I finished my VSPS and it works (first project), it is point to point on a generic PCB. It sounds pretty good but I have a bunch of hum (or hiss not sure), after reading through this thread it sounds like the main fix is to make sure the ground is working good so I'm going to work on that this weekend.
Another thing I have found above is people suggest using shielded RCA cables, what are they and how can I make them?
Another thing I have found above is people suggest using shielded RCA cables, what are they and how can I make them?
Thanks for the advice guys. I feel pretty confident that I have the circuit setup correctly, but my soldering could be suspect. I chased out part of the noise and it sounds pretty good but there is still some hiss/hum at normal levels. Even without the opamp in the socket there is some hum/hiss, what does that mean?
No sound
So I wired everything up for the VSPS and plugged it in and no sound comes out! what process can I go through to troubleshoot? there is power going to everything that I think power needs to be going to but, no sound. I'm using the NE5534, can I measure anything on that to see if it functions?
Where is the first point I could measure the voltage gain of the audio signal?
So I wired everything up for the VSPS and plugged it in and no sound comes out! what process can I go through to troubleshoot? there is power going to everything that I think power needs to be going to but, no sound. I'm using the NE5534, can I measure anything on that to see if it functions?
Where is the first point I could measure the voltage gain of the audio signal?
Re: No sound
Is today "my-VSPS-doesn't-work" day or something?
First thing is to substitute another phono stage into the system to check everything else works.
Second thing is to double check the voltages at the opamp power pins.
Third thing is to replace the opamp.
Fourth thing is to check continuity between the RCA jacks and the PCB.
Fifth thing is to look for the obvious, idiotic thing you forgot to do. (Posting a photo to the forum may prove helpful.)
jermo said:
Is today "my-VSPS-doesn't-work" day or something?
First thing is to substitute another phono stage into the system to check everything else works.
Second thing is to double check the voltages at the opamp power pins.
Third thing is to replace the opamp.
Fourth thing is to check continuity between the RCA jacks and the PCB.
Fifth thing is to look for the obvious, idiotic thing you forgot to do. (Posting a photo to the forum may prove helpful.)
voltages
the voltages are right, 24v difference between the two so there's +12 and -12 going into the thing, the op amp is brand new so I don't know why it wouldn't be working.
It may be my VSPS doesn't work day, either that or a chemical engineering student is attempting to wire up an amp and has no idea.
I would send you a photo but I've done the wiring in a very very messy way so I doubt it would help. I just followed the PSB drawing when wiring everything up. and I used wires not a PSB. I didn't use 24 ga I just took some copper lockwire that I had handy and spun two strands together, it looked like just over .5 mil so I assumed it was fine. I doubt that would be doing this though they would just be heating up if they were too skinny.
the voltages are right, 24v difference between the two so there's +12 and -12 going into the thing, the op amp is brand new so I don't know why it wouldn't be working.
It may be my VSPS doesn't work day, either that or a chemical engineering student is attempting to wire up an amp and has no idea.
I would send you a photo but I've done the wiring in a very very messy way so I doubt it would help. I just followed the PSB drawing when wiring everything up. and I used wires not a PSB. I didn't use 24 ga I just took some copper lockwire that I had handy and spun two strands together, it looked like just over .5 mil so I assumed it was fine. I doubt that would be doing this though they would just be heating up if they were too skinny.
yeah that's what I'm doing
where c2 is a bank of 3 caps, pretty much followed the directions to the tee, even got the 105k and 732k resistors.
An externally hosted image should be here but it was not working when we last tested it.
where c2 is a bank of 3 caps, pretty much followed the directions to the tee, even got the 105k and 732k resistors.
I was hoping you'd catch on yourself before posting that.
You are using a single channel op amp. You need a dual channel opamp in stereo layout, such as the NE5532.
From the web page:
"Any audio op-amp could be used with satisfactory results. Stereo layouts require dual op-amps e.g. NE5532, OPA134."
and again, right above the figure you just linked to..
"Below is an example layout for a basic stereo version using a dual op-amp (NE5532, OPA134). "
So it's not like I didn't tell you.
You are using a single channel op amp. You need a dual channel opamp in stereo layout, such as the NE5532.
From the web page:
"Any audio op-amp could be used with satisfactory results. Stereo layouts require dual op-amps e.g. NE5532, OPA134."
and again, right above the figure you just linked to..
"Below is an example layout for a basic stereo version using a dual op-amp (NE5532, OPA134). "
So it's not like I didn't tell you.