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AKG K240 Sextett--Grado'd AKG? - Page 55

post #811 of 1030

The Sextetts have a 200 mW power handling rating,   their published effeciency 94db?  I think is probably a little optimistic.

 

 

So working with the 200 mw,   that is 11Vrms voltage from the amp.    Most any headphone amp I have found is full of distortion at anywhere close the 11 Vrms.   Compared to a speaker amp to reach 11vrms across a 4 ohm speaker a 15W amp is required,  now the 600 ohm sextetts don't need as much current as the 15W 4 ohm speakers.   But no speaker amp less than true 15W rms power will drive the sextetts to full power.

 

Now throw distortion into the mix,  a speaker amp running full blast with 15 Vrms output (15W in speaker terms) is most likely not in a good spot for thd.

 

I can really understand how folks are reporting good results with 50W+ speaker terminals for the Sextett's.   There really aren't any amp designs out there that have low distortion 11 Vrms 200mW output (only 18 mw),  but you can see why it takes a 50W speaker amp to have reasonable distortion with the 600 ohm load.

 

Even tube amps which are supposed to be better for high voltage high ohm loads struggle because the output tube has to swing sp many volts before the step-down output transformer.

 

Has anyone found a reasonable amp that can deliver 10-11 V rms of clean power?

post #812 of 1030

I'm using this little amp: http://www.ebay.nl/itm/ws/eBayISAPI.dll?ViewItem&item=260646807864&ssPageName=ADME:B:EOIBSA:NL:1123

 

I works great with my Sextett LP.

The seller is a Headfi-er too.

post #813 of 1030
Quote:
Originally Posted by glenda View Post

The Sextetts have a 200 mW power handling rating,   their published effeciency 94db?  I think is probably a little optimistic.


So working with the 200 mw,   that is 11Vrms voltage from the amp.    Most any headphone amp I have found is full of distortion at anywhere close the 11 Vrms.   Compared to a speaker amp to reach 11vrms across a 4 ohm speaker a 15W amp is required,  now the 600 ohm sextetts don't need as much current as the 15W 4 ohm speakers.   But no speaker amp less than true 15W rms power will drive the sextetts to full power.

Now throw distortion into the mix,  a speaker amp running full blast with 15 Vrms output (15W in speaker terms) is most likely not in a good spot for thd.

I can really understand how folks are reporting good results with 50W+ speaker terminals for the Sextett's.   There really aren't any amp designs out there that have low distortion 11 Vrms 200mW output (only 18 mw),  but you can see why it takes a 50W speaker amp to have reasonable distortion with the 600 ohm load.

Even tube amps which are supposed to be better for high voltage high ohm loads struggle because the output tube has to swing sp many volts before the step-down output transformer.

Has anyone found a reasonable amp that can deliver 10-11 V rms of clean power?

1w@8ohms is around 2.23-2.75v so any amp with around 20-25wpc will feed them. tubes tend to have issues cause they're transformer coupled and the power transformer does all the impedance matching and give the tubes it's output impedance and are usually design around that impedance load so in order to get full use of any tube amps you'll gonna have to use resistors at the speaker terminals as well to have the amp see that specific load. Solid State amps output impedance are always close to 0(if they have dampen factor around 40@8ohms) making it an ideal voltage source and are push-pull circuits so it feeding a 600ohm load is no problem and will increase voltages when needed cause the power transformers are always rated for around 30vRMS loads for higher impedance speakers and most speakers spike up to around 50-100ohms at certain frequencies so the power transformer is constantly changing voltages on the fly.

they usually have no issues with voltages but it's amps/current which is their most limited at but most well built amps can push enough amps from the power transformer and close to double it's power for 4ohm loads if it's good speaker amp while maintaining consistent voltage.
post #814 of 1030

