[And now what did you do TODAY?]

yeah, I read that just now. Good Night that's some force to push a bit like that through your hand!

[And now what did you do TODAY?]

was that straight through with a nail?

opened a fat sack from mouser

[The Multi Amp aka Dynalo Mk2]

Right, I still have my original too

[The Multi Amp aka Dynalo Mk2]

should I socket the LED's?  I remember doing this on my original Dynahi to get the offset as low as possible.

 

Here's the latest with LED and cap changes

Dynalo MkII Rev 1.2.xls

[The Multi Amp aka Dynalo Mk2]

You're right, I had wondered if those LED's were wrong.  I've swapped them for what you posted.  For the 5pF I believe it's 5mm but will measure again tonight.

Back when I built the original Dynahi I had to swap out LED's to get the lowest offset IIRC.  Is that the case here?

[The Multi Amp aka Dynalo Mk2]

I noticed that some are using a better quality resistor for the 20R.  I was thinking of using Takman in this spot.  Does it pay to use something like Takman or PRP in this spot?

[The Multi Amp aka Dynalo Mk2]

Finished the BOM, I'm pretty sure I got it all.  This is for one board.

Take a look and let me know if I missed anything or there are better part choices

Dynalo MkII 1.2 Mouser.xls

[The Multi Amp aka Dynalo Mk2]

Yeah, I realized that about the PP 4.7uf early on, just thought I was missing something.  I'll swap the electrolytics out for these https://www.mouser.com/ProductDetail/667-63SXE100M

So I can definitely leave the 4.7uf film caps unpopulated then?

[The Multi Amp aka Dynalo Mk2]

Got it...  I see Pars left them unpopulated

[The Multi Amp aka Dynalo Mk2]

I can't seem to find Wima PP that fit at Digikey or Mouser.  I can find PET though, will these work?

https://www.mouser.com/ProductDetail/WIMA/MKS2B044701K00JC00?qs=sJjjjplDs9usMRoEQsMxiQ%3D%3D

[The Multi Amp aka Dynalo Mk2]

What type of caps should I use for the caps I circled in red?

 

 

[goldenreference low voltage power supply]

I thought about the parts I have for building 30V GRLV boards for my dynahi, I noticed that the tantalum caps are all rated at 25.  Should I increase them to 50V when building for 30V?

[How not to build amps...]

9 hours ago, Craig Sawyers said:

I feel the need to gag.

I felt a bit of throw up in my mouth as well

[And now what did you do TODAY?]

it makes me want to watch the series!  Love it!  Couldn't stop thinking Jesse was using meth again 

[How not to build amps...]

That's some sketchy shit right there

[HC Bike/Cycling Thread]

I'm not into bikes but that was really cool

[19V Linear PSU for PC]

better late than never...  Assembled the case today

[goldenreference low voltage power supply]

thanks Dr. Gilmore!  heard details I never heard before

[goldenreference low voltage power supply]

1 hour ago, Pars said:

I don't think you're going to get any closer than that

I'd agree...  I was quite pleased when I fired it up.  I'm inclined to just leave it.

Compared to the TPA bipolar supply it immediately sounded better.  The sound stage seems more dynamic and I hope it gets better.

[goldenreference low voltage power supply]

7 minutes ago, Pars said:

1. Steve,

I hadn't read that regarding a 4.5 digit DMM, but I would assume you would be able to see something? I've never used the trimpots for adjusting the voltages (I usually use either matched resistors using my HP bench meter, or 0.1% resistors and live with the results.)

That's what I was thinking.  Is there any harm leaving it as is?  I'm ok with the results

6 minutes ago, mwl168 said:

Judging by the photo you should definitely see output voltage change as you adjust the pots. If not, I would first check to see if the pins of the pot are soldered in correctly - is it possible you soldered pin 1 and 3 of the pots to the fixed resistor positions?

 

I'll check it tonight, anything is possible

[goldenreference low voltage power supply]

Another one lives...  This one is powering the IVY III output stage of my DAC.  I populated all the resistors with the trim pots.  I get -14.96 and +14.96

I noticed that when I adjusted the pots there was no change.  I read that my 4.5 digit meter will not have the resolution to display what's being adjusted when I adjust the pot.  Is that why I see no adjustment?

 

[goldenreference low voltage power supply]

Mundorf makes a cap that'll fit and it's rated at 40V.  It's probably not gonna make much difference but this one's going to power the output stage in my DAC and all the other PSU caps are mundorf so I was just trying to keep them all the same.

[goldenreference low voltage power supply]

Can I use 40V caps for the large 4700 uf 50V caps?  I think those see the rectified unregulated voltage.  The transformer I'm using would be 15 VAC with primary at 115V.  My mains usually run at 120 so maybe output would be 16VAC,  16 x 1.4 would  put the unregulated voltage at 22.4 VDC.  That's still ok right?

[goldenreference low voltage power supply]

Thank you sir...

[goldenreference low voltage power supply]

can someone tell me where R8 and R9 are on this board?  I need to build it for 15V.  I've circled the four 1.5K resistors are that I think are for setting the voltage.  I also circled a 10 ohm at the top of the board and wondered if I needed to populate that?