I purchased some second hand Hypex UCD400ST modules and have just hooked them up. They are the STV8 revision.
Power supply rails measure fine at ~60V, and all connections have been double checked.
When using a 2v source (CD player), and hooked up to a test speaker the volume is still very low.
A different source (phone) was used and the volume was still very low.
I noticed that there are two pots on each board. Are these somehow associated with setting the voltage gain?
Any other ideas as to why the output is so low?
Cheers, Josh
Power supply rails measure fine at ~60V, and all connections have been double checked.
When using a 2v source (CD player), and hooked up to a test speaker the volume is still very low.
A different source (phone) was used and the volume was still very low.
I noticed that there are two pots on each board. Are these somehow associated with setting the voltage gain?
Any other ideas as to why the output is so low?
Cheers, Josh
The pots do not adjust the gain.
I am assuming that both your sources are single ended, have you grounded the -In input and connected the signal to +In and GND ?
Has the previous owner bypassed the input buffer by any chance ?
I am assuming that both your sources are single ended, have you grounded the -In input and connected the signal to +In and GND ?
Has the previous owner bypassed the input buffer by any chance ?
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Have a look at the circuit diagram for the input buffer here -http://www.hypex.nl/docs/UcD400OEM_datasheet.pdf
Depending on the version you have there may be Rg (Gain Resistor) pads (very small !) on the top of the board, they should be open circuit for full gain.
Depending on the version you have there may be Rg (Gain Resistor) pads (very small !) on the top of the board, they should be open circuit for full gain.
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Sorted out the problem. It was just a gain-staging issue with other upstream components.
Thanks for the responses deanoUK.
Thanks for the responses deanoUK.
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