Pangolin QM20002 ADATconnections

[polishedball]

I have connected my QM2000 via the 1/4inch with resistor mod per documents on pangolins web site. (using only pins 1(X) and 2(Y) and ground) This becomes single ended this way. The problem I am experiencing is the Y input to the ADAT is down in signal. To the point where I set the X axis to 62 and Y to 100 to have proper size. I have proved it isn't the ADAT as if I swap the X Y channel inputs the problem follows Y. I have ohmed out and even changed the resistors in the cable that was made even though they were correct same problem. I have now shared the exact same ground point for the signal single ended for X and Y same problem. It acts like the Y drive doesn't have enough output when terminated with the ADAT. To the projector it is just fine no problems.

I am thinking I'll just change reduce the resistance inline till I get equal balance, but would really like to know what is going on.

The picture EE through the ADAT or layed off to tape looks just fine no other issues except the reduced Y output.

Ideas?

EDIT: wow butchered that title not sure how that happened thought I went from QM2000 2 ADAT, to QM2000 ADAT connections. Left some crap behind sorry it is a QM2000 not the ultra secret advanced 20002.

[DZ]

Makes me wonder if you have pin 14 grounded. If not, try grounding both pin 14 and pin 15 on the ilda connector and see what change that makes. If you have an ILDA breakout board, just turn on switch 1 and 2.

[polishedball]

Makes me wonder if you have pin 14 grounded. If not, try grounding both pin 14 and pin 15 on the ilda connector and see what change that makes. If you have an ILDA breakout board, just turn on switch 1 and 2.

I thought you don't use pin 14 and 15 between pango and ADAT, I have no connections made there (on the QM2000 card). Using only one side of the balanced output 1 and 2 then ground to the same ground as the color channels and pin 25 for the unbalanced inputs to the ADAT. The ADAT output is balanced diff out through its own internal conversion.

I am seeing this problem on the meters on the front of the ADAT so the problem is between the pango card and the ADAT it is present (low level) with no output connector (ilda) connected to the balanced out of the ADAT.

I may have totally miss understood what you were suggesting. Sorry if that was the case.

Also if I use the ADAT as a DAC from the lightpipe EE to projector all is OK or if playing tapes all is fine, so I believe the output to the projector path is good.

[DZ]

Gosh, it's been so long since I used ADAT, I'd hate to send you down the wrong road. An email to Bill at Pangolin would certainly get you the correct answer.

Last time I used ADAT was when I had a QM32, which was single ended output, if I remember correctly. Unless Bill has made a change on the QM2000, if you short -X and -Y (pin 14 and pin 15) to pin 25, then the output of +X and +Y doubles. Which was why I'm thinking your pin 14 is already grounded some how. My suggestion, was to short pins 14 and 15 to pin 25 on your db-25 connector that you have attached to the output of the QM2000. This will force the output of the QM2K to run single ended, again this is from old knowledge from several years ago, not sure if that was changed on the card to not work anymore, I know it works on my card though.

[polishedball]

Gosh, it's been so long since I used ADAT, I'd hate to send you down the wrong road. An email to Bill at Pangolin would certainly get you the correct answer.

Last time I used ADAT was when I had a QM32, which was single ended output, if I remember correctly. Unless Bill has made a change on the QM2000, if you short -X and -Y (pin 14 and pin 15) to pin 25, then the output of +X and +Y doubles. Which was why I'm thinking your pin 14 is already grounded some how. My suggestion, was to short pins 14 and 15 to pin 25 on your db-25 connector that you have attached to the output of the QM2000. This will force the output of the QM2K to run single ended, again this is from old knowledge from several years ago, not sure if that was changed on the card to not work anymore, I know it works on my card though.

Thanks! I didn;t know that about shorting the 2 pins. The manual I was following was for the old QM32 so that was all I had to go by. Will shoot and email off to Bill as well to verifiy.

[DZ]

Thanks! I didn;t know that about shorting the 2 pins. The manual I was following was for the old QM32 so that was all I had to go by. Will shoot and email off to Bill as well to verifiy.

No problem, let me know what you find out. I'm curious to see if it's still true that shorting -XY to gnd doubles +XY.

[polishedball]

No problem, let me know what you find out. I'm curious to see if it's still true that shorting -XY to gnd doubles +XY.

Will do, what concerns me is I can't increase the X output as it is already peaking at max.


Also I'll upload the board scans later and send you a link so you can see the work that was done on it as you were curious.

[polishedball]

I received an email reply from pangolin. It stated to never connect pin 14 or 15 to ground. Just use pin 1 and 2 then 25 for the ground.

Not sure why but I do not get correct output on the Y channel doing this, I did however just switch and use the balance inputs on the ADAT for X and Y and all levels are correct.