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

[amen88]

Hi, new here. Just finished my 1176 rev a build, was very enjoyable and a lot of attention to detail!

I did a few searches but could not find any results.

Basically my issue. I am at second step of calibrating. I cant Zero the meter, it only starts at +1 with R71 at  Full CCW.

Not sure where to go from here...

Thanks,

 

[dbonin]

Hi, new here. Just finished my 1176 rev a build, was very enjoyable and a lot of attention to detail!

I did a few searches but could not find any results.

Basically my issue. I am at second step of calibrating. I cant Zero the meter, it only starts at +1 with R71 at  Full CCW.

Not sure where to go from here...

Thanks,

This will help...
https://www.youtube.com/watch?v=PScAEEriE-Q

Tweak the R75 trimmer....

 

[amen88]

This will help...
https://www.youtube.com/watch?v=PScAEEriE-Q

Tweak the R75 trimmer....

Thanks. I didnt help as the both R75 and R71 are CCW and the needle is still to far right.

 

[dbonin]

This will help...
https://www.youtube.com/watch?v=PScAEEriE-Q

Tweak the R75 trimmer....

Thanks. I didnt help as the both R75 and R71 are CCW and the needle is still to far right.

Take a look at the values of your resistors and take some measurements and see if something  pops out at you.
Misplaced resistors can cause all sorts of mayhem.

Is the unit otherwise passing audio and compressing?

R44 is a 5k...  R71 and R75 are 2k - check that as well.

 

[amen88]

This will help...
https://www.youtube.com/watch?v=PScAEEriE-Q

Tweak the R75 trimmer....

Thanks. I didnt help as the both R75 and R71 are CCW and the needle is still to far right.

Take a look at the values of your resistors and take some measurements and see if something  pops out at you.
Misplaced resistors can cause all sorts of mayhem.

Is the unit otherwise passing audio and compressing?

R44 is a 5k...  R71 and R75 are 2k - check that as well.

I figured out the issue. I didnt have the q bias set properly.  After that the 2nd step went quick.

Thanks for all your help. I found your videos very helpful especially on the 3rd step.

It is fully functional now.

 

[weiss]

Hey Mike!  I just wanted to ask if there is any other reseller of J309 FET Transistors in EU? I'd need 2 pairs. I'm afraid shipping to germany is not so much reasonable..

 

[Echo North]

Hey Mike!  I just wanted to ask if there is any other reseller of J309 FET Transistors in EU? I'd need 2 pairs. I'm afraid shipping to germany is not so much reasonable..

Not that I'm aware of.  You may have to google around.  I'm sure there is someone or an equivalent part.

If you get stuck would could send some letter mail for maybe $3 I bet.

 

[weiss]

Hey Mike!  I just wanted to ask if there is any other reseller of J309 FET Transistors in EU? I'd need 2 pairs. I'm afraid shipping to germany is not so much reasonable..

Not that I'm aware of.  You may have to google around.  I'm sure there is someone or an equivalent part.

If you get stuck would could send some letter mail for maybe $3 I bet.

Hey thanks. What equivalent part? Only found some SMD FETs
Otherwise i wait until my next order at your store

best regards

 

[Echo North]

Hey thanks. What equivalent part?

I don't have that on hand.  I'm saying you could google it and see if there is one.  Guitar pedal guys are usually all over that kind of thing.

Mike

 

[weiss]

Thanks mike! found a substitution: http://www.mouser.de/ProductDetail/InterFET/J309/?qs=sGAEpiMZZMtzpSA5GSDwa5qY2wKNAuqKLjx3FCCibEw%3d

 

[thp]

I'm stuffing the 8 x 2n3708 transistors.
I have a set of 8 that are all around 300-330hfe
and a set of 8 that are all around 440-480hfe

Does it matter which set I use?

Thanks

 

[dbonin]

I'm stuffing the 8 x 2n3708 transistors.
I have a set of 8 that are all around 300-330hfe
and a set of 8 that are all around 440-480hfe

Does it matter which set I use?

Thanks

I have used them in both ranges (but I usually group them as you have and pick those closest in value)  I have yet to see a significant difference  after calibration...

