[BUILD] 1176LN Rev D DIY

[kato]

Looks great!

What kind of enclosure is that?

 

[Stagefright13]

It's yet another Tat Purusha case. His cases are really nice. And it is not dirty or anything. My camera makes white flakes and specs in macro mode. It's kinda old... Or maybe I should clean the lens?

It sounds REALLY sweet. Gonna use it on my next session friday doing electric guitar and vocals. And yes it does make stuff sound cool even with the gain reduction off lol.

Calibration was no problem after I went to the bottom half of the jbl manual. (to the page Mnats has on his monitor in the pic on page 1 of this thread.)

John

Thanks once again for the parts list Kato, helped alot. I like having all real nice parts in her. :thumb: :thumb:

 

[gevermil]

How are folks mounting the UTC 0-12 ?
I have some adm line amps that Im planning to use and they have 0-12s but attached to the pcb . Im going to try to use the cases but they are backward
So I gotta think of something

http://i133.photobucket.com/albums/q47/gevermil/IMGA0514.jpg

http://i133.photobucket.com/albums/q47/gevermil/IMGA0516.jpg

 

[codered]

Folks this question is for those who are using the pushbutton switches instead of the rotary switches:

Does anybody know where I can order the ITT switches used in the reissues.They are the interlocking type & I remember reading about someone using them in the builds(not rev d).Does anybody know if Purple would sell a couple?
thanks

 

[Stagefright13]

Holy crap this sounds great! Doing a session right now. Has a full up front sound. Killer on vocals! Thanks so much everyone.

Using an Eisen 512 copy into it and then 002r at 96khz. Gotta go but this thing rules!

Now I know why Andrew at Purple is worshiped for his 1176. Wish I had one of them 2.

Cya

John

 

[Bri]

Great to hear the good news, John!
Congratulations. :sam: :sam:

BTW, what did you do about R44?
Did you just leave it out, or did everything finally work out in the end.

--Brian

 

[Sleeper]

[quote author="ap123"][quote author="tommypiper"]The Purple shows 23VA.[/quote]

http://www.groupdiy.com/index.php?topic=22073&highlight=y236106

I have an avel lindberg Y236107 (30va 30+30) running two independently regulated rev d boards. This seems kind of hokey to me...but I built one rev d and decided to build a second a couple weeks later. I might convert my 2-1176 to use it as soon as someone tells me what I've done (two psu on one transformer) is a bad idea. There is an option to use trim pots for the adj legs of the regulators. The -10 is regulated by the 337.[/quote]

Hi ap... I have the same setup exactly. I wouldn't waste the time to rebuild it. if you look at the JLM power station, for example, you basically have 5 power supplies on one transformer. at the very least you have a couple of bridge rectifiers and whatever else comes after.
I'ts maybe easier to screw up your grounding, but thats about it.
Kelly

 

[Stagefright13]

I set r44 for 1k then stuck it back in and readjusted accordingly. So all trimmers are accounted for

John

 

[sleepingtiger]

I'm confused. I'm building a couple of single channel units and using the onboard power supplies and Avel Lindberg torroid's that are 30VA, 30-0-30. After building up the supplies on both boards I'm getting -9.75 and +24.5. Upon troubleshooting I realize that both Mnats and Kato's parts lists and the Mnats schematic call for a +24v regulator (I'm using the Fairchild regulator linked from Kato's list). To me, this explains why my + voltage is low but I'm reading through this thread and noticing that others are getting a correct voltage. Are you guys using adjustable regulators? Is this an oversight on the partslists and the schematic? Is there something that I'm missing here? Should I actually be seeing +30 with the regulators I'm currently using?

 

[mnats]

[quote author="sleepingtiger"]I'm confused...After building up the supplies on both boards I'm getting -9.75 and +24.5. Upon troubleshooting I realize that both Mnats and Kato's parts lists and the Mnats schematic call for a +24v regulator (I'm using the Fairchild regulator linked from Kato's list). To me, this explains why my + voltage is low but I'm reading through this thread and noticing that others are getting a correct voltage...Is there something that I'm missing here?[/quote]
Take a look at this schematic fragment (drawn right to left like the original power supply schematic):

The common or ground connection of the 7824 regulator does not connect to the ground directly, but sits between a voltage divider composed of R87 and R89. The regulator dutifully puts out 24 volts across R87, but as the ratio between the top and bottom resistor is 80%/20%, the remaining voltage goes across the bottom resistor.

I'm sure someone else can explain it better, but yes - you should get 30V from this arrangement. If not, there is something wrong. Check the usual things, covered many times in the big 1176 thread and elsewhere...

 

[sleepingtiger]

Thanks Mako, I appreciate your reply.

It was a dumb mistake on my part. I was trying to use some resistors I had lying around and on the package "22OHMS" looked a lot like "220Ohms", so I had 22 ohm resistors in there. The embarassing but funny thing about it is that I even measured them before I placed them in there. I suppose this shows that sometimes I see what I want to see rather than seeing what's really there...

