GGG's ultra clean power supply problem. voltage drop

[Tubenoise]

Hello there!

I've build Ultra clean power supply from GGG site. Made 9 dc jacks connected by dasy chain as suggested. So it gives me 9V on each jack when no effects connected. The prolem is when 1 stompbox connected to the supply others jacks give only 8.33V, when 2 effects connected others give 7.88 etc. Why the voltage is going down?That's not right! As far as I know the voltage should stay constant doesn't mattar how many pedals are connected. I'm not so experienced in radioelectronics to understand where mistake is.
Could anyone help me?

Tranny: 220/25V/600mA. All values the same as in project. No changes.

http://www.generalguitargadgets.com/wp-content/uploads/ultra_clean_ps_sc.gif

Really appreciate any help!

Anthony.

[canman]

I don't know much about electronics myself, but could it be you hooked up the daisy chain in series, rather than parallel? (Is that even possible?)  I'm not sure if that would cause the phenomenon you're experiencing or not, but it might be worth checking out.


EDIT:

Did you build this on a PCB?  Does GGG provide this as a kit?

[R.G.]

Measure the DC voltages at the input, output, and Iadj pins of the LM317 for no effects, one effect, two effects, etc. and report them here.

Did you read the datasheet for which pin is which on the LM317? They're wildly different from the 78xx series, and different yet from the LM317L, which is the TO-92 version of the TO-220 version of the LM317. Which version did you use?

Are any of the electro caps inserted backwards?

Is the wiring correct?

You'll no doubt recognize this advice comes directly from "Debugging thread: what to do when it doesn't work", the sticky thread at the top of the forum list that you have to ignore to get down to the rest of the topics.

[Tubenoise]

I don't know much about electronics myself, but could it be you hooked up the daisy chain in series, rather than parallel? (Is that even possible?)  I'm not sure if that would cause the phenomenon you're experiencing or not, but it might be worth checking out.


EDIT:

Did you build this on a PCB?  Does GGG provide this as a kit?

I thought about daisy chain, but I beleive i was hooked up right. Correct me if I'm wrong.



Does link work?

Don't know about the kit. I like making pcb by myself and this one is pretty easy to make.

[maiko]

your running from a 25V transformer and stepping down to 9v?   Thats too much a voltage differential.  alot of that is wasted as heat.  The part of the video that might explain your problem is at around 4:00

https://www.youtube.com/watch?v=GSzVs7_aW-Y&list=PLNYiQO1Y0dr78gSB-L26VCnmCkvQM65uW

The closer you are to your final voltage the better.

[Tubenoise]

Maiko, thanks for the video! Reeealy helphul. I have used 25V transformer just because that was said in project.  What I wanna say that Regulator doesn't really heating. But maybe it needs time to start doing that. Never leave it working more than 20 min...

Sent from my LG-H961S using Tapatalk

[Tubenoise]

Measure the DC voltages at the input, output, and Iadj pins of the LM317 for no effects, one effect, two effects, etc. and report them here.

Did you read the datasheet for which pin is which on the LM317? They're wildly different from the 78xx series, and different yet from the LM317L, which is the TO-92 version of the TO-220 version of the LM317. Which version did you use?

Are any of the electro caps inserted backwards?

Is the wiring correct?

You'll no doubt recognize this advice comes directly from "Debugging thread: what to do when it doesn't work", the sticky thread at the top of the forum list that you have to ignore to get down to the rest of the topics.

Hello, R.G.

I checked some typical issues for debugging (wiring, capacitors polarity, pinouts of LM317T, resistors values, solder briges). Everything seems to be fine.

Here is voltage chart you suggested me to make:



As you can see the output voltage is going down with each connected stombox. Any ideas?

And strange thing is that transformer gives 35V, not 25V as it's marked. Could it be the reason of my trouble?