[BUILD] 1176LN Rev D DIY

[berkleystudios]

Have you checked your DC voltages against the MNATS schematic on his site?

Start there.  Then we can trace the signal, see where it dies.

Here are my current voltage readings
Q1
G -0.42
S 0.00
D 0.00

Q2
E 0.54
C 1.77
B 0.86

Q3
E 1.16
C 11.50
B 1.77

Q4
E 0.42
C 0.96
B 4.18

Q5
E 2.73
C 24.7
B 2.98

Q6
E 2.18
C 28.1
B 2.75

Q7
E 3.85
C 14.72
B 4.14

Q8
E 14.26
C 29.9
B 14.72

Q9
E 2.84
C 16.01
B 3.38

Q10
E 15.95
C 29.9
B 16.00

Q11
G 12.01
S -0.83
D -0.26

Q12
E -1.42
C 11.26 (slightly off)
B -0.83

Q13
E -1.52
C 11.22 (slightly off )
B -0.99

Q14
E 11.11
C 29.9
B 11.55



what is the tolerance for this build? most of thiese are about a volt away or less Q12 &13 are the only ones I see more than a volt off...

 

[berkleystudios]

tested with no signal, in GR mode

 

[berkleystudios]

I almost dont want to admit what my mistake was.....

after scouring my pcb and my wiring for issues I decided to go over my solder joints and put heat shink on some areas I hadnt...

and then I see it..... after checking and checking and then rechecking and checking some more I found my fatal error...

X and Y on the meter switch were going to 15, 16 and 17.....

I had used balanced mogami cable instead of hook up wire for the added bonus of the shielded cable for the longest run in the box.

I mixed it up with the output knob cable which was the same colored balanced cable....


I find this out at 4:30am while obsessing over it and I bet it was caused during another late night when I was building it.



lesson here kiddos is never assume you have something right and just because you triple check something doesnt mean it right either it just means you to arrogant to see the problem haha


wiring has always been  and will always be my biggest challenge in DIY...


Thank you so much Echo North and sr1200 for putting up with my crap in this thread... I think I owe yall a beer

taking her to the studio tomorrow. Hopefully thats the last issue

 

[Echo North]

Awesome!  Glad you got it.  8)

We ALL make these mistakes.  Well maybe not PRR. 

Mike

 

[berkleystudios]

Awesome!  Glad you got it.  8)

We ALL make these mistakes.  Well maybe not PRR. 

Mike

yep tested it at the studio today and It works great!

 

[jplebre]

Berkeley, does your attack pot work like the original?

 

[berkleystudios]

Berkeley, does your attack pot work like the original?

as in 7 is the fastest attack? yes. or at least i think it is. its super fast either way

 

[Echo North]

Berkeley, does your attack pot work like the original?

as in 7 is the fastest attack? yes. or at least i think it is. its super fast either way

From UA facebook page:

LA-2A's in a bar. 1176 walks into the bar and immediately starts picking a fight with LA-2A. LA-2A just looks at 1176 and says, "Why do you always have to be so quick to attack?"

Har har

 

[jason baliban]

Hey Guys,

Just finished up a kit and i am calibrating.  When i get to the 3rd step, gain reduction meter.., i am having a prob.  First, I am getting no gain reduction.  If i max the in and out knobs i will see the meter start to pulsate.  I took a look at the schematic, i am just learning, and the voltage at Q10 and the voltage and the B and E are way off...

C 30v
B 5.1v
E 4.6v

Compared to my other working kit and the suggested voltages this is way off.

Any suggestion where to go from here?

Thanks so much,

jB

 

[Echo North]

Hey Guys,

Just finished up a kit and i am calibrating.  When i get to the 3rd step, gain reduction meter.., i am having a prob.  First, I am getting no gain reduction.  If i max the in and out knobs i will see the meter start to pulsate.  I took a look at the schematic, i am just learning, and the voltage at Q10 and the voltage and the B and E are way off...

C 30v
B 5.1v
E 4.6v

Compared to my other working kit and the suggested voltages this is way off.

Any suggestion where to go from here?

Thanks so much,

jB

Are your Q9 voltages ok?

If so, check R51 and R47 values.

 

[jason baliban]

Hey Guys,

Just finished up a kit and i am calibrating.  When i get to the 3rd step, gain reduction meter.., i am having a prob.  First, I am getting no gain reduction.  If i max the in and out knobs i will see the meter start to pulsate.  I took a look at the schematic, i am just learning, and the voltage at Q10 and the voltage and the B and E are way off...

C 30v
B 5.1v
E 4.6v

Compared to my other working kit and the suggested voltages this is way off.

