Bugle phono problems...

[eyevancsu]

I built a bugle phono for a friend a few days ago and when shipped to him, i have no way to plug and test it here, he said it didnt work. I really have no idea why though. He shipped it back and i checked for solder bridges, cold joints, polarity of caps and such but found no cosmetic flaw. One thing that he pointed out was that both of the batteries get quite hot, more than what would be reasonably expected. I used the stock parts from the hagtech.com site except for the switch (a black panel mount rocker) and the rca jacks, i used some digikey panel mount. When i wired it together, i connected all three , i guess "ground" points with resistor lead clippings, for each jack. Also, i left out R16 and R34.

Anyone have any ideas as to why the batteries overheat and no sound comes out?

Any help will be appreciated.

Ivan C.

 

[Dumbass]

When I first built the Bugle I installed one or two of the opamps backwards, and no sound came out. After switching them around, voila.

I have no idea if this is your problem.

 

[eyevancsu]

Thanks for that pointer but i just checked and checked before i posted and the opamps are on the right way.

Any other things to check for?

ivan c.

 

[Werner]

Anyone have any ideas as to why the batteries overheat and no sound comes out?

Obviously there is a lot of current flowing somewhere. Either the batteries are connected backwards, or there is a dead short somewhere.

 

[eyevancsu]

I figured there must be a short somewhere also but didnt find one by looking at it. Can i check any other way? Other tips?

thanks

ivan

 

[peranders]

My guess is that the batteries are connected wrong or the IC's are turned upside down. The pcb is 100% (I'm sure of it), what else can it be?

Can't you buy or borrow a DVM?

Can you take a photo?

 

[eyevancsu]

Peranders,

i built it according to the site, including onboard 9v holders, they were the ones suggested so i see no way of soldering it wrong. I triple checked to see if the chips were on right and they are, the little dot on the chip is aligned with the little dent type thing on the board pic. I do have a cheapy dvm, not the best but what they hey! How would i test the phono with it? I dont have a dig cmera but only a 6 year old webcam, below decent photos.

thanks

ivan c.

 

[eyevancsu]

I checked the voltage at the opamps and all come out to be around .6 with the chip in, but 8.87 without the chip, the batteries no longer get hot though, but still no sound.

ideas or tips?

ivan c.

 

[Cobra2]

Hi, eyevancsu !

What op-amps do you use?

Arne K

 

[eyevancsu]

im using the opa2134, i think its the one suggested in the site.
I also tried it with the ad 8620 but nope...

thanks

ivan c.

 

[Cobra2]

How 'bout that switch?

You have an external mounted switch...did you double-check the connection to pcb? And linked the right spaces?

Arne K

 

[eyevancsu]

About the linked spaces, was i supposed to connect those two sets of holes first and then put a switch? B/c i just connected it one wire to each of the six pads.

Ivan C.

 

[Havoc]

Power supply sequencing problem? Put over each battery a diode like a 1n4001 in reverse.