Sorry, not yet on the top of the projects pile.
Happy New Year!
Happy New Year!
Monitor Controller
- Thread starter JPK
- Start date
Help Support GroupDIY Audio Forum:
etiefenthaler
Active member
Hi, last two days I built an MC624 Monitor Controller successfully 
Pictures can be found here: https://www.dropbox.com/sh/5emp3xi7px24dc6/AACoCecGIMjkwpo5z1wb3s0ta?dl=0
Thanks a lot for this phantastic kit.
All is working fine.
One issue is, that on Headphone out theleft - right leves are not identical.
I noticed this on listening and then tested it out:
Fed the Controller with 1khz 1.274 V and measured Values on HP out
Pot Position Tip V trms Ring V trms
1 0.0002 V 0.0187
2 0.0502 0.0546
3 0.0956 0.0926
4 0.1400 0.1296
5 0.1956 0.1722
6 0.2478 0.2302
7 0.3333 0.3175
8 0.4751 0.4600
9 0.6879 0.6810
10 0.8577 0.8573
You see, the values differ a lot- maybe a bad 10K pot.
Is it possible to replace with dual gang pot with fixed values Switch?
Which part would you recommend?
Further question arose:
I try to measure Trms V Values @ 1Khz on XLR in and XLR out but I do not get usable values. Only on unbalanced Jack out.
There my meter detects 1khz only on 00 to -04 Setting.
Voltage values are equal on both channels on unbalanced Jack out.
Thanks a lot for Support.
Erich T
Pictures can be found here: https://www.dropbox.com/sh/5emp3xi7px24dc6/AACoCecGIMjkwpo5z1wb3s0ta?dl=0
Thanks a lot for this phantastic kit.
All is working fine.
One issue is, that on Headphone out theleft - right leves are not identical.
I noticed this on listening and then tested it out:
Fed the Controller with 1khz 1.274 V and measured Values on HP out
Pot Position Tip V trms Ring V trms
1 0.0002 V 0.0187
2 0.0502 0.0546
3 0.0956 0.0926
4 0.1400 0.1296
5 0.1956 0.1722
6 0.2478 0.2302
7 0.3333 0.3175
8 0.4751 0.4600
9 0.6879 0.6810
10 0.8577 0.8573
You see, the values differ a lot- maybe a bad 10K pot.
Is it possible to replace with dual gang pot with fixed values Switch?
Which part would you recommend?
Further question arose:
I try to measure Trms V Values @ 1Khz on XLR in and XLR out but I do not get usable values. Only on unbalanced Jack out.
There my meter detects 1khz only on 00 to -04 Setting.
Voltage values are equal on both channels on unbalanced Jack out.
Thanks a lot for Support.
Erich T
The headphone level is set by a "logarithmized" dual gang linear pot and does not have the same accuracy as the main level which is done by relays.
Your figures seem a bit "all over the place" and I am going to send you a replacement pot to check if it gets better.
It would be possible to use a 2x12 rotary switch and make a stepped attenuator. You will need a rather small device to fit the available space.
The AC voltage on XLR's must be measured between pins 2&3.
Your figures seem a bit "all over the place" and I am going to send you a replacement pot to check if it gets better.
It would be possible to use a 2x12 rotary switch and make a stepped attenuator. You will need a rather small device to fit the available space.
The AC voltage on XLR's must be measured between pins 2&3.
etiefenthaler
Active member
Thanks for fast answer.
I would really prefer a stepped pot for headphone. My Mytek 8/192 also has one on HP and i really like it.
I would be very grateful if you could source a matching dual gang stepped pot.
I do not understand why i firstly can measure Hz and trmsV with my Multimeter on XLR (pin 2-3) Cable befor plugging into Monitor Controller, but with cable plugged in I get other values and no Hz value on the MonitorController XLR Pins (2/3). This also on XLR out....
I really want to measure values on both Channels to be shure that there is no channel drift.
Edit:
Today I measured again. Values on XLR out are o.k. Must have been a contact issue with my DMM.
What I do not understand why my DMM only shows 1khz on att steps 00 to - 03. From -04 to -63 it doesent Show Frequenzy.
