E-mu Emulator Sampler User Forum for the EIII EII EI and EIII XP

I purchased a fixer upper EII+ HD over the weekend. I spent about 10 hrs+ trying to revive her, as she was dead when purchased. I got it to boot from the hard drive and loaded some sound banks, but during tests I discovered that voices 4 and 5 are not working. I get sound on output 5 sometimes but it sounds strange. The sound on output 5 sometimes just loops endlessly until I keep pressing other keys to cancel it out. I tried swapping the SSM chip with a known good voice but it did not work.

My other issue ,which is bigger than the dead voices, is the sampling does not work. When I hit the sampling module button I get loud (75%+ on the VU Meter) metallic noise. I get noise regardless whether there is an input source or not.

Any help or suggestions will be greatly appreciated. I wanted to be in this club for the longest and here I am, like most trying to bring this baby up to its fullest potential.

rtech

On the deficient voices, take off the S3528 and put them back in place.

Voice 5 : does it do the endless sound if you launch the note in MIDI, and ont from your E2 keyboard ?

dr. c,

  Thanks for the advice. I cleanded the ICs on the voice board and did get channel/voice 4 working, but 5 is still doing the looping thing. I will try using a midi controller to triger the voice later on tonight. I will get back with the results.

  On another post I read that sometimes this issue could be caused by a defective ram chip where the OS loads to. Which RAM IC # does the OS use? I have an EII+ HD so I figure I can swap them with the second bank chips. My Digital board is Rev.1 and it does not have the piggyback memory board.

Once again thanks for the advice. 

rtech

Dr. C and  any one else that can help,

  I tried triggering the sounds with a MIDI Controller and the same thing, Voice 5 loops endlessly until I cancel it out with other keys.

  I also did some more test on the Sampling Noise. I tried trimming the AD but when I test the voltage with the Sampling Module Selected on IC75(Pin 1) I get almost 10V, without Sampling Enabled it get a very small voltage in the mV range. I could be wrong about the IC Number as I am at work and going based on memory(I tried this over the weekend). According to the Repair Manual the difference in voltage between Sampling Enable and when it is disabled should be 10mV or less. When I sample something into the EII I can hear it but very distorted. I get the best sound when using the max Gain of +40DB, when I use no gain I can barely hear the sample(what I hear is mostly metallic sounding noise).

What could be the issue? A defective IC, Resistor or is the Trim defective?

  I am getting closer and closer to having a fully functioning EII, any help or advice will be apprecitated.

--Update: I did further test on Voice 5 and discovered that if it does not loop, the sound coming from it sounds at full level/higher than the other voices it also sounds distored. I know it is channel 5 related because when I dissable the voice the problem goes away.


Thanks.

rtech

Any one with any suggestions?   :-[

  I did some more tests but are still having issues with voice number 5. I swapped all the ICs listes on the service manual on voice 5 with a known good voice, but the problem of the voice looping endless still persist. I am begining to think the problem is within the digital board. Any tips on which IC to check?

  I am also trying to fix the sampling problem, like I stated on an earlier post the sound input gets clearer when i increase the Gain to 40DB and set the gain button to Max. When I try to Trim the sampling gain using the instructions on the Repair Manual does not improve the Noise.

Please help with any suggestions.

Thanks.

I can not believe no body has suggestions. Please help me solve my Sampling Issue?

... it's also possible that no one has a clue how to solve the problem  ;)
The kind of problem mentioned by rtech is not of the type "very common, have seen that many times, so here's a hint...".
Dr C is the reference on this group for hardware stuff.
I guess if he doesn't reply, he doesn't have a hint neither.

That's crap. I only got my EII a year or so ago and got help in here but had to put in the work myself too to understand these things. You were pulled up about reading the manual the other week and I thought exactly the same thing at the time... Anyway, I've offered to help you with your EII & Sound Designer issues as you're in exactly the same position as I was a year or so ago. Be cool and let me know when you get that Apple SCSI CD rom.  ;)

BTW, sorry to go OT, but as E-Synthesist said, not everyone has the answers, particularly on very technical stuff.  
Rtech, do you have a vintage synth/kit tech anywhere you can get to? Where are you located? Some issues are just best taking to the experts, I had to also when I first picked mine up to sort out several things.

I am here in southern California. I know of forat and other techs out here but, one local one told me that the output and digital board needed replacement so I took it back and cleaned both boards and got it working except the two issues mentioned on earlier posts. I think the tech that I took it to didn't even open it to test it. Since I got it almost working properly and have been reading this user forum I thought some one here could help me.
 
  I will probably have to take it to forat or some other tech familiar with EMU stuff. I just have to put some money aside since it will probably not be cheap.

rtech

Well, at this point, I simply neither have a solution.
If I had one, OF COURSE I would post it in this thread.

One more try at this. I am getting too much noise coming from voice 5. I know is voice 5 beacause even when I turn the voice OFF from the special menu I get noise(Huming/Electrical noise ) from the Individual Out 5 and from the Mix Out. All the other 7 voices are perfect, I get nice clear tones from them.

Is there a way to permanantly dissable the voice (5)? Can I take out a specific IC so that nothing comes out of it?

Thanks,

rtech

Mmm... that's interesting.
It indicates that the problem should be in the final stage of the audio processing circuitry.
Maybe I should have a detailed look at the schematics...
...it seems like a problem that can be solved without killing the 5th voice permanently

.

never mind. thanks.....

Do you have a (digital storage) oscilloscope ?
To check where in channel 5 the distorted sound starts...

No, but I can get one from work. Is there any specific model/type that I need? Is there a specific frequency it has to support?