Ok, so I finally had the chance to try my Sextetts with my Nad 3020, so far only on the headphone outs. Definately better than the Kenwood Basic c2. Bass goes deeper, and the sound no longer breaks apart on higher volumes. It's not more revealing in terms of detail, but  music is easier to follow with better separation of instruments. beyersmile.png

post #815 of 1030
Quote:
Originally Posted by kopeHUN View Post

Ok, so I finally had the chance to try my Sextetts with my Nad 3020, so far only on the headphone outs. Definately better than the Kenwood Basic c2. Bass goes deeper, and the sound no longer breaks apart on higher volumes. It's not more revealing in terms of detail, but  music is easier to follow with better separation of instruments. beyersmile.png



Amazing that someone else across the world has tried Sextetts with an old Kenwood Basic,  I had the same issue.  I also had a circa 2001 70 lb Harmon Kardon receiver that was fantastic with the Sextettes,  Unfortunately it didn't surve a lightning storm.   I am attempting to mod the O2 to power the Sextetts,  I think its a possibility.  But in the mean time the Audio-gd NFB12 does a very decent job,  a little more distortion than I like but for the price it isn't bad.

 

I still have a bothersome rattle with my Sextettes noticeble when they aren't on my head,  I replaced the pads and the foam inside.  Do all Sextettes "rattle" with bass at high volume (ie playing without them on your head.)

 

post #816 of 1030

What about a Schitt Lyr?  Would that be enough power according to these numbers?

post #817 of 1030
Quote:
Originally Posted by rhythmdevils View Post

What about a Schitt Lyr?  Would that be enough power according to these numbers?



The Sextett,  don't need a whole lot of power,  they need an unusually large voltage swing. 

 

Thats why a lot of folks like vintage receivers because they have huge distortion free voltage swing but the power knocked down with output resistors. 

 

For example the NFB12 has a spec of 10Vrms max,  and for $200 it does better with the Sextetts than most,  but it is not a low distortion amp,  I measured 2H &3H distortion at just 1Vrms output so by 10Vrms it is struggling, while the headphone output of a good vintage receiver is going to have practically no distortion at 1Vrms and 10Vrms is a walk in the park.

 

The Lyr claims 40Vp-p into 32 ohms,  which is a good spec to work with 'cause right of the bat we know it isn't going to be current limited into 600 ohm AKG's.  Now 40Vp-p=20Vp= 13.8 Vrms into 600 ohms = 317 mW.   So thats 50% headroom over the max allowed 200mW (.2W) of the AKG Sextetts.   Thats enough power no doubt.  And the tube-mosfet hybrid approach is an excellent approach. 

 

But if you have ever worked with a 6922 or a 6B7Z you will know that the distortion is directly proportional to the voltage swing,  the tube on the Lyr is being worked  with the Sextetts, while with Grados the Lyr is ideal because the tube is just idling along barely driving .4Vrms. These tubes are famous for their non-linearity and the 3rd harmonic sound signature in certain conditions.

 

For $440 I would say the Lyr looks like an excellent candidate as a fun amp that has the power needed for Sextettes, the concern would be the tube disortion which may or may not be an issue to the individual. Depends a lot on how the tube stage was designed and I can't answer but they claim 40Vp-p so it should be solid. The THD is spec'd at < .1% at 1V.    Maybe someone can ask what thd/imd is at 10vrms into 600 ohms ?

 

The alternate has the risk as when buying a vintage receiver with no warranty and limited parts availability.  One can easily find an old Sansui receiver that should have have lower distortion at these voltage swings but when it blows a diode it is totalled because the parts are hard as heck to find.

 

 

 

 

 

post #818 of 1030

Just got a pair of MP Sextett.  Initial impressions are: it really reminds of ATH-AD2000 in a big way.  Really up close midrange... nice with vocals.

I expected more bass though. The bass is also like the ATH-AD2000.  Not enough mid-bass for rock, but nice with vocals.

 

 

 

 


Edited by sling5s - 1/3/12 at 8:55pm
post #819 of 1030
Quote:
Originally Posted by sling5s View Post

Just got a pair of MP Sextett.  Initial impressions are: it really reminds of ATH-AD2000 in a big way.  Really up close midrange... nice with vocals.

I expected more bass though. The bass is also like the ATH-AD2000.  Not enough mid-bass for rock, but nice with vocals.

