You can save some more if you leave out the infilling. Depending in the color choosen it may or may not look good to you? Mine is Blue and the engraving being raw aluminum looks really nice.
The back is easy to do.....I took some paint and put it on the power connector slid it into the case with the back panel screwed on and it leaves a nice mark where to drill, cut, nibble, file the square hole.
Alex
The back is easy to do.....I took some paint and put it on the power connector slid it into the case with the back panel screwed on and it leaves a nice mark where to drill, cut, nibble, file the square hole.
Alex
Thanks for the tips! Mine is blue as well and going for the no-fill option. Got it down to $35.10 before shipping (pretty much just copied yours 😀 Removed the delay text and put agdr's name in the title rather than a subscript under the title.)
For the back I was going to drill the corners of the square and then use my dremel to cut between the holes. Hoping the metal cutting bit will be strong enough. Definitely going to take my time, and lubricate the bit to ease cutting. I have a stepped hole cutter for RCAs and heat sink bolt holes. The usb will be a little tough, but I have no way to cut the 0.2mm deep hole in the lower left corner. Probably just going to grind off some of the paint around the hole instead.
Oops! 😛 My screw-up there. Those temporary heat sinks for the ODA are the same thing. Hey please check that I sent the nylon bolts and nuts for mounting the ODAC.
Your power rail voltages look great. Sorting through the bunch of 1.5 meg resistors for that 0.2% paid off! That is a good alternative on the V3.6 boards for anyone building these up. At just 15 cents each buy a bunch of 1% 1.5 megs and measure through them to find the one with the best tolerance.
The extra 0.3V is there just because I could. Going through the numbers, even with a lowest expected power line voltage and full load there was still 0.3V of usable input voltage from the 16Vac xformer that I didn't want to leave on the table. Since I was using adjustable regulators, I figured why not.
Alex has the self-drilling and marking technique all figured out. 🙂 I'm impressed with the results.
Well...I just killed my back panel.... going to have to buy another enclosure just to get another panel and send off to FPE. Instead of saving $30, I just cost myself an extra $20 😡
My square hole ended up not so square, and then i managed to put my 2 heat sink holes about 3mm to the right of where they should be... I just give up...should have never even started the heat sink holes after my power connection hole was so horrible.
One of my favorite quotes: "Man's got to know his limitations" and I certainly didn't.
My square hole ended up not so square, and then i managed to put my 2 heat sink holes about 3mm to the right of where they should be... I just give up...should have never even started the heat sink holes after my power connection hole was so horrible.
One of my favorite quotes: "Man's got to know his limitations" and I certainly didn't.
Enough bad news on my progress, now some good: it works and sounds good on my crappy test headphones.
My DMM can only read as low as 0.1 mV and both channels have 0.0 mV of DC output 😀 so that's pretty awesome! I had to adjust trimmer resistors to get that on my ODA. Also voltages held steady with the jumpers in-place, +15.34 and -15.30 VDC. The only "unusual" behavior I notice is that the clipping indicator flashes really quickly during both turn on and turn off. Not a problem exactly, but is this normal?
Going to send off panels to FPE once i get my other case, so there's going to be a large delay before I can really compare it to the ODA. Will definitely post some subjective results in the future.
Oh, and here's a photo of the amp with all the parts soldered on and running.
My DMM can only read as low as 0.1 mV and both channels have 0.0 mV of DC output 😀 so that's pretty awesome! I had to adjust trimmer resistors to get that on my ODA. Also voltages held steady with the jumpers in-place, +15.34 and -15.30 VDC. The only "unusual" behavior I notice is that the clipping indicator flashes really quickly during both turn on and turn off. Not a problem exactly, but is this normal?
Going to send off panels to FPE once i get my other case, so there's going to be a large delay before I can really compare it to the ODA. Will definitely post some subjective results in the future.
Oh, and here's a photo of the amp with all the parts soldered on and running.
