Equalizing input volume

jaudio · 19th April 2005, 10:41 AM

What is the best why the equalize input levels. I have too much gain on the cd and phono amp inputs. The preamp has a 10k balance control in front,then a 100k volume control. I need suggestions.

thanks

carlosfm · 19th April 2005, 11:24 AM

Do you know the gain of the preamp?
What gain does your power amp have?

rabbitz · 19th April 2005, 01:46 PM

Try an in line attenuator.... worked for me and here's the link.

http://www.diyaudio.com/forums/showt...614#post547614

jaudio · 19th April 2005, 04:28 PM

Quote:

Originally posted by carlosfm
Do you know the gain of the preamp?
What gain does your power amp have?

Bridged lm3886 with 13 voltage gain
preamp has a gain of 2 its the opa2134 with buf634 3k in feedback and 2.k resistor from feedback to ground.

[QUOTE]Originally posted by rabbitz
[B]Try an in line attenuator.... worked for me and here's the link.
Thanks I used that idea a few times

carlosfm · 19th April 2005, 07:03 PM

Quote:

Originally posted by jaudio
Bridged lm3886 with 13 voltage gain

Change it for 10x gain per chip.

Quote:

Originally posted by jaudio
preamp has a gain of 2 its the opa2134 with buf634 3k in feedback and 2.k resistor from feedback to ground.

That's 2.5x gain.

jaudio · 19th April 2005, 08:46 PM

Quote:

Originally posted by carlosfm

Change it for 10x gain per chip.

That's 2.5x gain.

Sorry I meant 2.7k instead of 2k

I really dont want to do that because I will have to change resistors for 20 chips.

I will remove the resistors from feedback and feedback to ground in the opa2134 and buf634 preamp then replace it with wire.
Do you see any problems?

carlosfm · 19th April 2005, 09:31 PM

Quote:

Originally posted by jaudio
I really dont want to do that because I will have to change resistors for 20 chips.

Anyway, you have a higher than normal gain for a power amp.
It's your choice, but keeping things this way means that you are not going to be able to connect any "standard" preamp to your power amps.

Quote:

Originally posted by jaudio
I will remove the resistors from feedback and feedback to ground in the opa2134 and buf634 preamp then replace it with wire.
Do you see any problems?

Change the 2.7k resistor for 5.6k, that should be enough (~1.5x) , I think you don't need to go unity-gain.

jaudio · 19th April 2005, 10:27 PM

Is this a good or bad Idea : 10k pot at the input of each power amp

carlosfm · 19th April 2005, 10:33 PM

Bad.

19th April 2005, 10:41 AM	#1
jaudio diyAudio Member Join Date: Oct 2004	Equalizing input volume What is the best why the equalize input levels. I have too much gain on the cd and phono amp inputs. The preamp has a 10k balance control in front,then a 100k volume control. I need suggestions. thanks

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Input Volume Pot	kacernator	Tubes / Valves	4	28th May 2008 12:41 PM
Equalizing + & - output voltage?	Sherman	Tubes / Valves	3	2nd November 2007 06:56 PM
Input transformer & volume pot	abj1	Tubes / Valves	19	7th November 2005 10:38 AM
Bi-amplification equalizing options	Sony	Multi-Way	4	13th December 2004 03:09 PM
amp input volume	resident	Tubes / Valves	6	21st October 2004 11:52 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

19th April 2005, 11:24 AM	#2
carlosfm Banned Join Date: Mar 2003 Location: Lisbon, Portugal	Do you know the gain of the preamp? What gain does your power amp have?

19th April 2005, 01:46 PM	#3
rabbitz diyAudio Member Join Date: Jul 2003 Location: Newcastle, Australia	Try an in line attenuator.... worked for me and here's the link. http://www.diyaudio.com/forums/showt...614#post547614

19th April 2005, 10:27 PM	#8
jaudio diyAudio Member Join Date: Oct 2004	Is this a good or bad Idea : 10k pot at the input of each power amp

19th April 2005, 10:33 PM	#9
carlosfm Banned Join Date: Mar 2003 Location: Lisbon, Portugal	Bad.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)