[BUILD] 1176LN Rev D DIY

[HMPS]

Ok It's all calibrated!

Just have a few more questions.  I tested the transistors and they all look like they match except for Q13.

Measurements on Q13 are -.93, -1.52, -1.52

What process should I use to determine that the compression ratios are working properly?

I found this in the thread but would Like the grandmaster Echo North's opinion.
http://www.axtsystems.com/index.php?view=article&catid=34%3A1176ln&id=54%3A1176lnratios&option=com_content&Itemid=62

Thanks!

HMPS

 

[andydiy]

Hi!

I created the 1176LN Revision D Boards PCB. After doing Meter Circuit Board & Ratio Circuit Board PCB.

Yes, I want to buy Substitutes.

A lot of places the no spot so I want to buy Substitutes.

Thx!

Are you looking for a substitute for this part?

Any 240 ohm 5W resistor will do, either metal oxide or wirewound

Hi!

286-240-RC, There Substitutes?

Mouser Part #: 286-240-RC
Manufacturer Part #: 286-240-RC
Manufacturer: Xicon
Description: Metal Oxide Resistors 240ohms 5% Tol

 

[HMPS]

Do these values look backwards?

Shouldn't 20:1 compress the signal MORE than 4:1?

Here are the Gain Reduction readings I get, this seems backwards to me.


Input Level  0db    -3db    -5db  -7db    -10db

Ratio 

20                -10      -6.5      -4.5    -3      -1

12                  -12    -8        -5.5    -4.25  -2.25

8                    -13    -9        -6.5      -4.75    -3

4                    -15    -10      -7.5      -5.75    -4

 

[Echo North]

Nope. 

You're looking at it wrong.  It's a ratio of compression NOT overall compression.

Also the FETs have a sweet spot where you get advertised ratios.  Squish too much and you saturate the FET and the ratios crash, squish too little and you hit the knee and the ratios crash.

 

[HMPS]

Great! So it works?  I'm done?  Start using it?

 

[dbonin]

Ok my power rails look good!  I was measuring from star ground to the point instead of black to point.

Now for these trannies....

The HFE of these seems low, I know Hairball said that they'd be good,
however they measure the same on two different meters.

These are my numbers

209,233,232,223,226,225,222,221,223,229,222,229,221,219223,219,226,231,218,219,222

according to the directions


HMPS

Very same problem here today!!!

maybe their recent batch has those values ??

Same thing happened to me recently - all 20 were around 200 - I had to use my leftovers from my last 1176 to get Hfe over 250.  A pain for sure.

 

[HMPS]

echo says that you can use them.  I did and this thing sounds great!

Still curious about my Q13 voltages, but this thing is fast and sounds amazing!  Considering doing another

 

[rokus666]

I have a problem with GR meter:

When I press GR button,

At Ratio 4 Meter is all the way down and after a while it starts randomly jumping

Sometimes is dead, And at some ratios is jumping around???


And I tried to rewire the connections on GR control amp and the fuse blew again...

power supply voltages seems to be fine

 

[rokus666]

Also the voltages on GR control Amp seem to be fine....

Now since I changed a new fuse, When I press GR button at no ratio, meter goes to +1, stays there then jumps back and comes back up to around +1


Ratio 20 meter slowly starts climbing up and then starts jumping randomly...

it seems that all this meter chaotic behavior is random

ADDITION: Now when i press GR, the meter doesn't do anything. Only When I switch back from Ratio 20 to Ratio 4, the needle jumps all the way up and quickly comes back all the way down

 

[rokus666]

I was checking voltages on Q6 and I must of shorted something and R32 Blew off...

 

[HMPS]

When you switch ratios the meter jumps to the top

you should probably switch off the power when you are rewiring

what are your voltages reading at 20, 18, 22, 21 19

the calibration can be confusing

 

[rokus666]

As I replaced R32,

Voltages on Pads are:

20 is  -6.69
18 is -1.089
22 is 0
21 is -6.0
19 (yellow) when I put multimeter on it, it starts to drop gradually from 0.9 V


Also when I have a 1khz sine wave playing into the unit, the signal level drops occasionally and comes back to "normal" within 10-15 minutes of testing (output is unstable)

What voltages should I be getting on FET's?

I am getting:
Q11 G  -.712  S -.685  D  5.26 VDC
Q1  G  -.8      S  0      D  0 VDC

I will go through all the voltages and scrutinize this thing tomorrow...

 

[rokus666]

Ok my power rails look good!  I was measuring from star ground to the point instead of black to point.

Now for these trannies....

The HFE of these seems low, I know Hairball said that they'd be good,
however they measure the same on two different meters.

These are my numbers

209,233,232,223,226,225,222,221,223,229,222,229,221,219223,219,226,231,218,219,222

according to the directions


HMPS

Very same problem here today!!!

maybe their recent batch has those values ??

Same thing happened to me recently - all 20 were around 200 - I had to use my leftovers from my last 1176 to get Hfe over 250.  A pain for sure.

are you sure you measure these correctly?

I have two multimeters and they were showing 220's on one and 1000's on the other.

If we confirm that the batch from mouser is faulty, then our builds are faulty.

I was passing signal through my unit, and I had to try hard to hear some compression. All buttons in, I have heard close the sound of 1176

Considering my GR meter and output is not working properly- I have to sort this out. But once I fix this, I should do some comparisments with the original unit and wawes/uad plugins (have them all except the UREI)

I really believe in this build-that it will sound like a real thing.

 

[davidparkstenor]

Hello,

First post.

I have built 2 hamptone kits, 2 sca kits, and a Drip opto 4. 

