Results 1 to 29 of 29

Thread: Yamaha EMX2000 Conversion to Passive PA

  1. #1
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0

    Question Yamaha EMX2000 Conversion to Passive PA

    I have been given a mixing desk which is badly in need of a good clean but should go alright once I replace the blown fuse I found yesterday- I want to convert the 200W speaker output to the monitors and have a passive signal running to powered front-of-house speakers (800W per side). Any help please? Here is a video link to my primary inspection of the desk- https://www.youtube.com/watch?v=PWLZBtkvlag

    0 Not allowed! Not allowed!

  2. #2
    Old Timer Leo_Gnardo's Avatar
    Join Date
    Sep 2012
    Location
    Dogpatch-on-Hudson
    Posts
    6,393
    Thumbs Up/Down
    Received: 1,413/21
    Given: 1,196/0
    Rep Power
    14
    I'm not familiar with this particular mix/amp but there should be line outputs for each mix. You should be able to use them, and no "conversion" needed.

    0 Not allowed! Not allowed!

  3. #3
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    There are (passive) line outputs for the monitors and (200W) line outputs for the mains- I need a lot more power for the mains than the 200W supplied by this particular mixer (and have that in my 800W powered PA speakers)- so I just need a signal to go from the desk to my powered PA speakers without losing the use of the sliders/potentiometers. I would like to be able to power the backline/monitors with the 200W amp- can I just swap the signal output from the monitors with the mains running into the amp? (The mains line-outputs would then become the line-outs for the monitors and vice-versa)

    0 Not allowed! Not allowed!

  4. #4
    "Thermionic Apocalypse" -JT nickb's Avatar
    Join Date
    Dec 2009
    Location
    Devon, UK
    Posts
    3,566
    Thumbs Up/Down
    Received: 762/1
    Given: 600/1
    Rep Power
    13
    Yes!

    On the rear panel on the right are two jacks labelled Outout L and R next to the foot switch jack. All you need to do is connect these to your powered speakers.

    Click image for larger version. 

Name:	Yamaha 2000.JPG 
Views:	82 
Size:	41.1 KB 
ID:	45224

    Connect your backline/monitors to the speaker outputs.

    0 Not allowed! Not allowed!
    Experience is something you get, just after you really needed it.

  5. #5
    Don't forget the joker g1's Avatar
    Join Date
    Feb 2010
    Location
    Canada, somewhere north of Fargo
    Posts
    11,759
    Thumbs Up/Down
    Received: 1,615/23
    Given: 4,135/11
    Rep Power
    22
    To assign the mixers power amps to monitors, patch mon1 and mon2 outputs to PAMP IN L&R jacks.

    0 Not allowed! Not allowed!
    Just because they don't have tubes doesn't mean they don't have feelings! - glebert

  6. #6
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by nickb View Post
    Yes!

    On the rear panel on the right are two jacks labelled Outout L and R next to the foot switch jack. All you need to do is connect these to your powered speakers.

    Click image for larger version. 

Name:	Yamaha 2000.JPG 
Views:	82 
Size:	41.1 KB 
ID:	45224

    Connect your backline/monitors to the speaker outputs.
    Yeah- I kind of figured that one out- and then I can run each monitor as MON1 MON2 MONO on the sliders with ST1 slider still in operation (and ST2 control for another PA line out)

    0 Not allowed! Not allowed!

  7. #7
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Apparently the fuse had already been replaced since the desk crashed- I'm going to have to start from the beginning and maybe replace the power supply.

    0 Not allowed! Not allowed!

  8. #8
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by g1 View Post
    To assign the mixers power amps to monitors, patch mon1 and mon2 outputs to PAMP IN L&R jacks.
    Cheers- that might work.

