{"id":4649,"date":"2012-03-02T19:37:14","date_gmt":"2012-03-02T23:37:14","guid":{"rendered":"http:\/\/www.engineeringradio.us\/blog\/?p=4649"},"modified":"2023-04-29T11:12:25","modified_gmt":"2023-04-29T15:12:25","slug":"the-old-humming-console","status":"publish","type":"post","link":"https:\/\/www.engineeringradio.us\/blog\/2012\/03\/the-old-humming-console\/","title":{"rendered":"The old humming console"},"content":{"rendered":"\n

We are starting to work at a new client’s studios.\u00a0 It is a bit like stepping into a 1980s time machine, as the newest console seems to be the Broadcast Audio console in the FM studio.\u00a0 I feel I should wear a wide colorful tie and part my hair in the middle when working there.\u00a0 There is also an older UMC console in the second production room.<\/p>\n\n\n\n

A what?<\/p>\n\n\n\n

Exactly.<\/p>\n\n\n\n

It seems the UMC console (UMC was a Connecticut-based console manufacturer that was later sold to Broadcast Audio) was having an intermittent hum problem on all the audio buses.<\/p>\n\n\n\n

After poking around under the hood for a few minutes, I decided I should begin with the basics.\u00a0 Checking the power supply for ripple seemed like as good a place to start as any.\u00a0 This console has a 30-volt and a 12-volt power supply.\u00a0 The 30-volt supply checked out good, but the 12-volt supply, not so much:<\/p>\n\n\n\n

\"12<\/a>
12 volts DC, 2.7 volts AC<\/figcaption><\/figure>\n\n\n\n
\"12<\/a>
12 Volt power supply<\/figcaption><\/figure>\n\n\n\n

2.7 volts AC on the 12-volt DC power supply.\u00a0 That will put some hum on the audio, all right.\u00a0 I tried to replace the power supply main filter capacitor, but it had no effect.\u00a0 The regulator must also be bad and it is a Motorola part number which is likely not made anymore.<\/p>\n\n\n\n

\"12<\/a>
12 volt linear power supply<\/figcaption><\/figure>\n\n\n\n

This is a pretty standard off the shelf power supply, I should be able to get one from Mouser<\/a> for about $60.00 or so for a linear unit, which will be cheaper than us trying to trouble shoot and repair the old one.  In the meantime, I took the 10 amp 0-30 volt bench supply and pressed it into temporary service.  The console is working again, for now.<\/p>\n\n\n\n

At some point, all this old, um, stuff needs to be replaced.<\/p>\n","protected":false},"excerpt":{"rendered":"

We are starting to work at a new client’s studios.\u00a0 It is a bit like stepping into a 1980s time machine, as the newest console seems to be the Broadcast Audio console in the FM studio.\u00a0 I feel I should wear a wide colorful tie and part my hair in the middle when working there.\u00a0 … Continue reading The old humming console<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[102,4],"tags":[306,100,240],"class_list":["post-4649","post","type-post","status-publish","format-standard","hentry","category-audio","category-tech-stuff","tag-audio","tag-consoles","tag-power-supply"],"_links":{"self":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/4649","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/comments?post=4649"}],"version-history":[{"count":6,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/4649\/revisions"}],"predecessor-version":[{"id":11639,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/4649\/revisions\/11639"}],"wp:attachment":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/media?parent=4649"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/categories?post=4649"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/tags?post=4649"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}