[BUILD] 1176LN Rev D DIY

[synchroman]

I pulled the ratio board and shorted r10 and put it in must Rev A and it works... I un-shorted r10 and put it it mu rev D it does not work...

I have the ratio assembly out not screwed in to the chase and i plugged it in to the wire harness. Now, if no buttons pushed no compression if i ground the assembly it compresses.

Still same issue though when I press one of the ratio buttons no compression...

This is so weird..  The gain reduction circuit is working.

Help...

 

[synchroman]

Ok..first...looks like all of your trimmers are backwards...This the BLACK Rev D Board...not the BLUE Rev A that is pictured on mnats site...see the BOM rev D link at the bottom of the calibration section from mnats page...

Second...why are you using those huge yellow caps? Those are way too big to use on such a tiny board...

Third...from your pics..I would start checking my continuity off the ratio board to make sure it was testing correctly

Also..The ratio has lot to do with the actual board wiring...wheres all the pictures of it all wired up?

I want to help...Believe me...once we get it figured out, I am going to continue to help people with their builds...people are helping me and I want to help out...

I just wish someone could figure out my problem

looks like all of your trimmers are backwards

- Trims do not have a direction as long as the center pin is in the right place your good to go.... so this is not the probelm

Second...why are you using those huge yellow caps? Those are way too big to use on such a tiny board...

- Because they sound really good and this is the position that effect the sound the most.

Third...from your pics..I would start checking my continuity off the ratio board to make sure it was testing correctly

- I have and everything checks out

Also..The ratio has lot to do with the actual board wiring...wheres all the pictures of it all wired up?

I posted more pictures.

 

[college101]

This may actually go back to the R45 problem..compare the original ratio schematic to mnats schematic...R45

 

[synchroman]

I have a 10M ohm in that R45 is that not right? I am looking on the urei document there is no 10 M in there ratio board...

 

[edanderson]

I pulled the ratio board and shorted r10 and put it in must Rev A and it works... I un-shorted r10 and put it it mu rev D it does not work...

I have the ratio assembly out not screwed in to the chase and i plugged it in to the wire harness. Now, if no buttons pushed no compression if i ground the assembly it compresses.

Still same issue though when I press one of the ratio buttons no compression...

This is so weird..  The gain reduction circuit is working.

Help...

okay so you have a rev A unit that you built, and that works?  what if you take the ratio PCB out of the working rev A and put it in the rev D?

when you say you are shorting r10, can you explain that?

when you say you are "grounding the assembly" do you mean screwing it to the front panel?

ed

 

[synchroman]

I took the ratio board out of the D took R10 out of the ratioboard and added the wire jumper in r10,  to make the D ratio board an A ratio board.

I connected it to the rev A and it works

 

[college101]

Hey Ed

  I checked my R44..I checked for grounding on both sides of R44..and both sides tested to ground on a continuity test...but no amount of adjusting R44 moves my needle. The meter falls to -20 from zero with no GR via the attack switch

I'm getting 7.37 Ohms on each side of R44

 

[synchroman]

What is the R45 problem?

 

[Biasrocks]

Second...why are you using those huge yellow caps? Those are way too big to use on such a tiny board...

- Because the sound really good and this is the position that effect the sound the most.

They look like they could be shorting out other parts of the circuit, or at the very least cause shorting down the road.

You need to stand those big yellow caps on their ends and bring the other lead from the top down to the bottom cover the exposed wire with shinkwrap. No shorts.

Regards,
Mark

 

[synchroman]

There not shorting the Rev D 2.2 has space for longer caps... there are no componet near the leads and the are quite secure... I am passsing audio ther is no issue in the section... Amp section sound really good... Only haveing issue with the ratio board....

 

[Echo North]

There not shorting the Rev D 2.2 has space for longer caps... there are no componet near the leads and the are quite secure... I am passsing audio ther is no issue in the section... Amp section sound really good... Only haveing issue with the ratio board....

So the other ratio board makes your circuit work?

If so maybe a bad ratio board trace or switch.  If you want, send me an email and I'll send you new ones.

 

[synchroman]

There not shorting the Rev D 2.2 has space for longer caps... there are no componet near the leads and the are quite secure... I am passsing audio ther is no issue in the section... Amp section sound really good... Only haveing issue with the ratio board....

So the other ratio board makes your circuit work?

If so maybe a bad ratio board trace or switch.  If you want, send me an email and I'll send you new ones.

No the D ratio board works in the Rev A it does not work in the rev D so I don't really know what is wrong...  What is the issue with R45?

 

[Echo North]

What is the issue with R45?

The 10M resistor?  It's in some schematics and not others.  It just keeps the unit from "popping" when switching ratios.  Having it there or leaving it out should not affect operation.

 

[edanderson]

I checked my R44..I checked for grounding on both sides of R44..and both sides tested to ground on a continuity test...

I'm getting 7.37 Ohms on each side of R44

power off
r44 out of the circuit
one probe on ground
one probe on junction of q12-e and r68 - where one end of r44 would connect

you measure ~7 ohms?
same thing if you move the probe from q12-e to q13-e and r69?
what about at each of the three pads for the jumper?

ed

 

[synchroman]

I figured it out I had the attack pot pad 22 going to ground and ground going to Pad 22 - FIXED

Thank god.... and thank you all for trying to help

 

[edanderson]

I took the ratio board out of the D took R10 out of the ratioboard and added the wire jumper in r10,  to make the D ratio board an A ratio board.

I connected it to the rev A and it works

i guess i've never seen the version of the ratio PCB you have.  your reference to r10 is confusing because there is an r10 on the main PCB, but not on any of the ratio PCBs i've ever seen.

ed

edit: glad you figured it out anyway...

 

[Echo North]

Ed look here:

http://www.hairballaudio.com/docs/FET%20Compressor%20PCB%20Board%20Info%20V3.pdf

I named the resistors on the ratio board R1-R10 because the boards have to work with the A, D, F/G and J boards.  All of which have different designations and values depending on the revision.

 

[edanderson]

ah ha! i should have known...  thanks for clarifying.

ed

 

[college101]

Hey Ed, I just read your last post for me to check R44...I have to go out of town for 2 days...But once I get back...I will check...

After reading your post...yes...both sides of R44 get around 7.37 ohms


synchroman- GLAD you got yours working... I wish mine was that easy...Mine is not connected that way...

 

[Biasrocks]

There not shorting the Rev D 2.2 has space for longer caps...

Only haveing issue with the ratio board....

Really, 1.5 inch film caps mounted sideways huh?

I'm not suggesting anything radical.

If it's working for you, that's cool.

Regards,
Mark