Drawmer DS201 Overvoltage

[replaceablehead]

I did something very stupid yesterday. I've got quite a bit of rack gear of varying power requirements and while I was upside down behind by mixing desk plugging a few things in after moving house I went and plugged my 100v Drawmer gate into 240v. In my defense, the unit is labeled 100v/230v and it had been so long since I'd plugged it in that I'd quite forgotten that it was one I had bought from Japan. Suffice it to say it blew the fuse, but after swapping that out and plugging it into the right step-down transformer the unit seemed to be operational.

Anyway, today I've chained it up with my reverb and I was playing drums through it when I noticed it fizz for a few seconds and then sort of fade out. I went over and twiddled with the threshhold a bit and the sound abruptly returned I resumed drumming for a few minutes and it happened again. This time knob twiddling didn't work, but power cycling it did. I played for a few more seconds and it cut out again. I noticed that by power cycling I could get it to work again by only for about 20 seconds or so. I left the unit on while I had a think about what could be blown and then I tried power cycling it again which no longer worked.

The light meters on both channels work and show when the signal is passing and when the gate is closing, it's just no sound comes out when the gate opens. I'm just a little surprised because I thought if it was overvoltage it would have just blown the capacitors in the power supply or the transformer and it wouldn't turn on. I don't know much about circuits though to be honest and this is the first time I have every plugged something into the wrong power supply, I'm normally very careful.

The next step is to open it up, but any ideas on what I should check first?

 

[pucho812]

Start with the psu and work your way outward

 

[replaceablehead]

Thanks, I'll check it out and report any results.

 

[Tubetec]

You might find a service document for the Ds201 , normally Drawmer are quite good for giving the details of circuit opperation in an easy to follow way . Check the transformer for continuity on pri/sec windings .
I know one guy who bought an entire studio mostly with 110v gear , ran much of it off a stepdown TX
as he added new 230v equipment things got confused and he blew up lots of his gear with the wrong voltage . A colour coding system for 110/230 power cables ,yellow for 110 ,blue for 220 is helpful to prevent accidents but not totally fool proof either .

The DS201 is a versatile piece of kit , ever try using it to gate ambient mics on a drum kit ?

 

[MagnetoSound]

We all used it to gate snare reverb when it first came out. Not sure how gating room mics works with cymbals, though …?

 

[replaceablehead]

Can't say I have tried on room mics, but I'm sure I will get around to it. Today I actually had it on an SPX90 with an RX5 for drum sounds. Very cheesy stuff, but oddly addictive.

I've got it out of the rack and taken the cover off. No burnt smells. Haven't gotten to testing any, I'll start on that tomorrow.

To me the fact that the indicator LEDs are showing the expected opening and closing and are responding to changes in settings suggests the issue is in the audio signal near the output. Surely for any of that stuff to work the power rail must be getting proper voltage from the power supply.

 

[gyraf]

Not sure how gating room mics works with cymbals, though …

..would just be like the recent API stuff?

 

[zamproject]

Never open a 201, but IIRC my 301 have some tantal in the sidechain, for timing, hold or release or both.
If an over voltage pass the secondary and the regulation they can fail fast.

 

[Tubetec]

Generally Im filtering out lots of the highs on ambience mics to prevent interactions with the overhead drum mic , its all about room artifacts below around 1khz ,
The sidechain inputs could be used to trigger the ambience mics off the toms for instance ,
placing the amb mics on the floor with an upturned single seater sofa over the top is a good way to filter out top kit .

I found a few coupling caps had gone bad in my DS201 , the seals had bulged , so thats another issue worth looking out for .