Yeah, those heatsinks really do their job don't they? I had a difficult time especially with the heatsink tabs. I ended up having to use some liquid solder flux to get them to fully take.

I tested/trimmed 48V today, put the channel boards on the face, the feet on the bottom, and put the gain knobs on (just so it would look purty )

I might get some time tonight and hopefully I can get at least the back panel on and wired.

One question though, where did you guys ground your plug in to? The drawing says it goes to the chasis so I was just going to take a wire and go down to the nut that holds the foot on but I was wondering if there was a better place.

Let me know.


Jason A.

I ran a wire to the chassis exactly like you described.

quote:

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Originally posted by spiral:
I ran a wire to the chassis exactly like you described.

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Thanks. Before I got your answer, I decided to run in under the divider and around one of the bottom screws. It kind of makes my divider tilt slightly so I may end up having to move it. We'll see tomorrow.

I got the back panel wired, the front power light, and the P2P between the channels and the PS done. I sure wish my P2P twisting looked as pretty as Scotts. Mine look OK until you get to where they solder into the boards and then things get a little hairy.

Tomorrow, I'll be ready to clean the boards for the last time, plug the whole thing into the variac and test the 24 and 48. If nothing explodes I'll screw everything in place and do some test runs tomorrow night.


Jason A.

can anyone recommend a reliable cheap variac in case I have to buy one (im going to hit up a neighbor but they may not have one)? I don't need one that goes above 100V or anything since I'll probably need it rarely after this project.

<a href="http://www.sweatydudes.com/forum">The Sweaty Dudes</a>

quote:

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Originally posted by stubbadub:
can anyone recommend a reliable cheap variac in case I have to buy one (im going to hit up a neighbor but they may not have one)? I don't need one that goes above 100V or anything since I'll probably need it rarely after this project.

The Sweaty Dudes

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It's my understanding that a variac is not absolutely necessary. It will just allow you to possibly catch a problem earlier and only fry a few components instead of the whole circuit if something is wrong. I just use one because I have access to one.

At least that's how I see it. Anyone else?


Jason A.

I have to admit, I just assembled the whole deal in the box and turned it on. lights up! ..Wait....wait....no smoke....wait.....check voltage, check....no smoke....yeehaaa

I think the variac is a good idea but not having one or access to one I took the low road.

I will admit as well that i didn't test the power supply since i don't have the tools for that. You probably should though if you can, in case a component is bad or some other freak thing. Once i had it assembled, i did however check the pins on the XLR jacks to adjust the 48v phantom.

One thing i forgot to mention: I had to drill my power transformer. The hole was too small and just using a normal drill, carefully enlarged the hole.

quote:

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Originally posted by spiral:
...One thing i forgot to mention: I had to drill my power transformer. The hole was too small and just using a normal drill, carefully enlarged the hole.

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I just found a smaller diameter bolt and nut. I used the same nylon washers though.


Jason A.

Yeah I filed mine out as well - just one of the little bumps in the road!

Success! Uh, well sort of.

Channel 2 works and sounds great. Channel 1 I seem to have wired the send and return on the pot backwards. I fired it up and thought "Wow, that's a lot of gain." Checked it out and it is backwards from Channel 2. I'll take the solder sucker to it tomorrow and switch them back around. Kind of shaved some of the excitement off of the moment but I can't complain.

I seem to be the only bonehead here who made a mistake but at least my mistake doesn't seem to be permanent.

I should be able to lay some tracks tomorrow. I just did some playing around on Channel 2 tonight.


Jason A.

quote:

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Originally posted by Jason A.:
I seem to be the only bonehead here who made a mistake

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...don't sign that check yet, I haven't had a chance to plug mine in yet

<a href="http://www.sweatydudes.com/forum">The Sweaty Dudes</a>

OK, switched the wires around on the pot and all is well. Actually, better than well. This thing sounds really nice. Quieter than my RNP and more focused in the lower mids. I haven't done a formal A/B yet, just going on memory.

Gotta go. I have a feeling I'll still be hanging around here a lot though.


Jason A.

ok guys, without a load my 25.5vdc is actually running at 34V. it's supposed to be at 28V or so without the load....??? i double checked all the caps and everything, i can't see where i f*ed it up. anyone have any idea how to troubleshoot the problem?

<a href="http://www.sweatydudes.com/forum">The Sweaty Dudes</a>

quote:

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Originally posted by stubbadub:
ok guys, without a load my 25.5vdc is actually running at 34V. it's supposed to be at 28V or so without the load....??? i double checked all the caps and everything, i can't see where i f*ed it up. anyone have any idea how to troubleshoot the problem?

[URL]=http://www.sweatydudes.com/forum]The Sweaty Dudes[/URL]

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I don't have any of my stuff with me today but wasn't there a sheet that had a schematic of the PS board showing test values at various points around the board? Maybe it was on the same paper as the back panel wiring. I'm not claiming I know exactly where to test these values (I never honestly tried) but maybe this could help you narrow it down to a few component by starting at the beginning of the signal flow and slowly working towards the output.

Keep us posted.


Jason A.

heres how -

with the PSU plugged in, clip negative (usually black) probe of your multimeter to ground. set meter for DC volts. touch test point with positive probe. read voltage. try this out first on that old 9v stomp box battery sitting on your work table.

Isn't that how you got the 34V reading?

Maybe I should clarify.

I tested the 25.5 and the 48 at the test points but I didn't have the need to use the troubleshooting values listed in the chart on the drawing.

But ape has a point. Tell us how you are measuring it and then at least we can rule operator error out.


Jason A.

ya that's how I'm measuring it. I think I might have found the culprit, or at least the first. Can one of you guys take a look at whereD35 and D37 basically meet. Are those joints supposed to be touching? Before I go in trying to remove solder (and a layer of my pcb) I'd rather see if you guys can tell from yours because mine are completely bridged there.

I appreciate your guys' help on this too. I'll act as the resident electronics dummy to save someone else the trouble of asking all the questions

<a href="http://www.sweatydudes.com/forum">The Sweaty Dudes</a>

I don't relish the idea of unscrewing my circuit boards but rest assured if that is the only way I will.

However, if you look at the trace drawing for the PS board that was included with the instructions, it shows the pads you are refering to are actually on the same trace. And the PS component drawing seems to show the two pads as actually connected.

So, whether it be good news or bad, I don't think this is your culprit.


Jason A.

reality is setting in. I know shit about electronics. I'll try to describe what I'm getting but I think it's only going to go downhill from here. I have B50 in but no B30 in yet....

when I connect the negative arm of the DVM to the green wire (ground) and touch the positive dvm arm to the red wire im running at 36V with no load. when i touch the positive arm to test point V7 I get 36.6V. It should be 30.2V with a load. At test point V9 I'm at 36V when I should be at 24.3V with a load. I'm not sure where test point V8 is exactly but all the joints in that area are pretty much riding around these same numbers.

Anyone have any ideas or is this all worthless information?

<a href="http://www.sweatydudes.com/forum">The Sweaty Dudes</a>

I did my tests at the output pads that go from the PS board to the channel boards. There are two sets of three pads (G, 24, and 48) all together on the PS board around C53 and C36. I measured from G to 24 and then G to 48 (after B30) there on each output channel.

Maybe I was wrong but I thought the purpose of the test was to make sure the channels got the proper voltage so the place to test it is at the output of the PS.

Let me know if you have already tried this.


Jason A.