At first it would be for audio signal measurements (very simple - even analog - scopes can do this) to locate where it goes wrong, but of course finding the cause of that problem may require digital signal capturing, so having a certain amount of memory in a digital scope could help.
I'm using a Rigol DS1052E which is 2 channels at 50Mhz and 1MB of memory. The best buy I have ever done, and so cheap ! This DSO has been sufficient for me for servicing and reverse engineering all of my pre-1990 synths and samplers. 
Note that I don't know yet what is causing the problem in your EII - that's why signal measurements are important now, e.g. the output of the voice chips at channel 5 and comparing them with the other ones. Then let's see if we have to trace back OR forward from the SSM chip  ;) I hope forward...

The one at work is an older model, I check it today and it is only a 20MHz analog. I work at a computer store that used to repair computers back in late 80s early 90s. I dont think the scope has been turned on for about 10+ years. I hope it still works.  Will this do for just finding where the problem is? I have the schematics for the the eii, where will I need to probe?
Thanks for the help man, its greatly appreciated.

rtech

Sorry for late response - I forgot to check this thread...  ;)
The analog scope will probably be OK for finding out the location of the problem.
But I have to check my EII and the service manual now; unfortunately I will have less time to spend now because my holiday is over...
Anyway, maybe we'll have to go offline in order not to blow up this thread ? And come back with (hopefully) conclusions...

sounds good. When ever you have spare time, just tell me where to check/probe with the oscilloscope. I'll take it from there.

thanks

I'm checking the schematics...
But to be sure: you said that there's a distorted sound coming from voice 5 even if it is disabled.
Does this mean that you really ALWAYS have this hum coming from the mix out/channel 5 out, even without playing the EII but just having it powered on ? Or is the hum only there if you touch the keys ?

Probing would definitely start with measuring the signal on the IN and OUTs of the SSM2044 and the switched capacitor filter S3528. Both on voice 5 and another (good) voice, to compare signals.

(there may be a small practical problem though; I haven't opened my EII recently, but as far as I remember part of the output board on which we have to measure is beneath the PSU, so either the boards or the PSU will have to be moved a bit in order to get access to the ICs...)

I just tested it again and prior to playing anything on the keyboard there is no noise. After playing some notes I get the noise in both the mix out and channel/voice 5 regardless whether the voice is disabled. It sounds like residual noise after the notes are played back, I know is not the samples because the banks I am loading are original EMU sound disks.
You are correct about the power supply being above the voice 5 chips. It will get a little tricky testing them. I will open it and see what I can do. If it looks like too much for me to deal with I will take it to Forat or another repair shop.

And when you stop playing the keys this noise is remaining, so it's not disappearing anymore ? 

Thats correct it remains, even after I stop playing.

Although I don't own an Ell, I have a question and a comment.
Have you tried creating some samples of your own, and if so, do you still get the residual noise?
I recently picked up an Ensoniq EPS Classic with a library of 3.5 disks. Upon playing most of the samples on the disks I experienced the same thing you describe...a residual crackling type sound after releasing a note or chord.
If I turned the unit off and restarted it would be quiet in the outputs. I had purchased a new box of floppies to have on hand to save any samples I created.
When sampling my own sounds, and saving them to disk, I experienced no noise.

Thinking I might have to have it repaired, I went to the Ensoniq forum and described the problem. The overwhelming answer was corrupted disks, which most likely had deteriorated over time.

So I'm just wondering if this could be your problem as well. It would seem even if these are original EMU samples, if the media they were stored on is corrupted, then the source material wouldn't matter.

I hope it's something as simple as that, but as we know, it never seems to be. :-[

I cant sample with it because the sampling function is not working properly. There is a alot of noise on the sampling feature. I don't think it is because of corrupted data as the noise is there regardless whether I load sounds from a floppy, hard drive or transfer them from a Mac using SD for EII.

Another question (also interesting for me to know...): are the ICs such as the SSM voices plugged into a socket or are they soldered directly to the board ?
On mine, they are soldered directly, unfortunately...

Because one of the steps in tracing the problem would be to swap ICs between two channels. Desoldering will not be fun and can damage the ICs !

I would start with measuring the IN and OUT on the SSM2045 of channel 5:
- once before playing the a key for the first time
- once after playing the key (when noise has come up)
This is IC91, the IN is pin 2 and the OUT is pin 8; pin 9 can be used as ground for the probe (or another GND somewhere on the output board).
Is one of the signals changing into "noise" after hitting a key ?

If so, and it is the OUT but not the IN, the problem is quite clear.
If not, we have to go further (either back in the chain, or up to IC81)

I finally decided to go back and try to fix my sampling and voice issues with my EII+HD. Thanks to sfbaytech I was able to remove the HD option so I can have access to the voice 1 chips to try to fix the noisy sampling issue. I also used an analog oscilloscope to trace a sine wave input to see where it becomes noisy. The noise that i get sounds like "white noise" i tested with the scope and see the white noise going from Capacitor C95 on the service manual the label on that signal is +INPUT.V. it also comes out of IC86 pins 9,8 and 7. Does any one here know whether this is a blown capacitor issue? I already tried replacing the ICs that are listed on the schematics involved in the sampling circuit but the issues still persists.  

PS. Initially when i tried to fix this around a year ago, when I was in the sampling module the screen would show a very strong noise signal (almost the entire length of the display), but after i remove the HD components the noice is very small. When I first turn on the EII the noise is quiet high but after a few minutes of it being ON the noise decreases. It is still there but it is quiet low. I can sample but it sounds distorted like if its sampled at a very low sampling rate. I thought that I needed to do the sampling Trim procedure, but when I follow the instructions I am getting not Millivolts on the test point on IC 75 pin 1. What i get is a high voltage starting at a few volts and then rising to about 12+volts. If anyone has any suggestion I would appreciate it.

Thanks,

rtech