Members Blitzen Posted April 30, 2009 Members Share Posted April 30, 2009 OK, I've finally got a start on this build. Here's the progress so far; check my work please: Link to comment Share on other sites More sharing options...
Members Bluescout Posted April 30, 2009 Members Share Posted April 30, 2009 Yowzers, that's kinda sexy!!! Build 2 and send me one!!!! Link to comment Share on other sites More sharing options...
Members Guttermouth Posted April 30, 2009 Members Share Posted April 30, 2009 looking good so far man Link to comment Share on other sites More sharing options...
Members bassman1956 Posted April 30, 2009 Members Share Posted April 30, 2009 :phil: Link to comment Share on other sites More sharing options...
Members Blitzen Posted May 3, 2009 Author Members Share Posted May 3, 2009 Here's the latest pics. I wired up the heaters. First experience with cloth-covered wiring; even though I have plenty of multi-colored 600v wire, it seems a shame to not use this stuff at least to try: An "action picture" of the chassis cradle I built: Soldered board pictures: A couple things: I'm a little unsure about the orientation of output transformer- GM, your instructions first say to put the brown, blue, red wires through the hole closest the sockets. Then later you show it the other way...? Those capacitor clamp/mounts are a PITA... I formed them around a big (wrench) socket and used a longer screw; then the mounting tab holes didn't line up with the pre-drilled chassis holes. A little more creative bending of the tabs was needed- I kind of bent them down and then back up so the were effectively shorter; still the whole business wasn't easy and those cans are mounted really tightly once I tightened the whole business down. The verdict is yet to come out on the cloth vs. plastic insulation wire. I guess I'd really like to use the colored stuff 'cause it's purty, but don't know what the "right" colors are to use where... What are you guys using to get good pics? Lighting it right seems to be the key; I'm not getting it yet. Link to comment Share on other sites More sharing options...
Members Guttermouth Posted May 3, 2009 Members Share Posted May 3, 2009 A couple things: I'm a little unsure about the orientation of output transformer- GM, your instructions first say to put the brown, blue, red wires through the hole closest the sockets. Then later you show it the other way...? sorry man - i went back and rethought the output orientation due to the position of the bias pot. i must have skipped a step somewhere - i just went back and edited the original post to reflect the changes. sorry for the confusion. Link to comment Share on other sites More sharing options...
Moderators Kindness Posted May 3, 2009 Moderators Share Posted May 3, 2009 What are you guys using to get good pics? Lighting it right seems to be the key; I'm not getting it yet. Lighting is key. If you can't get good pics in your workspace, you need better lighting not just for the pics, but also for your own eyes. Get a work table/desk lamp and improve your work space. Link to comment Share on other sites More sharing options...
Members Blitzen Posted May 3, 2009 Author Members Share Posted May 3, 2009 Lighting is key. If you can't get good pics in your workspace, you need better lighting not just for the pics, but also for your own eyes. Get a work table/desk lamp and improve your work space. Well, I do have an 8' double-lamp fluorescent directly over the bench, and a 300-watt incandescent behind me. Plus I use an Optivisor to get in close...I can see fine, but apparently my camera doesn't like the light. It either flashes and glares off everything, or it just doesn't look right. I put a 500-watt halogenon for some of these pictures, and it still doesn't look right. Maybe I need to RTFM of the camera's! Link to comment Share on other sites More sharing options...
Members Blitzen Posted May 6, 2009 Author Members Share Posted May 6, 2009 I did a lot of work over the weekend; here's some shots before I started more work today: I decided to do the "deluxe" can cap mount version because I have a Greenlee 1-1/8" chassis punch. GM, you might want to mention at the point in the instructions where you mount the can caps about this later version; I mentioned earlier what a bitch it was to mount them to begin with. More importantly, tonight I got to the point where I would start wiring the preamp sockets and there are the instructions about the best way to wire it by running wires from the board underside. At this point I can't do this, because I've already run the signal wires to the power tubes on the top side of the board. So to do it "right" I'll need to desolder (cut through the heatshrink first) at least the wire going to v4. I don't know how Pickdust did this- it looks like he did it in order, too...he had to have caught this earlier...? Time to start desoldering:rolleyes: Link to comment Share on other sites More sharing options...
