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NAD Receiver beats LD MKIVse?? - Page 7

post #91 of 191
Quote:
Originally Posted by Headdie View Post

I'd like to lower the impedance of the NAD headphone out. I understand that I can lower it down to 68 ohms, simply by shorting to the ground R&L channels with two 100 ohms resistances. I'd probably do it on the headphone jacket, inside the cabinet.
Why would you want to do it inside the cabinet? Just do what you were going to do with an impedance adapter. I think the headphone adapter link on Meier Audio's site describes how to do it.
post #92 of 191
Quote:
Originally Posted by tfarney View Post
Oh we have tubes. Mine have been tied. It's an experience I'll never forget.

Tim
And wondering why you mentioned this on head-fi is a question I'll never forget
post #93 of 191
Quote:
Originally Posted by odigg View Post
And wondering why you mentioned this on head-fi is a question I'll never forget
Only because pp312 brought it up. I'm usually quite discreet.

Tim
post #94 of 191
Quote:
Originally Posted by Headdie View Post
I'd like to lower the impedance of the NAD headphone out. I understand that I can lower it down to 68 ohms, simply by shorting to the ground R&L channels with two 100 ohms resistances. I'd probably do it on the headphone jacket, inside the cabinet.

Could you confirm that it's ok this way? Sorry again for the wrong information...
It depends what do you mean by "ok", assuming the resistors are of suitable power rating and you are shorting at the right place (not after the original resistor network). Also assuming the amp uses a single 220 ohms resistor (or something to that effect) per channel. One thing for sure is you are reducing both the voltage and the current (aka juice) available to the headphone.
post #95 of 191
Slightly off topic (at least in relation to NAD headphone jacks), but while I was trying out using a really old Denon DRA-627R (1991) amp I have as a preamp, I tried plugging my HD650s into the jack, and I was REALLY suprised at how good it sounded. It wasn't better than the MKV, but it was much better than I had anticipated. It was rich and warm, but not muddy or unfocused. I thought "WTF?" and tried the Denon D2000 on it, and it was even better due to lower impedance. Nice and quiet background, gobs of power...I couldn't believe it. My much newer AVR-3805 (2005) receiver's jack sounds like crap in comparison. I guess Denon put more effort into the headphone outs back in the day. Humph...who knew?
post #96 of 191
Quote:
Originally Posted by Navyblue View Post
It depends what do you mean by "ok", assuming the resistors are of suitable power rating and you are shorting at the right place (not after the original resistor network).
Why does it matter where the resistors are placed? I assume that, other than wire or the connection on the circuit board, the resistors are the only thing between the headphone jack and the speaker out. If you add resistors inside the case (even by soldering directly onto the existing resistors) or outside it shouldn't make a difference.
post #97 of 191
Quote:
Originally Posted by Navyblue View Post
It depends what do you mean by "ok", assuming the resistors are of suitable power rating and you are shorting at the right place (not after the original resistor network). Also assuming the amp uses a single 220 ohms resistor (or something to that effect) per channel. One thing for sure is you are reducing both the voltage and the current (aka juice) available to the headphone.
Let's get back to why I want to do it first. Of the three amps that I have, the NAD is the best with my DT990-600 ohms, but behind the LILO3 with my D2000-25 ohms. The LILO3 is a USB DAC with a low impedance head amp. For sure the NAD doesn't lack power, so I suppose the high impedance out is the problem or part of it.

I don't fear lack of juice anyhow with the NAD behind, but you make me doubt on how to do it correctly. I was tempted to do it inside to get rid of an adapter and potential contact problems, but I guess I'll do it outside with an adapter.

Now, I see many serial adapters (to increase impedance) shopping on the web, but I don't see many parallel adapters (to decrease impedance). I understand this is what I need. Could you help me to locate a good parallel adapter?
post #98 of 191
Quote:
Originally Posted by odigg View Post
Why does it matter where the resistors are placed? I assume that, other than wire or the connection on the circuit board, the resistors are the only thing between the headphone jack and the speaker out. If you add resistors inside the case (even by soldering directly onto the existing resistors) or outside it shouldn't make a difference.
The placement of the additional parallel resistors with respect to the resistors in series have an impact on the impedance that the headphone would "see".

But, I made a mistake in what I proposed just now (it's late here ). The parallel resistor should be placed in between the series resistor already in the amp and the headphone. In which case it doesn't quite matter if the resistors are added in inside or outside the enclosure.

But there might be some advantage of having the resistor inside the enclosure. The should be less joints and shorter signal path, and amp casing provide interference shielding.
post #99 of 191
Quote:
Originally Posted by Headdie View Post
Let's get back to why I want to do it first. Of the three amps that I have, the NAD is the best with my DT990-600 ohms, but behind the LILO3 with my D2000-25 ohms. The LILO3 is a USB DAC with a low impedance head amp. For sure the NAD doesn't lack power, so I suppose the high impedance out is the problem or part of it.

I don't fear lack of juice anyhow with the NAD behind, but you make me doubt on how to do it correctly. I was tempted to it inside to get rid of an adapter and potential contact problems, but I guess I'll do it outside with an adapter.

Now, I see many serial adapters (to increase impedance) shopping on the web, but I don't see many parallel adapters (to decrease impedance). I understand this is what I need. Could you help me to locate a good parallel adapter?
I apologise that I have confused you.

The followings applied if the NAD uses a single resistor in series.