 

 

 

 



Maybe you need to replace the ear pads for a better seal, and the elastics for a tighter grip.

Sextett MP should have all the bass you need for rock.

Even my LP has.

 

post #820 of 1030
Quote:
Originally Posted by sling5s View Post

Just got a pair of MP Sextett.  Initial impressions are: it really reminds of ATH-AD2000 in a big way.  Really up close midrange... nice with vocals.

I expected more bass though. The bass is also like the ATH-AD2000.  Not enough mid-bass for rock, but nice with vocals.

 

 

 

 



Interesting that the AD2000's have that up close midrange,  I need to try these,  its why I only listen to Sextetts and Grados

 

post #821 of 1030

Yeah...the AD2000 has to most up close midrange of any headphones.  It's like the singer is singing right against your ear.


 

Quote:
Originally Posted by glenda View Post



Interesting that the AD2000's have that up close midrange,  I need to try these,  its why I only listen to Sextetts and Grados

 



 

post #822 of 1030

Yes could be the ear pads.  From my memory, the K240 M (600omhs) had more bass. 
 

Quote:
Originally Posted by Tiemen View Post



Maybe you need to replace the ear pads for a better seal, and the elastics for a tighter grip.

Sextett MP should have all the bass you need for rock.

Even my LP has.

 



 

post #823 of 1030
Quote:
Originally Posted by glenda View Post



The Sextett,  don't need a whole lot of power,  they need an unusually large voltage swing. 

 

...

 



Awesome post !!

 

post #824 of 1030

i just purchased a pair of AKG 240 monitor ( 600ohm)  i have a headroom little and the headphone out on my pioneer thx-908.  any ideas on which one is best suited to drive them after reading this post i am really excited to listen to them.

post #825 of 1030


Anyone know of any other amps that would have the required voltage swing plus low distortion? Thinking of trying the sextett or 'M' myself. I have the DF at present and like it a lot, but I don't know if my amp is doing it justice.

Quote:
Originally Posted by glenda View Post



The Sextett,  don't need a whole lot of power,  they need an unusually large voltage swing. 

 

Thats why a lot of folks like vintage receivers because they have huge distortion free voltage swing but the power knocked down with output resistors. 

 

For example the NFB12 has a spec of 10Vrms max,  and for $200 it does better with the Sextetts than most,  but it is not a low distortion amp,  I measured 2H &3H distortion at just 1Vrms output so by 10Vrms it is struggling, while the headphone output of a good vintage receiver is going to have practically no distortion at 1Vrms and 10Vrms is a walk in the park.

 

The Lyr claims 40Vp-p into 32 ohms,  which is a good spec to work with 'cause right of the bat we know it isn't going to be current limited into 600 ohm AKG's.  Now 40Vp-p=20Vp= 13.8 Vrms into 600 ohms = 317 mW.   So thats 50% headroom over the max allowed 200mW (.2W) of the AKG Sextetts.   Thats enough power no doubt.  And the tube-mosfet hybrid approach is an excellent approach. 

 

But if you have ever worked with a 6922 or a 6B7Z you will know that the distortion is directly proportional to the voltage swing,  the tube on the Lyr is being worked  with the Sextetts, while with Grados the Lyr is ideal because the tube is just idling along barely driving .4Vrms. These tubes are famous for their non-linearity and the 3rd harmonic sound signature in certain conditions.

 

For $440 I would say the Lyr looks like an excellent candidate as a fun amp that has the power needed for Sextettes, the concern would be the tube disortion which may or may not be an issue to the individual. Depends a lot on how the tube stage was designed and I can't answer but they claim 40Vp-p so it should be solid. The THD is spec'd at < .1% at 1V.    Maybe someone can ask what thd/imd is at 10vrms into 600 ohms ?

 

The alternate has the risk as when buying a vintage receiver with no warranty and limited parts availability.  One can easily find an old Sansui receiver that should have have lower distortion at these voltage swings but when it blows a diode it is totalled because the parts are hard as heck to find.

 

 

 

 

 



 

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