[geom_tol]

Quote:

Originally posted by Sovkiller Higher voltage, almost 33% over, depending on the design, with a good regulated and filtered power supply, means better sound, of course not out of a crappy wallmart. But anyway, there is a thread on that, and the guy who got the mod directly from Grado, explains his comparison, at least IIRC has a lot more gain, OTOH if Grado considered that the quality of sound would be compromised, I think that they would refused the idea instead of charging 75.00 for it.....Don't you think?

More gain does does not equal better sound either.

My opinion on this is that you need an expensive power supply to get the same quality power as a pair of good rechargable 9v's.

 

[Sovkiller]

Well according to the guy who ordered the mod, and had the amp on his hands, and had listened the amp both ways, he stated that IT SOUNDS BETTER with the AC adapter, at least he like it better, also Grado believes that, otherwise they would refuse to do the mod and charge 75.00 for it, but if you had heard it, and are absolutelly sure that the sound is not better, I can't argue with you, as I never had heard it.
My opinion is that you need a pair of ultraexpensive good rechargeables batteries to get the performance of a VERY GOOD designed power supply with more voltage.

BTW I have heard some portables devices, and even, with not so expensive power supplies, which performance is a way better with AC adaptors than with the batteries, even with the ultraexpensive recharchables.....

 

[Hirsch]

Quote:

Originally posted by Sovkiller My opinion is that you need a pair of ultraexpensive good rechargeables batteries to get the performance of a VERY GOOD designed power supply with more voltage.

"Ultraexpensive", in terms of rechargeable 9v battries, means $20 for a pair. It means something a bit more in terms of power supplies.

Whether or not voltage increases will make a difference will depend on whether or not the voltage the device is receiving is optimal to begin with. Try taking a 9v device and running 120 v directly through it. Put out the fire, and then realize there is a limit beyond which voltage increases will hurt, rather than help, the sound. Maxing out a device, within its usable range, isn't the right anwer either. You want the voltage that will give the best response from your device. If that's 9v, going to 12v may be within tolerances but won't help the sound. If the optimum spot is at 12v, it will.

The reason that some of your portable devices may sound better with wallwarts is that some of them turn off features to conserve battery life. Some of these features affect sound. Try running an external battery pack plugged in where the wallwart goes, as opposed to internal batteries. The unit will be fully operational, without the battery conservation modes on. IME this sounds better than a wallwart 100% of the time so far.

I have the Grado HPA-1, which is a better amp than the RA-1. It has the option to be driven from an AC supply or batteries. After comparing them, I put the AC supply into a drawer, and haven't touched it since.

 

[Sovkiller]

I agree that the voltage limit of the design, or the OP amp in question is very important of course, and not only the limit, the optimum range also, as you stated, but is 9volts this range??? IIRC, I think that this OP amp is capable even running on more than 12volts, so in this especific case, maybe the sound is better as stated by the owner, (I can't asure that as I never had heard it, he says that, not me, and what is good for one, maybe is not good for other) I don't know either if the two 9volts the RA-1 uses, is the optimum voltage range for that given OP amp neither, maybe a little bit more will give you a better sound (with batteries or not) and maybe the two 9v was only a convenient battery pack choice, as most of the times the 9v batteries last longer than the same quality AA or AAA batteries....maybe if you run it out of more than 9v battery pack the same happen, and it will perform better, who knows....what I'm trying to say is that in this case, according to the owner, with the AC choice, the sounds seems to be better...and the only explanation is the increase of voltage, as the current is 0.15 amp, less than a good battery....

 

[dfarina]

I have an ra-1 amp that has the ac conversion from Grado and am happy with the results.I don't know if I can say it sounds better(it might),but I can say it has a higher audio output due to the increased voltage.The conversion comes with a new plate on the bottom which does not have an opening for the batteries.As for the noise level compared to the batteries,it has not had a negative affect,I can turn the volume up all the way and hear NO noise at all.Don't miss charging batteries at all,just turn it on and listen.
Dave
http://www.pbase.com/image/15674866/large