Topics Topics Edit Profile Profile Help/Instructions Help Member List Member List  
Search Last 1|3|7 Days Search Search Tree View Tree View  

Sound Card Mixer (EPE Feb 2005) Help...

:: EPE Chat Zone ­:: ­Radio Bygones Message Board :: » EPE Forum Archives 2005-2006 » Archive through May 08, 2005 » Sound Card Mixer (EPE Feb 2005) Help wanted « Previous Next »

  Thread Last Poster Posts Pages Last Post
  ClosedClosed: New threads not accepted on this page        

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Alan_jones
Just joined
Username: Alan_jones

Post Number: 1
Registered: 05-2005

Rating: N/A
Votes: 0 (Vote!)

Posted on Monday, 02 May, 2005 - 12:33 pm:   Edit Post Delete Post Print Post

I have finally finished this, and can't get it to work! I've checked all the joints with a magnifying glass, they look good, there are no obvious short circuits, and everything appears to be the right way round on the board.

Question: Is 9V enough? I seem to remember reading that the op amps used need a minimum of +/- 5v (10V in total) to operate. Before I go out and get more batteries and holders, can someone confirm my suspicions that 9V will not turn on thr op-amps.
Top of pagePrevious messageNext messageBottom of page Link to this message

Glen_williams
Just joined
Username: Glen_williams

Post Number: 4
Registered: 05-2005

Rating: N/A
Votes: 0 (Vote!)

Posted on Monday, 02 May, 2005 - 09:14 pm:   Edit Post Delete Post Print Post

Alan
I am also building this project, but just the
Headphone Amp, as stand alone.
I am hoping it will work @ 6v!
Now I am wondering if EPE have made an error?
Regards,
Glen
Top of pagePrevious messageNext messageBottom of page Link to this message

Robs
Just joined
Username: Robs

Post Number: 5
Registered: 05-2005


Rating: N/A
Votes: 0 (Vote!)

Posted on Tuesday, 03 May, 2005 - 04:21 pm:   Edit Post Delete Post Print Post

I checked out the Texas and Fairchild datasheets. They were a bit vague on minimum voltage. Texas said it would work from +/-3V but went on to recommend +/-5V. Neither datasheet gave useful specifications at low voltage.

My guess is it will work at 9V (+/-4.5V), but 6V is pushing it.

My advice would be to start at the output stages and work back. What are the voltages on the pins of IC4, for example?
Top of pagePrevious messageNext messageBottom of page Link to this message

Alan_jones
Just joined
Username: Alan_jones

Post Number: 2
Registered: 05-2005

Rating: N/A
Votes: 0 (Vote!)

Posted on Wednesday, 04 May, 2005 - 11:20 pm:   Edit Post Delete Post Print Post

Thank you both.

Robs, your advice about starting at the back was good! That Op Amp was a NE5534 not the specified 5532! I checked the other three again, just to be certain, and that was the only rogue in the batch. Bit of luck really that it went into the last slot. Oh well, we all make mistakes (as the Dalek said when he got off the dustbin) but as I had paid for a batch of NE5532s I assumed that they all were NE5532. Trouble is it's now 1115pm and I have no spares in the stock box, they were brought in specially for the project.

Moral of this story, always check that you get what you paid for.

Administration Administration Log Out Log Out   Previous Page Previous Page Next Page Next Page