Alesis SR18 Drum Machine

[bsco]

This might be a long shot but what the hell.......I have one of these here and it will run on batteries fine....When I plug the adapter in, the backlight will light up but there is no data on the display.....Checked the output of the adapter and it was fine.......took the unit apart and couldn't see anything gone....there are two diodes close to the power input jack...they checked fine....On the rear of the unit it specifies that the power input is 9VDC...center pin negative....however on the adapter that came with the unit, it says the output is 9VAC@830mA......I can't get the unit to work with any ac adapter.....but it will work with other DC adapters.......Had a look on line for a replacement adapter and it showed DC output....not AC output.....also checked the user manual and in the specs it calls for an AC output......but the sticker on the rear of the machine calls for a 9VDC input......so do I have a problem still or do I have the wrong adapter.......I emailed Alesis but don't expect a replay for a few days...if I get one at all......any comments????anyone
Cheers

[Randall]

I'd say if it works on baatteries, and it works on other DC adaptors, then it is a DC device. Put a DC adaptor on it and call it good.

[bsco]

I'd say if it works on baatteries, and it works on other DC adapters, then it is a DC device. Put a DC adapter on it and call it good.

That was an idea I was thinking about....however, I don't understand why the two RECT. diodes are there.....Alesis won't release schematics....anyway, thanks for the reply....
Cheers

[nosaj]

That was an idea I was thinking about....however, I don't understand why the two RECT. diodes are there.....Alesis won't release schematics....anyway, thanks for the reply....
Cheers

Input protection from using too high a DC voltage?

nosaj

[John_H]

I have an Alesis SR-16. It's 9v AC only. No batteries.

[bsco]

Input protection from using too high a DC voltage?

nosaj

I thought that but it has two diodes...not one....

[bsco]

I have an Alesis SR-16. It's 9v AC only. No batteries.

This one takes six AA's......I am going to do another quick search again to see if I can find one...If I do, I'll post it....

[g1]

The 16 and 18 are different.
If yours say 9V on the actual unit, then they have changed. New units are 12VDC. Maybe there are different versions of the manual/spec sheet too. Go by what it says on the unit itself.

[bsco]

Thanks for the reply g1....Just checked the adapters on line...The one that I have with the unit is model A30910C....( a 9VAC unit).... and the rear of this unit is 12VDC@500mA......not 9V like I had said in post #1......so I screwed up there....sorry......

[g1]

Did L&M rentals send that? That adaptor is for a Microverb III.

And there is a typo in the SR18 manual on the specs page, where they call for AC. Should be DC like they show in the main part of the manual with pictures.

[bsco]

Did L&M rentals send that? That adaptor is for a Microverb III.

And there is a typo in the SR18 manual on the specs page, where they call for AC. Should be DC like they show in the main part of the manual with pictures.

Yes they did actually...so they have the wrong adapter......or...it was rented and somebody switched it....I have actually seen that one before......
Cheers

[g1]

Seen any board swaps yet? I recall a busted up PCB that got the switcheroo. I think it was back in the PortaOne or Two days. I do recall someone went to an awful lot of work to do it.

[Randall]

Maybe one diode is a zener for voltage clamping?

[bsco]

Seen any board swaps yet? I recall a busted up PCB that got the switcheroo. I think it was back in the PortaOne or Two days. I do recall someone went to an awful lot of work to do it.

I haven't seen that sort of stuff yet....Lots of missing knobs...and sometimes the wrong ones installed.......wrong adaptors, but not boards.....