{"id":568,"date":"2020-12-16T13:12:02","date_gmt":"2020-12-16T19:12:02","guid":{"rendered":"https:\/\/funkwerkes.com\/web\/?p=568"},"modified":"2022-07-08T14:08:59","modified_gmt":"2022-07-08T20:08:59","slug":"universal-audio-tube-mixer-project","status":"publish","type":"post","link":"https:\/\/funkwerkes.com\/web\/universal-audio-tube-mixer-project\/","title":{"rendered":"Universal Audio Tube Mixer Project"},"content":{"rendered":"\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20201216_134429-2-1024x576.jpg\" alt=\"\" class=\"wp-image-625\" srcset=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20201216_134429-2-1024x576.jpg 1024w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20201216_134429-2-300x169.jpg 300w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20201216_134429-2-150x84.jpg 150w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20201216_134429-2-768x432.jpg 768w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20201216_134429-2-1536x864.jpg 1536w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20201216_134429-2-2048x1152.jpg 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>I&#8217;ve built several pieces of audio gear over the years, but this one is special to me.  In the late &#8217;80s I had an audio repair shop in Sheffield, Alabama (just like now).  I&#8217;d been doing repair work for Rick Hall at <a rel=\"noreferrer noopener\" href=\"https:\/\/famestudios.com\/\" data-type=\"URL\" target=\"_blank\">Fame Studios<\/a> in Muscle Shoals.  Rick had just upgraded studio A with the <a href=\"https:\/\/funkwerkes.com\/web\/miscimages\/studio_a_2.jpg\" target=\"_blank\" rel=\"noreferrer noopener\">Neve 8232<\/a> still in use today.  The echo chamber was full of retired &#8220;junk&#8221; of all varieties.  There was lots of stuff I could use at my shop, so I made a trade with Rick for some chairs, old test gear, junk boxes full of wire scraps, parts etc.  <\/p>\n\n\n<div class=\"wp-block-image is-style-default\">\n<figure class=\"alignleft size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/47038491_2090138124558750_2315945575452770304_o-1024x791.jpg\" alt=\"\" class=\"wp-image-579\" width=\"320\" height=\"247\" srcset=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/47038491_2090138124558750_2315945575452770304_o-1024x791.jpg 1024w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/47038491_2090138124558750_2315945575452770304_o-300x232.jpg 300w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/47038491_2090138124558750_2315945575452770304_o-150x116.jpg 150w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/47038491_2090138124558750_2315945575452770304_o-768x593.jpg 768w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/47038491_2090138124558750_2315945575452770304_o.jpg 1080w\" sizes=\"auto, (max-width: 320px) 100vw, 320px\" \/><figcaption><center><em><span style=\"color: #ff9900;\">My Repair Shop In The Eighties Using Test Equipment From Fame Studios<\/span><\/em><\/center><\/figcaption><\/figure>\n<\/div>\n\n\n<p>In the midst of random bits I find two Universal Audio <a rel=\"noreferrer noopener\" href=\"https:\/\/funkwerkes.com\/web\/wp-content\/techdocs\/MixedProAudio\/UniversalAudio\/100D-with-EQ.png\" target=\"_blank\">100D tube preamps<\/a>. I had no idea what they were, and there wasn&#8217;t really an internet to search then. They were just some old tube modules retired like the rest of the stuff. They lived in a box for the next 30 years with other &#8220;junk&#8221; from that trade with Rick. By this time, I understood these were some of the maiden microphone ampifiers hand-built by <a rel=\"noreferrer noopener\" href=\"https:\/\/www.uaudio.com\" target=\"_blank\">Universal Audio<\/a> in 1958\/59 and that they surely had some funky electrons flowing through them in that era.