[BUILD] 1176LN Rev D DIY

[pH]

OK, now that makes sense. Thanks fellas.

BTW, thanks Ed, Mnats and everyone else involved in this project. I'm so excited to have a piece of gear this fine.

 

[sysexguy]

John, thanks ever so much, the build continues!!!!

Andy

 

[Stagefright13]

No problem Andy. Enjoy your build!

 

[tommypiper]

Hi guys, I've been away a long time due to family comittments... I'm trying to catch up with my build.

Is it possible your backwards ratios are from soldering to the wrong side of the ratio board? Which side did you put the switch on? The silk screened or the other?

I read MNat's explanation about the R-Opti1 trimmer on the ratio board. And I see the "invisible" writing on the back to cut the link... but does this give a higher or lower threshold? Is it then set to higher or lower? I totally do not get this.

I'm also confused about the meter board and switch. How do I wire this with a toggle instead? I mean, what is the Y and X? Do they attach to something?

 

[CJ]

Todd, go back to your corner.
Did I say you could come out?
Remeber, no LA2, no Freedom.
You have it built then right?
:razz:

Ok jus chill, already.
How is the elbow grease box doing?

I still say that avatar looks like Bolin on Private Eyes.

 

[tommypiper]

Thanks for the encouragement.

I have no idea who Bolin is or who Private Eyes is, or what. I don't even know who your avatar is. (Mine is a potrait of me from 1783.)

Yeah, maybe the LA2 would be easier. I'm feeling a little lost at the moment overall.

 

[Stagefright13]

CJ's Avatar looks like Lemmie from Motorhead but I could be wrong lol...

 

[okgb]

Tommy Bolin , made a mark on the rock world [ only a footnote ? ]in the 70s
Spectrum with Billy cobham was a good moment from him as well as his first two releases ,
one of the early guys to Jam with Jan , not a superstar
i'd say but he had his own vibe which is more than most can claim these days , also played with deep purple for a stint but already too smacked up by then . [ oh that sexy second cover with the oriental girl ]

Nice work on the 1176s , this thread will help when i finally get to mine

 

[tommypiper]

I'm hopelessly out of the loop in more ways than one. I have heard of Billy Cobham, the rest is over my head. I must be too young, or too old, or both. :grin:

Back to topic, what is the function of the meter switch? I know the original push-buttons show GR, output, +4, -10... But the schematic shows only a two position switch. So what functions is the switch?

 

[CJ]

hey, a rare video, chk it:

http://www.tbolin.com/audiovideo/index.html

more on youtube:

http://www.youtube.com/watch?v=Squ4C6919aY

Todd, don't sweat it.
We will build an LA2 in one day, just to show these punks whats up.
cj

 

[tommypiper]

CJ, I was just watching yer Tommy B and the earth shook. Man. I guess he made the earth move. My avatar does look like him and my handle namesake as well, well, cosmic. Or earth shaking, anyway. I hit him up on the video.

Thanks for not taking the piss out of me again. I haven't given up on the LA2, it's gonna happen. In fact, I was going to buy some parts from you but you never replied to my emails, so I gave up. What's up with that? You living in a tree house with free WiFi now?

Don't wanna waste two much bandwidth here off topic. Has anyone built this 1176 with a meter switch toggle, GR and output? What resistors in the schematic do I include, if any? What is the schematic showing the switch doing, anyway? I can't figure out the circuit by reading the schem, I'm an illiterate musician. I know it's only a click away.. ha ha.. heard that one before. But, duh, I dunno where to click. Already clicked all over. As usual, I'm missing something. Over and out.

The earth did move. The winders rattled. The foundation shimmied. I'm going nuts. DIY is my undoing.

 

[Stagefright13]

I built one with pushbuttons. I used the Purple schematic to wire them.

http://www.purpleaudio.com/pdflib/PurpleMC77v34.pdf

I also used the original schematic from the JBL pro site.

http://www.jblproservice.com/pdf/Vintage JBL-UREI Electronics/UREI-1176LNmanual.pdf

 

[CJ]

actually, that video was crap, i didnt even watch it, he looked junked out.

hereis a studio track no video, kind of cool
i have orig 5532/34 Siemens, "the kind" opamps, gotta builsd a 1176 also.

http://www.youtube.com/watch?v=jqKZEoY1rgU

 

[tommypiper]

Thanks, John. I know, those related docs are even more confusing to me. I see the X and Y points in the Urei schem, but I don't know where they go and I don't know what they're doing on our project. The Purple schem is even wilder. What I don't get is why Mnat's schem has all those poles showing and what do they do? When the meter board is 4 pole, but the schem shows 6 poles, two position. So maybe he is only switching some of them at some of the time. Seems to me the GR works by reversing the voltage polarity to the meter. But why is it so complated with all the poles? I'm lost about what all those poles and the whole network is about. The Purple is even introducing a meter buffer, so apparently the meter amp is not buffered from the audio? Huh?