Below Values on XLR out:
Step CH1 In 1.280 V Ch2 In 1.280 V
00 1.2594 1.2580
-01 1.1248 1.1240
-02 1.0003 1.0000
-03 0.8930 0.8919
-04 0.7916 0.7905
-05 0.7073 0.7062
-06 0.6314 0.6300
-07 0.5635 0.5600
-08 0.5012 0.5016
-09 0.4474 0.4479
-10 0.3992 0.3995
-11 0.3564 0.3564
-12 0.3150 0.3148
-13 0.2813 0.2812
-14 0.2500 0.2508
-15 0.2239 0.2238
-16 0.1995 0.2002
-17 0.1781 0.1788
-18 0.1590 0.1596
-19 0.1418 0.1424
-20 0.1255 0.1254
-21 0.1114 0.1118
-22 0.0993 0.0996
-23 0.0889 0.0889
-24 0.0789 0.0790
-25 0.0704 0.0705
-26 0.0628 0.0628
-27 0.0558 0.0559
-28 0.0492 0.0492
-29 0.0434 0.0439
-30 0.0387 0.0390
-31 0.0344 0.0347
-32 0.0296 0.0298
-33 0.0263 0.0264
-34 0.0233 0.0234
-35 0.0206 0.0209
-36 0.0181 0.0183
-37 0.0161 0.0162
-38 0.0143 0.0144
-39 0.0125 0.0127
-40 0.0110 0.0112
-41 0.0096 0.0099
-42 0.0085 0.0087
-43 0.0074 0.0077
-44 0.0064 0.0066
-45 0.0056 0.0058
-46 0.0049 0.0051
-47 0.0043 0.0044
-48 0.0037 0.0039
-49 0.0033 0.0034
-50 0.0025 0.0028
-51 0.0023 0.0023
-52 0.0019 0.0019
-53 0.0016 0.0016
-54 0.0013 0.0013
-55 0.0010 0.0010
-56 0.0008 0.0009
-57 0.0006 0.0006
-58 0.0005 0.0005
-59 0.0004 0.0004
-60 0.0003 0.0003
-61 0.0002 0.0002
-62 0.0001 0.0001
-63 0.0000 0.0000
I think these values are really o.k. - bearing the inaccuracy of DMM in mind ..
For HP stepped Pot replacement I found this one:
http://www.ebay.com/itm/DACT-Type-SMD-Stepped-Attenuator-21-step-Volume-control-pot-D-Shape-Shaft-/181534837651?pt=LH_DefaultDomain_0&hash=item2a4451cb93
better part is always welcome.
I checked dimensions: max diametre could be 29 mm to main PCB. Front PCB could be cut out.
I want to say again, this is a phantastic kit and it is really a pleasure to build
Erich T
I would really prefer a stepped pot for headphone. My Mytek 8/192 also has one on HP and i really like it.
I would be very grateful if you could source a matching dual gang stepped pot.
I do not understand why i firstly can measure Hz and trmsV with my Multimeter on XLR (pin 2-3) Cable befor plugging into Monitor Controller, but with cable plugged in I get other values and no Hz value on the MonitorController XLR Pins (2/3). This also on XLR out....
I really want to measure values on both Channels to be shure that there is no channel drift.
Edit:
Today I measured again. Values on XLR out are o.k. Must have been a contact issue with my DMM.
What I do not understand why my DMM only shows 1khz on att steps 00 to - 03. From -04 to -63 it doesent Show Frequenzy.
Below Values on XLR out:
Step CH1 In 1.280 V Ch2 In 1.280 V
00 1.2594 1.2580
-01 1.1248 1.1240
-02 1.0003 1.0000
-03 0.8930 0.8919
-04 0.7916 0.7905
-05 0.7073 0.7062
-06 0.6314 0.6300
-07 0.5635 0.5600
-08 0.5012 0.5016
-09 0.4474 0.4479
-10 0.3992 0.3995
-11 0.3564 0.3564
-12 0.3150 0.3148
-13 0.2813 0.2812
-14 0.2500 0.2508
-15 0.2239 0.2238
-16 0.1995 0.2002
-17 0.1781 0.1788
-18 0.1590 0.1596
-19 0.1418 0.1424
-20 0.1255 0.1254
-21 0.1114 0.1118
-22 0.0993 0.0996
-23 0.0889 0.0889
-24 0.0789 0.0790
-25 0.0704 0.0705
-26 0.0628 0.0628
-27 0.0558 0.0559
-28 0.0492 0.0492
-29 0.0434 0.0439
-30 0.0387 0.0390
-31 0.0344 0.0347
-32 0.0296 0.0298
-33 0.0263 0.0264
-34 0.0233 0.0234
-35 0.0206 0.0209
-36 0.0181 0.0183
-37 0.0161 0.0162
-38 0.0143 0.0144
-39 0.0125 0.0127
-40 0.0110 0.0112
-41 0.0096 0.0099
-42 0.0085 0.0087
-43 0.0074 0.0077
-44 0.0064 0.0066
-45 0.0056 0.0058
-46 0.0049 0.0051
-47 0.0043 0.0044
-48 0.0037 0.0039
-49 0.0033 0.0034
-50 0.0025 0.0028
-51 0.0023 0.0023
-52 0.0019 0.0019
-53 0.0016 0.0016
-54 0.0013 0.0013
-55 0.0010 0.0010
-56 0.0008 0.0009
-57 0.0006 0.0006
-58 0.0005 0.0005
-59 0.0004 0.0004
-60 0.0003 0.0003
-61 0.0002 0.0002
-62 0.0001 0.0001
-63 0.0000 0.0000
I think these values are really o.k. - bearing the inaccuracy of DMM in mind ..
