EMU 1820M not working properly

[savroo]

Re: EMU 1820M not working properly

Hi I'm not sure if this forum is still live or not. My 1616m had problems with phantom power. Whenever a powered mic was used I would get a lot of noise and output number 2 failed ie no sound. I changed all aluminium cylinder type capacitors within the external dock. The unit works but balance between left and right is now not right. Right hand is 5 db higher than left. Would anyone know what the problem could be??? I did all the soldering myself and bought audio type capacitors. The 4x caps near the phantom power input are bi-polar so changed them with the correct ones aswell.

[Agent24]

Re: EMU 1820M not working properly

Not sure about the audio level difference, if you have a scope you can maybe trace through the signal path and find where it changes and get some idea what might be wrong...

But if you replaced *ALL* the electrolytics with audio grade capacitors that is a problem, some of the capacitors are for the onboard power supply circuit which will require Low ESR capacitors.

[savroo]

Re: EMU 1820M not working properly

Thks for your feedback. I was trying to put pics up of my soundcard with new caps but I'm on my iPhone so can't get to upload. I don't have a scope but all but 1 capacitor I managed to get audio quality which I think was fitted in the power supply area. So I need to change power supply to low ESR. Is there anyone in the UK who would repair this for me???

I have limited knowledge about electrics,bought the capacitors from digikey all are correct values but when choosing selected audio use and just bought the most expensive ones that would fit.

I have emailed a few audio repair places but no one has replied back. I have 2x external docks and probably wAnt both repaired.

Regards

Sav

[Agent24]

Re: EMU 1820M not working properly

They will work for now, but in a switchmode DC\DC converter or whatever this thing has, audio grade capacitors will not last long. Of course, audio grade capacitors would be great in the actual audio circuitry, you don't need to change those ones.

But, the wrong capacitors are probably not the cause of one channel being quieter than the others. If you changed any capacitors in the signal path, though, you may have caused a problem if you have a bad solder joint somewhere for example.

Put up some photos of your soldering, what you changed including what was there and what you changed them to.

[fabiophonic]

Re: EMU 1820M not working properly

Hi, I have a little problem with my E-MU 1820. The 4R Out has drop volume respect to 4L Out. The outputs are balanced and if I connect the ring, the voulme is ok, but the tip is very low. Is there any solution? For now I'm using a mono jack plugged partially inside the 4R Out connector, so the tip touch the ring part. Same for the 4L for phase reason.

Thankyou in advice.

[naichi2]

Re: EMU 1820M not working properly

I have a Card Bus 1616 with the Breakout box and have got this Crack and pops & clicks for a while. Later it became worse but it doesn't show up right away. When it was at its worst I had to shut it down but trying turning it on just lit all the light and never went online again and it had to be off for like 20+ min. Then I could start it again.

I have replaced all in the power circuit except to yellow ones due I got the wrong voltage for some reason. So I have to order new ones but the question is, Should I even change these many small ones to?

My error before was like if I had a TRS cable connected on one of the inputs it didn't start, but if I removed it, it would start.

After changing these caps it now have become better, even if it clicks sometimes I can shut it off and on again. (yay?) either way. Suggestion? I know I have some Jamicon caps but that's what I got from the dealer. They should be okay for a while.

Funny is those RN Caps on picture three. They didn't have any polarity marking but I put my new ones as the rest. Perhaps I messed up with the parts ? Those I got was considerably smaller than the original but I know that caps get smaller and better? The 4x RN Caps were sitting in picture two top right.

Best Regards Jonas

EDIT : I just realize I put Polar caps instead of Bi-polar caps at the Mic Preamp. Need to change that.

[mhelin]

Re: EMU 1820M not working properly

Hi, I have a little problem with my E-MU 1820. The 4R Out has drop volume respect to 4L Out. The outputs are balanced and if I connect the ring, the voulme is ok, but the tip is very low. Is there any solution? For now I'm using a mono jack plugged partially inside the 4R Out connector, so the tip touch the ring part. Same for the 4L for phase reason.

Thankyou in advice.

Check the output section. I had similar problem (1820M) with the SMD MOSFET's used as switches, they were marked "6K". Measured (without power) the Rds and in lower output level channels that was way below (something like 18k vs. 54k) causing voltage drop.

[Agent24]

Re: EMU 1820M not working properly

6K on the package will not mean '6k ohms', you need to look up that code in an SMD codebook and find what type of device it is

[budm]

Re: EMU 1820M not working properly

"Check the output section. I had similar problem (1820M) with the SMD MOSFET's used as switches, they were marked "6K". Measured (without power) the Rds and in lower output level channels that was way below (something like 18k vs. 54k) causing voltage drop."
Rds in K Ohms range? That will be very lousy switch.

"6K on the package will not mean '6k ohms', you need to look up that code in an SMD codebook and find what type of device it is" +1

[redwire]

Re: EMU 1820M not working properly

Can you post a clear pic of the board. I can't find any schematics or service manual for the EMU 1820M.
People using the wrong cable wiring to connect balanced outs to unbalanced ins. One of the balanced outputs gets shorted to GND and damages the line driver IC. I'm assuming the EMU has 600 ohm bal outs?

SMD marking code "6K" could be an On-Semi/Central Semi N-ch JFET switching transistor MMBF4392 or Vishay P-ch MOSFET TP0610K

If it's a JFET, it might be for muting and would explain strange ohmmeter readings.

[mhelin]

Re: EMU 1820M not working properly

The measured ohms are in circuit without power, the device is biased by the DMM and resistors around. Using another DMM you might get different readings.

Anyway, I used TP0610K and was able to fix all but one channel (it still measures the lower ohmage). I also noticed a similar problem in one input channel (didn't fix that yet).

[deemic]

Re: EMU 1820M not working properly

Hi everyone. New here so I don't know if this was already addressed, but I just wanted to let the 1616m owners know that the fix for the 1820 (replacing the two 680 uf 10V caps next to the transformer on the breakout box) also worked to fix my 1616m. I also replaced the five 220uf caps in the same area that appeared to be bulging. None of the caps were leaking, but all seven of them were bulged. The original problem with the unit was that I could only get minimal and unusable output from any of the outputs. There was also a lot of "popping" if I tried to increase the volume through Patchmix.

[kozard]

Re: EMU 1820M not working properly

I am in the process of trying to fix an E-MU 1616m. When I opened it up I found that quite a few capacitors had already been replace by someone else. (The previous owner claims to know nothing about that.) I did find that the two 680uF 10V caps for the 5V SMPS were completely shot and had not been replaced while the 220uF caps had already been replaced. (However I wonder if the 220uF replacements are fake Nichicons or real Nichicon BT series.) In addition 8 capacitors had been replaced next to two of the AKM ADC chips.

However I also removed and measured some of the other capacitors.

I found that the little (4mm?) Jamicon 10uF 16V capacitors next to the AKM ADC chips were bad. Two measured around 30 Ohms and the others measured around 130 Ohms. I did not have any 4mm caps but I was able to fit in some 5mm Panasonic "M" 22uF 63V 5mm diameter caps.

So while this is an old thread I was wondering if anyone could advise which other capacitors I should look at replacing while I am trying to repair this. (Such as on the other card in the two PCB sandwich.) Given how old these 1616m are I was wondering if anyone else had ventured beyond the G-Luxon capacitors in the SMPS and found others that need replacement that I should look at?

I noticed that my PCI card for my E-MU 1820 also contains the same G-Luxon capacitors as well as those Jamicon 10uF 16V capacitors. As a result I am thinking I should replace those on the PCI card and also consider which should be replaced on the "other" card with the DAC, Xilinx FPGA and mic preamps on it.