Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › Amp to drive vintage AKG K240DF 600ohm?
New Posts  All Forums:Forum Nav:

Amp to drive vintage AKG K240DF 600ohm?

post #1 of 10
Thread Starter 

Hi people,

 

I posted this in the Headphone Amp section, but haven't received any replies, so I'm posting it here too.  Sorry for the double post..

 

 

 

I've just recently received a pair of these used from eBay and I'm presently running them from either my Arcam Alpha 8 integrated amp or my Asus Xonar Essence STX soundcard.  I'm mightily impressed with them up to now.  Having read some glowing reviews about how these are a hidden gem in the headphone world, I couldn't resist when I saw a pair crop up on the bay.  I think I may have paid a little over the odds for them (£72), but they are worth every penny and more and the build quality is second to none.  I've been keen to try a pair of AKGs and these cute vintage cans are a very nice way to experience that.

 

The mids and highs are especially revealing and open, but in accordance with what everybody has said about them, they are lacking in the bass department.  This is not a massive issue, especially if the recording has good bass to it, but I'm finding a lot of my orchestral LPs, running through my Arcam integrated really lacking downstairs and was wondering if I could improve on this with alternative amping?  I should add that I'm wondering whether this Arcam is running them adequately at the moment.  I have read and been advised that the old 70s receivers are a good starting point.  The Arcam can drive them very loud, but I'm not sure if the output is matching to the cans' needs.  I'm not technical enough to understand the specs, but the manual says the Arcam can drive headphones between 30 and 2000ohms.  The Max output level into 600ohms is 10V rms and the output impedance is 330ohms.  Can anyone make sense of these figures and do they compare to these 1970s receivers?

 

I have already done a fair bit of research, but it seems up-to-date info/feedback on these is hard to find.  I understand that by nature, these are a bass light/neutral phone, but I've also read that they benefit more from tube amplification in terms of feeding them the voltage/current they need to sing?

 

I'm not familiar enough with this area of physics to be able to make good judgements about this, so could anyone recommend me some amp options?  I don't want to spend mega money.  I would possibly go up to $200/£150.  I've noticed this amp that seems quite cheap and gets good reviews - 

 

http://bravoaudio.com/Bravo%20Ocean.html

 

Would this be better than my present set-up, or do I need something more?

 

I would also like to mention - as very much a side note - that my other cans are HD598, Grado SR80 and some soon to arrive HifiMan HE-400s.  If possible, it would be nice to think that any amp I did buy would be compatible with them too (though not a neccesity, as I realise they don't demand the juice that these AKGs do and I'm already getting great results with what I have), but I understand that finding an amp that runs both high and low impedance cans is pretty hard to come by?  Driving the AKGs is my priority though.

 

Many thanks in advance!

 

Matt

Gear mentioned in this thread:

post #2 of 10
Thread Starter 

Anyone?
 

post #3 of 10
I think the Arcam is more than suitable (and the specs look to be in-line with what you'd expect from a receiver (as an aside, the entire "1970s vintage receivers" as a suggestion is troublesome - people need to be MUCH more specific)). I'd leave well enough alone, unless you like spending money.
post #4 of 10
Thread Starter 
Quote:
Originally Posted by obobskivich View Post

I think the Arcam is more than suitable (and the specs look to be in-line with what you'd expect from a receiver (as an aside, the entire "1970s vintage receivers" as a suggestion is troublesome - people need to be MUCH more specific)). I'd leave well enough alone, unless you like spending money.

Thank you for your reply. I was just hoping for more bass from a different setup. I've gone and ordered the Bravo Ocean anyway as a first foray into tube world. I'll post back impressions of anyone is interested.
post #5 of 10
Quote:
Originally Posted by amigomatt View Post

Thank you for your reply. I was just hoping for more bass from a different setup. I've gone and ordered the Bravo Ocean anyway as a first foray into tube world. I'll post back impressions of anyone is interested.

Does the Arcam have tone controls? Have you tried them? redface.gif

Alternately - if you've got an impedance plot for the K240, you could figure out FR changes due to Zout. But I'm going to add that the Arcam is probably near the tip-top in "bass boost" (I'm going to assume they have a big peak in the mid-bass, like a lot of headphones do), given that it already has a fairly high output impedance.