Okay, another question for Mako or anyone who might know. On one of the boards, when desoldering the regulator to get to the resistor in question I lifted the two outside solder pads on the components side of the board. Have I ruined this board? The pads on the other side are intact so I could solder the regulator back in place but I don't know if losing the top pads will cause a short. I don't know enough about reading the diagrams of the pcb to figure this out.

Thanks again!

 

[josh]

[quote author="sleepingtiger"]
Okay, another question for Mako or anyone who might know. On one of the boards, when desoldering the regulator to get to the resistor in question I lifted the two outside solder pads on the components side of the board. Have I ruined this board? The pads on the other side are intact so I could solder the regulator back in place but I don't know if losing the top pads will cause a short. I don't know enough about reading the diagrams of the pcb to figure this out.
Thanks again![/quote]

I've done that many times and jumpering a wire to the next position on down the trace usually works just fine.

 

[dissonantstring]

hi sleeping tiger,
if you indeed only lifted the top pads for the +v-reg. then you are o.k. because they do not connect to anything. if you reference mnats top layer (ground plane side) image in his DIY Rev.D document you will see that they do not connect to anything. ohm out the pads to the traces connected to the v-reg. legs on the trace side to make sure that they are still o.k.

BTW, i just finished soldering all my components to my Rev.D board and ran a test. no smoke, but the 7824 gets pretty hot even with a heatsink (i'll probably add a larger one or possibly run leads and mount it to the chassis).
also the 2N3053 gets screaming hot. i bought a larger heatsink for it as well, but i'm wondering how normal this is? i've read a few posts about them running hot, but this seems like the life of these components will be significantly shortened running this way.

cheers,
grant

 

[wmb]

I'm about to start stuffing these boards over the weekend and I have a question. Is there any particular order compnonent-wise that I should follow? I've not built anything from the qround up that used as many transistors. Usually I have always dealt with them last but it looks like it could get tight in a few places.

I usually start with the smallest components and work my way up to the larger ones. This generally means resistors, caps, transistors, connectors, pots, transformers, case in that order.

It there any reason I should wait and install any board components as a final step?

Cheers, Wm.

 

[mnats]

Grant - looking at the data sheet the operating temperature of the 2N3053 is -65 - 200°C. With the heatsink that I used (the one on Kato's list, I believe) I measured 50°C after the unit had been on for an hour or so.

If you fooled around in the days of germanium the idea of 200°C is scary, but at my job we rework SMDs at 300°C+ and still have functioning boards!
[quote author="wmb"]It there any reason I should wait and install any board components as a final step? [/quote]
Only if you want to calibrate your meter circuit. Have you read the Rev D page?

 

[dissonantstring]

[quote author="mnats"]Grant - looking at the data sheet the operating temperature of the 2N3053 is -65 - 200°C. With the heatsink that I used (the one on Kato's list, I believe) I measured 50°C after the unit had been on for an hour or so. [/quote]
thanks that gives me a baseline to measure the temp on the 2N3053 and i do need a better heatsink. i did see that they are rated up to 200°C, but i get nervous sometimes. thanks for the confirmation.

[quote author="mnats"]If you fooled around in the days of germanium the idea of 200°C is scary, but at my job we rework SMDs at 300°C+ and still have functioning boards![/quote]

+300°C! :shock:

thanks for the info mako, much appreciated! :thumb:

 

[sleepingtiger]

Thanks, disonantstring (and everyone else). That's what I thought that I was seeing but I wasn't confident that I was perceiving correctly. I checked continuity and it looks like everything is in order...

 

[wmb]

[quote author="mnats"]
[quote author="wmb"]It there any reason I should wait and install any board components as a final step? [/quote]
Only if you want to calibrate your meter circuit. Have you read the Rev D page?[/quote]

Yeah, I have read the rev D page. Mentally I was excepting those components. I was mostly wondering if I should hold off on the transistors so they don't get damaged or something. Looks like I can just start building it.

Cheers, Wm.

 

[Stagefright13]

Yeah WMB just build her up :thumb:

Just watch the voltage regulator and 3053 bend easily just looking at them the wrong way. LOL So handle the board carefully when installing it and all. And GL is a great diy project!

P.S. And don't forget to test all the transistors and match the required ones.

John

 

[Stagefright13]

Other tips would be keep R87 off the board a bit so it has better cooling underneath. And bend the pins of the voltage regulator slightly forward. (Away from C25) So your heatsink doesn't touch C25. And put the screw in from the back of the heatsink. So the actual threads face forward. Away from C25. And is always good to use a thin coating of heat sink paste or Artic Silver when mounting heatsinks. And cut a 6 pin dip socket like Aaron suggested to mount R44 trimmer. It just makes it so easy to calibrate. Umm all I can think of...

And the heatsink for the 3053 that Kato has listed seems to work fine. It may feel hot but is WAY under spec as noted earlier. Have Fun!

John