Moderators Kindness Posted May 6, 2009 Moderators Share Posted May 6, 2009 I don't know how Pickdust did this- it looks like he did it in order, too...he had to have caught this earlier...? Time to start desoldering:rolleyes: I need to start on mine this weekend so I can give an alternate process. I couldn't do it in the order GM did. Link to comment Share on other sites More sharing options...
Members Blitzen Posted May 6, 2009 Author Members Share Posted May 6, 2009 I need to start on mine this weekend so I can give an alternate process. I couldn't do it in the order GM did. I was originally going to wait to start mine after yours, so I could get an alternate version, but then I got antsy and had to get going on it. My wife is blowing down the house with the amp I BUILT FOR HER FIRST. Link to comment Share on other sites More sharing options...
Moderators Kindness Posted May 6, 2009 Moderators Share Posted May 6, 2009 So the good news is you know you can do it. I'm sure you'll do just fine with GM's instructions. They will be more complete than mine. I expect mine will be mostly alternate steps and big picture stuff. The connections will all be the same. I wish I had gotten an earlier jump, but I'm in month one of my new business and startups take a lot of work to get rolling. Link to comment Share on other sites More sharing options...
Members Pickdust Posted May 6, 2009 Members Share Posted May 6, 2009 I did a lot of work over the weekend; here's some shots before I started more work today: I decided to do the "deluxe" can cap mount version because I have a Greenlee 1-1/8" chassis punch. GM, you might want to mention at the point in the instructions where you mount the can caps about this later version; I mentioned earlier what a bitch it was to mount them to begin with. More importantly, tonight I got to the point where I would start wiring the preamp sockets and there are the instructions about the best way to wire it by running wires from the board underside. At this point I can't do this, because I've already run the signal wires to the power tubes on the top side of the board. So to do it "right" I'll need to desolder (cut through the heatshrink first) at least the wire going to v4. I don't know how Pickdust did this- it looks like he did it in order, too...he had to have caught this earlier...? Time to start desoldering:rolleyes: Nope! Didn't catch this earlier. My first reaction was how the hell am I going to to fix this! I actually de-soldered the leads to the power tube pins 6 (I originally used electrical tape) got some heat shrink and re-soldered them after I did the under board leads. My next one will include all the underboard leads first to avoid the multiple board de-installs. Absolutely nothing against Guttermouth's instructions. If I hadn't been so anxious I would have spotted all this up front....but NOOOooooooooo! Link to comment Share on other sites More sharing options...
Members Guttermouth Posted May 6, 2009 Members Share Posted May 6, 2009 Nope! Didn't catch this earlier. My first reaction was how the hell am I going to to fix this! I actually de-soldered the leads to the power tube pins 6 (I originally used electrical tape) got some heat shrink and re-soldered them after I did the under board leads. My next one will include all the underboard leads first to avoid the multiple board de-installs. Absolutely nothing against Guttermouth's instructions. If I hadn't been so anxious I would have spotted all this up front....but NOOOooooooooo! sorry about that man. i forgot about you guys doing your phase inverter leads over the board. Link to comment Share on other sites More sharing options...
Members Blitzen Posted May 8, 2009 Author Members Share Posted May 8, 2009 I finished soldering last night. OK, I know GM wants me to "wait a couple days"; ain't gonna happen! So, tonight it's getting power. Here's the sequence of events: First, a power tube doesn't light up on initial turn-on. I check for heater voltages, OK. Switch the power tubes, now they're both coming on. OK!? Flip the standby, no smoke. GM, there should be something in these instructions before this point about always having speakers plugged in...yes I had them plugged in. I'm checking voltages when I hear a hum start developing. I take a look at the tubes, and one's starting to red plate! Click, off it goes. OK, at least I have some idea about voltages in there now- I look up what the bias is supposed to be, and come up with about 37ma (w/ 420 plate volts). Flip it back on again and check bias- eek, like 20-something! Turned up (down?) all the way, I'm on 33ma... What now? Link to comment Share on other sites More sharing options...