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4x4F150 - looks good! 😀 That clipping indicator flashing is normal. I decided to call that a feature rather than a bug. It gives indication all is OK with the clip led and circuit. 🙂
Congrats on the build!! Sorry about the case, If we were close I would drill out the back panel for you!
I have the same clip light coming on when powering up etc....like AGDR says its a "feature"! Ha!!
I have never seen the clip light come on playing songs....with any gain setting....on the ODA and O2 I do see clipping if playing hot songs with high gain...must be this amp with its higher rails is helping.
I am very interested in your comments on comparing to the ODA and O2 I have posted mine.
Enjoy!
Alex and thanks AGDR for the new toy!
I have the same clip light coming on when powering up etc....like AGDR says its a "feature"! Ha!!
I have never seen the clip light come on playing songs....with any gain setting....on the ODA and O2 I do see clipping if playing hot songs with high gain...must be this amp with its higher rails is helping.
I am very interested in your comments on comparing to the ODA and O2 I have posted mine.
Enjoy!
Alex and thanks AGDR for the new toy!
Hey Alex!
You are right, the clipping LED not coming on much while running is a combination of the higher +/-15.3Vdc power rails in the inverting O2 and the lower maximum (default) voltage gain of 2.5x. With the ODA the rails in the standard build are the +/-12Vdc and the high gain position is 6x. Much easier to clip.
On NwAvGuy's O2 headamp there is the problem of switching to batteries from AC. The rails suddenly drop from +/-11.8vdc to +/-8Vdc or worse! Signals that were doing fine and not clipping on AC suddenly can start clipping on the lower battery power rails. Probably another reason the O2 gets a bad rap from time to time. People hear distortion suddenly occuring like this and don't know why.
That is why I use a window comparator that stays a certain voltage difference away from the power rails. On batteries (the Inverting O2 was originally going to have batteries of course) that clipping detect circuit will "track" the voltage rails right on down as the batteries drain and still work correctly.
Lol - typing this has been difficult because a cat tail keeps whacking the keyboard and I have to keep moving it aside. 😛
You are right, the clipping LED not coming on much while running is a combination of the higher +/-15.3Vdc power rails in the inverting O2 and the lower maximum (default) voltage gain of 2.5x. With the ODA the rails in the standard build are the +/-12Vdc and the high gain position is 6x. Much easier to clip.
On NwAvGuy's O2 headamp there is the problem of switching to batteries from AC. The rails suddenly drop from +/-11.8vdc to +/-8Vdc or worse! Signals that were doing fine and not clipping on AC suddenly can start clipping on the lower battery power rails. Probably another reason the O2 gets a bad rap from time to time. People hear distortion suddenly occuring like this and don't know why.
That is why I use a window comparator that stays a certain voltage difference away from the power rails. On batteries (the Inverting O2 was originally going to have batteries of course) that clipping detect circuit will "track" the voltage rails right on down as the batteries drain and still work correctly.
Lol - typing this has been difficult because a cat tail keeps whacking the keyboard and I have to keep moving it aside. 😛
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Received my panels from FPE yesterday and they look great!
But now I have to buy my 3rd case for this amp 😡
The screws heads broke off again while trying to tighten the back panel to the case. (This happened to me when building my ODA) And this time I even used MoM as an anti-seize. 2 screws broke off in a row, so I threw the case on the floor and stepped on it (see pic below). I made sure to remove the amp before crushing this POS case so the only thing damaged was a case that was already useless.
agdr, maybe you should start designing boards for cases from a different company??????? Or maybe we just need to find alternate hardware and just throw away what come with it???
And trust me, I'm not done tearing up this case yet; my next trip out to my uncle's farm, this thing is gonna be a target for my 308 rifle.
