[BUILD] 1176LN Rev D DIY

[Ringwraith]

Thanks Mike got the switch taken care of & that makes sense about the Ratio's!  ;D

I've got another concern but maybe it's just the nature of the beast...
The cable running from the output pot to the board (pad 16/15/17) is a bit microphonic.
Is this normal? I know with tube amps there are areas in the circuit like this. It's not
causing any issues that I'm aware of (yet) but when I tap or handle this cable you
can hear it. I just cut & redid the ends but it's still happening. It goes away when
the output pot is at about 3/4 to max but before that you can hear it.

Also... is it normal for the meter to be pinned to the right in slam mode?
It shows reduction with the signal but zeros fully right.

Cheers
Sean

 

[Echo North]

I've got another concern but maybe it's just the nature of the beast...
The cable running from the output pot to the board (pad 16/15/17) is a bit microphonic.
Is this normal? I know with tube amps there are areas in the circuit like this. It's not
causing any issues that I'm aware of (yet) but when I tap or handle this cable you
can hear it. I just cut & redid the ends but it's still happening. It goes away when
the output pot is at about 3/4 to max but before that you can hear it.

That doesn't seem right to me but I really don't know.  I'd have to check on mine.

Also... is it normal for the meter to be pinned to the right in slam mode?
It shows reduction with the signal but zeros fully right.

Yes that is right and functioning correctly.

Mike

 

[Stagefright13]

Nothing should be "Microphonic" in this. Maybe a bad solder joint?

John

 

[mnats]

Finally managed to finish the third calibration video (scroll down).

 

[bdubya]

Thanks alot for doing that.  And such a smooth, sonorous narrator!  ;D

i fumbled my way through the calibration the first time and got it going; this'll make a nice reference the next time around.

 

[Ringwraith]

OK this calibration has me stumped...
I've done the first two with no issues but I can't get past the first step on this one.
I end up with my input all the way down & output all the way up never attaining the difference.

When I start with both in/out at noon I adjust the out for 0db with the +4 button pressed & GR switched off.
This puts the knob at about 48. (8:00) I turn on the GR & the meter drops to about -8.5. I drop the input dial to 36 (9:30) to attain -10. Now here's where it gets weird... I switch GR of & it's still sitting at -10. I move the output to bring it back up to 0, switch the GR on & it stays at 0. So I keep doing this until I run out of dial space.

Any suggestions?
Thanks
Sean

 

[Stagefright13]

I haven't done any calibrations recently. But will soon. Maybe I can help you then.

I have been too busy for projects lately. Everyone always shows completed projects so I figured I would show mine "In progress". I have 4 days off and working like crazy to complete it. Wish me luck.

And thanks again Mako and Ed and Mike at hairball.

I used the flying saucer heatsinks on the output transistors and a bigger heat sink on the regulator. Neither are nessessary but I thought it looked cool. It powers up fine with no explosions or smoke. Just gotta get my brain away from the pushbutton setup. Doing rotaries for the first time.

Only problems I have had was the Lorin flat spots on the shaft for the knobs and one of the T-Pad pots fell apart and had to epoxy it back together. Now all I need is to light those Sifams somehow and put a Stagefright logo on it. LOL. Thanks everyone once again. And Kato for his great BOM.

When this is done it will be my most used compressor and passed down to my son someday. 

 

[canidoit]

I haven't done any calibrations recently. But will soon. Maybe I can help you then.

I have been too busy for projects lately. Everyone always shows completed projects so I figured I would show mine "In progress". I have 4 days off and working like crazy to complete it. Wish me luck.

And thanks again Mako and Ed and Mike at hairball.

I used the flying saucer heatsinks on the output transistors and a bigger heat sink on the regulator. Neither are nessessary but I thought it looked cool. It powers up fine with no explosions or smoke. Just gotta get my brain away from the pushbutton setup. Doing rotaries for the first time.

Only problems I have had was the Lorin flat spots on the shaft for the knobs and one of the T-Pad pots fell apart and had to epoxy it back together. Now all I need is to light those Sifams somehow and put a Stagefright logo on it. LOL. Thanks everyone once again. And Kato for his great BOM.

When this is done it will be my most used compressor and passed down to my son someday. 

Very neat job mate. I like your layout!

 

[Stagefright13]

Still plugging away with wires LOL. I did all the shielded ones first. But my eyes and brain have given out and know it is time for a rest. Guess it will take 2 more days but time has run out. Will have it done soon tho. And the Skylar flowchart is useless for a rotary build. But Mnats offered a great rotary wiring thing at his site. Which is now mnats.net so his original links don't work.

John

 

[Stagefright13]

So here goes my first rotary build. After reading Mnats site it is actually easier. Getting ready to hook it to my stuff. And calibrate. I ordered the link kit from Mike at hairball and is on the way. Still didn't hook up my lights.

 

[ilfungo]

ciao
about a year ago I bought on ebay a output transformer  for 1176
No. 11148 apparently old (who sold it to me told me that he was an original Urei processor) without any other written ...
I think it is the processor used in the Rev F
Can you tell me something?
Thanks

 

[T-rex]

Just a quick substitution question; I am having trouble sourcing R32, the 39 ohm resistor.  It's been on backorder for a while and I found some 39.2 ohms locally.  Would this small substitution in the line amp cause any issues? 

From my limited schematic experience, I would think it based on R32's position it would be fine, but I thought I would check.

Thanks!

 

[Echo North]

Just a quick substitution question; I am having trouble sourcing R32, the 39 ohm resistor.  It's been on backorder for a while and I found some 39.2 ohms locally.  Would this small substitution in the line amp cause any issues?  

From my limited schematic experience, I would think it based on R32's position it would be fine, but I thought I would check.

Thanks!

Yes that is fine.

I think I remember reading that the original UREI units used 20% tolerance resistors?!  That may have been the typical tolerance at the time.

Mike

 

[T-rex]

Thanks for the info! 

 

[mpc3000limited]

Looking nice so far! 
Do you have a shot of the front panel? I am trying to decide on front panel designs for my 2-1176 Rev D's or spend the extra and make 2 regular blackface case units...

 

[luis]

Hi,

I noticed an intermittent noise in my compressor that only goes away when the input attenuator is completely turned off, or when I disconnect the input transformer from the main PCB. So. While trying to figure the problem (checking for shorts,etc) I noticed that the + and -  pads in the input transformer PCB have continuity. Can someone tell-me if this is normal  ????

Thanks

 

[bdubya]

Doesn't sound right.  Is your transformer soldered snug against the PCB, or lifted up off it slightly?  I seem to recall someone noting the potential for shortz from the traces to the can if its mounted flush against the pcb . . .

 

[mnats]

I noticed that the + and -  pads in the input transformer PCB have continuity.

Is the transformer installed?

 

[luis]

Thanks for all your help,

bdubya: I think you are referring to to the the links on the pcb. They are not touching the transformer.
Mnats: The tranformer is mounted!

Since I think the countinuity test measures the resistance, maybe the problem is my DMM that is not accurate. In my dmm the resistance is 12.
Is there any way  to isolate the problem, for example connecting some signal directly to the main PCB + and - pads, without passing in the input transformer ??



Thanks

 

[mnats]

Mnats: The tranformer is mounted!

Then you are measuring the DC resistance of the transformer primary winding which should be low. A better test might be to run a signal into the primary and look at the secondary output. Push on the transformer and move it around - if the signal changes then you may have found your intermittent problem.