[BUILD] 1176LN Rev D DIY

[rob61]

I have two original "F"s and an original "G". They have never been re-capped or or gone through. Is there anyone here that can tell me which caps to replace is those, and then afterwards how to align it to factory specs?

 

[Stagefright13]

David Kulka has what you need for that. http://www.studioelectronics.biz/
And check the jbl pro site for calibration. Once I saw a recap kit for them on ebay but not up right now.

John

 

[Randyman...]

Quick troubleshooting Q - Likely Ratio Switch related.

Just finished up a 2-1176 Rev D rotary version.  CH1 is perfect.  CH2 has low gain (approx -15dB down) on all ratios until I put it in "All buttons" mode - then the gain of CH2 matches CH1 exactly.  Is this likely an issue with my Ratio switch wiring/jumping - or should I be looking elsewhere?  I swear I did both switches identically (had them side-by-side when doing the leads and jumpers).  I can set Q-Bias on CH2 - so it's not the fact that the Q-Bais is reducing too much "at rest" (-1dB per calibration procedure).

Thanks for any pointers.  Close to having 4 channels of mnats 1176 very very soon!!!   8)

 

[baadc0de]

Hi guys,

could I sub the 2n3391 in the preamp/signal amp sections with BC327?

Cheers,
B.

 

[pietro_moog]

hi guys.
i just rewired (in a nice way) my 1176, and i noticed that my VR heatsink is HOT, the 2n3053 heatsink too.
what did you use?

 

[tazman]

Out of curiosity.  I just go tmy kit and I see that on the RATIO board, the resistors are marked with numbers, but where is the legend for them? 

Thanks,

Rob

 

[Majestic12]

You can find the list directly on the hairball site

http://hairballaudio.com/shop/bom.php

Just follow the "ratio board pcb values" link in the support corner

 

[tazman]

I completely missed that on their website!!!!  I spent an hour looking!!!  I was up too late soldering the main PCB, I must still be asleep.

BTW, I was trying to figure out how to install the 2N3708.  The sockets on the board have 4 holes.  I'v been going through the schematics and I'm getting lost.  One of the pics I found in the forum shows them installed using one of the holes that is not in line, yet other pics show them installed with th eholes in line.

I have been searching the forum, but I can't find anything or if I did maybe I didn't understand it!?!  Any suggestions as to what I'm supposed to do as far as their installation?



Maybe I just need more sleep, LOL

Thanks,

Rob

 

[canidoit]

From what I have been told, some designers leave testing holes on their board during development for testing and troubleshooting purpose when they are developing the boards. Also the holes could be used for certain part options. The EQN and NV73 had a couple of those that had me stumped also

 

[tazman]

Hi - I just completed my Rev D 1176, but I got problems and I'm a newby:

The compressor turned on without any smoke, so good at first. 

I plugged the output of the compressor into the input of the only sound card I have available today, an M-Audio Fast track pro.  The first thing I noticed is that when the 1176 was turned off, but plugged in, I got a lot of noise from its output, once turned on, the noise level subsided.  I can make it go quite by lifting the ground at the IEC (it's currently connected to the case).  WHy is this happening?  What's wrong with it?  What should I be checking?  ANy suggestions?



Thanks

Rob

 

[baadc0de]

A question here regarding the 1176 "slam" rotary switch thing. Instead of a 2 pole 5 position alpha, I have a 2 pole 6 position alpha. It's essentially the same as far as I know, sans the extra position. I've built the switch, but before I wire it all up, I thought you guys may want to look it over and see if I did everything alright.

http://www.flickr.com/photos/36524125@N06/sets/72157626588765341/with/5716513065/

 

[tazman]

I think I got everything working.  Calibrated and all.  I still have one issue that I cannot resolve.  When it's being bypassed (switch to off on the attack knob), the signal is a bit distorted.  I ran a bass drum through it and you could hear distortion when the transient hit. 

Can anyone suggest what I should be looking at?

Thanks,

Rob

 

[baadc0de]

Back off the input gain, boost the output gain. Bypass here only turns off the GR circuit, not the amps inside.

 

[tazman]

Thanks.

So the distortion is normal?  I need to get my hands on another 1176 to compare it.

Thanks,

Rob

 

[canidoit]

Thanks.

So the distortion is normal?  I need to get my hands on another 1176 to compare it.

Thanks,

Rob

Rob, go down to a proaudio store and see if you can demo one on display. Then just have a play and try to remember the settings that it was distorting on your unit and replicate it at the store.

Is your signal correct to your Rev D? Impedance, line/mic levels, etc. I remember, when I plug certain other units to my Rev D, I would have to put the input level low on my 1176 otherwise it would distort with or without attack on.

 

[tazman]

I need to call around and find who's got one in stock...

Rob

 

[Randyman...]

Same here.  The input gain on my Rev A's is generally around 9-10 O'Clock, and needs to be even lower on hotter sources like Snare off an API Preamp.

Do you hear the distortion if the 1176 is engaged, but well below the threshold (no GR activity even though the GR circuit is active)?  Sounds like it could be simple gain-staging (input down, output up), but more info is needed...

8)

 

[tazman]

I didn't hear any distortion when the 1176 compression was engaged.  Unfortunately the testing setup was not optimum and my main studio is unavailable right now.  I'm trying to find somebody in the area that will let me patch the 1176 in to do some more

I want to build a second one,  but I first want to make sure this one is running perfectly.

Rob

 

[baadc0de]

A question here regarding the 1176 "slam" rotary switch thing. Instead of a 2 pole 5 position alpha, I have a 2 pole 6 position alpha. It's essentially the same as far as I know, sans the extra position. I've built the switch, but before I wire it all up, I thought you guys may want to look it over and see if I did everything alright.

http://www.flickr.com/photos/36524125@N06/sets/72157626588765341/with/5716513065/

Hey guys.. sorry to be such a bother, but could someone with a completed 1176d slam rotary check if my wiring is correct? I'll add the pictures to this thread, maybe easier to analyse for some..







Thanks for looking them through!

 

[tazman]

Here is an example of the distortion I mentioned.  I pushed the input.  This is really bad with things like bass drum.  Is it normal when pushed?

http://www.robertocerini.com/1176test.mp3

Thanks,

Rob