OK that looks ok. The clue will be what ac volts you are getting at pin 6 on each IDC 10 pin header on the mac link pcb when separate and when linked measured to 0v while -5dB GR is on each channel. Make sure the switch and threshold settings on both comps are the same.
Ok,
So just and FYI that I was gonna try to fix with you after I got the outputs to match closer. When I have -5 db on both meters the threshold knobs are about a 1/4 of a mark off from each other using the marks on the front panels as a guide. So from one white line to the next they are about a 1/4 of that distance off from each other. Channel A threshold always had to be turned up CW a little more than channel B. This is next on my list to fix but not sure if it can be done.
Here are my measurements for pin 6 on the link pcb. I used the middle pins closest to the switch on each side. Settings are 1:3, GR, and Flat
When both meters say -5DB with the link switch off I get 1.832VAC on Ch A pin 6 and 1.800 on Ch B pin6 . When the link switch is on I get .416vac on ch A pon 6 and .415vac on ch B pin 6.
When I adjust the the thresholds to have equal .855vac on the xlr outputs (same amount of compression on both sides) these are the measurements I get on pin 6. Same settings as before.
Link switch off I get 1.833vac on ch A pin 6 and 1.832vac on ch B pin 6. Link switch on I get .124vac on ch A pin 6and .128vac on ch B pin 6.
The only thing I can see that would do this out of the blue is if one channel is out of phase with the other as then they cancel when joined together.
Have you got both channels in phase (preferably using a Y cable in so both channels have identical input level)?
Are both phase jumpers behind the input XLR's on the dingo-T set the same (pin 2-3 & pin 5-6 jumpered)?
The only thing I can see that would do this out of the blue is if one channel is out of phase with the other as then they cancel when joined together.
Have you got both channels in phase (preferably using a Y cable in so both channels have identical input level)?
Are both phase jumpers behind the input XLR's on the dingo-T set the same (pin 2-3 & pin 5-6 jumpered)?
Joe you are the freaking man. That was it, I guess through this process as I switched to this other interface it must have one of the channels phase switches on. I will have to investigate that in a bit. I am using outs 1&2 on an Apogee Duet. Not sure how one of the channels is flipped. I am such an idiot. I just now used a Y cable and made sure to get 1.23vac on the output of each channel then I set -5DB on each channel and then turn the link on and Bingo it works perfectly. ERRRRRR I am so sorry for wasting your time. I should have always used the Y cable never thinking the phase switch could be active on a channel. So it was good from the get go with the Trimmer added. Again I am an idiot and you are the man. Thank you thank you thank you so much for a great product and great support for us musicians and green horn / diy builders.
One more fix then if possible. Can I get my threshold knobs to be closer aligned when both meters say -5db? like I said in the last post they are about a 1/4 of the distance between white lines apart. They are close but not equal in appearance on the front panel and with the VAC on the outputs. I think you said .5db in difference is ok for ananlog gear but I would like to make that smaller if possible.
I found the culprit, not sure how this got checked on or if it is set this way by default in REW but I went back to not using the Y cable and then I unchecked this and the link switch works perfectly. Such a stupid waste of time trying to troubleshoot a problem that really wasn’t there.
IMG_6982.jpeg
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I found the culprit, not sure how this got checked on or if it is set this way by default in REW but I went back to not using the Y cable and then I unchecked this and the link switch works perfectly. Such a stupid waste of time trying to troubleshoot a problem that really wasn’t there.
IMG_6982.jpeg
Cool. With Y cable and thresholds CCW measure the voltage across the outside threshold pot tags again. If one is higher voltage a resistor can be added to bring it down to match the lower voltage side and then the makeup trim will need to be redone. This can sometimes balance the threshold pot mid point but not always as pots are +/-10%
Cool. With Y cable and thresholds CCW measure the voltage across the outside threshold pot tags again. If one is higher voltage a resistor can be added to bring it down to match the lower voltage side and then the makeup trim will need to be redone. This can sometimes balance the threshold pot mid point but not always as pots are +/-10%
Thanks so much for the info Joe. Will another 500k trimmer work ok? Just to clarify I’ll be measuring voltage on the pot tabs when the unit is on and running with no compression and not the ohms when unit is off. Since I will only add a max of 1-2 db of compression as a 2buss compressor should I set the meters to -2db of compression and check the VAC on the outputs and adjust the new trimmer on the threshold pot until outputs are equal? Is it better to make adjustment at where the compressor will be set most of the time such as 2-3 db of compression or is it better to stick with 0db of compression or go higher to -5db of compression. I hope to mess around with this this weekend.
