[dj_mocok]

ok, last question. i promise i wont hijack this thread any more further after this... sorry !

so, say, if i have my headphone and amp already gain-matched, then in the future, if i get a headphone that has a higher impedance, that means that for that new headphone, i will need to turn the volume knob a bit further than normal (with old one) in order to achieve similar loudness ?
and as long as its not clipping yet, turning the volume knob louder to listen to higher impedance phone is ok ? wont sacrifice sound quality ?

thanks.

(if i make this question to long for this thread, could you send me a PM please? thanks.)

 

[shimage]

Quote:

Originally Posted by dj_mocok ok, last question. i promise i wont hijack this thread any more further after this... sorry ! so, say, if i have my headphone and amp already gain-matched, then in the future, if i get a headphone that has a higher impedance, that means that for that new headphone, i will need to turn the volume knob a bit further than normal (with old one) in order to achieve similar loudness ? and as long as its not clipping yet, turning the volume knob louder to listen to higher impedance phone is ok ? wont sacrifice sound quality ? thanks. (if i make this question to long for this thread, could you send me a PM please? thanks.)

As I understand it (and I'm not saying that I do...), that's correct. One thing to be careful about though, is that you don't want to get too close to the extremes. Things seem to get a little hairy there on most equipment, which is why you want the gain matched to your headphones.

Oh, and to clarify my previous post, the gain is only a proportionality constant if it's a pure number. If it's in dB, then it scales logarithmically (because dB are logarithmic units...).

edit: oh yeah, I forgot to say that you really shouldn't worry too much about the gain. I use my go-vibe with impedances from 32 Ohms to 250 Ohms, and it plays nice with all of them.

 

[shimage]

Quote:

Originally Posted by Escape Your Mind Could thoes of you who have the classic comment on the gain you got with your amp and the headphones you have. I dont have any experience with amps, so I'm not sure which gain I would use with HD595's or if its more of a personal preference of how much louder the amp would get at a certain level.

Since no one appears to have replied to this post... I don't know what the gain is on my amp, and I don't even have a Classic, but here's my 2 cents anyway. Most people agree that the gain should be set as low as possible. I believe that this is because higher gains tend to make the circuit less stable (more noise). So yes, the gain does depend on your own tastes.

There is, however, an order of magnitude difference between, say Grados and Senns (though not yours...), so there is a distinction between what generally works for low-impedance cans and what generally works for high-impedance cans. This is why some of the more expensive amps come with gain switches.

My advice is just to ask Norm. He knows best how his amp behaves. People have mentioned here that he's got good ears. Ergo, he should know better than most of the people here how to make your amp sound its best.

edit: god, i'm stupid. didn't see that exchange up there. i think i'll stop now, while i'm ahead (of where i'll be if i keep this up).

 

[adhoc]

it should be noted that some opamps (ie [iirc] the opa637) are not stable below a certain gain level. for the opa637 (once again iirc), it would be unstable below a gain of 5.

 

[Solude]

Quote:

Originally Posted by shimage Since no one appears to have replied to this post... I don't know what the gain is on my amp, and I don't even have a Classic, but here's my 2 cents anyway. Most people agree that the gain should be set as low as possible. I believe that this is because higher gains tend to make the circuit less stable (more noise).

Other way around. Higher gain improves circuit stability and lowers noise and like has been said some opamps REQUIRE gain to be stable. Others are ABLE to run at unity gain but are more stable at higher gains. That said you try to balance opamp stability with volume pot range. A high gain will give you high stability but may require that you stay very low on the pot to not go deaf. On some pots the balance is off until you come to about 8 o'clock. So you try to pick gain so that your comfortable listening will be at roughly the 10 o'clock position to avoid pot errors. I like a gain of around 5 is pretty safe bet for most phones.

 

[shimage]

Quote:

Originally Posted by Solude Other way around. Higher gain improves circuit stability and lowers noise and like has been said some opamps REQUIRE gain to be stable. Others are ABLE to run at unity gain but are more stable at higher gains. That said you try to balance opamp stability with volume pot range. A high gain will give you high stability but may require that you stay very low on the pot to not go deaf. On some pots the balance is off until you come to about 8 o'clock. So you try to pick gain so that your comfortable listening will be at roughly the 10 o'clock position to avoid pot errors. I like a gain of around 5 is pretty safe bet for most phones.

Thanks for clearing that up. I was aware that a lower stable gain was harder to get in an opamp (and yes, I know that unity gain opamps are "special"), but I'd read here and elsewhere of people trying to keep the gain down for purposes of stability. It's been so long since I've done signal theory, that I can barely remember anything anymore (but wait.. I thought I was still young?! maybe it wasn't so long ago).

