Audeze LCD-4
Dec 31, 2018 at 4:29 PM Post #7,231 of 11,957
Dec 31, 2018 at 4:31 PM Post #7,232 of 11,957
current drawn / voltage required will be smaller for the headphones with lower impedance.

Well, no. The Current won’t be lower for lower impedance... it will be higher. That’s what I was clarifying.
 
Dec 31, 2018 at 4:37 PM Post #7,233 of 11,957
Well, no. The Current won’t be lower for lower impedance... it will be higher. That’s what I was clarifying.
My bad, you are right, current drawn will be higher at a lower voltage with a lower impedance headphones. You weren't very clear in your last post xD
 
Dec 31, 2018 at 4:41 PM Post #7,234 of 11,957
Good question, I may ask the designer.
It doesn't really matter. All you need to know is how much power it's able to provide at a given impedance.
Dave can do 1.4W at 33 Ohms and 154 mW at 300 Ohms. By using the dB/mW Efficiency rating of a headphone, you can figure out if it will be enough.

Edit:
I am looking at the Dave specs right now.

It provides 1.4W at 33 Ohms and 154mW at 300 Ohms and it can go upto 6.8V so applying Highschool Physics,
it can do 0.2A at 33 Ohms and 0.02A at 300 Ohms
 
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Dec 31, 2018 at 4:51 PM Post #7,235 of 11,957
It doesn't really matter. All you need to know is how much power it's able to provide at a given impedance.
Dave can do 1.4W at 33 Ohms and 154 mW at 300 Ohms. By using the dB/mW Efficiency rating of a headphone, you can figure out if it will be enough.

Yes, I know. By the numbers DAVE will easily be enough for 110dB peaks with the LCD-4, which should be plenty for most (at the risk of long term hearing damage), but others are free to disagree with the numbers.... or sonic preferences.

I need to clarify that I was simply discussing the differences with Voltage and Current delivery, not any specific gear’s capability.
 
Dec 31, 2018 at 4:53 PM Post #7,236 of 11,957
Yes, I know. By the numbers DAVE will easily be enough for 110dB peaks with the LCD-4, which should be plenty for most (at the risk of long term hearing damage), but others are free to disagree with the numbers.... or sonic preferences.

I need to clarify that I was simply discussing the differences with Voltage and Current delivery, not any specific gear’s capability.
Oh yeah! Purely by looking at the specs, Dave has more than enough power to drive the LCD 4.
 
Dec 31, 2018 at 4:58 PM Post #7,237 of 11,957
Yes, I know. By the numbers DAVE will easily be enough for 110dB peaks with the LCD-4, which should be plenty for most (at the risk of long term hearing damage), but others are free to disagree with the numbers.... or sonic preferences.

I need to clarify that I was simply discussing the differences with Voltage and Current delivery, not any specific gear’s capability.

Yeah I don't know if its necessarily a power thing with the Dave but it sure does sound a little lack luster to me, maybe the TT2 will work better.
 
Dec 31, 2018 at 5:01 PM Post #7,238 of 11,957
Yeah I don't know if its necessarily a power thing with the Dave but it sure does sound a little lack luster to me, maybe the TT2 will work better.
I think it's the DAC and not necessarily the AMP, the AMP is fine. When I tried the DAVE with an LCD 4, I found it too warm and the soundstage quite a bit small, or maybe the AMP colors the sound. I usually find Chord products to make the sound warmer and the soundstage smaller, it's kinda their house signature. However, purely looking at Power, it's more than enough for LCD 4.
 
Dec 31, 2018 at 5:36 PM Post #7,239 of 11,957
The LCD-4 is similar in terms of ability to be driven by the Dave alone vs an external amp to the Abyss Phi.....both are kind of on the borderline as to efficiency with the DAve IMHO....I have found that if you can get by without an amp it is the way to go with the Dave given the wonderful transparency one archives....on the other hand there are situations and recording where the amp does enhance the experience...it is a totally subjective thing and i have always found myself going back and forth
 
Dec 31, 2018 at 6:41 PM Post #7,240 of 11,957
I think it's the DAC and not necessarily the AMP, the AMP is fine. When I tried the DAVE with an LCD 4, I found it too warm and the soundstage quite a bit small, or maybe the AMP colors the sound. I usually find Chord products to make the sound warmer and the soundstage smaller, it's kinda their house signature. However, purely looking at Power, it's more than enough for LCD 4.

The two are essentially one in the same and not seperate components like in traditional DAC/amp combos. You can’t seperate the sound of the analogue output from the DAC with Chord products. Think of the output more like other DAC’s line-out.
 
Dec 31, 2018 at 6:46 PM Post #7,241 of 11,957
The two are essentially one in the same and not seperate components like in traditional DAC/amp combos. You can’t seperate the sound of the analogue output from the DAC with Chord products. Think of the output more like other DAC’s line-out.
Interesting....so something like the Mojo where it does not have a dedicated AMP section, just caps?
 
Dec 31, 2018 at 6:48 PM Post #7,242 of 11,957
Interesting....so something like the Mojo where it does not have a dedicated AMP section, just caps?

It’s a single output stage that does not require buffer/filter/or seperate gain stage because of the Pulse Array DAC. It’s all combined with the I/V stage (the critical Current to Voltage conversion) and volume is controlled digitally. That’s basically how he designs his gear, but the DAVE’s,output is more sophisticated than the Mojo with the second order noise shapers.

TT2 Super Caps are a slightly different story and the output stage is a little different as I understand it. The TT2 is supposed to have elements of his new digital amp design (NOT class D) based on the same Pulse Array as his DACs..
 
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Dec 31, 2018 at 6:50 PM Post #7,243 of 11,957
It’s a single output stage that does not require buffer/filter/or seperate gain stage because of the Pulse Array DAC. It’s all combined with the I/V stage (the critical Current to Voltage conversion) and volume is controlled digitally.
Makes sense. So it was designed to be used as a DAC instead of a 2 in 1.
 
Dec 31, 2018 at 6:55 PM Post #7,244 of 11,957
Makes sense. So it was designed to be used as a DAC instead of a 2 in 1.

Getting off topic, but no, it’s designed to have the fewest amount of components in the signal path for the best transparency. It’s a design approach that is more ‘as a whole’ than combining separate components to work together, and it’s more difficult to do this way.
 
Dec 31, 2018 at 7:05 PM Post #7,245 of 11,957
Can someone relate "efficiency" to input impedance of a load? If the LCD4 has input impedance of 200 ohms, but equal efficiency as the LCD4z which has input impedance of 15 ohms, how does that work? Within the bounds of ohms law...

Just in case we haven't confused you enough yet... one other important thing...

The output impedance of the amplifier and the impedance of the headphones have to be matched well too. The ideal amplifier output impedance is zero ohms, in this case, all the power gets delivered to the headphone and the headphone can be any impedance. Most solid state amps have less than one ohm amplifier output impedance, so it can be regarded close enough ideal and ignored. If the amplifier output impedance was 15 ohms, then with the 4z, 50% of amplifier power would get wasted as heat in the amplifier output impedance and never reach the 4z. As the amplifier output impedance gets larger compared to the headphone impedance, this situation gets worse. If the amplifier output impedance was 100 ohms, the 4z could be a total no go but this could still sound the best thing ever on the 4. Generally, tube amps can have 10's to 100's of ohms amplifier output impedance, they will possibly favor the 4 rather than the 4z. So, in some cases, the whole thing can work backwards.

Best just to listen and maybe there will be some special synergy happening!
 

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