1: Amp with a Output Impedance of say .... 2 Ohms. Lets call this "Ra" while the loudspeaker's impedance is "RL"
Taking
a holistic view of the amp's output circuit, we have , V = I x ( Ra +
RL) , where (Ra + RL) is the total impedance in series of the complete
circuit.

So to drive the loudspeaker to make a noise of XX dB,
the amp needs to put 2.83Volts across RL. But due to the Amp's output
impedance of 2 Ohms in this example, the Amp actually needs to crank
out V[case 1] = I x ( 2 + 8 ) , but we know that I x 8 must be equal to
2.83 , hence I = 2.83/8 = 0.354 A
Therefore, V[case 1] = 0.354 x (2+8 ) = 3.54 Volts.



Case 2: Amp has an output impedance of only say... 0.1 Ohms.
Same
method of calculation... Current needed to put 2.83Volts across the
loudspeaker is 0.354A to make the loudspeaker make the same noise level
of XX dB. But now, Ra is only 0.1 Ohms whereas RL is still at 8 Ohms.
Therefore, V[case 2] = 0.354 x (0.1 + 8 ) = 2.87 Volts.


Conclusion
, for Amp-1 to make the loudspeaker boogie at XX dB, it needs out pump
out 3.54Volts , compared to Amp-2 which only needs to output 2.87
Volts. If the Amp needs to put out a higher voltage, it means it has to
work harder. So there u have it. Amplifier power ratings demystified!!

Moral
of the story, you can have a 100W rated amp but if its got high output
impedance .. its a whimpy amp (coz maybe only 15% of its wattage is
delivered to the speakers)
Same rule applies, u can have a very
conservatively rated amp of say 25W but its built with very low output
impedance, it can be a very strong (efficient) amp (say if it can
deliver 95% of its wattage to the speakers) !

This problem is even more pronounced with loudspeakers with lower impedances (i.e. 4 Ohms or so)

The
sad part is that most electronics manufacturers will proudly boast the
Wattage ratings .. but almost never reveal the Amp's output impedance.


So
what determines a loudspeaker that's " hard" or "easy" to drive ? Its a
combo of its impedance and its sensitivity .. but this should warrants
a separate topic/thread by itself...

sivaguru wrote:What is the sensitivity of the speakers? Low sensitivity speakers require a beefier amp to sing.
Regards,
Sivaguru
PS Would like to add a XX to my collection

i got an Exposure XX thats just sitting around doing nothing... Hmmm....

short and simple, very well explained. Passlab Aleph5 power amp has 60W into 8ohms while Passlab F5 has 25W into 8ohms.

Yet F5 can deliver happily that 10A at 2ohms happily into the toughnut Dynaudio Focus 140 and Aleph5 will be sweating to do that. Even though F5 is only 25W, it is burning hot.


The damping factor. To achieve such high damping factor require careful design and implementation.

to get high damping factor, the Amp's output impedance will need to be really really low. Which also makes the Amp to be more capable in terms of power delivery efficiency to the loudspeakers.

So high damping factor goes hand in hand with the example formulas above.

DF = Z_L / Z_A

where DF is Damping factor, Z_L is loudspeaker impedance, Z_A is amp output impedance.

What if I cannot find the output impedance of the amplifier?
How to justify whether they have a healthy output of watts?

Lots of manufacturers dont reveal the figures.
That means it will be very difficult for me to calculate.

Wow, wow what we have here! I think i must pop in my head here to join this discussion here.

Most amplifier do not reveal the output impedance but they reveal the damping factor. By using the formula given by mugenfoo, you can determine the damping factor. The other way around this is to know the output and the numbers of drivers transistors being used. By paralleling the output drivers, one can lower down the output impedance. The more the better however there is a tradeoff the purity of signal is compromised. That is why i have respect for Rotel amps coincidence made by the Japanese. For their 30watters they use 4 nos power transistor, not the whimpy type! instead of 2 usually practise by other amp makers. They have adopt this method on the RA820, award winner what hifi 1985. (in my knowledge and thats the year i started serious in hifi, they might have adopted it much earlier ) i was used by the Sansui era where speaker woofer size of 10"-12" is considered norm. Bookshelf considered mini hifi. Till date they still employ in their RA04(still a winner in what hifi for a few year now) You might not like the sound or presentation, but it easily drives any lazy speaker around. (I am not a Rotel salesman but a fact is a fact) Actually I like Sugden amp A21 and these are the worst in driving lazy speaker. But they sound music to my ears with sensitive speaker.

IMHO, better find a sensitive speaker and easier to drive. It is harder for speaker manufacturer to make sensitive speaker than lazy speaker. I will consider sensitive speaker a premium.

I have tried out the calculations. The 2.83V across speakers of 8ohms.
But I have no idea of teh value of Volt if the speakers are 4ohms.

Can I say that the lower the amplifier output impedance, the healthier the amp's output?

And also the damping factor has to be the higher the better?

There is no volt in the equation DF=Z_L/Z_A

Work around, Z_A= Z_L/ DF where Z_L= 8 ohms. The DF check your manufacturer spec or write email to them. Ask them for Damping Factor. Best just ask them the Z_A straight away no need to crack your head on equation.

The lower output impendance does not mean is healthy or sick but rather it was due to the ilmitation technology employed. Yesteryear transistor amp has low damping figure coz transistor technology the last time has its limitation compare with nowadys transistor that is faster can handle high current. Best very linear...It is so linear that crossover distortion is approaching class A. It is no surprise nowadys amp sound like class A eventhough they are in ab or b mode. The trend of manufacturer nowadys are moving away from class a except a few that has made their name in class A of yesteryear , manufacturer like sugden or the recent resurrected mf a1....