The tube amp may be inherently non-linear, and have boost in the low-end; but I'd still compare/contrast with tone control or EQ. If you're finding that you want very dramatic changes though, I'd probably consider a different headphone.
post #6 of 10

I once wrote a review of the K 240 DF where I pointed out some negative aspects of the sound (e.g. the lack of bass on my pair). I was promptly told that it was all due to the amplification, and was asked to buy a vintage receiver to power them. I did just that, but the lack of bass (among the other negative aspects) remained.

 

So in my opinion either get a really beefy receiver if you want to go down that path - and expect the possibility that you see no benefit - or do perhaps the more sensible thing and use quality EQ.

post #7 of 10
just find a good preamp. cheap good headphone amping is a kenwood C2 if you can find them. i found a C2 for 40 bucks cause i was looking for an extra preamp for my yamaha m-45 power amp and was very surprised on the headphone out. made my sextetts and DF's sound really nice. DF's naturally have a bass roll off(below 50hz) so only tone controls can help. thing that makes them sound bass light too is cause the DF's have a pretty flat mid-bass with no emphasize. people like and use to that ''boom-boom''.

the z-out should only affect FR slightly cause the DF's peak to 1000ohms in the FR somewhere. i forgot where i saw the graph though. it was in dutch.
post #8 of 10
If the graph is reactive, Zout will influence it. Its only not a "thing" when the graph is basically flat.
post #9 of 10
Thread Starter 
Quote:
Originally Posted by obobskivich View Post


Does the Arcam have tone controls? Have you tried them? redface.gif

Alternately - if you've got an impedance plot for the K240, you could figure out FR changes due to Zout. But I'm going to add that the Arcam is probably near the tip-top in "bass boost" (I'm going to assume they have a big peak in the mid-bass, like a lot of headphones do), given that it already has a fairly high output impedance.

The tube amp may be inherently non-linear, and have boost in the low-end; but I'd still compare/contrast with tone control or EQ. If you're finding that you want very dramatic changes though, I'd probably consider a different headphone.

 

I do have tone controls on my Arcam, but to enable them, I switch off the 'Direct' button.  The problem is that with the 'Direct' switched off, there is a bit of channel imbalance and the sound is noticeabley worse (most likely due to the age of the amp), so I'm keeping it on 'Direct' out, it's much cleaner that way.  I may try a quality EQ, as suggested by vid below.  I have a really good software one, so will try that first, but can obviously only apply that from my PC output via the Essence STX.

 

Quote:
Originally Posted by vid View Post

I once wrote a review of the K 240 DF where I pointed out some negative aspects of the sound (e.g. the lack of bass on my pair). I was promptly told that it was all due to the amplification, and was asked to buy a vintage receiver to power them. I did just that, but the lack of bass (among the other negative aspects) remained.

 

So in my opinion either get a really beefy receiver if you want to go down that path - and expect the possibility that you see no benefit - or do perhaps the more sensible thing and use quality EQ.

 

Quote:
Originally Posted by RexAeterna View Post

just find a good preamp. cheap good headphone amping is a kenwood C2 if you can find them. i found a C2 for 40 bucks cause i was looking for an extra preamp for my yamaha m-45 power amp and was very surprised on the headphone out. made my sextetts and DF's sound really nice. DF's naturally have a bass roll off(below 50hz) so only tone controls can help. thing that makes them sound bass light too is cause the DF's have a pretty flat mid-bass with no emphasize. people like and use to that ''boom-boom''.

the z-out should only affect FR slightly cause the DF's peak to 1000ohms in the FR somewhere. i forgot where i saw the graph though. it was in dutch.

 

Thanks for all your input, guys, I'll chime back when I get the Bravo Ocean tube amp.  At the moment, I'm just enjoying my brand new HifiMan HE-400s that have just arrived! 

post #10 of 10

Hmm.. I was wondering...

 

My headphones are the famous K141 Monitor (600 ohm impedance) from circa 1990.

On my pc they are perfect at 100% volume and flat EQ on my Soundblaster X-Fi. If I even rise anything in EQ I can hear some distortion.

 

Now, my question is: if any of you used K141 monitor a lot, do you know if there is a similar (sounding) model?

 

The K121 looks similar, and the K141 Mk II looks as an evolution.

 

But no headphones are 600ohms now, they are all 55ohms.

 

And I wonder which one uses the same "speaker" (driver?).

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphones (full-size)

Gear mentioned in this thread:

Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › Amp to drive vintage AKG K240DF 600ohm?