[vii_haven]

What is a portable amp that is produces the FLATTEST frequency response for recording? As above. As I might be thinking of getting the Beyer DT150 for monitoring purposes to replace my 7506. I think the beyer does need some sort of an amp for it to work properly.

 

[adanac061]

Thats a great question . But how would you know what the most neutral amp is?

I once brought up the topic of R.M.A.A (http://audio.rightmark.org/products/rmaa.shtml) measurements for amps only to be told that they are useless because the response changes under load?

p.s
BTW Id still like to see some amp rmaa measurements anyway.

 

[cotdt]

it's hard to measure. using RMAA all amps have a flat response unless EQ is applied. but i think opamps are colored in general since they sound thin.

 

[adanac061]

Quote:

Originally Posted by cotdt /img/forum/go_quote.gif it's hard to measure. using RMAA all amps have a flat response unless EQ is applied. but i think opamps are colored in general since they sound thin.

Thats probably true for well made amps ..although I ran a few of those vintage integrated amps that some people are using to power nice headphones and the graphs were horrible

 

[cotdt]

Quote:

Originally Posted by adanac061 /img/forum/go_quote.gif Thats probably true for well made amps ..although I ran a few of those vintage integrated amps that some people are using to power nice headphones and the graphs were horrible

very interesting... can you show me? i'm just curious to see.

 

[adanac061]

Quote:

Originally Posted by cotdt /img/forum/go_quote.gif very interesting... can you show me? i'm just curious to see.

Sure .... I only have one on hand .an 80's Jvc integrated amp that would of cost $800 in 1980's. It's not the worst offender ..but still, i wouldn't want it for monitoring purposes or listening for that matter.

The jvc is compared against the source Juli@ neutral rca cables are used in between.

 

[vii_haven]

doublepost.

 

[vii_haven]

so there's no such thing as an amp with a FLAT frequency response even if i pair it with a good pair of studio monitor reference headphoens like the sony 7506 or the beyer DT150?

then how do recording studios use such studio monitor headphones with higher impedence like the DT 150?

 

[kramer5150]

the gilmore lite is one of the least-colored amps I have heard.... but thats relative to my amps which are very colored (IMHO)

 

[cotdt]

Quote:

Originally Posted by kramer5150 /img/forum/go_quote.gif the gilmore lite is one of the least-colored amps I have heard.... but thats relative to my amps which are very colored (IMHO)

is there a portable version now? as far as i know, this amp is a power-sucker. a portable version of this amp would be amazing.

i'm shocked that an $800 amp would measure like that. i guess SS amps have come a long way since the 1980s.

 

[meta03]

Check the frequency response curve in this review. Portable, looks like what you want.


http://www.head-fi.org/forums/showth...hlight=0HA-rep

 

[ppl]

The reason The frequency response Graph of the Vintage receiver is not flat is because the receiver drives the Headphones from it's Loudspeaker terminals via a rather large series Resistor typically 330 Ohms for most Asian Gear and as low as 150 ohms in Vintage US Gear.

So what you are seeing in that Graph is the Impedance Curve of your Headphones. measure directly from the Loudspeaker terminals and that Graph will be allot better.

What is obvious hear is what i have been Preaching for years and That is "Headphones are a reactive Load that will have a different impedance depending upon what frequency it is measured at. I recommend selecting a Headphone Amp with a separate voltage and Current gain stages, the Basic version of this is a Buffered op-Amp and more complex versions are implemented with Discrete components Like the Gilmore Dyna might and AMB's B22 Designs, just to name two of the more populer Amps hear, there are of course many others also available that will meet the Low output impedance High Output Current demands required to obtain the flattest frequency response from any headphone.

 

[MaloS]

Meier products are known for being neutral, so I wonder if Porta Corda is on the flat side of things? My ear is not picking up any emphasis.

 

[S4NDmaN]

Phil, interesting post! makes me wonder then, which buffered op-amps would you consider flatt, or less coloring?

 

[evil-zen]

Equipment used:
Headamp Gilmore V2
Beyerdynamic DT931. 250ohm
Westone UM1. 25ohm

FR
http://img.photobucket.com/albums/v2...n/Spectrum.png

IMD
http://img.photobucket.com/albums/v29/evil-zen/IMD.png

Crosstalk
http://img.photobucket.com/albums/v2.../crosstalk.png

The lower the impedance, the more it deviates. But even with the um1, the variation is only 0.5db which is non-perceptible.