    0 Not allowed! Not allowed!

  9. #9
    Don't forget the joker g1's Avatar
    Join Date
    Feb 2010
    Location
    Canada, somewhere north of Fargo
    Posts
    11,759
    Thumbs Up/Down
    Received: 1,615/23
    Given: 4,135/11
    Rep Power
    22
    If you want 2 monitor mixes like that.
    Whatever you patch into the PAMP IN jacks will over-ride the setting of the power amp assign switch.

    0 Not allowed! Not allowed!
    Just because they don't have tubes doesn't mean they don't have feelings! - glebert

  10. #10
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0

    Power supply problem

    Quote Originally Posted by g1 View Post
    If you want 2 monitor mixes like that.
    Whatever you patch into the PAMP IN jacks will over-ride the setting of the power amp assign switch.
    Any tips on where I should start to test the power supply? Will I need a variac for this job? I'm still considering removing the amp and making it run as an unpowered desk.

    0 Not allowed! Not allowed!

  11. #11
    Old Timer Leo_Gnardo's Avatar
    Join Date
    Sep 2012
    Location
    Dogpatch-on-Hudson
    Posts
    6,393
    Thumbs Up/Down
    Received: 1,413/21
    Given: 1,196/0
    Rep Power
    14
    Quote Originally Posted by RandomJRogers View Post
    Any tips on where I should start to test the power supply? Will I need a variac for this job? I'm still considering removing the amp and making it run as an unpowered desk.
    How do you know whether it's power supply or power amp problem? Has the fuse blown again since you've replaced it?

    If you bring up power with a variac it's sensible to monitor the current with an ammeter. No ammeter? We have directions how to build and use a light bulb current limiter as a sticky.

    Let's not go about rebuilding power supplies or amps until proven necessary.

    If the power amps are shot your proposed solution of removing them may be a good way to go.

    0 Not allowed! Not allowed!

  12. #12
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Leo_Gnardo View Post
    How do you know whether it's power supply or power amp problem? Has the fuse blown again since you've replaced it?

    If you bring up power with a variac it's sensible to monitor the current with an ammeter. No ammeter? We have directions how to build and use a light bulb current limiter as a sticky.

    Let's not go about rebuilding power supplies or amps until proven necessary.

    If the power amps are shot your proposed solution of removing them may be a good way to go.
    I don't have any equipment besides a multi-meter and a soldering iron- but I will be looking at buying some new gear as required. I would really like to just run the desk without the amp so if any help can be given in that regard then it would be much appreciated- my next project will probably be using the (uninstalled) amp to build a 400W bass head.

    0 Not allowed! Not allowed!

  13. #13
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    And I don't have any replacement fuses right now- have to wait until I get into town.

    0 Not allowed! Not allowed!

  14. #14
    Old Timer J M Fahey's Avatar
    Join Date
    Oct 2007
    Location
    Buenos Aires, Argentina
    Posts
    11,753
    Thumbs Up/Down
    Received: 1,881/23
    Given: 1,463/35
    Rep Power
    27
    Very little info supplied so far, but it looks like te power amp, or *maybe* the power supply is damaged, and blowing fuses.
    IF so, new fuses will also blow, unless you repair the main problem.
    Blowing fuses is a symptom, not the cause of the problem.

    If your mixer is built as 3 well separated systems, such as preamp/power amp/power supply, then you might unplug just the power amp board and run just the mixer, fed from the power supply, canīt be more precise until somebody posts the schematic.

    Just to save time, search for it and post it here.

    0 Not allowed! Not allowed!
    Juan Manuel Fahey

  15. #15
    Supporting Member Jazz P Bass's Avatar
    Join Date
    Dec 2008
    Location
    Wernersville, PA
    Posts
    12,924
    Thumbs Up/Down
    Received: 523/3
    Given: 280/0
    Rep Power
    26
    Here is the SM: yamaha_emx-2000_sm.zip

    0 Not allowed! Not allowed!

  16. #16
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by J M Fahey View Post
    Very little info supplied so far, but it looks like te power amp, or *maybe* the power supply is damaged, and blowing fuses.
    IF so, new fuses will also blow, unless you repair the main problem.
    Blowing fuses is a symptom, not the cause of the problem.

