another question about a audio spectrum analyzer

TR1, R5 and C41 can be revoved in your circuit because they do nothing.
Your link is WRONG about R5.

The LM3916 has a max output current of about 30mA. The CD4017 circuit switches the LM3916 LEDs on one column at a time (multiplexing) so with 10 columns the LEDs will appear dimmed to only 3mA which is dim. With multiplexing, each lighted LED is turned on for only 1/10th of the total time (if there are 10 columns).

But you have much less than 30mA in each LED so with multiplexing they will appear very dim.

The 15 ohms resistor will reduce the heating of the LM3916 ICs if their current is high because their supply voltage is much higher than is required.

will make changes to power supply as suggested.

that link, I wondered if it worked as the poster said it does.

power supply revised

took out tr1, R5 and C41
hopfully have connections right??

MrDEB said:

took out tr1, R5 and C41
hopfully have connections right??

Click to expand...

Now it can supply about 8V at up to 10A.

Thanks Audioguru

you never fail to amaze me.
now I need to get the pcb designed.

The fuse is in a strange place......

????

I plan on another before the transformer.
where do you suggest as I am open to any and all suggestions