But now I have to buy my 3rd case for this amp 😡
The screws heads broke off again while trying to tighten the back panel to the case. (This happened to me when building my ODA) And this time I even used MoM as an anti-seize. 2 screws broke off in a row, so I threw the case on the floor and stepped on it (see pic below). I made sure to remove the amp before crushing this POS case so the only thing damaged was a case that was already useless.
agdr, maybe you should start designing boards for cases from a different company??????? Or maybe we just need to find alternate hardware and just throw away what come with it???
And trust me, I'm not done tearing up this case yet; my next trip out to my uncle's farm, this thing is gonna be a target for my 308 rifle.
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Suggestion: send that photo to Box Enclosure's customer service! In fact I have an email address to send it to. 😀 It looks like they are not tempering their screws enough. I'm guessing case hardened rather than all the way through. I'll see if I can come up with screws from an alternate source.
Hey don't order that 3rd case yet! 🙂 I'm going to send you a pm.
That or use self-drilling screws. It's odd that there isn't a full boss for the threads but I guess that's what you get at that price level.
4x4F150 - I've ordered a bunch of similar M3 x 0.5 x 10mm torx-head thread-forming screws. I can't get eBay to produce a useable link, but search there for "M3 x 0.5 x 10 Taptite Thread-Forming Screws by Camcar, Black". I'll send you a set for your box when they arrive. 🙂
Hopefully these are better than what Box Enclosures is shipping. The listing says they are hardened to Rockwell C 33-39 range, which according to this
www.ea-products.com/files/tensilechart1.pdf (opens PDF)
is equivalent to a grade 8 bolt. From my experience with grade 8 that should be more than enough to be twist-off proof, if the seller's claim is really true. 🙂
Based on comparing the pictures, I'm fairly sure these are not the same bolts that Box Enclosures is using. The Box bolts have rounded heads while these are angled a bit. The finish on the Box screws looks shiny, like paint! These claim to have a black chromate finish and what I'm seeing in the photo backs that up. Not shiny.
The suggestion of using the tap is a good idea too! I would say that is the ultimate solution.
Hopefully these are better than what Box Enclosures is shipping. The listing says they are hardened to Rockwell C 33-39 range, which according to this
www.ea-products.com/files/tensilechart1.pdf (opens PDF)
is equivalent to a grade 8 bolt. From my experience with grade 8 that should be more than enough to be twist-off proof, if the seller's claim is really true. 🙂
Based on comparing the pictures, I'm fairly sure these are not the same bolts that Box Enclosures is using. The Box bolts have rounded heads while these are angled a bit. The finish on the Box screws looks shiny, like paint! These claim to have a black chromate finish and what I'm seeing in the photo backs that up. Not shiny.
The suggestion of using the tap is a good idea too! I would say that is the ultimate solution.
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Agreed, investing in a tap and die set that includes the relevant (M3 x 0.5) size for this project will be money well spent... this will likely not be the only manufacturer/vendor issue of this king that you'll run across, and when the day eventually comes that the "custom" bug really bites you, you'll have tools in hand to get you started.
One cannot have too many tools, headphones, adapters, or rolls of solder... (or so I've been told ...cough, cough, cough...)
One cannot have too many tools, headphones, adapters, or rolls of solder... (or so I've been told ...cough, cough, cough...)
OMG - I have to hire a medium to find where I stashed away my non-inverting board;(
To many projects in every corner...
Regards
To many projects in every corner...
Regards
Good screw
Funny title right?... I have been having trouble with screws breaking and finally got a set that works...get it? (I have the mind of a 12 year old lol)
Anyways, I got my inverting O2 amp assembled with new screws that don't break when making the threads in the enclosure. After contacting box enclosures (the company the makes the enclosure for this build), they admitted to having several complaints about the screws that come with the unit. They shipped me 2 new enclosures since this was the 2nd time that I had screws break off in the enclosure before tightening on the front and back plates.
The company says that they have fixed the problem and now include screws that are not only shorter, but smaller in shaft diameter. (I took a pic of the new vs old). And since I had a backup enclosure because they sent 2, I tried the ones that came with the enclosure before using the super tough ones that agdr sent me. If the new version screws failed, I would have used the agdr set which I have 0 doubt that they would fail. But since the included screws worked with no issues, I think it is safe to say that anyone buying an enclosure in the future will not have this problem.