<\/p>\n\n\n<div class=\"wp-block-image is-style-rounded\">\n<figure class=\"alignright size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/19441868_1525549344186621_2181410377600740210_o-569x1024.jpg\" alt=\"\" class=\"wp-image-617\" width=\"228\" height=\"410\" srcset=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/19441868_1525549344186621_2181410377600740210_o-569x1024.jpg 569w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/19441868_1525549344186621_2181410377600740210_o-167x300.jpg 167w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/19441868_1525549344186621_2181410377600740210_o-83x150.jpg 83w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/19441868_1525549344186621_2181410377600740210_o-768x1382.jpg 768w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/19441868_1525549344186621_2181410377600740210_o.jpg 800w\" sizes=\"auto, (max-width: 228px) 100vw, 228px\" \/><figcaption><center><em><span style=\"color: #ff9900;\">Matt Ross-Spang At Gus&#8217;s Chicken In Memphis Protecting The Hot Sauce<\/span><\/em><\/center><\/figcaption><\/figure>\n<\/div>\n\n\n<p>Enter <a rel=\"noreferrer noopener\" href=\"http:\/\/www.southerngrooves.com\/\" target=\"_blank\">Matt Ross-Spang<\/a>.  Check him out if you&#8217;re not familiar.  I&#8217;d known Matt a while by then, and the tale of the Fame UA-100D channels stuck in his mind.  Matt was headquartered at the historic <a rel=\"noreferrer noopener\" href=\"https:\/\/samphillipsrecording.com\/\" target=\"_blank\">Sam Phillips Recording Service<\/a> in Memphis and knew of the same type modules stored within.  Matt has the upmost respect for the history of these types of artifacts, making him the perfect curator for equipment such as this.  He worked a deal for a pair of 100Ds from the Phillips studio and we got to work on a four channel mixer with two channels from Fame Studios in Muscle Shoals, and two from Sam Phillips Recording Service in Memphis.  That still sort of blows me away.<\/p>\n\n\n<div class=\"wp-block-image is-style-default\">\n<figure class=\"alignleft size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200805_131126-2-1024x742.jpg\" alt=\"\" class=\"wp-image-573\" width=\"386\" height=\"280\" srcset=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200805_131126-2-1024x742.jpg 1024w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200805_131126-2-300x217.jpg 300w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200805_131126-2-150x109.jpg 150w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200805_131126-2-768x557.jpg 768w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200805_131126-2-1536x1113.jpg 1536w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200805_131126-2-2048x1484.jpg 2048w\" sizes=\"auto, (max-width: 386px) 100vw, 386px\" \/><figcaption><center><em><span style=\"color: #ff9900;\">Beginning To Figure Out Component Layout<\/span><\/em><\/center><\/figcaption><\/figure>\n<\/div>\n\n\n<p>We rounded up four <a href=\"https:\/\/funkwerkes.com\/web\/miscimages\/508A.jpg\" target=\"_blank\" rel=\"noreferrer noopener\">Universal Audio 508 envelopmental equalizers<\/a>, two of which randomly presented themselves for purchase to Matt during a recording session.  These things are rare!  Matt has a lot of positive karmic equity, I&#8217;m sure of it.<\/p>\n\n\n<div class=\"wp-block-image is-style-rounded\">\n<figure class=\"alignright size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_105415-1024x576.jpg\" alt=\"\" class=\"wp-image-583\" width=\"223\" height=\"125\" srcset=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_105415-1024x576.jpg 1024w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_105415-300x169.jpg 300w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_105415-150x84.jpg 150w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_105415-768x432.jpg 768w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_105415-1536x864.jpg 1536w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_105415-2048x1152.jpg 2048w\" sizes=\"auto, (max-width: 223px) 100vw, 223px\" \/><figcaption><center><em><span style=\"color: #ff9900;\">Weston\/UA Faceplates &amp; Trim On MCI VU Meters<\/span><\/em><\/center><\/figcaption><\/figure>\n<\/div>\n\n\n<p>We settled on a split layout, with two channel pairs to infer their separate histories.  Space forced the VU meters into an overbridge with switching between channels 1-3 and 2-4.  Interestingly, I had three bad original UA Weston VUs from another &#8220;junk&#8221; buy.  I also had several nice VUs from MCI gear.  I swapped the Weston trim and faceplates onto the MCI VUs (with a little trimming) and they look great.  The VUs are driven by balanced buffers and lit by LED.<\/p>\n\n\n\n<p>We wanted as much flexibility as we could squeeze from the modules.  