ACR Volume Too Low

[TomL_12953]

What would cause the output of an ACR cassette interface to be very faint? I tried a friend's ACR board and when I plug its output into an amplifier and do a CSAVE from BASIC, I can hear the correct sound but it's so faint, it's almost lost in the background noise. Is this a problem that's easily fixed?

TIA
Tom Lake

[marty]

Hi Tom;
As I have never gotten my ACR to work, It is the blind leading the blind, but, what I would suggest IS get a couple of wire Jumpers that you have or from Radio Shack, and see if this helps -- IC H pin 8 is the output look at it with a 'Scope' if you have one, and compare it to your output from the 'plug in' , where you attach you cassette. (Also check your 'plugs' for corrossion). then you can try this, as I am not an engineer, and it looks like there is a filter made up of R51 and C22, I would leave these alone, so that leaves R 50 and R36, I would jump R36 first and see if it helps, otherwise I would take two jumpers and put in parrellel with R 50 another Resistor to lower its value and see if that helps, R 50 may be a part of the filter, so I wouldn't fool around with it unless I had to.... on R 50 you could put in parrellel another 220K ohm resistor.. and see what it does.....
THANK YOU Marty

[TomL_12953]

Originally Posted by TomL_12953

What would cause the output of an ACR cassette interface to be very faint? I tried a friend's ACR board and when I plug its output into an amplifier and do a CSAVE from BASIC, I can hear the correct sound but it's so faint, it's almost lost in the background noise. Is this a problem that's easily fixed?

TIA
Tom Lake

I finally ot it fixed! the guy who fixed it said:
"The tape write section had some damage. It wasn't even generating a carrier tone. I had to replace 2 chips. They were both binary counters and they simply weren't counting. They were Fairchild 9316s, no longer in production. So I replaced them with compatible 74161s. And that solved the write problem."

Thanks to all who offered to help!

Tom L