Harbinger one build doc power question?

[pryde]

I am looking at the harbinger build doc and in the BOM on pg 2 says that parts highlighted in green are only needed when using 18v adapter....

however, on page 6 it says if using a 9v wall-wart then you must populate the filter board (i.e. 470uf caps) and then connect it to the pcb.

I did not order any 470uf caps cause I did not think I needed them based on the BOM. Am I SOL? I plan to power it using a 1 spot 9v adapter. what is needed exactly?

Thanks for the help

[Haberdasher]

nah, if you're using 9v with the lt1054/LM7815 combo for power I don't think you need it.  That's only if you're using an 18v dc wall wart.

but just to throw it out there, I will sell you a 470uF tayda cap for one beeellion dollars.

[pryde]

Ha, deal 

I think the build doc might need revised unless I am not getting it, which very well could be. So then I assume the filter pcb would not be used at all if using a one spot 9v adapter?

[Haberdasher]

Oh I see what you're saying now.  Down in the power options chart is does say to populate the filter board for use with unregged wall wart such as one spot.

I don't know then, better wait for bean.  Or just get some 470uf's. 

[madbean]

On my proto I used a One Spot and did not have any significant noise without the filter PCB. However, other 9v wall warts may not be so lucky. It seemed easier for the documentation just to make generalized suggestions because there is no real downside to using it. IOW, you can use the filter PCB for any non-regulated wall-wart, but it may also not be necessary for every wall-wart.

Also, if you want to use it, you can sub in smaller values for the caps. 220uF is adequate.

[pryde]

Thanks Bean. I did manage to find a couple 470uf in my stash so I can use them but they are HUGE. I will also keep in mind just using some 220uf that are much smaller. Thanks for clarifying