[BUILD] 1176LN Rev D DIY

[Jeag]

hey all, i have been troubleshooting my first 1176 for a couple of weeks now,
its my first electronics project, so far its been mostly rewiring the pots and going over solder joints, a little more confident with an iron now thankfully 

i have gotten as far as to try the q bias adjustment but when i turn r59 i see no change in the meter, i have switched out the resistor with another one but still no change.
it's passing audio but seems to be returning it a little quieter.
the meter works fine on +4 & +8 but in GR it goes to -20 and doesn't move.
when i checked the voltages everything seemed fine apart from the q11 fet which seemed a bit low, i dont have the voltages with me now but can post them tomorrow if it anyone wants to see.
also when i switch the attack knob in +4 or +8 mode it does drop a small amount, about 1db or so.

i feel like i should order another pair of fets from hairball but postage to ireland is expensive so i wanted to see if anyone has an opinion before i order.

cheers dudes...j

 

[Trench Recordings]

andydiy... Glad you found your problem.

No offense but looking at your soldering in the picture, you need some practice to improve your skills. Try using a smaller tip temperature controlled soldering iron. The solder in the bottom left of the picture needs to be redone. And what do you mean link r5 / r6 ? did you create that solder bridge on purpose ?

 

[Trench Recordings]

These solder joints look  ??? some cold solders and that solder bridge

 

[earthsled]

Hi all.

I have questions about the built-in power supply on the MNATS REV-D board...

A few posters have suggested that it's okay to barrow some current from the +30V rail (for LEDs and such), but what about the -10V rail? Does anyone have a rough idea about how much current draw each rail can comfortably handle versus the demands of the circuit? Or, in other words, how much "extra" current is available on each rail?

Thanks for your help!

 

[Echo North]

There is no extra current on the -10V rail. Because that rail has the dropping R any extra current will toss the rail to sag.  It's an ohms law thing.

The +30 rail with the V regulator is more stable and can adjust to extra current demand.

For LED the AC secondary will work too.  The reverse V won't be enough to kill them if you use the proper dropping R.

Mike

 

[earthsled]

Thanks Mike!

Okay, I will leave the -10V rail as is.

The stereo link kit shouldn't have much of a current draw. Maybe something like 6mA? The LEDs in the VU meter will take another 20mA. Is the +30V rail going to be okay if I barrow 26 to 30mA of current from it?

I've never tried using AC for LEDs. Apparently it works, but wouldn't this cause some flicker or cause the LEDs to be at half the brightness?

As an alternative, I suppose I could add a couple diodes and caps to the AC secondary for the LEDs. Maybe I could build my own +10V supply using the same parts found in the MNATS -10V circuit. Would something like this handle 40mA or so?

 

[dandeurloo]

I just replaced some transistor from the 2N3707 to 2N5088.  I didn't realize I had to use the alternate hole for the BASE.  So I soldering it inline like I had the 2N3707's.  I smoked R32.  I am wondering did I fry my 2N5088 as well?

Thanks

 

[andydiy]

Hi!

When I connected to two feet in R5 and R6 together,  compressor have 4:1 and 8:1 , I do not know the correct I only know the have effect.

Is this right?

andydiy... Glad you found your problem.

No offense but looking at your soldering in the picture, you need some practice to improve your skills. Try using a smaller tip temperature controlled soldering iron. The solder in the bottom left of the picture needs to be redone. And what do you mean link r5 / r6 ? did you create that solder bridge on purpose ?

 

[andydiy]

I have the same problem.

try the q bias adjustment but when i turn r59 i see no change in the meter。

I hope  can help us.

Thank you!

hey all, i have been troubleshooting my first 1176 for a couple of weeks now,
its my first electronics project, so far its been mostly rewiring the pots and going over solder joints, a little more confident with an iron now thankfully 

i have gotten as far as to try the q bias adjustment but when i turn r59 i see no change in the meter, i have switched out the resistor with another one but still no change.
it's passing audio but seems to be returning it a little quieter.
the meter works fine on +4 & +8 but in GR it goes to -20 and doesn't move.
when i checked the voltages everything seemed fine apart from the q11 fet which seemed a bit low, i dont have the voltages with me now but can post them tomorrow if it anyone wants to see.
also when i switch the attack knob in +4 or +8 mode it does drop a small amount, about 1db or so.

i feel like i should order another pair of fets from hairball but postage to ireland is expensive so i wanted to see if anyone has an opinion before i order.

cheers dudes...j

 

[Jeag]

just noticed somethin, the resistor (R65 - 3.9M) before the q11 fet seems to be bringin the voltage down too low, i measure about 9v before the resistor and 1.3ish after it, but it should be around 9 going into the fet from what i can gather. could pullin that resistor out fix it? is that possible to do?

 

[Echo North]

just noticed somethin, the resistor (R65 - 3.9M) before the q11 fet seems to be bringin the voltage down too low, i measure about 9v before the resistor and 1.3ish after it, but it should be around 9 going into the fet from what i can gather. could pullin that resistor out fix it? is that possible to do?