I will be taking my sweet time comparing my inverting O2 to my ODA over this long weekend and will post my subjective results (dont expect any measurements from me...lol) I might also compare it to my regular O2 amp with agdr booster board but that amp is my work amp so I would have to remember to bring it home one day next week. I'm guessing that the inverting version might become my new work unit.
Till then,
Cheers!
Funny title right?... I have been having trouble with screws breaking and finally got a set that works...get it? (I have the mind of a 12 year old lol)
Anyways, I got my inverting O2 amp assembled with new screws that don't break when making the threads in the enclosure. After contacting box enclosures (the company the makes the enclosure for this build), they admitted to having several complaints about the screws that come with the unit. They shipped me 2 new enclosures since this was the 2nd time that I had screws break off in the enclosure before tightening on the front and back plates.
The company says that they have fixed the problem and now include screws that are not only shorter, but smaller in shaft diameter. (I took a pic of the new vs old). And since I had a backup enclosure because they sent 2, I tried the ones that came with the enclosure before using the super tough ones that agdr sent me. If the new version screws failed, I would have used the agdr set which I have 0 doubt that they would fail. But since the included screws worked with no issues, I think it is safe to say that anyone buying an enclosure in the future will not have this problem.
I will be taking my sweet time comparing my inverting O2 to my ODA over this long weekend and will post my subjective results (dont expect any measurements from me...lol) I might also compare it to my regular O2 amp with agdr booster board but that amp is my work amp so I would have to remember to bring it home one day next week. I'm guessing that the inverting version might become my new work unit.
Till then,
Cheers!
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4x4F150 - Interesting about Box Enclosures changing screws! I would say it is about time. At least they are 'fessing up to the design mistake. Sounds like maybe they have gone to 2.5mm diameter from the 3mm. Yeah those screws didn't need to be so long, shortening them is another good change. It was only during the last 3 or 4 turns when they would gall and seize up anyway it seemed. You efforts here are going to help a *lot* of folks. I'll bet a bunch of people building O2 headamps have had broken off screws over the years.
Well I'm glad you finally are all screwed together. 😀 Please do post some listening results!
Well I'm glad you finally are all screwed together. 😀 Please do post some listening results!
Ok, been listening to the new amp all weekend and I do think you would be able to tell the difference between this amp and the ODA with a blind test. But before I post my listening impressions, I am having trouble with the clipping circuit.
The clipping light will come on even when there is nothing plugged into the amp other than the power cord. Now it always flashed right when you turn it on, but it goes off and stays off for some time. After about 5 min (haven't timed it exactly), the clipping light starts to come on really gradually. Eventually going to bight red and stays on until I turn the amp off. Turing it back on will repeat the process.
The only reason even ran the amp with no source is that the light was coming on during my listening tests, but I couldn't hear any clipping, so I think the amp is fine, just the clipping circuit is giving a false positive. I double checked my photos from a few posts back and I have D7 and D8 backwards (according to the board) which is correct (according to the instructions). Anyone have any idea on the problem before I open this thing back up and start troubleshooting?
The clipping light will come on even when there is nothing plugged into the amp other than the power cord. Now it always flashed right when you turn it on, but it goes off and stays off for some time. After about 5 min (haven't timed it exactly), the clipping light starts to come on really gradually. Eventually going to bight red and stays on until I turn the amp off. Turing it back on will repeat the process.
The only reason even ran the amp with no source is that the light was coming on during my listening tests, but I couldn't hear any clipping, so I think the amp is fine, just the clipping circuit is giving a false positive. I double checked my photos from a few posts back and I have D7 and D8 backwards (according to the board) which is correct (according to the instructions). Anyone have any idea on the problem before I open this thing back up and start troubleshooting?
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