[Perfectionist]

Thanks for all the replies. It's given me an insight into the wonderful world of headphone amps. I do understand that $'s do not always equal good quality sound, and that only I can say what "does it for me", at whatever cost that might be

Spad, a slightly presumptuous post but funny at the same time

I know what you are saying, because it has been said many times before on other forums I attend, but I will say to you what I said to them. Do you have any figures to back that up, for every amp in production ? I can tell you now, my amp does not struggle at the 9oClock position, and it just goes louder (with no audible distortion, or clipping) above 12oClock, peaks or not.

Regards, Rick

 

[Joe Bloggs]

Quote:

hey I wouldn't mind doing that test for a A/B comparison too.. how do I go about producing highs and lows for burning?

Well... get a tone generator

I use Stomper Hyperion--just search for it on Google.

Remember to set it to 44.1kHz output--it's more accurate that way

 

[Spad]

Quote:

Originally posted by Perfectionist Spad, a slightly presumptuous post but funny at the same time I know what you are saying, because it has been said many times before on other forums I attend, but I will say to you what I said to them. Do you have any figures to back that up, for every amp in production ? I can tell you now, my amp does not struggle at the 9oClock position, and it just goes louder (with no audible distortion, or clipping) above 12oClock, peaks or not. Regards, Rick

Perhaps your response was appropriate in the case(s) you mention. It is not in mine.

I wrote " . . . volume controls are rarely linear, particularly in mid-fi equipment. In many cases a quarter turn of the control results in three-quarters or more output. . . ."

How did you manage to construe ". . . in many cases . . . ." to mean "every amp in production"?

Are you simply being polemical, or do you really not understand?

Spad

 

[Joe Bloggs]

Erm, in many other cases, the pot has a slow rate of gain change in the first half of its travel, and a much faster rate in the last half. This is to allow the pot to be used with low-impedence and high-impedence headphones. Low-impedence headphones would use the first half of the pot, and the slow gain change allows one to fine-tune the volume even though a similar change of gain causes a bigger change in volume in low-impedence headphones than in high-impedence ones.

High-impedence headphones would use the last half of the pot.

This is exactly the reverse of what you mentioned.

In fact I would see little value in a pot that reaches 3/4 of its maximum gain in a quarter turn, as that would make

(1) low-impedence phones change from dead quiet to painfully loud in the quarter turn, making volume adjustment excruciatingly difficult;

(2) high-impedence phones change from 'loud' to 'erm... slightly louder' in 3/4 of the range of turns of the pot--an annoyingly large range of travel for a small adjustment.

(and besides, because the ear perceives loudness so that 10 times the output only equals double the loudness, in order for a pot to cause a 'linear' change in loudness, (i.e. a similar turn of the pot can cause the loudness to double, whether the pot was at 9 o'clock, 12 o'clock, 5 o'clock or anywhere to start with) a logarithmic change in rate of gain is required, so that, say, if a turn from 9 o'clock to 12 o'clock causes the gain to change from 0.1 to 1, 12 o'clock to 3 o'clock would cause the gain to change from 1 to 10!)

 

[ai0tron]

Listen "perfectionist". If you want the best sound get an amp. Otherwise stop bitching about it. What else can we say except YES an amp improves the sound???? NOT MUCH REALLY. It sounds better, what do you want now, a headphone amp thesis, a scientific dissertation, speculative fiction of some sort?? How about you buy one and find out.

 

[Joe Bloggs]

ai0tron, I don't think he's arguing about the need for a headphone amp anymore, but arguing with spad about the technical point of just how pots are calibrated...

Perhaps someone should change the title of this thread.

 

[Perfectionist]

Spot on Joe. Spad please read and digest Joe's post, I think you will find it agrees with pretty much everyone else who understands the more technical aspects of electronics.

I understand perfectly Spad. I just don't like people who generalise with no foundation other than inaccurate personal opinion. There are simply to many factors involved in a volume controls potentiometer (transitor banking of any kind), and different peoples systems, to accurately say one way or the other. Even if you did use the words “in many cases”, I don’t even think that is accurate, simply because I don’t believe it is “in many cases”.