Cool. With Y cable and thresholds CCW measure the voltage across the outside threshold pot tags again. If one is higher voltage a resistor can be added to bring it down to match the lower voltage side and then the makeup trim will need to be redone. This can sometimes balance the threshold pot mid point but not always as pots are +/-10%
Thanks so much for the info Joe. Will another 500k trimmer work ok? Just to clarify I’ll be measuring voltage on the pot tabs when the unit is on and running with no compression and not the ohms when unit is off. Since I will only add a max of 1-2 db of compression as a 2buss compressor should I set the meters to -2db of compression and check the VAC on the outputs and adjust the new trimmer on the threshold pot until outputs are equal? Is it better to make adjustment at where the compressor will be set most of the time such as 2-3 db of compression or is it better to stick with 0db of compression or go higher to -5db of compression. I hope to mess around with this this weekend.
The resistor will probably need to be higher than that. But unplug the 2 pot pcb cables from the sidechain pcb and measure the 2 threshold pot outside terminals with pot fully CCW. And let me now the ohms for each. Then plug it all back together and let me know the vac across each pot still fully CCW with the Y cable 1.23v input so I can double check and I can then calc the value needed.
Ok here are the measurements CH A had .316 vac and 98.8k ohms with pcb cables unplugged. Ch B had .307 vac and 88.3k ohms with pcb cables unplugged. Settings are, y cable with 1.23vac at inputs. 1.3 ratio, VU, and flat. Do people tend to just build these units and not fine tune them at all? Have people added stepped pots for recall purposes?
Thanks,
-Scott
Ok here are the measurements CH A had .316 vac and 98.8k ohms with pcb cables unplugged. Ch B had .307 vac and 88.3k ohms with pcb cables unplugged. Settings are, y cable with 1.23vac at inputs. 1.3 ratio, VU, and flat.
Ok 98.8k in parallel with 831k = 88.3k. So you can try a 1Meg pot. Since pots are +/20% it will not guarantee the pots will be at the same point in the turn of the pot due to the log curve mismatch but can help. Once you balance the ac volts at these 2 points you will need to redo the makeup balance
Do people tend to just build these units and not fine tune them at all? Have people added stepped pots for recall purposes?
There is no need as it is all 0.1dB differences. So is a very percentage when even the best analog great +/-1% which is much great. Once you compress and makeup 0.1dB difference is nothing.
We have done fully stepped master comps with all this adjusted for some mastering places but there are a lot of other mods we do for that.
Ok 98.8k in parallel with 831k = 88.3k. So you can try a 1Meg pot. Since pots are +/20% it will not guarantee the pots will be at the same point in the turn of the pot due to the log curve mismatch but can help. Once you balance the ac volts at these 2 points you will need to redo the makeup balance
When you say 1Meg pot do you really mean 1Meg Trimmer? I won't do this if I have to switch out the pot, lol.
There is no need as it is all 0.1dB differences. So is a very percentage when even the best analog great +/-1% which is much great. Once you compress and makeup 0.1dB difference is nothing.
I know it is a very small difference but I think visually I just like to see the pots match, lol. OCD
Ok 98.8k in parallel with 831k = 88.3k. So you can try a 1Meg pot. Since pots are +/20% it will not guarantee the pots will be at the same point in the turn of the pot due to the log curve mismatch but can help. Once you balance the ac volts at these 2 points you will need to redo the makeup balance
When you say 1Meg pot do you really mean 1Meg Trimmer? I won't do this if I have to switch out the pot, lol.
There is no need as it is all 0.1dB differences. So is a very percentage when even the best analog great +/-1% which is much great. Once you compress and makeup 0.1dB difference is nothing.
I know it is a very small difference but I think visually I just like to see the pots match, lol. OCD
-Scott
1meg trimpot across the threshold outside pads. I would try 820k and 910k resistors myself and see which is closest to match and stay with that as it will drift less than a trimpot over time.