Any suggestion where to go from here?

Thanks so much,

jB

Are your Q9 voltages ok?

If so, check R51 and R47 values.

Thank you for quick reply

All my voltages seem to be ok EXCEPT the gain reduction stage....Q7, Q8, Q9, Q10.

Here are those voltages...

Q7
B  13.86
C  26.7
E  21.5

Q8
26.7
30
26.2

Q9
4.84
5.19
4.26

Q10
5.18
30
4.62

Here are the values of the others...

Q2
1.05
1.78
.54

Q3
1.79
11.5
1.17

Q14
11.56
30
10.95

Q4
1.0
5.05
.409

Q5
4.03
24.7
3.53

Q11
D  8.98
S  -.76
G  -.685

Q12
-7.6
7.5
-1.35

Q13
-.89
8.2
-1.45

I guess Q12 and Q13 may be a little low?

Thanks a bunch!

jB

 

[Echo North]

I wouldn't worry about Q12/13 until it's calibrated.

Check all of your R values in GR amp section.  Make sure you don't have a 4.7K and a 470K swapped or something.  CHeck all of them closely.

Mike

 

[jplebre]

Berkeley, does your attack pot work like the original?

as in 7 is the fastest attack? yes. or at least i think it is. its super fast either way

As in ridículos fast, or allowing transients through. Mine seems To be stuck at about 6 comparing to an original seems i have a short so that c22 sees as if the pot was halfway

 

[jason baliban]

I wouldn't worry about Q12/13 until it's calibrated.

Check all of your R values in GR amp section.  Make sure you don't have a 4.7K and a 470K swapped or something.  CHeck all of them closely.

Mike

Found it.

R4, R41...270R, not 27k.

Thanks for your help, Mike!

jB

 

[U87610]

Hey again DIY'ers!!!

Thanks for everyone's advice and for helping me with my build!!

I finished populating the board and fired it up the other day, calibrated it, and wasted a whole day running old tracks through it.  I don't know how I got by mixing without a real 1176!!  It sounds incredible!!

Thanks Mike and MNATS for the materials, and thank you DIY'ers for your input and for helping a newb like me get this far!! 

Now it's time to buy and build a Rev A!!  8)

 

[Echo North]

Berkeley, does your attack pot work like the original?

as in 7 is the fastest attack? yes. or at least i think it is. its super fast either way

As in ridículos fast, or allowing transients through. Mine seems To be stuck at about 6 comparing to an original seems i have a short so that c22 sees as if the pot was halfway

I recall reading that the original attack pot may have been a log pot.  Might be worth trying.  I can only get the 25K with sw in lin right now.

 

[jplebre]

I recall reading that the original attack pot may have been a log pot.  Might be worth trying.  I can only get the 25K with sw in lin right now.

I think it's weirder than that. Really, the difference between CW and CCW is almost un-noticeable, whilst the original ones have an audible difference.
I've seen videos and my friend put together a handfull of A's and D's a few years back so I'm pretty sure I did something wrong.

I hear a lot of people saying the difference is almost un-noticeable. When we browsed through the forum we thought that the mistake might be something really common as it's not that noticeable (on the original 1176's and his hairballs)

could be something on the newer rev, but doubt it. MNATS and your's job is insane.

I'm hoping I can look into it in July as i'll have some free time.

 

[Echo North]

True.  A log and lin are the same at their extreme CW and CCW.

 

[chris1986]

Hey guys,

sr1200, thanks for the suggestion with the noisy output pot I have on all 3 of my blackface 1176's. I tried putting in the pot from my blue-stripe 1176 and I still get the same problem.

Should I maybe get a plastic conductive Bourns pot for all of the blackfaces? Is there potentially a wiring problem? Everything works perfectly on the blackface units apart from the noisy output pots.

Thanks!

 

[ffarrell]

Hi all

I am building a 1u stereo 1176 D and I'm looking for what would be the best cable management.

Power iec is on the back right power tranny in front of the iec about 3 inches. 

XLR I/O on back left  both audio trannie mounted to the side 4 inches in front of the XLR's.

Would you orient the main boards for shorter power run or shorter audio tranny run.

Thanks
Fvf


EDIT::

I found this in a stereo link thread.  from the man himself.

But the board is required to power two units with one transformer? So I can't stuff both boards and dual wire them?

The separate power supply is not required, but suggested to reduce component count. You can still power two boards each stuffed with power supply components from a single transformer.

You can see an example of a stereo unit wired with the separate power supply board in the photos posted on Reply #21 above.

Please take note of my AC warning above. I believe that many people just ignore the warnings on my page.