For HP stepped Pot replacement I found this one:
http://www.ebay.com/itm/DACT-Type-SMD-Stepped-Attenuator-21-step-Volume-control-pot-D-Shape-Shaft-/181534837651?pt=LH_DefaultDomain_0&hash=item2a4451cb93
better part is always welcome.
I checked dimensions: max diametre could be 29 mm to main PCB. Front PCB could be cut out.
I want to say again, this is a phantastic kit and it is really a pleasure to build
Erich T
This 21 steps attenuator looks very interesting.
It almost fits the available space , only requiring filing half a mm from the side of the front PCB.
Use the 10K one. The attenuator surely has a log law so you should remove R103 and R119 which were used to give the linear pot a log response.
Please keep us posted about your results.
It almost fits the available space , only requiring filing half a mm from the side of the front PCB.
Use the 10K one. The attenuator surely has a log law so you should remove R103 and R119 which were used to give the linear pot a log response.
Please keep us posted about your results.
etiefenthaler
Active member
Hi Matteo,
Yes I installed this stepped pot and desoldered the two resistors.
Its working great. Mounting shaft diameter is too small so i had to make a bush for proper fitting.
Besides that, one day surprisingly I had a replacement pot from JPK in my mail. Awesome service!
Kudos
At the moment I am happy with the low cost stepped pot.
Erich
Yes I installed this stepped pot and desoldered the two resistors.
Its working great. Mounting shaft diameter is too small so i had to make a bush for proper fitting.
Besides that, one day surprisingly I had a replacement pot from JPK in my mail. Awesome service!
Kudos
At the moment I am happy with the low cost stepped pot.
Erich
Trench Recordings
Well-known member
Hi,
Can i get a north America 120V powersupply with the kit ?
Can i get a north America 120V powersupply with the kit ?
ruairioflaherty
Well-known member
Trench Recordings said:
The outboard PSU is a switcher and is happy with anything from 100 to 240VAC.
Trench Recordings
Well-known member
Super fast shipping and it comes with m&m's
kinglok
Member
- Joined
- Jan 9, 2015
- Messages
- 9
Hi,
Finally, I have built the monitor controller. It is just GREAT.
However, I would like to ask two things.
1. Is it possible to use OP604 instead of OP134? The sound quality would be much more superior if changing that? They are directly interchangeable?
2. I would like to add a meter for the monitoring. Would you mind pointing me what part / product I can buy for 624?
Kinglok, Fong
Finally, I have built the monitor controller. It is just GREAT.
However, I would like to ask two things.
1. Is it possible to use OP604 instead of OP134? The sound quality would be much more superior if changing that? They are directly interchangeable?
2. I would like to add a meter for the monitoring. Would you mind pointing me what part / product I can buy for 624?
Kinglok, Fong
Attachments
1. Yes you can use OPA604 in place of OPA134, they are compatible. I doubt you can hear a difference but I could be wrong.
2. You can use any meter as long as it is buffered (and powered). Are you looking for moving coil or LED?
2. You can use any meter as long as it is buffered (and powered). Are you looking for moving coil or LED?
Trench Recordings
Well-known member
Just wanted to say Thanks! Amazing kit, had everything needed and went together easy. I can already hear the difference from my last setup.
IR Remote control works great too 8)
IR Remote control works great too 8)
My personal experience with stereo pots is that they never match.
The same thing happens in the Dangerous Monitor ST on all of the physical pots.
When you are in the lower range of the pot, the stereo is way off balance.
Had the same with a SPL stereo monitor box, had to keep the DIM on the be in the right range of the pot.
It just has to be expected I guess.
These stepped pots are more acurate but they feel strange, no?
The same thing happens in the Dangerous Monitor ST on all of the physical pots.
When you are in the lower range of the pot, the stereo is way off balance.
Had the same with a SPL stereo monitor box, had to keep the DIM on the be in the right range of the pot.
It just has to be expected I guess.
These stepped pots are more acurate but they feel strange, no?
Andy Peters
Well-known member
j.frad said:
I've been working on a monitor controller (scratching an itch, you know), and I went with the PGA2320 chips instead of stereo pots for exactly that reason.
-a
chadblinman
Member
kante1603
Well-known member
A very nice project you have here,exactly what I was after,thank you for sharing.chadblinman said:
I wished I could do this for my controller,but sadly I have no idea what's going on when it comes to digital stuff like this.
Best,
Udo.
Spiritworks
Well-known member
chadblinman said:
Very nice job
Similar threads
Latest posts
-
-
-
FEELER - Solid-state microphone upgrade boards (OpAmp, JFET, U87A, FET847, ORS87-Plus)
- Latest: wanderingengineer
-
-
-