 

[adhoc]

Quote:

Originally Posted by Solude Other way around. Higher gain improves circuit stability and lowers noise and like has been said some opamps REQUIRE gain to be stable. Others are ABLE to run at unity gain but are more stable at higher gains. That said you try to balance opamp stability with volume pot range. A high gain will give you high stability but may require that you stay very low on the pot to not go deaf. On some pots the balance is off until you come to about 8 o'clock. So you try to pick gain so that your comfortable listening will be at roughly the 10 o'clock position to avoid pot errors. I like a gain of around 5 is pretty safe bet for most phones.

thanks for that clarification. i've edited my previous post slightly.

 

[DrTacoElf]

What gain an opamps woudl be best for grado phones?

 

[sbulack]

Quote:

Originally Posted by DrTacoElf What gain an opamps woudl be best for grado phones?

The stock OPA2227 and the stock gain of 5 suit grado phones beautifully. With the OPA2227, I recommend the 24v PSU, as the OPA2227 increases its sound quality very nicely with increased source voltage. But the Burr Brown dark, richness of the OPA2227 and the forwardness of the Grado phones complement each other sonically very well. IMO, the only improvement you could make beyond that is to go for the OPA627 upgrade. The even darker, richer OPA627's complement the forwardness of the Grado phones even better than the OPA2227 to my sonic tastes. The OPA2227 with 24v and the stock gain of 5 is a great match for Grado phones. And you can always ask Norm at Headsave. He owns Alessandro's and has a great ear, so he can guide you well in the configuration of a Classic or Vibe to feed your Grado phones.

 

[adhoc]

Quote:

Originally Posted by sbulack The stock OPA2227 and the stock gain of 5 suit grado phones beautifully. With the OPA2227, I recommend the 24v PSU, as the OPA2227 increases its sound quality very nicely with increased source voltage. But the Burr Brown dark, richness of the OPA2227 and the forwardness of the Grado phones complement each other sonically very well. IMO, the only improvement you could make beyond that is to go for the OPA627 upgrade. The even darker, richer OPA627's complement the forwardness of the Grado phones even better than the OPA2227 to my sonic tastes. The OPA2227 with 24v and the stock gain of 5 is a great match for Grado phones. And you can always ask Norm at Headsave. He owns Alessandro's and has a great ear, so he can guide you well in the configuration of a Classic or Vibe to feed your Grado phones.

i would recommend the opa627 based solely on how my alessandros are doing with them. a gain of 5 gives me more-than-plenty-of-volume at 10 o'clock.

a proper 24V psu arrived at my place this morning. after doing some quick a/b with my old 12V psu, it's clear to me - 24V is a must.

 

[dj_mocok]

adhoc, whats the difference in terms of sound quality (well, what else? hehe..) between 12V and 24V ?

 

[adhoc]

Quote:

Originally Posted by dj_mocok adhoc, whats the difference in terms of sound quality (well, what else? hehe..) between 12V and 24V ?

1. extreme low bass no longer clips (bass tone replaced by a 'flap flap flap' sound).

2. transients seem faster somehow. the snap of a snare drum's initial strike is more 'thack' than 'thazzzck' now.

3. volume seems slightly louder. however this might just be due to..

4. ..the mids are now more forward and rich-sounding. i hear more details. aimee mann's voice seems more crisp and clear now.

to sum up.. if you're thinking of saving a few bucks by getting a 12V psu instead of a 24V psu to go with your opa627-based ss amp, you're only shortchanging yourself.

 

[dj_mocok]

adhoc, what is flap flap flap sound ?

so the snaredrum's sound, its more like solid ? not "runny" or "splattery" ?
hang on... snaredrums dont sound splat... ummm.... can i say, less buzzy?
man, its so hard to describe sound isnt it ? hehe..


i was just curious (again) about the difference. im not going to be tight and get 12V ones... cost almost the same anyway. you reckon if get even higher than 24V one (if such thing exists), will it be better or its an overkill ?

 

[adhoc]

Quote:

Originally Posted by dj_mocok adhoc, what is flap flap flap sound ?

that's literally the sound they made.

Quote:

Originally Posted by dj_mocok so the snaredrum's sound, its more like solid ? not "runny" or "splattery" ? hang on... snaredrums dont sound splat... ummm.... can i say, less buzzy? man, its so hard to describe sound isnt it ? hehe..

yes, less buzzy would be another valid way to describe them.

Quote:

Originally Posted by dj_mocok i was just curious (again) about the difference. im not going to be tight and get 12V ones... cost almost the same anyway. you reckon if get even higher than 24V one (if such thing exists), will it be better or its an overkill ?

there are high quality >24V linear regulated psus.

however, attempting to run the opa627 off a >24V psu will likely result in equipment damage, destruction or a mixture of both.

the opa627 is spec'd to run between 12V and 24V - anything else would be asking for trouble.

and i forgot to mention one more (imo very important) improvement - no more hissing at all volume levels with my er-4p!

 

[sbulack]

Adhoc,
Thanks for the descriptions of how your Classic sounds with your various headphones. How is it working for/with your AKG 501's?