    If your mixer is built as 3 well separated systems, such as preamp/power amp/power supply, then you might unplug just the power amp board and run just the mixer, fed from the power supply, canīt be more precise until somebody posts the schematic.

    Just to save time, search for it and post it here.
    F103 is the fuse that has burnt out (thanks for the schematic)- 1A 250V- I don't seem to be able to order this fuse (5mmX20mm) unless it is a 250VAC.
    There is obvious damage to D115 and D116 caps on the power amp board but I don't know where to start to find out why the F103 fuse is blowing- any help?
    And what kind of power supply would I need just to run the pre-amp/mixer desk? That is actually my first priority as I plan to separate the power amp from the mixing desk.
    I have cleaned the pots and sliders and everything is moving nicely- one potentiometer (Effects Monitor1) had some severe rust/corrosion and may need replacing but everything else looks good- https://youtu.be/ILkn7fxp5uQ

    0 Not allowed! Not allowed!

  17. #17
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    32,042
    Thumbs Up/Down
    Received: 1,825/7
    Given: 0/0
    Rep Power
    55
    F103 is the fuse that has burnt out (thanks for the schematic)- 1A 250V- I don't seem to be able to order this fuse (5mmX20mm) unless it is a 250VAC.
    I don't understand the problem, you need a fuse rated for 250 volts, and all you can find are fuses rated for 250 volts.

    0 Not allowed! Not allowed!
    Education is what you're left with after you have forgotten what you have learned.

  18. #18
    Old Timer Leo_Gnardo's Avatar
    Join Date
    Sep 2012
    Location
    Dogpatch-on-Hudson
    Posts
    6,393
    Thumbs Up/Down
    Received: 1,413/21
    Given: 1,196/0
    Rep Power
    14
    Quote Originally Posted by RandomJRogers View Post
    F103 is the fuse that has burnt out (thanks for the schematic)- 1A 250V- I don't seem to be able to order this fuse (5mmX20mm) unless it is a 250VAC.
    There is obvious damage to D115 and D116 caps on the power amp board but I don't know where to start to find out why the F103 fuse is blowing- any help?
    And what kind of power supply would I need just to run the pre-amp/mixer desk? That is actually my first priority as I plan to separate the power amp from the mixing desk.
    Don't worry about the voltage rating on that fuse. 250V is the usual item.

    If the damaged caps were replaced maybe the fuse would hold? It's worth a try. Age damages electrolytic caps - it may be a good idea to replace the matching caps on the other power amp.

    If you disable or remove the power amps, the power supply you have will work just fine for the mixer. There are voltage regulators in it to run the preamp/mix department. The power supply will be relieved of its task running the power amps, so that's also a no worry situation. Why replace it unless you want to spend a lot of time & effort doing something you don't know how to do. Granted a smaller supply would reduce some weight. But is it worth the effort to save a couple of kilograms?

    0 Not allowed! Not allowed!

  19. #19
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Jazz P Bass View Post
    Here is the SM: yamaha_emx-2000_sm.zip
    Thanks!

    0 Not allowed! Not allowed!

  20. #20
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Leo_Gnardo View Post
    Don't worry about the voltage rating on that fuse. 250V is the usual item.

    If the damaged caps were replaced maybe the fuse would hold? It's worth a try. Age damages electrolytic caps - it may be a good idea to replace the matching caps on the other power amp.

