Audeze LCD-2

[Currawong]

810mW not enough for a pair of headphones? Like Nebby suggested, wouldn't it just be bad amp design if an amp that amount of output can't do a good job?

[mypasswordis]

An amp needs to get "loud enough", past that is overkill and there may be issues like noise floor. Given an actual 810mW max power going into the 91dB/mW LCD-2 means 120dB peaks, and 2W means 124dB peaks. I wonder about the WA22 though, if it's really just a balanced WA2 then I wonder what the output impedance is and thus how much power is being transferred. Regardless, I'm pretty damn sure the stock tubes can output 200mW into the 62 ohm K701, and with its sensitivity of 93dB/mW means 116dB peaks.

Edit: As in the maximum a K701 is rated to play at is 116dB. Shave a couple dB off all the above numbers just in case and you still have mind-blowingly loud sound.

Edited August 15, 2010 by mypasswordis

[Nebby]

But with 2W you can get driver-blowingly loud sound! [/couldn't resist]

[DefectiveAudioComponent]

But with 2W you can get driver-blowingly loud sound! [/couldn't resist]

You need over 15W to blow the drivers with an output of 133db.

(but that's the specification... I havent actually tried it...)

[Solude]

The efficiency given is conservative. Tyll measured 110mV for 90dB ~.25mW.

[Solude]

Think they were referring to the AKG 200mW cap.

[Nebby]

You need over 15W to blow the drivers with an output of 133db.

(but that's the specification... I havent actually tried it...)

I was speaking of the Akg k702's which have a 200mW rating.

[swt61]

An amp needs to get "loud enough", past that is overkill

That's a pretty simplified statement, and I can't agree with that. I've heard plenty of amps that will get loud enough, but then run out of steam on difficult passages. Dynamic headroom is very important IMO, and I'd personally rather have more than enough power than not enough.

For example I used to own a pair of ESS AMT 1Ds, with the famous Heil Air Motion Transformers. I powered those speakers for about a year with an NAD 2200 stereo power amp. That amp was conservatively rated at 100 wpc, with pretty respectable dynamic headroom. I thought it sounded great. But when my stereo sales rep offered to bring a second NAD 2200 by and run the pair in bridged mono mode, I was floored at the way the speakers opened up. That was 400 wpc in bridged mode, and I would have thought complete overkill for my ESSs, but I was wrong. I did buy the second NAD on the spot BTW.

[spritzer]

Simply stating some power rating is highly simplifying the matter IMO. How the amp handles the load is far more important than some number taken out of thin air. Can the amp retain it's full voltage swing into any given load or is it far from linear?

[mypasswordis]

That's a pretty simplified statement, and I can't agree with that. I've heard plenty of amps that will get loud enough, but then run out of steam on difficult passages. Dynamic headroom is very important IMO, and I'd personally rather have more than enough power than not enough.

For example I used to own a pair of ESS AMT 1Ds, with the famous Heil Air Motion Transformers. I powered those speakers for about a year with an NAD 2200 stereo power amp. That amp was conservatively rated at 100 wpc, with pretty respectable dynamic headroom. I thought it sounded great. But when my stereo sales rep offered to bring a second NAD 2200 by and run the pair in bridged mono mode, I was floored at the way the speakers opened up. That was 400 wpc in bridged mode, and I would have thought complete overkill for my ESSs, but I was wrong. I did buy the second NAD on the spot BTW.

I think you are overcomplicating things. If you want more volume, you will need more output power to prevent clipping/distortion/compression. Whether that be extra voltage swing or more current depends on the load. If you don't listen that loudly, you will never use that extra power. It's kind of a pet peeve of mine when people say certain amps "can't drive" certain headphones or speakers, when in reality it is most likely the other characteristics of the amp that they don't like. But then again, given some comments of dumbasses I've read over the past couple days, I guess a large number of people really do listen at what I would consider ridiculous levels, but what they would consider "live" so I guess they do need that much power.

Bridging not only can double voltage swing, it doubles output impedance and slew rate. Granted, the output impedance of the NAD is probably small so that shouldn't make much difference, but it definitely makes a difference in OTL designs with inherently high output impedance already (no to minimal NFB). How the amp handles different loads is definitely important, but for normal dynamic/ortho headphones, no more than a couple hundred mW (measured into the load! is ever needed. Do correct me if I'm wrong about any of this.

Edited August 15, 2010 by mypasswordis

[spritzer]

The rated sensitivity of the transducers tells you everything about how much real power they need to reach a certain volume level. This naturally doesn't account for wild changes in impedance and the crap that goes with it.

I also hate the crap about this amp can drive full size cans just because it is loud enough. Fucking retarded idiots have no idea what they are talking about...

[mypasswordis]

Yup, as we all know impedance can vary drastically with frequency in speakers, but it's more tame in headphones due to needing only one driver and no crossovers so usually dynamics have got a hump in the resonance frequency range and then slowly rises with frequency due to inductance. Edit: Oh wait, nvm. That second statement is exactly my pet peeve. It can 'drive' them since it does get loud enough. It's the other factors that are lacking.

Edited August 15, 2010 by mypasswordis

[spritzer]

Yup, pretty much anything can give enough voltage for the "moar loudz" idiots but the rest is trickier.

[Nebby]

Yup, pretty much anything can give enough voltage for the "moar loudz" idiots but the rest is trickier.

It's what I've always suspected, but thanks for making it clear There are a lot of those folks that are religiously enthusiastic about the Asus STX sound card.

[digger945]

There are a lot of those<narrow minded kool aid drinkin cult> folks that are religiously enthusiastic about the Asus STX sound card.

emphasis mine

[swt61]

Granted. I'm specifically talking about speaker amps, where volumes are generally higher, and loads can typically be more difficult.

I agree that headphone amps don't require as much headroom, but the idea still applies, just on a smaller scale.

FWIW I listen at pretty low volumes, but I do think most orthos do better with reserve power over not enough power. Do I need the balanced Beta 22 to drive the LCD-2?...no, but it certainly doesn't hurt.

[mypasswordis]

No argument from me there and headroom is nice, but I don't understand why volumes would be higher for speakers... why wouldn't they be similar? I actually find it the opposite case for me, I like listening at low levels with speakers.

Edit: Well if you factor in distance it makes sense, actually.

Edited August 15, 2010 by mypasswordis

[swt61]

What I meant is that it takes a lot more power to create that same volume with speakers, especially in a large room.

[emelius]

today marks 2 months on the waiting list for me...

hopefully i'll (eventually?) get a pair with this updated “A” grill that i've heard so much about...

i'm probably gonna use my Portal Panache with 'em for now until i decide which amp route to take & how to finance it...

[shellylh]

Mine arrive today with the "A" grill so you'll probably be fine.

Listening to them at work with the Stello DA100/HP100 stack. It is making for a very enjoyable day.

I took a few pics but don't have my camera card reader or cable so I'll have to wait until tonight to post the Audez'e pr0n.

[emelius]

they are quite the fashion statement...

Help me, Obi-Wan Kenobi; you're my only hope!...

[swt61]

I'd like to see the new grill Shelly. Did the headband get a leather covering as well?

[shellylh]

Charcoal of course. Who would buy a gas grill?

No on the leather headband.

[morphsci]

Congratulations on the new LCD-2 Shelly. I agree charcoal >>> gas.

[Solude]

I know pretty much everyone thought leather headband was a no brainer but I don't think they ever agreed. Felt covered foam is the current model. And what colour is gas? Got my Nugget B22 today, thinking it might mate well with the LCD-2 if I ever get the call. Killer control, dead quiet but not a whole lot of umph down low... so far.