 

[Stagefright13]

I'll get back to you shortly but I am sure I can help you. Passing out Halloween candy right now.

How many positions on your switch? 4? Then you would use GR, +8, +4, and off. This is for the gain reduction switch. Correct? THAT I can help with just tell me what you want exactly. I did the pushbuttons point to point.

You can also rig an all buttons IN with the rotary. And the original URIE had no buffer. Purple made some upgrades to the design. Including true bypass. Very well done I might add. However it took me ALL 3 schematics to build mine.

More switch info here:

http://geocities.com/m_natsume/1176_slam_mode_rotary.html

The slam mode is not critical tho. I have used it and it is interesting. But I never actually recorded anything with it yet.

The switch has only 1 common that switches between the row of resistors. Check schematic again.

 

[CJ]

ok ,here is TB with his witchy woman, tell me that aint tommy piper ?
I knew that was a match, kept buggin me, where have I seen that dude.

 

[tommypiper]

All right, CJ. Busted. Got me. I've been trying to conceal my identity, but now I've been outed. On an 1176 thread to boot. Man. You coulda at least lured me into an LA2 thread. Or something with tubes, or Neve, or something. Just don't ask me to sing next time I see you.

Sf13, thanks. I just sent my kids out the door with flashlights and their mom. :grin:

Yes, there's enough info out there to do the pushbuttons p2p. I've seen a lot of that, thanks. I'm trying to do a toggle instead, so I'm not clear what to include, how many poles, etc. I was originally trying to decode the schematic, which I can't do. I mean, it looks like a 6 pole two position switch. But is it? What does what? What does the rotary version do? (Where is the documenation, hello?) Banging my head on the wall. I'll try to translate the pushbuttons to a toggle. So, is Mnat's schematic showing all those poles because they are the original pushbutton configuration? If so, how do we know which switch does what? And if so, how does the rotary switch fit in? As you mention, I'll have to use all three schematics to make sense of it for the pushbuttons configuration. Then try to translate that to a toggle. I got very sidetracked trying to go the other route - understanding it in a rotary configuration first, which I still don't get. BTW. Do you know what the X and Y points are? Since our project doesn't have a buffered meter, I guess I need an off position to keep distortion to a minimum at times. So that would mean I'm building a three position toggle: GR, +4 out, and off.

Re Slam, I have not tackled the ratio switch yet. One switch at a time. :guinness:

 

[tommypiper]

OK, that already helped, Sf. Thanks. I think I'm getting it. X and Y are the output transformer outs. That's what feeds the meter when it's reading output level. UNBUFFERED. The Purple schem makes things much clearer. I'm not sure how to translate it to Mnat's schem. (I'm a poor schematic reader, I get physically dizzy.) But I think I need a 2 pole, three position toggle.

Follow up. It looks to me when it's in GR mode, the meter is fed by the meter driver circuit, and is not connected to the output transformer at all. I'm not sure if this would introduce distortion into the audio, via the meter driver circuit. Can anyone say?

If no distortion, then one doesn't really need an off position in the switch.

 

[tommypiper]

OK, I finally got on the right track. (The key to understanding the schematic is that the meter switch is not a 6 pole single throw, as it appears.) I have it figured out. I made a drawing for a DPDT toggle. I'll post it if anyone wants to see it.

However, I can't understand how to connect it to the board in real life. I see these numbers on the small meter board, and I guess these connect to the same numbers on the large pcb? Is that the idea? Connect the numbers. Have I missed some documentation somewhere? One of the numbers is 4, but I cannot find any 4 on the large PCB. Heck, why make it easy? I'm supposed to know it's the left leg of the third transistor on the fourth plane of the dehummifier reducer? Got it.

The other numbers are oddly out of sequence, 22, 29. Why not start with 1? How did you connect your pushbuttons to the main PCB? I don't understand the logic to these numbers. And more frustrating, they are not on the schematic. Again. Mm. How do I know what I'm connecting? I guess we have to follow traces and try to deconstruct the PCB layout? OK... Again, I don't understand why so much is left out of the documentation.

BTW, what is the single switch shown just above C17 below the ratio switch?

 

[Stagefright13]

The switch above c-17 turns gain reduction on and off. (Off is switch to left) You will want that on your toggle. I traced the board to figure out wich wire went where. And I checked each off on the schematic with a pen as I went. I personally leave mine on GR all the time. Have no need for an output meter. And no distortion occurs cause of meter. It's how the original was.

Off on the original turns power off. On mine I hooked it to turn gain reduction off and used a switched IEC. You can run stuff thru the 1176 without gain reduction and still get the transformer and FET sound. So off is useful.