 

[Spad]

I hate to appear so damned argumentative, but I seem to be disagreeing with more than my usual quota lately. I realize this is bad form for a newbie such as I, but I've been 'into' serious audio for more than 30 years, and it's hard not to comment occasionally.

I'll try to tread lightly, at least until I'm better known, but I have a well tuned BS detector, and I have to say it has rarely rung with such frequency as when perusing some of these forums.

I'll make a couple of quick points and then scat:

Regarding why a manufacturer would choose to have a volume control so front loaded: "Perfectionist" is a perfect example of why this is done. It is a marketing ploy--a very effective one--to convince the uninformed that an amp is more powerful than it is. A typical neophyte will be impressed by loud sound levels when the volume control is "only at 9 o'clock" because he assumes a direct ratio between the amount of turn and the amp's available power.

Concerning the impact that such a control has on 'phones of varying impedance: Joe's statement is only partially true because it doesn't address the far more important ingredient--sensitivity. Sensitivity, as it applies to this discussion, is simply the sound pressure level (expressed in db) produced when a given voltage is applied. This is dependant on several factors, only one of which is impedance. It is not uncommon for higher impedance loads to have greater sensitivity than designs of lower impedance. Although I don't have AKGs, a case in point might be the 501s compared to the HD-600s.

Only when all else is equal--as in the case of the Ety 4S and 4P, which are identical except for their respective impedance--would impedance have a direct correlation to volume.

With apologies to all who find this response unduly contentious,

Spad

 

[MacDEF]

spad has a good point, though, about front-loading of volume pots. At least in the realm of low-fi and mid-fi equipment, I've found it to be a widespread practice. Many manufacturers really do front-load their volume pots so that the customer thinks the amps have far more power than they really do.

 

[Xander]

Quote:

Originally posted by MacDEF spad has a good point, though, about front-loading of volume pots. At least in the realm of low-fi and mid-fi equipment, I've found it to be a widespread practice. Many manufacturers really do front-load their volume pots so that the customer thinks the amps have far more power than they really do.

This is true. I'm a bit irrtated at Spads posts, since eeyssjr pretty much already covered this issue partly. In a few other ways however, Spads post can go both ways. Most amps do run out of gas a bit past the 9 o clock position, however I'd really hate to run out of volume knob so to speak, then to run out of gain. It could be a marketing ploy, it could also be added extra gain to ensure that you DONT run out of volume knob. I wonder if the Max does this? And I wonder if HeadRoom designed it that way as a "marketing ploy". Perhaps we should ask them? I doubt it.

The mild insults directed towards the other members and people in this thread is really un needed though. Perfectionist may not know as much as you do, and I think offering him some information to direct him in the right path would be a much better way to go about this. kwkarth is a perfect example as to how this should be done. Resulting to insults the first time around is definatly not the way to do this.

 

[Perfectionist]

Ah, there’s that presumptuous arrogant **** Spad again. Tell me Spad, how old am I ? How long have I been into serious audio ? Define why I am the uninitiated amateur you seem to think I am ? No answers ?, no I didn't think so.

I think the only person here who clearly has no idea what he is talking about, and can take an argument no further than basic waffle (opinion), as oppose to getting deeper and backing up with any authority, my friend, is you.

You have clearly reached your limits, as eloquently as you have put the fact you are running away with your tail between your legs, good riddance.

 

[Joe Bloggs]

 

[Dusty Chalk]

EDIT: Post deleted in the interest of going back to minding my own business.

 

[taoster]

theres alot of heat generated over nothing

if its not hifi related lets keep it off the forum.

 

[morphsci]

Quote:

Originally posted by DustyChalk OTOH, "Perfectionist"'s posts aren't any better.

Agreed. Let's at least be consistent in our critical assessments, or maybe we should just go back to discussing headphone related topics rather than voting on popularity. The last I heard, being popular doesn't make your opinions correct, just look at the political scene.