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

Welcome, Guest. Please login or register.
Did you miss your activation email?
March 28, 2024, 11:01:21 PM
Home Help Search Login Register
News: Problems registering? Send an email to: EIII @ telenet.be (without the spaces)

+  E-mu Emulator Sampler User Forum for the EIII EII EI and EIII XP
|-+  General Category
| |-+  EII Technical Issues / Tips
| | |-+  finally!
« previous next »
Pages: [1] Print
Author Topic: finally!  (Read 2819 times)
logiclust
Full Member
***
Offline Offline

Posts: 36


i like toast


WWW
« on: May 07, 2014, 09:14:39 AM »

so... i've finally benched my e2 and am happy it's only taken 2 years since i said i'd do it.  Roll Eyes
anyway, i've replaced all the switches and the thing is so much less annoying to use. most of the switches were fine, but some on the 10-key may it very frustrating to use. all better now

everything seems to function, but maybe not as well as it should. i'd like to know if there is some test/calibration procedure to attempt prior to pulling chips. luckily i have a puller, scope and a real test bench and a part store not too far away. my thought was to sample a 1k test tone at perhaps 1.2v (is the sampler +4 ref or -10)

My brother bought this new in '85 and it's been under my care for the past 15-20 years.

specs:
output board is Rev.1 - 15 May 1984 (30 years, yikes!)
memory option board Rev.0 - 30 april 1984
scanner 2.1
os 2.3
digital board Rev.0 - 10 April 1984
2 floppy drives

current issues:
-the backlight is out and i plan to swap with an LED ala http://www.vintagesynth.com/forum/viewtopic.php?f=3&t=48114&p=514848

- it seems some of the voices are a bit brighter. i use to think there was a stuck LFO on the filter freq but after picking through this board it sounds like the voice circuits are the issue so i need to learn how they work. I always used this think on its mix out so last night played with the voice outs. for each of the voice outs, if i play a note 8 times it will trigger once. is that normal?  without plugging it into my scope to look at the waveform, the note played out the individual voice outs sounded similar in tamber/level. I also noticed that there seemed to be less noise out the individual outs compared to the mix out. hmmm...

- while playing a note and adjusting filter settings with the sliders (which are shot btw) i experience some serious lag (~half second to a second) betwixt playing a note and hearing the note. i don't think that's normal.

- sliders are shot - what are the specs for them? i'd like to replace them with a newer part.

- it's a bit noisy and there's some distortion that wasn't there before, but i kinda like it. i don't want it there all the time though so i'll need to fix that.

- i've learned that emuser isn't possible for me. that makes me super sad. I thought emuser negated the need for rs422. Anyway, i don't have some piggy-back board plugged into the computer interface connector (protocol converter i'm assuming) maybe i'll make one. any specs on that thing?

Planed work:
- replace display (http://www.powertip.com.tw/products_2.php?product_id=1171043433&area_idbk=1170985616)
- install HxC (http://hxc2001.free.fr/floppy_drive_emulator/index.html#SDCARDFloppyemulator)
- replace LEDs - what's the LED package size? i'm assuming 5mm
- replace sliders - mouser/digikey part# or just the length should suffice.
- find spare chips
- replace PS with modern/efficient one. (maybe build my own? - just need to know proper voltages)

cheers and pics soon!

oh, i've got extra buttons

-L
Logged

EII, E4k, E4XT, Darwin
logiclust
Full Member
***
Offline Offline

Posts: 36


i like toast


WWW
« Reply #1 on: June 11, 2014, 01:41:29 PM »

UPDATES:

I've swapped all the switches and sliders and all calibrates.

Installed a new display from Newhaven, mentioned in another post. had to swap IC25 with 74LS04N to get it working correctly.

Installed the HxC and am playing with some sounds. I think the black celebration bank is a fake or partial btw definitely not way alan or martin played.

I've gotten a memory error so i'm debugging that one and still have to clean up the voices. good thing i have an IC puller!
Logged

EII, E4k, E4XT, Darwin
logiclust
Full Member
***
Offline Offline

Posts: 36


i like toast


WWW
« Reply #2 on: June 13, 2014, 08:32:10 AM »

I've isolated and replaced the bad DRAM (MT4264-15) chip with a KM4164A-15 and now the memory tests good. I've read that swapping a 4264 with a 4164 doesn't always work but so far so good. I suppose i'll try the sample test next.

2 questions:
I've run the scanner test disk from HxC and from what i can tell it just tests the switches/leds/keys/wheels. Am i missing something?

I can't get the e2 to load the universal test disk. why would that be?

I'm joining the yahoo group to find some of these mythical docs...
Logged

EII, E4k, E4XT, Darwin
Pages: [1] Print 
« previous next »
Jump to:  


Login with username, password and session length

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

SEO light theme by © Mustang forums. Powered by SMF 1.1.21 | SMF © 2015, Simple Machines