You could solder a piece of resistor across the L/R channel and the ground right on the jack itself (inside the amp enclosure). This I think provide the least interference to the signal (no additional cable and jacks for the signal to pass through). And fairly easy IMO. Just make sure that the resistor has enough power rating so that it doesn't burn up.

I don't know of any source of parallel adapter, I DIYed mine.
post #100 of 191
Reading this thread, it seems like the issue with receivers and headphones is matching the impedance.

The Onkyo receiver I had before sounded quite good with headphones, but I noticed that the A900s needed quite a bit more volume for roughly the same loudness as the HD580s. I would assume that different receivers would be different.

I'm curious, how good would the analog out of a decent receiver be? Basically use the receiver as just a DAC, feeding another amp. Do receivers have pretty clean output there?
post #101 of 191
Quote:
Originally Posted by darkswordsman17 View Post
Reading this thread, it seems like the issue with receivers and headphones is matching the impedance.

The Onkyo receiver I had before sounded quite good with headphones, but I noticed that the A900s needed quite a bit more volume for roughly the same loudness as the HD580s. I would assume that different receivers would be different.

I'm curious, how good would the analog out of a decent receiver be? Basically use the receiver as just a DAC, feeding another amp. Do receivers have pretty clean output there?
That is weird, I always though that A900 (I assume it's the AT?) is an efficient phone. If the circuit employs parallel resistor, low impedance can will in fact allows more power to the headphone.

As for the DAC output, I guess it depends, but sometimes we get what we paid for.
post #102 of 191
Quote:
Originally Posted by Golden Monkey View Post
Slightly off topic (at least in relation to NAD headphone jacks), but while I was trying out using a really old Denon DRA-627R (1991) amp I have as a preamp, I tried plugging my HD650s into the jack, and I was REALLY suprised at how good it sounded. It wasn't better than the MKV, but it was much better than I had anticipated. It was rich and warm, but not muddy or unfocused. I thought "WTF?" and tried the Denon D2000 on it, and it was even better due to lower impedance. Nice and quiet background, gobs of power...I couldn't believe it. My much newer AVR-3805 (2005) receiver's jack sounds like crap in comparison. I guess Denon put more effort into the headphone outs back in the day. Humph...who knew?

I think this is an experience a number of people could duplicate if they kept an open mind. It's been my experience over many years, such that I wondered at all the posts here assuming speaker amp HP outs were all crap without trying them, based on the infamous "10c op-amp myth".

As for the newer receiver not sounding as good, that's not surprising. For my money the sound quality of amps generally began to deteriorate with the home theatre takeover, when the 6 x 100 watts requirement dictated the use of IC power stages. If you're looking for quality HP jacks look look for 80s and 90s integrateds/receivers from the majors--Marantz, NAD, Rotel etc. I assume you have an Ebay account?
post #103 of 191
Quote:
Originally Posted by Navyblue View Post
That is weird, I always though that A900 (I assume it's the AT?) is an efficient phone. If the circuit employs parallel resistor, low impedance can will in fact allows more power to the headphone.

As for the DAC output, I guess it depends, but sometimes we get what we paid for.
I think there's a lot of misconceptions when it comes to driving headphones. There were a lot of people that said A900s don't need amping, and a few that even said it doesn't benefit from it, but they responded to it better than the 120 ohm HD595s and 250 ohm DT770 Pros I've had.

The DAC/analog output question is in reference to say Denon/Marantz/Onkyo/etc that MSRP for about $750. I'm curious what the focus of receivers in different price brackets are. One of the Marantz seems to be mostly perfect as far as features, but I don't know if the extra money compared to the lower end models was spent on the speaker amplification or other parts.
post #104 of 191
Quote:
Originally Posted by vvanrij View Post
Did some testing between my MKIVse and my NAD receiver's headphone out, and I thought the MKIVse would easily win, but I was proven very wrong. They almost sounded identical, but the NAD just sounded a bit more 'lively' and 'musical', hard to explain, it comes down you just don't want to turn it off .
Does this mean LD IVSE is mediocre or NAD is really good? How would this stack up to a DV332 or WA6?

There are lots of positive postings but I seldom see benchmarking against other popular amps - will be a lot more useful with some frame of reference.

Same for LD V, like how they would stack up to other SS amps?
post #105 of 191
Quote:
Originally Posted by darkswordsman17 View Post
I think there's a lot of misconceptions when it comes to driving headphones. There were a lot of people that said A900s don't need amping, and a few that even said it doesn't benefit from it, but they responded to it better than the 120 ohm HD595s and 250 ohm DT770 Pros I've had.
If the amp employs parallel resistor, this would make sense. When using lower impedance headphone, the amp "sees" lower impedance in the circuit, thus the headphone would receive less voltage in relative to higher impedance headphone. Voltage correspond to volume, thus you'd get louder volume with higher impedance headphone, assuming the headphones mentioned has similar efficiency.

At the same time lower impedance headphone would receive more current, especially when the impedance of the headphone is lower than the resistance of the parallel resistor. When the impedance of the headphone is higher than the resistance of the parallel resistor, the opposite happens, the headphone would receive even less current. This is the "side effect" of employing parallel resistor. This might explain why the A900 is responding better to such an amp compared to DT880.

If you still observe more jump in quality with an amp that is known to not to employ parallel resistor (like a dedicated headphone amp) with A900 than the DT880, it would proof that what I typed above is all BS.
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