[bcwang]

Just got an RA1, unfortunately I can hear a noticeable hiss out of my RS1 and even more out of my HD497. This hiss stays constant in volume no matter where the volume control. I searched and found a few others also had this problem. Some solutions were to connect a wire between some points but where exactly was not mentioned.

Does anyone know what causes the hiss and how to get rid of it? Could it be batteries that aren't exactly the same voltage as each other causing some strange effect? I already tried it with nothing but headphones connected, and walked around with it to see if it was affected by nearby electronics. The hiss was still there.

I'm not sure if returning it for a replacement would get me one without any hiss. From a previous post, one with a hiss was checked out by Grado to be fine. So I'm just hoping there is some cause of this I can just fix myself. Any ideas?

Thanks!

 

[Hirsch]

When I had an RA-1, it was dead quiet. That's one of the advantages of a battery-powered amp. I'd talk to Grado Labs and see if they can tell you what's up. Even if the unit is sound, they may replace it with a different one, if it's under warranty. Nothing to lose and lots to gain. If you bought from a dealer, I'd take it back to them and let them deal with it. Try a new unit and see if the problem persists.

 

[KR...]

My RA-1 is perfectly quiet as well at any volume, something must be wrong with your unit.

 

[Rameish]

Could the hiss be coming from your source. When I had the RA-1 it was dead silent as well - even at max volume with an RS-1.

 

[Zanth]

I concur...dead quiet.

1) Check recording, is this consistant across all your albums?

2) Check batteries, buy two new Duracell Ultras to be sure.

3) Check cables, are they plugged in tight? Are you receiving any RF noise?

4) Check source, is your source introducing this hiss?

5) If under warranty, bring back to dealer and/or ship directly to Grado after conversing with them.


Good luck!

 

[bcwang]

It's definitely not my source, since I tried it without any interconnects connected.

Sigh, too bad I bought it mail order, this could start to become a burden of money and time sending stuff back and forth. Especially if I end up with another defective one. It takes 1 week to ship there, and 1 week to ship back, if they had it in stock. I had to wait a month just to get this first unit from when I ordered it.

I'm using fully charged plainview 9.6v nimh batteries, so I don't think it's a low battery issue. But it could be imbalanced battery voltages, have any of you tried charging one to a higher voltage than the other and had it produce hiss?

I walked around the room with the unit too so it's probably not RF noise either.

 

[Zanth]

Quote:

Originally posted by bcwang It's definitely not my source, since I tried it without any interconnects connected.

Okay, I'm assuming you mean you hear the hiss pretty clearly without a signal right? Cause otherwise I'm quite confused

Try the batteries. For 5 bucks your problem could be solved, just buy some new batteries and give it a shot and then you know right away.

 

[KR...]

If it's not hooked up to anything and you still hear something, then it must be the batteries like Zanth said. Just pop in some fresh batteries. If that doesn't solve the problem then shoot Grado Labs an e-mail or give them a ring.

 

[bcwang]

I guess I'll try the batteries first to see if that's the problem. By the way, does the amp start hissing for you guys when the batteries start getting low?

Yup, when I say no interconnect is connected, I mean the amp isn't plugged into anything other than the headphone.

 

[Zanth]

Yessir, when the batteries start to die...you will DEFINITELY know

 

[Chinchy]

Quick question--is there a sonic difference between the battery and AC version of the RA-1?

 

[bcwang]

Well, just went and bought 2 matched alkaline 9v to try, and the unit still hisses. So I guess it's a problem with the unit. Unless my hearing is just too good, doubtful though, since my supermini is quieter than this.

I guess it's time to do an exchange.

By the way, something peculiar. My unit goes from no volume to quite loud after only turning about 1mm from zero. I don't see how I'm going to use the other 99% of the volume dial. Does this sound normal?

Thanks!

 

[Zanth]

no it does not sound normal...I think you may have a dud...


as for the ac/battery sound, I have no idea never heard the ac version.

 

[bootman]

Quote:

Originally posted by bcwang By the way, something peculiar. My unit goes from no volume to quite loud after only turning about 1mm from zero. I don't see how I'm going to use the other 99% of the volume dial. Does this sound normal?

Nope, not normal and it explains the hiss.
Sounds like the gain is way too high.
Grado should be able to fix/replace this with little trouble.
Give them a call @ 718-435-5340 (better than email) and explain your problem.
Tell them Head-fi sent you.

They are great to deal with and will get you working in no time.

 

[Beagle]

Quote:

Originally posted by bcwang By the way, does the amp start hissing for you guys when the batteries start getting low?

When the batteries are about to die, my RA-1 begins to distort when you turn the volume.

My RA-1 has a very slight hiss, really only noticable when you plug and unplug microscopic phones like the Sony 7506 or the SR60. I don't notice it otherwise.