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

General Category => EI Technical Issues / Tips => Topic started by: brian_ronn on January 07, 2018, 01:27:55 PM



Title: Upper keyboard weirdness
Post by: brian_ronn on January 07, 2018, 01:27:55 PM
Hi Emulators

The upper keyboard is not playing the right key on certain keys. I've loaded the same sample to the lower and upper keyboard to compare the keys and here are the result:

Lower:   Upper:

C1            C1  (Thinner)
C#1          C#1 -
D1            F1   -
D#1          F#1 (Thinner and slightly out of tune)
E1            G#1 (Thinner)
F1             F1   -
F#1           F#1 -
G1            G1   -
G#1           G#1 -
A1             D2   -
A#1             E2   (Thinner and slightly out of tune)
B1             F2   (Thinner)
C2             F#2 (Thinner and Slightly out of tune)
C#2             G#2 (Thinner)
D2             D2   -
D#2             D#2 -
E2             E2    -
F2             F2    -
F#2             F#2  -
G2             G2    -
G#2             G#2  -
A2             A     (pitched higher than keyboard range)
A#2             A#    -
B2             E       -

Do you think this is this a wireing issue inside, faulty chips or another problem?

Best regards

Brian




Title: Re: Upper keyboard weirdness
Post by: Rio on January 08, 2018, 02:01:03 PM
Hi Brian,

did your Emulator react correctly to the Upper-Tune Pot, Upper Vibrato and the Pitch-Wheel ?

To me it looks like an issue with your Upper HF-VCO. It is located on the left front board and controls the pitch. At the schematic it is the upper part.

Did you have access to a oscilloscope and a little knowledge in measurement ?

Best regards
Rio

   


Title: Re: Upper keyboard weirdness
Post by: brian_ronn on January 09, 2018, 11:46:55 AM
Hi Brian,

did your Emulator react correctly to the Upper-Tune Pot, Upper Vibrato and the Pitch-Wheel ?

To me it looks like an issue with your Upper HF-VCO. It is located on the left front board and controls the pitch. At the schematic it is the upper part.

Did you have access to a oscilloscope and a little knowledge in measurement ?

Best regards
Rio

Hi Rio

Thank you for your reply :-)

The E1 reacts well to the upper tune pot but not to the upper nor lower vibrato. The upper and lower keyboard reacts well to the pitch wheel.

Today I tested the upper and lower keyboard with a choir. The lower part plays it well but the choir on the upper part is unrecognizable. On the upper part the choir sounds more like between a distorted choir and a didgeridoo. And many of the keys plays on the wrong key.

Unfortunately I don't have access to an oscilloscope and I'm a novice in that field. So I guess I'll have to find a skilled technician nearby.

Rio, thank you for the schematic too :-)

Best regards

Brian



   


Title: Re: Upper keyboard weirdness
Post by: Rio on January 10, 2018, 11:30:14 AM
Hello Brian,

interresting ... Tune Pot and Pitch Wheel are using the same path to propagate their control voltage to the HF-VCO. If both working correctly than it is unlikely a issue of the HF-VCO.
 
If distortion appears during playback of a note, it is also possible that a DMA Chip is not working properly.

Normally the voice distribution is as following :
- Lower Keyboard : 5 Voices   
- Upper Keyboard : 3 Voices
If you activate "Dynamic Allocation" and play more than 3 Notes in the Upper Keyboard at the same time the Emulator will use different DMA Chips. If this fix your problem than you should only replace the broken DMA Chip(s). If not ... it's better to contact a technician.

Good luck, and best regards from Germany
Rio