CV noise from analog synths.

EQ2K · Post by **EQ2K** » Thu Nov 16, 2006 10:44 am

I picked up a TR-606 off eBay the other day and have noticed that it is outputting a very high pitched tone. Sometimes this tone is a little louder when I connect other CV gear to it.
Does anyone have any experience with this and know how I might be able to repair it? Thanks.

Altitude · Post by **Altitude** » Thu Nov 16, 2006 1:38 pm

probably the transformer. Try running it off of batteries and see if it still does it

Post by **nathanscribe** » Thu Nov 16, 2006 11:12 pm

Yeah, mine does this, quietly enough not to worry. It's just electronic noise from all the gubbins inside being tightly packed, I think. Turn it up enough and there's a pulse; could be the CPU or clock. Anyhow, some kind of gate should sort it out.

EQ2K · Post by **EQ2K** » Fri Nov 17, 2006 2:00 am

yr right, it doesn't grumble wit batteries. i think i'm going to buy one of those roland power cords. i don't have the original and have been using one of those radio shack adapters. thanks.

Altitude · Post by **Altitude** » Fri Nov 17, 2006 5:01 am

i don't have the original and have been using one of those radio shack adapters

Be really careful with that, the 606 draws very little current and using a high rated PSU (say 500 mA) may result in a high voltage issue since most transformers get a little squirrelly when your only sucking ~100 mA through them. The orginal boss one is a 200 mA max. Using a unsuitable PSU is a common failure mode for the power transistor on both the 606 and 303 since pumping more than 9 V through it degrades it pretty quickly

Post by **nathanscribe** » Fri Nov 17, 2006 10:59 am

Altitude wrote:Be really careful with that, the 606 draws very little current and using a high rated PSU (say 500 mA) may result in a high voltage issue since most transformers get a little squirrelly when your only sucking ~100 mA through them. The orginal boss one is a 200 mA max. Using a unsuitable PSU is a common failure mode for the power transistor on both the 606 and 303 since pumping more than 9 V through it degrades it pretty quickly

As long as your power supply is regulated it should provide a constant, fixed voltage even with a relatively low current draw. But yes, you won't want a 1.5A wart or anything like that.. Just get a regulated 300mA 9V supply from any manufacturer, you don't need an original Roland one. I use a bunch of those switchable ones with the interchangeable plugs. Pity they don't sit next to each other on the distribution board though, slightly too wide. Grr!

Altitude · Post by **Altitude** » Fri Nov 17, 2006 1:54 pm

As long as your power supply is regulated it should provide a constant, fixed voltage even with a relatively low current draw.

This is true, however most cheapo wall warts are not regulated an they rarely say if they are.

Here's a site about the issue:

http://www.firstpr.com.au/rwi/dfish/rel ... l#adaptors