Thanks for the reply Tom. I got some good information from many of your posts in this thread while doing my research.
My pleasure!
I ordered 12 of these (mouser # 532-531102B25G) for my 2 builds I am doing: Access to this page has been denied.
I need to buy the hardware to keep the surfaces tight. I have some random nuts and bolts that are kind of working for the moment so I could get the soldering height correct but I don't have enough and the bolts are too long and are slotted (ugh). I would prefer to order the right size stuff, like the phillips-head ones in the picture with the star nut or clip on ones I have seen, if that is better.
A word of caution about the height for the mounting of the transistor. Enough people have tried to drill their own mounting holes in the heatsinks to better match the height and have encountered issues specifically around jagged edges or even residual metal flakes breaking through the silpat and shorting the transistor's case.
With that in mind, I recommend that you take a look at these "TO-220 mounting kits" on amzn. They are reasonably priced and come with the bolt (m4), k-nut, insulated bushing for isolating the bolt and k-nut from the heatsink, and silpat/silicone insulator pad. If you are not buying in large quantities, these are convenient and good quality stuff:
https://www.amazon.com/Insulator-Mo...55ca8&pd_rd_wg=29wgi&pd_rd_i=B00KR4KFH2&psc=1
Are you referring to the LEDs after the voltage regulators or otherwise (i.e.: power indicator tapped off the supply somewhere)?
--Tom
I already put the grease on and soldered the 2 in on each board for the power supplies and everything measures close to +15/-15 volts. I just need more hardware and was wondering what the ideal mounting size screws/star nuts were for the heatsinks that were suggested. I was planning to buy the right stuff and swap out the ones I am using plus I need more for the other 8 heatsinks as I don't have enough of this temporary hardware I am using to do them all. I used the middle hole and it seems like ~80% of the surface is on the heatsink. Since these heatsinks were in the BOM others were using I assume people have done as I did without issue.
Is it that desireable to have the bolt/nut insulated from the heatsink? Are those pads better than using thermal grease? The hardware in the link seems like it would work. Thanks for that. I have 12 heatsinks so I would need 2 or just keep 2 of them done the way I have them with the grease and my current bolts and nuts.
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You should be able to use 3mm or #4 size bolts. Also, I believe the heat sink is isolated from the ground plane. If that is the case you wouldn’t need to worry about shorting your transistor to the heatsink. But you wouldn’t want to touch it if it were turned on.
Volume is equal but noise is louder on the right side.
D6 is the one that goes off almost immediately, D5 stays on for a while.
I have no plans to touch anything while it is on. Thanks for the info on the bolts.
I am going to go to the hardware store and try to pick something up that fits better. The ones I have are too small for the hole and a half inch long. I noticed the hole in the board and threads for the transformer box but wonder what size bolt and thread pattern that is and if many people use it or just hold them in via the soldering points?
The 4 letter word searching minimum has to be the most annoying thing when trying to do this project. Everything I need to research seems to have a three letter acronym . There are so many posts in this thread if you can't search for it..you probably won't find it.
Since I can't search for LED and have had a hard time trying to find what I need, what is the best way to connect a power LED? (power indication, power light - putting these here for search terms longer than the three letters of LED to maybe help someone in the future). Looking to use a Blue LED with Forward Current: 20 mA, Forward Voltage: 3.8 V, Power Rating: 116 mW.
I'm also interested in setting up RCA outs. Searching for preamp yielded 141 posts to go through. So, I might be able to find something in there but if I could get some direct information or a link to a good way to set those up, I'd appreciate it. Thanks.
Also FYI, the amp worked on the first go. Tested it with junk and now about to test with my HD600s
. There are so many posts in this thread if you can't search for it..you probably won't find it.Since I can't search for LED and have had a hard time trying to find what I need, what is the best way to connect a power LED? (power indication, power light - putting these here for search terms longer than the three letters of LED to maybe help someone in the future). Looking to use a Blue LED with Forward Current: 20 mA, Forward Voltage: 3.8 V, Power Rating: 116 mW.
I'm also interested in setting up RCA outs. Searching for preamp yielded 141 posts to go through. So, I might be able to find something in there but if I could get some direct information or a link to a good way to set those up, I'd appreciate it. Thanks.
Also FYI, the amp worked on the first go. Tested it with junk and now about to test with my HD600s
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The 4 letter word searching minimum has to be the most annoying thing when trying to do this project. Everything I need to research seems to have a three letter acronym
Since I can't search for LED and have had a hard time trying to find what I need, what is the best way to connect a power LED? (power indication, power light - putting these here for search terms longer than the three letters of LED to maybe help someone in the future). Looking to use a Blue LED with Forward Current: 20 mA, Forward Voltage: 3.8 V, Power Rating: 116 mW.
I'm also interested in setting up RCA outs. Searching for preamp yielded 141 posts to go through. So, I might be able to find something in there but if I could get some direct information or a link to a good way to set those up, I'd appreciate it. Thanks.
Also FYI, the amp worked on the first go. Tested it with junk and now about to test with my HD600s
Tap off the positive side of the power supply. If you have an LED google the formula for determining resistor value for LEDs. Put them in series.
So, use the +15v...like at R10 (which is open for me - I'm using the naked regulators configuration)? Or could that affect things and I need to take it from elsewhere? Thanks for the response.
Straightforward, I believe. You probably want to use a switched headphone jack. Then the RCA outputs come off that, and it turns them off when headphones are plugged in. You could also just take the RCA outs from the same place as the headphone output. Ground is common to the two channels. Then the RCAs are parallel to the headphone output.
I have the jack for it. When the headphones are plugged in it disconnects the 3 wires that would go to the back. I just thought I might need to put some other hardware in there like some resistors. Thanks.
Also, should I connect it to the same ground at the back as the input RCAs with the connection to earth and the 250v .47uf film cap?
I had tried to calculate it and it seemed like a 1k would be enough. I guess I'll see how bright it is.
Where do you think an optimal place to ground it would be?
After I built mine, there was a common suggestion to put some resistors, from 20R to 50R, or even up to 100ohm (I remember? could be wrong!) resistors after the headphone jack to raise the output impedance and avoid problems.
I did not do it. Have not seen a problem that I can tell. But if you are starting fresh, perhaps follow that advice?
Also, you can overcome the 3 letter issue by using google. Searches like this work our reasonably well:
Code:
whammy line rca output site:[url]https://www.diyaudio.com[/url]In there, you can find this post by a very reliable source!
:WHAMMY Pass DIY headphone amp guide