Yup you are right the higher higher damping factor the better. You will hear the difference, instead of wolly bass you get thight bass, tighter response in whole range of audio spectrum.

yes, the damping factor "DF" is a dimensionless value.

Also, more sensitive speakers doesn't necessarily mean more high-end. Speaker efficiency is just one of the many design parameters .... there are other things like cone stiffness, natural resonance, cone-travel distance, etc etc etc.

But in the absence of mfg specs, just trust your ears. This is all part n parcel of hi-fi.

DF=Z_L/Z_A

Let's say the damping factor is around 100.
As for Z_L = 8ohm, the Z_A will be 0.08ohm.
and for Z_L = 4ohm, the Z_A will be 0.04ohm.

Can I say that.......

The output impedance for the amplifier will vary with the speaker impedance but the damping factor will remain the same??

The cone stiffness, cone travel, surface area, the magnet, will effect the effeciency of the speaker driver. The effeciency of the speaker driver is not independent but interelated with the factors mentioned. When a manufacturer built the driver they cannot determine the driver sensitivity until they built the sample and test it...right.

Damping factor figure will vary acording to your speaker load.

Got it! Thanks..

This thread is gathering more and more info.
I hope that the info will give us more guidelines while choosing an equipment for upgrade.

After getting my speakers, I think I would like to let go of my ES11.

ES11 are not easy speakers to drive. But when partnered with a good amp, they can really sing.

Same goes for Sonus Fabers especially the older generation ones. Very unforgiving on wimpy amps.

If you can get a good used pair, the ES11 are really worthy.
I have been using them for 10yrs. They gave me so much memories.

At the meantime, I am just using the Exp XX to drive the SFCD.
I know they will require a better amp to make them sing.
With the Exp XX, it is like the SFCD's potential not being revealed.

how much does an EPOS ES11 sold for a pair?

A very important in the audio upgrade exercise is the crossover network, sharing an equal important factor in the audio path.

I dont think I would have the chance to see and know all the material and design used in the crossover network. But it would be great experience if someone share it here.

Sometimes you may why for the same speaker, one may sound sexy than the other.

some juice wellknown in the upgrade network such as the supreme silver gold oil, TFTF, OIMP, Jensen, Duelund, copper foil inductor.

azri wrote:how much does an EPOS ES11 sold for a pair?

You are looking for a pair?

Yup you are right the higher higher damping factor the better. You will hear the difference, instead of wolly bass you get thight bass, tighter response in whole range of audio spectrum.

Hi hoysum, in lay man's term, how high is high? Could you please let me know what the range is?

Many thanks in advance.

car o scope wrote:

azri wrote:how much does an EPOS ES11 sold for a pair?

You are looking for a pair?

not yet, just to make price comparison

I am thinking of letting go mine.

how can u let go something u love??
anyway whats the price? hehe

I am not sure what's the current market price for it.
Have to let them go so that they can be optimised by new owner.

chua55 wrote:A very important in the audio upgrade exercise is the crossover network, sharing an equal important factor in the audio path.

I dont think I would have the chance to see and know all the material and design used in the crossover network. But it would be great experience if someone share it here.

Sometimes you may why for the same speaker, one may sound sexy than the other.

some juice wellknown in the upgrade network such as the supreme silver gold oil, TFTF, OIMP, Jensen, Duelund, copper foil inductor.

Most crossover networks are an integral part of the speakers ... so its better to just evaluate them part of the complete loudspeaker section.

Unless you're a NAIM lover and are doing stuff like active X-overs and bi-amping ... like a Lego building block system.

caroskop, QUAD 12L 2 seems very nice for an upgrade
i gonna have an audition this next weekend
& wait for the price to drop by the end of the year LOL

i dont care if its designed in UK & perfected in china LOL LOL

Oh.. I have listened to the Quad 11L but not the one you mentioned.
I have a friend who is selling Quad products too.

If want to buy speakers, I really have to say auditions with your own ears will give the best judgement.
Not just by reading comments, reviews and specs.
You will know what you like during auditions and you will know whether the speakers manage to pass your requirement 'test'.

In the end, I bought myself a pair of SFCD and I have to say I finally got the speakers that I want.

how much did u spent for the EPOS (previously) & SF??
which SF & does it comes with the stand??

i thought u gonna change the amp? & now its a double cost for u
1st the SF & then new amp to force feed SF potential

The SF stands are optional.
I think it is best to upgrade the speakers 1st rather than amp.
After getting the speakers, then only find the matching amp for them.

This is my opinion though..
I feel that the sound is greatly determined by the speakers.

Honestly, SF is totally a whole new experience to me.
It is different compared to Epos.
Or I shall not compare them at all.

aiyah, cannot compare the Epos against the SF.

its like comparing Proton Wira vs Audi A4.

Adoi !

You are right..
They are from different levels.
That's why I called it as an upgrade.

If play the Planet Drum through Epos using the KAV-300i, aiyoyo.. dont know what will happen.

mate.. a4 is nothing

so if A4 is nothing ... Wira is what then ? ... even crappier sh!t ? hahahahaha

Let's put it this way..
Epos ES11 is good at the sort of money.
SFCD is even better than Epos ES11 but at a higher price.

For SFCD, you really get what you paid for at that sort of money.
If not, I would not even think of breaking my bank for them.

I guess members are very well familliar with what the gears are capable of. I hope we can stay on course about the subject. More often than not, diversions take the subject out of topic.

I believe with reasonable money well spent, you can enormous improvement in sound. Not necessary the big buck way. start analyze what your system is capable of.

I have set my direction in equipment upgrading.
Speakers 1st followed by amplifier.
Cables should be last.

Anyhow, this is my direction and not a must for audiophiles.