[Lil' Knight]

Very nice, Nate!

I wonder when the 1.2 board comes out? I'm thinking of getting one to use with my SE phones, so tempting

 

[tomb]

Great job, Nate! Glad to see everything turned out OK in the end.

 

[tomb]

Quote:

Originally Posted by Lil' Knight /img/forum/go_quote.gif Very nice, Nate! I wonder when the 1.2 board comes out? I'm thinking of getting one to use with my SE phones, so tempting

I'm afraid we waited too long and now cetoole's schoolwork is getting the way. I'm sure he'll finish it up first chance he gets.

BTW, the regular MAX will always be more flexible, but the MiniMAX makes a nicer package. Except for the flexibility of parts, the only real difference is that flexibility (1-1/2" heat sinks) will allow the regular MAX to use MOSFETs. Except for that, the MiniMAX gives up nothing and adds the cool packaging.

 

[oneplustwo]

Anyone have any suggestions for a volume knob? I just realized there wasn't one on the BOM so I'm looking for suggestions. Or is there a DIY knob I can try to make on my own? (My CMoy had a friggin' $5 knob which seems kinda ridiculous given the cost of the rest of the parts.)

 

[tomb]

Quote:

Originally Posted by oneplustwo /img/forum/go_quote.gif Anyone have any suggestions for a volume knob? I just realized there wasn't one on the BOM so I'm looking for suggestions.

Really? It's right there on the BOM under "MISC:"
"Volume Knob, e-bay Partspipe"

Originally, I had suggested the 24 x 25mm knob, but everyone seems to think the 30mm x 22mm knob used on the regular MAX looks best.

Whichever, they're usually about $9.95 for two, shipping included. I think the case deserves at least this much.

 

[GeWa]

My MiniMax board was laying here finished for quit some time now and yesterday I finally had the time (and courage) to fire it up. I first dialed in the power supply voltage and after that the tube bias, no problems so far. I than started to try to set the bias for the DB's and because my meter stayed at 0,0V, after several turns, I became a little worried. After powering down the whole thing and checking the board I came to the conclusion that I soldered my transistors in the wrong location.

Now I have to desolder them and also the heatsinks to get deicent access to the screws. I HATE THIS PART OF DIY.

Regards

 

[tomb]

Quote:

Originally Posted by GeWa /img/forum/go_quote.gif My MiniMax board was laying here finished for quit some time now and yesterday I finally had the time (and courage) to fire it up. I first dialed in the power supply voltage and after that the tube bias, no problems so far. I than started to try to set the bias for the DB's and because my meter stayed at 0,0V, after several turns, I became a little worried. After powering down the whole thing and checking the board I came to the conclusion that I soldered my transistors in the wrong location. Now I have to desolder them and also the heatsinks to get deicent access to the screws. I HATE THIS PART OF DIY. Regards

Goodness! I would try some needlenose pliers before I considered un-soldering the heat sinks. If you go back with some socket head screws, it's easy to tighten them by holding on the head sideways with some needlenose pliers.

You may find it's easier to destruct the board than it is to remove soldered-on heat sinks!

n_maher just a recent similar experience with his, and I guarantee he didn't remove the heat sinks.

 

[cetoole]

Actually, removing the heatsinks isnt too bad. I have done it a few times, on a Max once and on a M3. Of course, I cut the transistor legs first, then wiggled it out.

 

[ruZZ.il]

As Tom suggests, you probably don't need to remove those heat-sinks.

There shouldn't be too much problem getting the screws open. May be a little tricky depending on how you installed them, but I'm pretty sure you'll be able to get at it.

Once you've got those screws out, though, I suggest looping something through the transistors hole, like some wire, or string. Put a *little slack on it while you melt a large blob of solder on the solder points, and get your iron at a good angle to get contact with all 3 pads at the same time. The transistor should elegantly slide out if done right. Don't pull too tight, or you may mess up some pads.

Getting them back in is a little trickier. If you have some solder wick, or a pump, and manage to clean up the holes nicely, it'll be a breeze. Just get the transistor in the right way, screw it in nice and tight, then solder... if you cant clean the holes too well, you'll be doing a somewhat reverse process of getting them out, which.. isn't as sympathetic.

 

[pinkfloyd4ever]

Quote:

Originally Posted by ruZZ.il /img/forum/go_quote.gif Once you've got those screws out, though, I suggest looping something through the transistors hole, like some wire, or string. Put a *little slack on it while you melt a large blob of solder on the solder points, and get your iron at a good angle to get contact with all 3 pads at the same time. The transistor should elegantly slide out if done right. Don't pull too tight, or you may mess up some pads.

oooo ya a great trick!
I've heard of this before but kinda had forgotten about it. Glad it came up now, as I'm about to remove the whole buffer of one channel on a standard Max. Anyone got any adaptations of this that work well with TO-92 packages? I was thinking of looping some fishing line around twice (once on each side of the middle lead), but i dunno if the line would melt thru before I could get the the solder joints of all 3 leads melted....hmmm

 

[cetoole]

Not necessarily the right way to do things, but what I do is flood all the pins with solder so I can heat them all at the same time, then pull while heating. For the TO92 parts, I would just cut them off and replace. Removing pins one at a time is very easy, and I feel more comfortable using new parts, especially when they cost what, $0.03 each?

 

[GeWa]

Thanks for the suggestions and making it look easy. I removed the screws with a pair of needle pliers without to much problems. I never tighten those things to hard anyway. I than succeeded in removing the transistors with a good blob of solder on the tip trying to heat up the three pins at once. Bit of a hassle and a blister on my fingertip but I got them all of without ruining my board. Transistors didn't survived the surgery though!
Will leave the rest for tomorrow

Regards

 

[ruZZ.il]

Quote:

Originally Posted by pinkfloyd4ever /img/forum/go_quote.gif Anyone got any adaptations of this that work well with TO-92 packages?

Works well with just a little wire.. I use that solid core telephone wire.. have loads of it. scooby doo we used to call it, I still do.

Colin: I'd just snip them too when I have loads lying around.. any by now, I usually do

But I've been at times when I don't, and getting specific ones to here sometimes takes ages...


GeWa: Glad you're making progress. You sure they're busted ? They're pretty resilient buggers.. sometimes..

 

[tomb]

Quote:

Originally Posted by ruZZ.il /img/forum/go_quote.gif <snip> GeWa: Glad you're making progress. You sure they're busted ? They're pretty resilient buggers.. sometimes..

Agreed. Those output transistors can often survive being soldered in backwards. I'd stick them in the HFE socket of a DMM. If they register OK, then put 'em back in.

 

[aphexii]

So as it turns out, there is a local Acrylic shop very close to home who happens to stock the exact 1/16" acrylic I need for the top panel of my ET1 case.

I went ahead and converted the PDF of the custom design from the MiniMAX site into an Adobe Illustrator file for him and he's gonna work on fabbing the tops for me sometime in the next few days. He said he should be able to do all the custom vents as well.

I did have to make some slight adjustments to the file as the original top is 5.528" wide and the ET1 top needs to be 5.295" wide so it can slide into the case. I adjusted all the measurements and everything seems to be spot on.

Really exited to see how this comes out!