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

[evilcat]

Hi evilcat Unfortunately I didn't have the chance to listen to them because they're not available anymore - I tried to download them but the link didn't work...but I followed what other people said about your test and from there I tried to find out more...until I ended up just trying it myself

I have 3708s installed - I heard people on this forum saying the unit sounds a little brighter with 5088s? But soundfiles to compare would be nice for sure!

I'll upload those samples and will post a link here.
Yes, 5088 are brighter.

 

[frazzman]

Forgive me if I'm rehashing what may have already been covered but to verify:
- for C16 is 39p cap ok in place of 38p - can't find 38p anywhere?
- omit Cx6 and Rx14 ? Do I jumper these or just leave them out entirely?
Thanks!

 

[evilcat]

Here is the link :
https://www.wetransfer.com/downloads/a481cb5e3dcdf234942ea96211439c8f20130614081637/5d829809136daf3bfd8ea5b63110bc2f20130614081637/b01ad0
Will work for 2 weeks. Then I would have to re-uploaded files. The better if you're interested would be to PM me and I would send files directly to people. There are tests for acoustic guitar, drums, electric guitar and vocals. It's up to you.

Ben

 

[lowend]

Hi !

I just finished a Rev A and it works well, compression OK, sound's good etc.
But I can hear a "hummmm"

I already build this unit and I never had "hummm" So I dont know where to look...
I posted some pictures here : http://flic.kr/s/aHsjG44PHk

I got 29,7V / -9,6V
Voltage looks OK everywhere....
My case have a good electric conductivity, my solder looks correct...

Do you know where I can modify something to turn off that "hummmm" !!???

Thanks

 

[Echo North]

Forgive me if I'm rehashing what may have already been covered but to verify:
- for C16 is 39p cap ok in place of 38p - can't find 38p anywhere?
- omit Cx6 and Rx14 ? Do I jumper these or just leave them out entirely?
Thanks!

Sounds like you have the first Rev A board.

That cap substitution is fine.

Refer to the build doc:
http://mnats.net/files/DIY_1176_REVA_V1.pdf

I believe it says in the BOM to link(jumper)the cap pads, and leave the resistor empty.

 

[Echo North]

Hi !

I just finished a Rev A and it works well, compression OK, sound's good etc.
But I can hear a "hummmm"

I already build this unit and I never had "hummm" So I dont know where to look...
I posted some pictures here : http://flic.kr/s/aHsjG44PHk

I got 29,7V / -9,6V
Voltage looks OK everywhere....
My case have a good electric conductivity, my solder looks correct...

Do you know where I can modify something to turn off that "hummmm" !!???

Thanks

Check your shielding on your cables.  Make sure only one end is grounded.  Ground the (-) side of your filter cap. Make sure you case has good continuity.

Start there.

Mike

 

[germoju]

Hi !

I just finished a Rev A and it works well, compression OK, sound's good etc.
But I can hear a "hummmm"

I already build this unit and I never had "hummm" So I dont know where to look...
I posted some pictures here : http://flic.kr/s/aHsjG44PHk

I got 29,7V / -9,6V
Voltage looks OK everywhere....
My case have a good electric conductivity, my solder looks correct...

Do you know where I can modify something to turn off that "hummmm" !!???

Thanks

Check your shielding on your cables.  Make sure only one end is grounded.  Ground the (-) side of your filter cap. Make sure you case has good continuity.

Start there.

Mike

Not sure about what you mean by "make sure only one end is grounded"
Hère is my continuity test video : http://youtu.be/cHk5JcavpC4
My c25 is grounded...

 

[Echo North]

Hi !

I just finished a Rev A and it works well, compression OK, sound's good etc.
But I can hear a "hummmm"

I already build this unit and I never had "hummm" So I dont know where to look...
I posted some pictures here : http://flic.kr/s/aHsjG44PHk

I got 29,7V / -9,6V
Voltage looks OK everywhere....
My case have a good electric conductivity, my solder looks correct...

Do you know where I can modify something to turn off that "hummmm" !!???

Thanks

Check your shielding on your cables.  Make sure only one end is grounded.  Ground the (-) side of your filter cap. Make sure you case has good continuity.

Start there.

Mike

Not sure about what you mean by "make sure only one end is grounded"
Hère is my continuity test video : http://youtu.be/cHk5JcavpC4
My c25 is grounded...

I was referring to the shielded cabling that carries audio.  Like the input XLR->Tpad->input trans->PCB input wiring.  This should all have one continuous shield that is terminated to ground at only one end.  The other end is left unconnected.  Terminating both leaves you susceptible to ground loops.

Mike

 

[lowend]

oh yes OK
I did exactly as Mnats says on building guide...  :-\

 

[Echo North]

oh yes OK
I did exactly as Mnats says on building guide...  :-\

Are you having a hum issue as well?

 

[lowend]

no no... no issue... hummmmm always here...
I just mean I did all good as Mnats says on the building guide...

http://flic.kr/p/eLWToz
http://flic.kr/p/eLWU28
http://flic.kr/p/eLWUNR

Do you know what can I test now ??

 

[lowend]

you like my last message because you believe I fund an issue ?

 

[Echo North]

you like my last message because you believe I fund an issue ?

Ha oh I thought you didn't have one.  I'm confused. 

So you have a hum?

 

[lowend]

NO ! 
my machine is "hummmmmming"
AHAH !!

 

[Echo North]

NO ! 
my machine is "hummmmmming"
AHAH !!

Ah I'm getting user names mixed up.

Hummmm is tricky.  Does it sound like 60Hz hum?

 

[lowend]

yes... for me is more 50hz....

I 'm uploading a video where you can see and hear the "hummm" or "Bzzzzzzz" I dont know
3 minutes left on youtube....

 

[Echo North]

yes... for me is more 50hz....

I 'm uploading a video where you can see and hear the "hummm" or "Bzzzzzzz" I dont know
3 minutes left on youtube....

Video probably won't help.  You have some supply noise.  Could be a mains line thing or environmental.  With the unit off move the torrid, if you can out of the case then try again, see if that helps.  If the torrid is bad it can shoot off a huge magnetic field.  Also make sure your input transformer can has continuity to your star ground.

Mike

 

[lowend]

here it is.... http://youtu.be/RxOpP-qGyBA

something happen when my hand come near the first sprague cap... I discover that in making the video....
Take a look...

 

[lowend]

yes... for me is more 50hz....

I 'm uploading a video where you can see and hear the "hummm" or "Bzzzzzzz" I dont know
3 minutes left on youtube....

Video probably won't help.  You have some supply noise.  Could be a mains line thing or environmental.  With the unit off move the torrid, if you can out of the case then try again, see if that helps.  If the torrid is bad it can shoot off a huge magnetic field.  Also make sure your input transformer can has continuity to your star ground.

Mike

Yeah Mike !
I put the torroid out of the case and hum disappear. I replace it in case and hummm doesn't exist anymore
Tomorrow I will do the same with my rev D who is doing the same !!!
I let you know if it's OK ! Now I'm tired and I wanna sleep

 

[lowend]

Thanks Mike for your precious help !! My rev A doen't "hummm" anymore !!! Youuuhuouuuu !!