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

[hymentoptera]

Wasn't sure where to post this, but I found a cheaper source for R71 (2k 2W honeywell/clarostat part #53C22K), which cost $11.22 at Mouser, but they're only $6.52 at Newark right now, currently 51 in stock.

http://www.newark.com/honeywell-s-c-clarostat/53c22k/conductive-plastic-potentiometer/dp/14T1394

I just received 2 of these are they are identical to the ones I got from Mouser, except they are loose bagged instead of in a nice pretty little Honeywell box. If you're building multiple units and plan to use the front panel mount "0" adjust (i.e. if using a Hairball chassis, instead of just putting a trimmer on the PCB @ R71) then save yourself some cash and buy these parts from Newark.

Newark part# 14T1394

 

[Echo North]

Wasn't sure where to post this, but I found a cheaper source for R71 (2k 2W honeywell/clarostat part #53C22K), which cost $11.22 at Mouser, but they're only $6.52 at Newark right now, currently 51 in stock.

http://www.newark.com/honeywell-s-c-clarostat/53c22k/conductive-plastic-potentiometer/dp/14T1394

I just received 2 of these are they are identical to the ones I got from Mouser, except they are loose bagged instead of in a nice pretty little Honeywell box. If you're building multiple units and plan to use the front panel mount "0" adjust (i.e. if using a Hairball chassis, instead of just putting a trimmer on the PCB @ R71) then save yourself some cash and buy these parts from Newark.

Newark part# 14T1394

You can also really use  any 2K pot, curve doesn't really matter.

 

[Echo North]

Hi all,

I recently built my first Hairball Audio 1176 Rev A. Once I had finished the calibrating I started to use it and it work no problem. I haven't moved it or disconnected it from my system but last night I went to use it and there seems to be a lot of noise as I turn up the output. There is also a point at which there is a very loud noise that sounds like interference. Im not to sure what this could be. I have uploaded a little video clip to youtube as I guess that will show the noise better than my explanations.

https://www.youtube.com/watch?v=iBKvW8i9M-4&feature=youtu.be

Any ideas?

Cheers in advance.

Are your output wires traveling under your PCB?

Get all of your wiring around the edge of the enclosure.

Mike

 

[PeteStyles]

Hi Mike,

I don't have anything running underneath the PCB at the moment, the only cables that seem to be going above the PCB slightly are the twisted orange and green.

It happens also when changing the ratio if that helps. I get a loud buzz for a second then it stops.

 

[Echo North]

Hi Mike,

I don't have anything running underneath the PCB at the moment, the only cables that seem to be going above the PCB slightly are the twisted orange and green.

It happens also when changing the ratio if that helps. I get a loud buzz for a second then it stops.

The output getting real loud words the end of rotation sounds like oscillation to me.  Hard to say without hearing it.  That can happen when output and input signal are close in proximity.

Play with your wiring routing and see if you can get it to rectify.

Mike

 

[PeteStyles]

Thanks for the reply again, I will have another try tomorrow with the wiring positions.

https://www.youtube.com/watch?v=spErvA2UlN8

that link is a video I made that shows the problem I'm having if that helps you any more.

Cheers

Pete

 

[Echo North]

Thanks for the reply again, I will have another try tomorrow with the wiring positions.

https://www.youtube.com/watch?v=spErvA2UlN8

that link is a video I made that shows the problem I'm having if that helps you any more.

Cheers

Pete

Ya that seems like an oscillation freak out w/ the most likely culprit being wires too close to the PCB or ins/outs too close.  Looks like you have a lot of floating around and extra long wires.  Try to get something closer to the last image on this page:

http://mnats.net/1176_reva-d_hairball_wiring_meter_lamp.html

Mike

 

[PeteStyles]

Thanks for the reply, I will give this a go tomorrow as it pretty late in the UK now.  Hopefully should resolve the issue.

