Forum for all other samplers & synths such as Maschine, MVs, Akai S & Z series, Roland, Korg, OP-1, analog synths etc.
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By Lampdog Sun Aug 06, 2017 9:28 pm
My ASR10 once did that to me over a decade ago. Fortunately there was a place in SD here that specialized in and was an authorized Ensoniq dealer/repair shop. I asked them to take it apart, unplug everything, clean, and put everything back together again. They charged $150 and MAAANNN it made a difference. It was snappy as **** when pressing buttons, menus reacted instantly. That shop is gone now but back in the day they were ALWAYS packed with used gear for sale which people didn't come get after 60 days which was in PERFECT condition after repair. It was like a high end authorized repair/pawn shop.
By Rooster Tue Jul 07, 2020 3:15 am
I just repaired my ASR-10 with blank screen and self test characters on the display. The problem was a bad capacitor inside the keyboard assy on the "coil board". It's laborious because you got to remove all the boards from the ASR and then remove the keyboard assy and then remove all 61 keys just to get to the plastic mount that holds the 2 coil boards. I found schematics for the coil board but had to be careful because the schematics are not accurate. The capacitor was right on the threshold of working. When it heats up it "pops" on. It's part of the "power on reset" for the keyboard processor. And of course when I desoldered the capacitor it stunk pretty bad. For those tech savvy guys out there The capacitor is a 3.3 microfarad surface mount cap. It is tied to pin 6 of IC part number 7555 (It's a standard 555 timer IC) U9 is the location designation. The schematic is not accurate and does not show the cap in the circuit. But I know enough about 555 timers to know and see "no reset signal" coming out the chip. I had data coming in from the digital board to the Ensoniq 5702000102 chip U2 pin 27, but no data out from pin 26 to the digital board. That's when I noticed no power on reset. The cap was just bad enough to hold keep the timer from resetting. I didn't have a 3.3 microfarad cap so I used a 2.7microfarad. Actually, it worked without a cap installed. This cap value just provides "reset delay time". Anyway its fixed.
By Rooster Tue Jul 07, 2020 3:21 am
The floppy drive will not format the standard 1.44 meg discs anymore. I get "file operation error". It will however format 720-800k discs. I swapped the drive out with a known working drive and it formatted fine. I know it's the floppy drive but curious what happened to it. Both floppies are Sony MPF-420 -1.
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By Lampdog Tue Jul 07, 2020 5:22 am
THANK YOU for that info!
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By NearTao Tue Jul 07, 2020 10:51 am
You specified that it won’t format, will it write data to a 1.44mb disk? Just curious, because formatting is mostly a write operation, and it would be odd to me that you would be able to write 1.44, but not format 1.44.
By Rooster Fri Jul 17, 2020 10:35 pm
NearTao, I can write to the floppy and come close to filling it up. (1.44m) She just will not format. I popped in a known working floppy drive,same make and model from a working ASR-10 and it formats fine. (Go figure). I'm more happy I got the display problem fixed. I'm sure the floppy is not worth repairing or even possible. Now if I knew what part was bad I could attempt to replace it (if it's even worth the trouble). I mean I'm using a SCSI2sd.
Last edited by Rooster on Fri Jul 17, 2020 10:45 pm, edited 1 time in total.
By Rooster Fri Jul 17, 2020 10:37 pm
NearTao wrote:You specified that it won’t format, will it write data to a 1.44mb disk? Just curious, because formatting is mostly a write operation, and it would be odd to me that you would be able to write 1.44, but not format 1.44.
By Rooster Mon Nov 07, 2022 4:07 pm
I have updated the ASR-10 coil board schematics. Can someone tell me how to post it?
They are in jpg
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By bitermc Mon Nov 07, 2022 4:47 pm
I'm truly amazed by the longevity of this sampler and the fact that it keeps a solid user base after almost three decades.

I honestly don't know what that special about it, because I've never put my hands on one, but whatever it is it must be for real.
By Rooster Tue Nov 08, 2022 2:44 am
https://ibb.co/6N2679Z Low coil board
https://ibb.co/xf0xcx2 High coil board

Updated schematics for ASR-10 coil boards. Special thanks to R.Grieb Tauntek who painstakingly created the schematic. The low board contains the MPC (U3) and Ensoniq processor (U2). Capacitor C28 has been added to the power on reset chip (U9). Keys 1 thru 32 have been applied to U8 and U7. Keys 33 thru 61 (and the dummy keys) have been applied to U2 and U3. V+ has been changed to +12V.
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By Lampdog Tue Nov 08, 2022 4:06 pm
bitermc wrote:I'm truly amazed by the longevity of this sampler and the fact that it keeps a solid user base after almost three decades.

I honestly don't know what that special about it, because I've never put my hands on one, but whatever it is it must be for real.

It has a certain timber/tone. No other gear I've had sounds THAT warm and cozy.
It's only when you use the samples in RAM, not audio passed through the inputs.
I can't explain it, but it's a BEAST of old technology. Also, the key bed feels better than any other key bed I've had.
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By bitermc Tue Nov 08, 2022 4:32 pm
Must have some sort of internal resampling, I had a Gravis Ultrasound eons ago and had a similar characteristic sound, as if it was less digital than the rest of samplers.

Sometimes I've considered buying a second hand unit, just to play for a while and resell, but the prices are ridiculous for a sampler with 16 MB of RAM and floppies...
By TIMO33 Sun Nov 20, 2022 4:48 pm
Rooster wrote:I just repaired my ASR-10 with blank screen and self test characters on the display. The problem was a bad capacitor inside the keyboard assy on the "coil board". It's laborious because you got to remove all the boards from the ASR and then remove the keyboard assy and then remove all 61 keys just to get to the plastic mount that holds the 2 coil boards. I found schematics for the coil board but had to be careful because the schematics are not accurate. The capacitor was right on the threshold of working. When it heats up it "pops" on. It's part of the "power on reset" for the keyboard processor. And of course when I desoldered the capacitor it stunk pretty bad. For those tech savvy guys out there The capacitor is a 3.3 microfarad surface mount cap. It is tied to pin 6 of IC part number 7555 (It's a standard 555 timer IC) U9 is the location designation. The schematic is not accurate and does not show the cap in the circuit. But I know enough about 555 timers to know and see "no reset signal" coming out the chip. I had data coming in from the digital board to the Ensoniq 5702000102 chip U2 pin 27, but no data out from pin 26 to the digital board. That's when I noticed no power on reset. The cap was just bad enough to hold keep the timer from resetting. I didn't have a 3.3 microfarad cap so I used a 2.7microfarad. Actually, it worked without a cap installed. This cap value just provides "reset delay time". Anyway its fixed.




Hey Rooster I'm aving the same Problem. Changed the 7555. All caps around the 7555 are OK but I'm also getting nothing out of the pin 26 like you had
Voltage on pin 27 is there. Do you have any idea?
By asr10user Fri Dec 02, 2022 11:29 pm
Hmm my ASR10 has had a blank screen for years, but I dont get any characters on the screen, it just looks to be off while the rest of the board seems to work. I need to get that thing looked at.

On another note, does anyone know if people are installing SD card readers into the ASR10 yet? I see lots of other samplers with them, a big reason I stopped using my ASR10 is because I got tired of scsi drives failing.
By terry towelling Mon Dec 05, 2022 1:22 am
I have sd card readers in both my EPS and ASR10 -- not sci, just card readers that replace the discs drive.
the SCSI card reader look to be much better. I think the one you want is called Zulu SCSI and just plugs directly into the SCSI outlet on the back, with a 25 pin to 56 pin converter (or whatever the correct numbers are)