I have read all materials on the mnats site and hairball and most of the pages in this thread prior to beginning my build of the mnats/hairball 1176 Rev d.

As hairball recommends, I will populate the PSU part of the board first and check voltages.

My question concerns what happens next.  I am used to populating with the lowest profile parts, resistors, diodes, etc, working my way toward the taller profile caps.  But once the PSU is populated for the voltage test the tallest parts of the PCB are present.  So, is there a "trick" or a cleaver way to populate the lower profile components to the board in a snug manner after previously installing the tall caps?

Thanks for your help.

 

[HMPS]

Hello,

First post.

I have built 2 hamptone kits, 2 sca kits, and a Drip opto 4. 

I have read all materials on the mnats site and hairball and most of the pages in this thread prior to beginning my build of the mnats/hairball 1176 Rev d.

As hairball recommends, I will populate the PSU part of the board first and check voltages.

My question concerns what happens next.  I am used to populating with the lowest profile parts, resistors, diodes, etc, working my way toward the taller profile caps.  But once the PSU is populated for the voltage test the tallest parts of the PCB are present.  So, is there a "trick" or a cleaver way to populate the lower profile components to the board in a snug manner after previously installing the tall caps?

Thanks for your help.

Get a vice grip

or use tape on the resistors and solder from the side

 

[HMPS]

As I replaced R32,

Voltages on Pads are:

20 is  -6.69
18 is -1.089
22 is 0
21 is -6.0
19 (yellow) when I put multimeter on it, it starts to drop gradually from 0.9 V


Also when I have a 1khz sine wave playing into the unit, the signal level drops occasionally and comes back to "normal" within 10-15 minutes of testing (output is unstable)

What voltages should I be getting on FET's?

I am getting:
Q11 G  -.712  S -.685  D  5.26 VDC
Q1  G  -.8      S  0      D  0 VDC

I will go through all the voltages and scrutinize this thing tomorrow...

your 20 is too low

what is your measurement at the -10v rail with all those wires plugged in?

This is what I did.....

unplug all but 20 check your -10v rail
it should be the same as the -10v rail
add in the wires one by one and check your -10v rail each time, when it drops that will show you where your problem is at

 

[rokus666]

I have measured the voltages:

Q1 GSD -.619  0  0
Q2 BCE  1.046  1.739  0.557
Q3 1.739  11.91  1.148
Q4  0.99  3.68  0.43
Q5  3.23  24.41  2.701
Q6  blew up R32 when measuring Emiter
Q7  4.41 0.88  3.86
Q8  14.92  29.77  14.29
Q9  3.39  16.55  2.831
Q10  16.55  29.77  15.98
Q11  0.55(var)  0.742  7.8(var)
Q12  0.743  5.5  -1.319
Q13  -0.926  -1.513  -1.519
Q14  11.91  29.76  11.33

Power Rail - 9.72  +29.76 VDC

Pad:
20  -6.9V
18  -1.03
22  0
21  0
19  -.67 (variable)

Is there anything else I should look into ?

 

[rokus666]

Alright here you go....read this as well but note it's rev a so some values (DC and component) will be different.
http://www.groupdiy.com/index.php?topic=29981.msg615080#msg615080

Print off the rev D schematic from the MNATs site.  Now go to the rev A schematic and write in the pad numbers from there on to your Rev D schematic...20,21,18 and so on.

Now here is one of your issues....you have no DC voltage at pad 21.  Here is how you get that voltage.  Look at your schematic, R64 connects to your -10V rail and then to pad 20.  From here is runs up to the ratio board and feeds the R63, R62, R61, R58 divider network and back down to the Qbias wiper where it connects to ground closing the circuit.  Looking at the schem R64 is 1.5K and the rest of the R in the chain are like 2K all together.  So you'll a sizable drop across R64.  Rail on one side (-10V) and something like -6V on the other.  If you don't at least have this with PAD 20 disconnected you have a main board issue at R64.  Edit: With pad 20 disconnected you'll have no path to ground...so no voltage drop accross this R.  Just make sure you have that side of the R64 going to the raio PCB pad 20. [End edit] Now this 6V gets connected to that R network with pad 20.  Now if you follow those resistors in order you should see a stepped drop -6V -> -4V -> -3.2V -> -2V (real roughly) until you get to the other side of R58 where it should be near fairly low, like -1V.

Now the switch just taps off those stepped voltages 6V -> -4V -> -3.2V -> -2V and feeds them to pad 21.

You've got basically no voltage anywhere in that chain I just described.  If you have -6V or whatever on the on side of R64 and not at pad 20 on the ratio, then you have wiring issues.  Likely it's miss wired, which would also help explain your voltage sag.

Good luck.

I have followed those steps up untill I disconected Pad 20 and measured R64 (voltage was 9.75 on both sides)
After I connected the wire back to pad 20, powered the unit and another fuse blew off. This is like the fourth fuse so far.

Another fuse blew when I replaced it, and after I disconnected pads 20, 18, 22, 21, 19, the unit powers on normally. I assume something is wrong with ratio board.

I am triple checking the wiring and I cannot find a mistake (it seems)
:'( :'( :'(

 

[HMPS]

What does 20 measure when you plug it in?  Make sure that your wire connections to the ratio board aren't solder bridged and have good contact with the metal they are touching.

Also when the wires are disconnected make sure they dont touch each other or anything else on the board, it'll screw up your readings or possibly short it.

The ratio board wouldn't be causing the fuse to blow by itself, one of the wires probably touched something it shouldn't have.

If 20 is ok plug in another wire and check the measurement, eventually it will drop and that will show you where the problem is.

 

[HMPS]

Whatever is causing the voltage to drop, that is the question you are trying to answer