Pete

 

[PeteStyles]

Hi Mike,

I organised the wiring and shortened any that seemed to long but the sound is the same. Could it be the potentiometer thats faulty?


Pete

 

[Echo North]

Hi Mike,

I organised the wiring and shortened any that seemed to long but the sound is the same. Could it be the potentiometer thats faulty?


Pete

Anything is possible but that wouldn't be my first guess.  Q6 is always suspect when there is loud output like that.  Do you have it heat sinked?  Check it's voltages against the schematic w/ voltages on the MNATS.NET site.

Mike

 

[PeteStyles]

I have used the heat sink provided and have check the voltage with Mnats. Q6 is working fine. The output noise is lower when the ratio is set higher if that helps.

Pete

 

[JeroenRoth]

Hey All,

First of all thank you guys for putting together this nice kit!

Sofar I'm happy with it but I've stumbled across two possible problems. In the following video a demonstration:https://www.youtube.com/watch?v=XUbyS_bPXzQ

And in text:
When I have the compression off and the meter showing gain reduction, the meter will still slightly move if I crank the input. If I go past half on the input with the compression off I get distortion.

Attached is a photo of the wiring.

-Jeroen

 

[Siegfried Meier]

I have a pair of original V1 Rev A's that are both burning up R32 when I fire them up.  I initially was looking at an incorrect output wiring document, but have since corrected that.  R32 take about a minute to burn up now, but it still does...

Anyone have any ideas as to why this is?

Thanks!
Sig

 

[Echo North]

I have a pair of original V1 Rev A's that are both burning up R32 when I fire them up.  I initially was looking at an incorrect output wiring document, but have since corrected that.  R32 take about a minute to burn up now, but it still does...

Anyone have any ideas as to why this is?

Thanks!
Sig

If you burned R32 with a wiring error there is a 50/50 chance you killed Q6 which is why R32 may still be burning.  Confirm the output wiring with the original file.

http://mnats.net/files/DIY_1176_REVA_V1.pdf

Mike

 

[Siegfried Meier]

2nd unit brand new Q6, burned up R32 as well.  Rev1 boards kicking my ass...

 

[Echo North]

2nd unit brand new Q6, burned up R32 as well.  Rev1 boards must be flawed and defective.  Did anyone here actually even finish any of the first versions?  Waste of time, time to junk them and start over again with new boards.

I have two V1's here working fine.  I know a number of people with them.  The changes between V1 (Original A) and the current boards (Rev A/B) are very small and just there to make compression a little more controllable.  Nothing in the output IIRC.

Mike

 

[Echo North]

You saw that note on the PCB  to link Cx6 and omit Rx14?

Mike

 

[Siegfried Meier]

Uhhhh no...?  I see it now though...I have components in both of these...doh...would those cause R32 to burn?

 

[Siegfried Meier]

Ya, those components might have something to do with the sonics or operation of the compressor, but they have nothing to do with R32 burning up.  I've socketed that resistor now because I've had to pull it 9 times.  It's still burning up, and I'm lost at this point.  If it's not a defective transformer, and I've got a perfect +30 and -10 voltage, what else is causing this to happen??

 

[hymentoptera]

Ya, those components might have something to do with the sonics or operation of the compressor, but they have nothing to do with R32 burning up.  I've socketed that resistor now because I've had to pull it 9 times.  It's still burning up, and I'm lost at this point.  If it's not a defective transformer, and I've got a perfect +30 and -10 voltage, what else is causing this to happen??

most common cause of R32 burning up (this has been mentioned earlier in the thread, several times) is incorrect wiring of the output transformer. You mentioned previously using an out-of-date wiring diagram?

I'd recommend disconnecting the output transformer and rewiring it again, or at least checking every single connection where it goes in/out of the PCB. 30v goes through the black wire and the brown wire of the primary side of the output transformer, and it's a common mistake to swap one of these with another connection and shoot 30v thru R32 to ground, and let out the magic smoke.