    If you disable or remove the power amps, the power supply you have will work just fine for the mixer. There are voltage regulators in it to run the preamp/mix department. The power supply will be relieved of its task running the power amps, so that's also a no worry situation. Why replace it unless you want to spend a lot of time & effort doing something you don't know how to do. Granted a smaller supply would reduce some weight. But is it worth the effort to save a couple of kilograms?
    Yes, I think so- mostly because I want to use the power supply later if I do something else with the power amps- and I'm thinking the pre-amp/mixer will run on a pretty small transformer? I will look at testing/replacing any similar caps but I think I really need a variac to do any serious testing- would a 5A variac be sufficient for this job? These are the specs-

    'Single Phase 200 to 250 Volts Variable AC Transformer output from 0 to 270 volts 1000VA 5 Amps'

    -otherwise I would be keen to build the light bulb current limiter (does this function in place of a variac or an ammeter? I think my multi-meter will do the job of an ammeter, otherwise I can buy one if I think I'm going to be using it a lot)

    0 Not allowed! Not allowed!

  21. #21
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Jazz P Bass View Post
    Here is the SM: yamaha_emx-2000_sm.zip
    I just found the part number/s for the blown fuse and there are three different parts listed- none of them 1A 250V as was installed.
    How do I know which of these is the correct part (page 66 of the above schematic)?
    F103 (fuse)
    *VS823400 (10.00A JUC)
    *VV314500 (SIC(TL) 7.00A JU)
    *VV071700 (TSD 3.15A 250V SEM)

    0 Not allowed! Not allowed!

  22. #22
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    32,042
    Thumbs Up/Down
    Received: 1,825/7
    Given: 0/0
    Rep Power
    55
    You look at the notes column. Now refer to the opening page of the parts list, page 37 of the file. The A is for Australia. SO you want the fuse with the A note, looks like 3A slow.

    0 Not allowed! Not allowed!
    Education is what you're left with after you have forgotten what you have learned.

  23. #23
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0

    Cool

    Quote Originally Posted by Enzo View Post
    You look at the notes column. Now refer to the opening page of the parts list, page 37 of the file. The A is for Australia. SO you want the fuse with the A note, looks like 3A slow.
    3.15A? I'd like to know what 'TSD' and 'SEM' stand for but that's definitely the right one. Cheers!

    0 Not allowed! Not allowed!

  24. #24
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    32,042
    Thumbs Up/Down
    Received: 1,825/7
    Given: 0/0
    Rep Power
    55
    I think SEM is short for SEMKO, spelled out in some descriptions farther up the page.

    TSD is the type fuse, a time delay fuse, aka slow blow.

    http://www.optifuse.com/PDFs/TSD.pdf

    0 Not allowed! Not allowed!
    Education is what you're left with after you have forgotten what you have learned.

  25. #25
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Enzo View Post
    I think SEM is short for SEMKO, spelled out in some descriptions farther up the page.

    TSD is the type fuse, a time delay fuse, aka slow blow.

    http://www.optifuse.com/PDFs/TSD.pdf
    All I could get at the electrical shop was a ceramic 3.15A fuse- I installed it and turned on the power- the power indicator light came on for an instant but nothing else.
    Time to buy a variac?

    0 Not allowed! Not allowed!

  26. #26
    Old Timer J M Fahey's Avatar
    Join Date
    Oct 2007
    Location
    Buenos Aires, Argentina
    Posts
    11,753
    Thumbs Up/Down
    Received: 1,881/23
    Given: 1,463/35
    Rep Power
    27
    Build a lamp bulb limiter which is faster, cheaper, and "automatic".
    if you still have a short (I guess you still do), it will harmlessly shine bright and let you do some measuring.
    And you won{t blow fuses while testing.

    0 Not allowed! Not allowed!
    Juan Manuel Fahey

  27. #27
    Old Timer J M Fahey's Avatar
    Join Date
    Oct 2007
    Location
    Buenos Aires, Argentina
    Posts
    11,753
    Thumbs Up/Down
    Received: 1,881/23
    Given: 1,463/35
    Rep Power
    27
    Just checked the schematic.
    1) you certainly chose a complex amplifier to "start swimming" into Electronics.
    Like being dropped in the middle of the Atlantic

    2) those are Darlingtons, whicnh means replacing the power transistors automatically replaces drivers with them.
    You might give it a try.