Moderators Kindness Posted May 8, 2009 Moderators Share Posted May 8, 2009 I'd check the components and voltages along the bias circuit. You should be able to get it above 33 ma. I'll pull up the schematics in a bit and see what it looks like. Link to comment Share on other sites More sharing options...
Members Guttermouth Posted May 8, 2009 Members Share Posted May 8, 2009 GM, there should be something in these instructions before this point about always having speakers plugged in... actually, no there shouldn't.you don't need speakers plugged in untill you start running signal through it. Link to comment Share on other sites More sharing options...
Members Blitzen Posted May 8, 2009 Author Members Share Posted May 8, 2009 OK, the grid resistor values are different- one is 5.64 and the other is 5.88. Both higher than specified 5.1. I don't know exactly what they were when I put them in, but I know they were closer than that. Could this be the problem? These are the resistors I had to unsolder to get at the bottom of the board. So they've had heat put to them 4 times- apparently the value has drifted? Link to comment Share on other sites More sharing options...
Members Guttermouth Posted May 8, 2009 Members Share Posted May 8, 2009 I'm checking voltages when I hear a hum start developing. I take a look at the tubes, and one's starting to red plate! Click, off it goes. OK, at least I have some idea about voltages in there now- I look up what the bias is supposed to be, and come up with about 37ma (w/ 420 plate volts). Flip it back on again and check bias- eek, like 20-something! Turned up (down?) all the way, I'm on 33ma... What now? if you've got high voltage and bias on your tubes you can swap out the 47k bias range resistor attached to the bias pot to get more or less voltage. chances are though, with all your other issues - you've got something wired incorrectly or a bad tube. can you post a couple of close up pics of the finished amp? Link to comment Share on other sites More sharing options...
Members Guttermouth Posted May 8, 2009 Members Share Posted May 8, 2009 OK, the grid resistor values are different- one is 5.64 and the other is 5.88. Both higher than specified 5.1. I don't know exactly what they were when I put them in, but I know they were closer than that. Could this be the problem? These are the resistors I had to unsolder to get at the bottom of the board. So they've had heat put to them 4 times- apparently the value has drifted? you probably have a bum tube or short somewhere that is pulling waaay too much current. Link to comment Share on other sites More sharing options...
Moderators Kindness Posted May 8, 2009 Moderators Share Posted May 8, 2009 OK, the grid resistor values are different- one is 5.64 and the other is 5.88. Both higher than specified 5.1. Those aren't bad values. Certainly within the 20% tolerances. Link to comment Share on other sites More sharing options...
Members Blitzen Posted May 8, 2009 Author Members Share Posted May 8, 2009 can you post a couple of close up pics of the finished amp? Will do, but it's going to have to be tomorrow at this point... Link to comment Share on other sites More sharing options...
Members Blitzen Posted May 8, 2009 Author Members Share Posted May 8, 2009 you probably have a bum tube or short somewhere that is pulling waaay too much current. I've got another tube set. I'll post pictures first tomorrow before I go that route. Link to comment Share on other sites More sharing options...
Members sub5ound Posted May 8, 2009 Members Share Posted May 8, 2009 Who built your chassis? Link to comment Share on other sites More sharing options...
Members Blitzen Posted May 12, 2009 Author Members Share Posted May 12, 2009 Just to let anyone know...I came home early Friday to (at least in part) work on the amp. At 1:20pm, we had the storm of the century hit here. 100mph straight-line winds came through and dropped trees all over the place. One fell on our van parked in the driveway... Power still hasn't been restored to most of the city, and needless to say I'm not doing any amplifier work. mostly I've been using a chainsaw f or the last 3 days! I'm here at my workplace this morning; they got power back yesterday. Link to comment Share on other sites More sharing options...
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