Don

 

[thp]

Thanks Don

 

[thp]

A few random questions as I make it down the home stretch!
I'm using hairball kits and instructions but am still a bit unclear:

The (green) wire that attaches from pad C25 to output transformer with a lug - Should I use the 16awg or 22awg wire?

The (white) wire that I am connecting the lamp terminal to the 240ohm resistor and then to the terminal strip - Is this the 22awg wire?

The blue and red twisted pair that goes from the VU meter to the XLR output - It says to make sure that it is long enough to route them clear of the input circuit.  When I look at the Mnats picture it is going all the way ccw around the perimeter of the frame but in the hairball picture it looks like it is cutting through the middle, which is correct?
The input circuit that is being referred to is not the actual XLR input but the power transformer and that is what I'm trying to stay away from - yes? 

What should I do with the ground wire that is soldered to the output transformer on the side?  It is not used is it?

Lastly, and this is merely cosmetic, but can I run wires under the pcb?  For example the wire that runs from the output pot to 16, 15, & 17 on the pcb?


Thanks for the help!

 

[Echo North]

A few random questions as I make it down the home stretch!
I'm using hairball kits and instructions but am still a bit unclear:

The (green) wire that attaches from pad C25 to output transformer with a lug - Should I use the 16awg or 22awg wire?

You should use the 16AWG for that.

The (white) wire that I am connecting the lamp terminal to the 240ohm resistor and then to the terminal strip - Is this the 22awg wire?

Yep, 22AWG is good for that.

The blue and red twisted pair that goes from the VU meter to the XLR output - It says to make sure that it is long enough to route them clear of the input circuit.  When I look at the Mnats picture it is going all the way ccw around the perimeter of the frame but in the hairball picture it looks like it is cutting through the middle, which is correct?
The input circuit that is being referred to is not the actual XLR input but the power transformer and that is what I'm trying to stay away from - yes? 

It's best to keep all wiring, when possible, as close to the edge of the enclosure as possible and avoid running under or over the PCB.  MNATS is correct.

What should I do with the ground wire that is soldered to the output transformer on the side?  It is not used is it?

You need to ground the channel frame around the transformer.  In our guide this is done by clearing powder from the transformer mounting hole and grounding using the screw.  That means the wire attached is redundant and can be clipped.

Lastly, and this is merely cosmetic, but can I run wires under the pcb?  For example the wire that runs from the output pot to 16, 15, & 17 on the pcb?

See above.  Avoid running over/under the PCB.

Thanks for the help!

No problem!

Mike

 

[thomasdf]

I am sorry if it was discussed before but can I use a 0.01uF capacitor on the attack pot instead of the 0.012uF without affecting too much the attack behavior? My guess is that it's fine but you never know!!

 

[Echo North]

I am sorry if it was discussed before but can I use a 0.01uF capacitor on the attack pot instead of the 0.012uF without affecting too much the attack behavior? My guess is that it's fine but you never know!!

That's fine.  0.12 was probably a common value at the time.  Now 0.01 or 0.015 is far more common.

Mike

 

[thomasdf]

If 0.012uF 's code is 123 I have found one in my spare parts... Will try and see how it works... And then maybe I'll swap back to 0.01
Thanks Mike!

 

[Timh]

Hey guys. I finshed my Rev A a few months ago. I began to notice that it blew through a fuse or two, but everything would work fine. Now it's not turning on at all  . I replaced the fuse, I used a new power cable, different plugs in the house, etc. Nothing has worked. Does this sound like something that is a common problem? I tried my best to see if something is shorting out but I can't find anything.
Thanks.

 

[Echo North]

Hey guys. I finshed my Rev A a few months ago. I began to notice that it blew through a fuse or two, but everything would work fine. Now it's not turning on at all  . I replaced the fuse, I used a new power cable, different plugs in the house, etc. Nothing has worked. Does this sound like something that is a common problem? I tried my best to see if something is shorting out but I can't find anything.
Thanks.

That's odd.

Check the post I just made in the D thread about testing the power transformer.

Mike