[BUILD] 1176 Rev A - Back to the beginning...

[phatmateo]

ahh ok, I'll put a 5k pot on R44 and see if I can get it to work.  Thanks for the quick response.  I'm using a hairball meter so I'll let you know how it goes

 

[Stagefright13]

Wow that's a time saver Spica. Always takes me forever and a day to type that stuff in. And I always miss something. I am building a 2-1176 right now and just realized I forgot 2 xlr's and a couple standoffs. If it wasn't for that I would be double squishing tonight LOL.

John

 

[spica]

Thanks, John.  I usually spend the better part of a day ordering parts for projects as well so I thought it would be helpful to share it.  I'm planning on sharing future projects.  I have one made for the Rev. D but want to check it first before I post it.

-Tony 

 

[outoftune]

Are you using a rotary or buttons?

I would start by looking at your ratio board's resistor values and checking for shorts.

Start at the source and move backwards.

Mike

i checked the resistor values and they all seem to be fine. didn't find any shorts. i am wondering if my switch has crapped out.

since two of the ratio values appear to be acting as normal and doing GR, does this indicate that it is something to do with the ratio board/switch?

 

[Echo North]

Use the continuity tester on your multimeter to test that the rotary is functioning correctly.  Make sure the proper poles are conducting/not conducting in each position.  That should rule out/confirm a defective switch.

Mike

 

[outoftune]

Use the continuity tester on your multimeter to test that the rotary is functioning correctly.  Make sure the proper poles are conducting/not conducting in each position.  That should rule out/confirm a defective switch.

Mike

seem to have figured out the switch issue.

now i am getting GR in all 4 ratios and the vu sits at 0vu in GR mode.

i was able to do the q bias adjustment, but...when i had it in 20:1 mode and shorted pad 22 to ground (as per the mnants video) it kills the signal. it works fine and i was able to do the qbias 1db drop in 12:1, just wondering if this is an issue for something else.

i am not able to get the null adjust to 0.00vdc, it just sits at 0.90vdc, the pot doesn't seem to change it. i am able to get the meter to 0 properly.

thanks so much for all the help. i am going to try running audio through it sometime soon to double check it by ear.

 

[Echo North]

seem to have figured out the switch issue.

now i am getting GR in all 4 ratios and the vu sits at 0vu in GR mode.

i was able to do the q bias adjustment, but...when i had it in 20:1 mode and shorted pad 22 to ground (as per the mnants video) it kills the signal. it works fine and i was able to do the qbias 1db drop in 12:1, just wondering if this is an issue for something else.

That is a problem.  Shorting pad 22 to ground should disable GR not the signal.  If you're getting no signal with GR disabled in 20:1 something isn't right.

i am not able to get the null adjust to 0.00vdc, it just sits at 0.90vdc, the pot doesn't seem to change it. i am able to get the meter to 0 properly.

Are you taking R44 out of circuit? 

I have found those muti-turn trimmers can be damaged easily if you over rotate them.

Mike

 

[phatmateo]

Mnats, just gotta say thank you for all your hard work.  My Rev A is working great and sounds sooooo good when paired with my 7th Circle audio N72 and A12 pres.  On male vocals it brings out such a smooth yet agressive midrange that cuts through the mix.  I'll be trying it on snare soon.  If anyone wants to see pictures, let me know. 

Oh and thanks to Ed and mike @hairball for all the help

 

[stereokillah]

i've try to draw a wiring guide for REV A with on off position on switch and without gr disable,

i checked all the 1176 topic to know and modified the rev D wiring guide v3, i think it's good but no sure cause i'm beginer.

PISTURE ERASED CAUSE WRONG

Let me knows if thereis some wrong link.
thank you

 

[stereokillah]

Have a question for the output transformer from hairballshop.Still have the orange and yellow wire , what must i do with it please?

Secondly, i have Mnats web site to know how to calibrate the rev.A look some differnce for it somebody could help me please?

thank you

 

[luis]

Hi,

You should connect them together.

 

[stereokillah]

thank you luis

 

[luis]

This Rev A  wiring guide is exactly the same for the Rev D isn´t it?
Are you using a SPDT switch, in your pushbutton 1176? (Just asking because it is not shown in your wiring guide).

Thanks

 

[stereokillah]

i use pushbutton and use the T pad from hairballshop, i use the mode on off not GR off it's differents link.
i have just modified the wiring guide rev D ver3.

 

[Rob Flinn]

I've just got my 2nd blue stripe up & running.  The 1st I used the rotary switches, because I was waiting for some panels for the push switches.  Anyway for this one I have the push switches & a modutec meter.  I'm experiencing a strange problem that doesn't happen with my real UREI's in that if I switch the compressor in & out the meter sort of wiggles above & below for 1/2 a second before settling where it should be for 1/2 a second before settling.  It looks like it needs some damping or is missing some damping.  Any ideas ??

 

[orangerec]

Rob,
What do you mean by "switch the compressor in and out?" Bypassing the unit with the attack turned all the way CCW or switching the ratios? I have two original blue stripes and the mnats RevA. Both my Urei's meters bounce around a bit when changing my the ratio, this is normal for this model. My 1176LN's both UA and mnats meters respond in a smoother, more stable fashion. It must be the design.

 

[phatmateo]

I'm sure its just the design.  I experience the same thing, but I figured it was normal.  It even makes a soft popping noise when I switch ratios...again, I figured it was normal.  Let me know if I'm wrong, but it doesn't bother me

 

[Rob Flinn]

Mmm wierd.......  Maybe it's the meter driver circuit.  I think that this discreet meter circuit is poor.    On my Purples I cobbled in the later op amp based circuit from the silver faced 1176.  It's much more stable & easier to calibrate.

 

[mnats]

Totally agree, Rob. But when I made this and the D I thought I should keep them as authentic as possible. It's also an interesting circuit to play with - try heating up one transistor, then the other while watching the meter.

Maybe the next version should have the IC meter circuit grafted onto the board. After all, it's the audio path we're mostly interested in keeping original right?

 

[Rob Flinn]

Mako,

Sounds good.    I really like your boards, because they offer a lot of flexibilty in terms of component choice & the layouts are well thought out.  But.......... if you could add an option for the op amp meter driver .............................. well.....