Bottlehead Forum

General Category => General Discussion => Topic started by: aragorn723 on August 04, 2014, 04:57:09 PM

Title: help with resistors please
Post by: aragorn723 on August 04, 2014, 04:57:09 PM

Hi,

I want to reduce the output of my quickie 6db, and was wondering if this would be a good choice?

http://www.radioshack.com/product/index.jsp?productId=12554379&prodFindSrc=cart

Not too familiar with NTE, can someone say whether these are good for audio or not?

Thanks,

Dave

Title: Re: help with resistors please
Post by: mcandmar on August 05, 2014, 02:40:17 AM

Not heard of them myself, and the specs are nothing stellar but should work fine for attenuating an audio signal.

These ones have slightly better tolerances http://www.radioshack.com/product/index.jsp?productId=12554370&filterName=Type&filterValue=1%26amp%3B%23047%3B4-watt+resistors (http://www.radioshack.com/product/index.jsp?productId=12554370&filterName=Type&filterValue=1%26amp%3B%23047%3B4-watt+resistors)

Title: Re: help with resistors please
Post by: Grainger49 on August 05, 2014, 05:35:50 AM

As luck would have it, Radio Shack doesn't make resistors.  They just sell them. 

Metal film are low noise resistors.  Flameproof is not necessary in this situation.  The power rating could be as low as 0.1W.  Higher power ratings are fine. 

Dave, I don't know where you are.  If in the states I buy from Mouser and Digi-Key often.  Digi-Key has a first class mail option for shipping and resistors are small.

Title: Re: help with resistors please
Post by: Paul Birkeland on August 05, 2014, 09:05:44 AM

Quote from: aragorn723 on August 04, 2014, 04:57:09 PM

I want to reduce the output of my quickie 6db, and was wondering if this would be a good choice?

Hello Dave,

Just for clarification (mostly for other readers), the goal would be a 6dB reduction at the input of the Quickie. 

Any old carbon film or metal film resistor should work well.

-PB

Title: Re: help with resistors please
Post by: aragorn723 on August 05, 2014, 10:53:39 AM

how about these?  Didn't see the option for $3 shipping last night.

http://www.digikey.com/product-detail/en/CMF60100K00FHEK/CMF100KFA-ND/3621895

Would I need a set of these for each of the 2 inputs?

Dave

Title: Re: help with resistors please
Post by: Paul Birkeland on August 05, 2014, 02:12:46 PM

1W resistors will be large and completely overkill.  Try RN55D's from Mouser, or CMF501's from Digikey.

In the Quickie, these are best installed at the pot, so you wouldn't need two sets.

-PB

Title: Re: help with resistors please
Post by: aragorn723 on August 05, 2014, 03:14:06 PM

ok, how about this one then:

http://www.mouser.com/Search/ProductDetail.aspx?qs=MB8hUBX66%252b9HjQXk7SpPSw%3d%3d

so the resistors would replace the two wires that come off the selector switch and go to the pot?  Thanks,

Dave

Title: Re: help with resistors please
Post by: Paul Birkeland on August 05, 2014, 06:27:31 PM

Yeah, replacing the pieces of wire with the resistors is one way to do it, though if they don't reach you may just want to instal the resistors with the bodies right up against the pot lugs, then solder the wires to the free resistor leads.

-PB

Title: Re: help with resistors please
Post by: Grainger49 on August 06, 2014, 01:46:01 AM

And, yes, those are excellent resistors.

Title: Re: help with resistors please
Post by: aragorn723 on August 15, 2014, 05:13:10 PM

Thanks.. just got the new resistors soldered in tonight.  Will this change the resistance and voltage measurements?  Thanks,

Dave

Title: Re: help with resistors please
Post by: Grainger49 on August 16, 2014, 08:39:11 AM

This should not change the voltage measurements.  It might change a resistance measurement on each channel.

I would check the voltage measurements and if they are good don't bother with anything but listening.

Title: Re: help with resistors please
Post by: aragorn723 on August 31, 2014, 04:04:25 PM

Thanks everyone, this made a difference in the volume control :)