    * replace the 3.15A main fuse
    * plug amp into bulb limiter (use a 60/75W incandescent or quartz bulb)
    * it will probably shine bright, indicating a short
    * measure all power transistors for shorts, with amp unplugged from mains and after , say, 10 minutes so all voltages discharged. Just in case measure voltage across main caps.
    With meter set to diode check, check for CE shorts at Q117-119-123-121-111-118-120-124-122-112 and replace any bad one.
    Also check that resistors R131-132-231-231 have not blown open.
    Just replacing blown power transistors might restore amp function.

    The amp is more or less conventional, although Class F/G/H (never remember the differences) but an experienced Tech can repair it, the keyword is *experienced* , definitely not a project for a beginner .
    You may try your luck at replacing the main suspects I mentioned above, they are less than $5 each at Digikey ... any more complex problem turns the amp into a boat anchor.

    3) all supplies and power amps lie on the same PCB, so you can{t separate them.
    IF you wish to disconnect the Power Amp and try to use the Mixer (plus effects, Phantom power, etc) on its own, feeding an external power amp, you have two "crude but simple" ways to avoid the dead power amp sucking all blood from your current power supply and blowing the main fuse:
    a) remove the main rectifier bridge, D307
    b) cut transformer wires leading to pins 4-6 on Connector CN102, coming from the power transformer.
    Leave 2" pigtails on the connector, tape ends, same with transformer cable ends and tie them safely so they are not bouncing around, you cut main amp power feed but Mixer supply should still work.

    Some day in the future you might repair that power amp or pay a Tech to do so.

    0 Not allowed! Not allowed!
    Juan Manuel Fahey

  28. #28
    Junior Member
    Join Date
    Oct 2017
    Location
    Herberton, Qld.
    Posts
    15
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    I have made a neat little light bulb tester and my 100W globe is shining brightly- now I will start following the above advice. What are the chances that the power transformer has shorted?

    0 Not allowed! Not allowed!

  29. #29
    Old Timer J M Fahey's Avatar
    Join Date
    Oct 2007
    Location
    Buenos Aires, Argentina
    Posts
    11,753
    Thumbs Up/Down
    Received: 1,881/23
    Given: 1,463/35
    Rep Power
    27
    You can check it yourself, unplug the 6 wire connector CN102 which feeds both power amp and preamp supplies and turn amp on again, still through limiter.
    If bright shining, the PT is kaputt.
    If dark orange or red, thatīs the normal idle current pulled by any healthy transformer, no big deal.
    In this case momentarily disconnect power amp feed by any of the methods suggested above, plug CN102 again into the main board and turn amp on (still through limiter), mixer Leds should turn on , in fact mixer "should" work, although maybe at reduced performance.
    IF it works (hope so), plug mixer straight into mains, main fuse should not blow, and mixer should work properly, which was your basic goal.
    You may then try to repair the power amp, now witfidence that effort wonīt be in vain.

    It would be VERY frustrating to spend time and money to repair power amp and then find mixer section is dead or something, although I think it will work, the **abused** parts in any amplifier are Power Amp and then Power Supply.

    0 Not allowed! Not allowed!
    Juan Manuel Fahey

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Davis 201A PA Conversion
    By Pdavis68 in forum Conversion Projects
    Replies: 87
    Last Post: 08-10-2015, 12:29 AM
  2. Help with PA Conversion
    By Jeru in forum Guitar Amps
    Replies: 18
    Last Post: 04-30-2015, 09:59 AM
  3. Help with a Yamaha EMX2000 Schematic
    By stereomonostereo in forum Other Amps
    Replies: 3
    Last Post: 03-03-2015, 07:58 PM
  4. Thordarson PA amp conversion
    By Rhodesplyr in forum Conversion Projects
    Replies: 0
    Last Post: 12-19-2008, 07:01 PM
  5. Old swedish pa amp conversion
    By 5Trout in forum Conversion Projects
    Replies: 9
    Last Post: 03-06-2007, 05:43 PM

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •