Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Input sound to vintage computer circuit

Status
Not open for further replies.

neazoi

Advanced Member level 6
Advanced Member level 6
Joined
Jan 5, 2008
Messages
4,148
Helped
13
Reputation
26
Reaction score
15
Trophy points
1,318
Location
Greece
Activity points
37,119
hello This circuit is from an old computer which loaded the programs using recorded wav files on a tape.

I have two such computers. The first missing the red resistor and the other has it.

I was wondering, what is the effect of the resistor in such an audio circuit?
 

Attachments

  • input.PNG
    input.PNG
    8.3 KB · Views: 124

Resistors 6.8k and 1k are used for setting bias voltage to the next stage
Bias volt. is 0.64V

TTL integrated circuits LS series used those days, had input low level 0.6...0.7V and high level 2.0V
So biasing near input low , gives more sensitivity for first stage ( amplification and pulse former )

Regards KAK
 
Resistors 6.8k and 1k are used for setting bias voltage to the next stage
Bias volt. is 0.64V

TTL integrated circuits LS series used those days, had input low level 0.6...0.7V and high level 2.0V
So biasing near input low , gives more sensitivity for first stage ( amplification and pulse former )

Regards KAK

Thank you very much!

So it is better to leave the resistor ther?

What about the 54LS series ICs, is it the same?
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top