Help

Matthias Krause · February 27th, 2008, 08:12 AM

I got my first mixer off of ebay but there seems to be something wrong with it. It`s a Shure FP24 which to my knowledge is identical to the Sound Devices Mixpre and besides the fact that it shows some signs of use and seem to have been dropped, there are two things that are strange:
1. When I first put fresh batteries in, it didn`t turn on. I unscrewed the battery cap and put it back on - and everything worked fine. But then after I hadn`t used it for an hour or so the same thing happened again. It did turn on only after I opend the battery compartment and closed it again. Same thing this morning... Does anybody have any idea what could be wrong?
2. The headphone out seem very hissy - is that normal?
I have to decide if I keep it or send it back. So quick help would really be appreciated.
Thanks,
Matthias

Seth Bloombaum · February 27th, 2008, 11:16 AM

About #1, it is not uncommon for someone to chuck their battery powered device in the closet for a few months, sometimes with batteries in it. This of course can lead to battery leakage in the batt compartment.

Get some good light and a pair of reading glasses if you need them, and closely inspect both the terminals in the battery compartment and cap. If you see anything other than shiney metal, some cleaning might fix you up fast.

A q-tip slightly damp with water is one good approach to cleaning out any goo, which typically looks like whitish/greenish crystal deposits. Be very sparing with the water, you don't want it running out of the compartment into other areas of the mixer! Just clean out all the crud. And don't get it in your eyes!

Then, get a pencil with a good eraser on the end, and use that to burnish the terminals, removing all corrosion down to bare metal.

Another occasional problem is that the terminals or springs don't maintain good contact - careful work with a dental pick can solve this, or break the terminals off, in which case you need repair.

All the above not specific to the FP24, but any battery powered device.

I've never had my hands on an FP24 or MixPre, so I can't comment on the headphone amp.

Jeffery Magat · February 27th, 2008, 11:23 AM

The Shure headphone amps are known to be noisy.

Matthias Krause · February 27th, 2008, 07:12 PM

Thanks, cleaning the contacts is kind of tough due to the design but I tried and it seems to help. Good to know about the headphone amp too. It´s not a big deal for me anyway, I just wanted to know.

Ty Ford · February 28th, 2008, 07:23 AM

Sound Devices and Shure both have excellent track records with service. I'd send the MixPre in for a little vacation asap to make sure it was in top shape.

BTW, I think there are a few design differences between the two.

Thanks for the cautionary tale about buying used gear on the Internet.

Regards,

Ty Ford

Matthias Krause · February 28th, 2008, 08:52 AM

Ty, ebay is always a risk, but as long as the inital price is right it might be worth a repair. From their website I take that Shure is still serviceing their mixers, I´ll just give them a call as soon as I have a minute.

Brooks Harrington · February 28th, 2008, 09:52 AM

I don't think you should use rechargeables in that mixer. Go with new alkalines.

February 28th, 2008, 07:23 AM	#5
Ty Ford Inner Circle Join Date: Nov 2004 Location: Baltimore, MD USA Posts: 2,337	Sound Devices and Shure both have excellent track records with service. I'd send the MixPre in for a little vacation asap to make sure it was in top shape. BTW, I think there are a few design differences between the two. Thanks for the cautionary tale about buying used gear on the Internet. Regards, Ty Ford __________________ Ty Ford's Audio Bootcamp Field Guide Ty Ford's Audio Video Blog

February 27th, 2008, 08:12 AM	#1
Matthias Krause Major Player Join Date: May 2007 Location: NYC Posts: 203	Help - What´s wrong with my FP24? I got my first mixer off of ebay but there seems to be something wrong with it. It`s a Shure FP24 which to my knowledge is identical to the Sound Devices Mixpre and besides the fact that it shows some signs of use and seem to have been dropped, there are two things that are strange: 1. When I first put fresh batteries in, it didn`t turn on. I unscrewed the battery cap and put it back on - and everything worked fine. But then after I hadn`t used it for an hour or so the same thing happened again. It did turn on only after I opend the battery compartment and closed it again. Same thing this morning... Does anybody have any idea what could be wrong? 2. The headphone out seem very hissy - is that normal? I have to decide if I keep it or send it back. So quick help would really be appreciated. Thanks, Matthias

February 27th, 2008, 11:16 AM	#2
Seth Bloombaum Inner Circle Join Date: Sep 2003 Location: Portland, Oregon Posts: 3,420	About #1, it is not uncommon for someone to chuck their battery powered device in the closet for a few months, sometimes with batteries in it. This of course can lead to battery leakage in the batt compartment. Get some good light and a pair of reading glasses if you need them, and closely inspect both the terminals in the battery compartment and cap. If you see anything other than shiney metal, some cleaning might fix you up fast. A q-tip slightly damp with water is one good approach to cleaning out any goo, which typically looks like whitish/greenish crystal deposits. Be very sparing with the water, you don't want it running out of the compartment into other areas of the mixer! Just clean out all the crud. And don't get it in your eyes! Then, get a pencil with a good eraser on the end, and use that to burnish the terminals, removing all corrosion down to bare metal. Another occasional problem is that the terminals or springs don't maintain good contact - careful work with a dental pick can solve this, or break the terminals off, in which case you need repair. All the above not specific to the FP24, but any battery powered device. I've never had my hands on an FP24 or MixPre, so I can't comment on the headphone amp.

February 27th, 2008, 11:23 AM	#3
Jeffery Magat Regular Crew Join Date: Feb 2007 Location: Toronto, ON Posts: 186	The Shure headphone amps are known to be noisy.

February 27th, 2008, 07:12 PM	#4
Matthias Krause Major Player Join Date: May 2007 Location: NYC Posts: 203	Thanks, cleaning the contacts is kind of tough due to the design but I tried and it seems to help. Good to know about the headphone amp too. It´s not a big deal for me anyway, I just wanted to know.

February 28th, 2008, 08:52 AM	#6
Matthias Krause Major Player Join Date: May 2007 Location: NYC Posts: 203	Ty, ebay is always a risk, but as long as the inital price is right it might be worth a repair. From their website I take that Shure is still serviceing their mixers, I´ll just give them a call as soon as I have a minute.

February 28th, 2008, 09:52 AM	#7
Brooks Harrington Regular Crew Join Date: May 2007 Location: Pasadena, CA Posts: 152	I don't think you should use rechargeables in that mixer. Go with new alkalines.