These boards (J, F, A, D..) dating back to the original  G1176 boards have been built by probably 1000's of people over 10 years.  I definitely would not remove or add any components.

Mike

 

[Echo North]

hey all, i have been troubleshooting my first 1176 for a couple of weeks now,
its my first electronics project, so far its been mostly rewiring the pots and going over solder joints, a little more confident with an iron now thankfully 

i have gotten as far as to try the q bias adjustment but when i turn r59 i see no change in the meter, i have switched out the resistor with another one but still no change.
it's passing audio but seems to be returning it a little quieter.
the meter works fine on +4 & +8 but in GR it goes to -20 and doesn't move.
when i checked the voltages everything seemed fine apart from the q11 fet which seemed a bit low, i dont have the voltages with me now but can post them tomorrow if it anyone wants to see.
also when i switch the attack knob in +4 or +8 mode it does drop a small amount, about 1db or so.

i feel like i should order another pair of fets from hairball but postage to ireland is expensive so i wanted to see if anyone has an opinion before i order.

cheers dudes...j

Read the 2-3 pages of this Steve_H exchange.  See if you get similar issues.  Your bias may be way out dragging down your output.  Check your DC through the sidechain.

http://www.groupdiy.com/index.php?topic=29981.msg614820#msg614820

 

[andydiy]

Hi!

Sorry I do not quite understand, there are other examples of this?

hey all, i have been troubleshooting my first 1176 for a couple of weeks now,
its my first electronics project, so far its been mostly rewiring the pots and going over solder joints, a little more confident with an iron now thankfully 

i have gotten as far as to try the q bias adjustment but when i turn r59 i see no change in the meter, i have switched out the resistor with another one but still no change.
it's passing audio but seems to be returning it a little quieter.
the meter works fine on +4 & +8 but in GR it goes to -20 and doesn't move.
when i checked the voltages everything seemed fine apart from the q11 fet which seemed a bit low, i dont have the voltages with me now but can post them tomorrow if it anyone wants to see.
also when i switch the attack knob in +4 or +8 mode it does drop a small amount, about 1db or so.

i feel like i should order another pair of fets from hairball but postage to ireland is expensive so i wanted to see if anyone has an opinion before i order.

cheers dudes...j

Read the 2-3 pages of this Steve_H exchange.  See if you get similar issues.  Your bias may be way out dragging down your output.  Check your DC through the sidechain.

http://www.groupdiy.com/index.php?topic=29981.msg614820#msg614820

 

[benlindell]

Hey everyone, I've got a weird problem happening with one of my 1176s I built for a friend. It functions perfectly everywhere but in their studio.

The issue they are having is that it'll work fine for a day, then the next day it'll blow a fuse right away. I've inspected the unit and tested it for a week at my place with no problems. I've had them try different IEC cables, different power outlets/power conditioners, they even had an electrician check out the studio and couldn't find anything.

Can anyone think of something we're missing?

 

[MicDaddy]

What is the fuse rated at?  Both of my units consistently popped T250mA during power up so I bumped to T500mA with no issues.  Others may say it's not safe, do what you feel is in your best and safest interest.

 

[Echo North]

What is the fuse rated at?  Both of my units consistently popped T250mA during power up so I bumped to T500mA with no issues.  Others may say it's not safe, do what you feel is in your best and safest interest.

I think a 500mA slo blo is reasonable.  Some weird high toroidal in-rush I in that studio maybe?  You could try a new toroid (email me if you do).

 

[liljeblad]

Hi!

Today I soldered on R42(183KOhms). When I checked the value with my multimeter it said 182KOhms as I should(or around atleast). Then I soldered it on the PCB and checked again - 34KOhms. So I took it of and got another 182KOhm resistor. I measured that one as well, it said 182 KOhm. Then I soldered it on and measured again - 34 KOhm again.

I must say I'm kind of confused and would appreciate some help with this..

 

[ln76d]

Hi!

Today I soldered on R42(183KOhms). When I checked the value with my multimeter it said 182KOhms as I should(or around atleast). Then I soldered it on the PCB and checked again - 34KOhms. So I took it of and got another 182KOhm resistor. I measured that one as well, it said 182 KOhm. Then I soldered it on and measured again - 34 KOhm again.

I must say I'm kind of confused and would appreciate some help with this..

It's because in circuit You have other resistive parts. If they are joined in parallel to each other, multimeter will show the resultant resistance. In this case it looks fine for me. If i'm wrong, please somebody for correction.

 

[Echo North]

It's because in circuit You have other resistive parts. If they are joined in parallel to each other, multimeter will show the resultant resistance. In this case it looks fine for me. If i'm wrong, please somebody for correction.

You are correct.

 

[germoju]

hello DIYers !  ;D

I am building a Dual 1176 with Revision D boards and I have a question about ground. In a single 1176 we take the negative C25 to ground. For my project I use the Mnats PSU board to aliment the 2 PCBs, so I dont use C25 cap on PCBs...
So my question is : how to connect mains PCBs boards to ground ?

Thanks a lot !!