The feature set wound up being:<\/p>\n\n\n<div class=\"wp-block-image is-style-default\">\n<figure class=\"alignright size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200820_160556-1024x576.jpg\" alt=\"\" class=\"wp-image-576\" width=\"322\" height=\"181\" srcset=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200820_160556-1024x576.jpg 1024w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200820_160556-300x169.jpg 300w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200820_160556-150x84.jpg 150w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200820_160556-768x432.jpg 768w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200820_160556-1536x864.jpg 1536w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200820_160556-2048x1152.jpg 2048w\" sizes=\"auto, (max-width: 322px) 100vw, 322px\" \/><figcaption><center><em><span style=\"color: #ff9900;\">Machine Work Finished, Headed To Paint!<\/span><\/em><\/center><\/figcaption><\/figure>\n<\/div>\n\n\n<ul class=\"wp-block-list\"><li><em><strong>Phase\/Phantom<\/strong><\/em><\/li><li><em><strong>10dB pad, 15dB pad, 25dB pad (both on)<\/strong><\/em><\/li><li><em><strong>50\/150 ohm input selection<\/strong><\/em><\/li><li><em><strong>Original UA 508 Equalizers in the feedback circuit<\/strong><\/em><\/li><li><em><strong>L-C-R panned passive mix bus<\/strong><\/em><\/li><li><em><strong>Channels switchable between &#8220;Stand Alone&#8221; mode or mix bus.<\/strong><\/em><\/li><li><em><strong>Langevin 600 ohm attenuators<\/strong><\/em><\/li><\/ul>\n\n\n<div class=\"wp-block-image is-style-rounded\">\n<figure class=\"alignleft size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200916_113826-613x1024.jpg\" alt=\"\" class=\"wp-image-595\" width=\"77\" height=\"128\" srcset=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200916_113826-613x1024.jpg 613w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200916_113826-180x300.jpg 180w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200916_113826-90x150.jpg 90w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200916_113826-768x1282.jpg 768w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200916_113826-920x1536.jpg 920w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200916_113826-1227x2048.jpg 1227w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200916_113826-scaled.jpg 1533w\" sizes=\"auto, (max-width: 77px) 100vw, 77px\" \/><figcaption><center><em><span style=\"color: #ff9900;\">Lever Switches From An Early Broadcast Mixer<\/span><\/em><\/center><\/figcaption><\/figure>\n<\/div>\n\n\n<p> Matt sourced four period correct leaf lever switches for bus assignment.  They went through the ultrasonic bath and work great.  We decided to leave the output of the passive stereo mix bus unamplified to allow the user to choose any flavor of amplifer with 35-40dB of gain for makeup.  The bus is coupled to the outside world through UTC A22 transformers.  A flip of a switch gives you an independent channel on its own output jack.<\/p>\n\n\n<div class=\"wp-block-image is-style-rounded\">\n<figure class=\"alignright size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200821_113018-891x1024.jpg\" alt=\"\" class=\"wp-image-598\" width=\"139\" height=\"159\" srcset=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200821_113018-891x1024.jpg 891w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200821_113018-261x300.jpg 261w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200821_113018-131x150.jpg 131w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200821_113018-768x883.jpg 768w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200821_113018-1337x1536.jpg 1337w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200821_113018-1782x2048.jpg 1782w\" sizes=\"auto, (max-width: 139px) 100vw, 139px\" \/><figcaption><center><em><span style=\"color: #ff9900;\">All Four Power Supplies Built In!<\/span><\/em><\/center><\/figcaption><\/figure>\n<\/div>\n\n\n<p>The power supplies were built into a Hewlett-Packard VTVM shell retaining its original dB meter.  A tube rectified and regulated section delivers 335 volts DC to the modules.  When the high voltage is correct, the dB meter reads &#8220;0dB&#8221;.  Filament voltage is DC biased at about 80 volts.  A separate switching supply provides 24 volts to the meter bridge while an additional 48 volt supply is used for phantom power. The wires for the different voltages were enclosed in a grounded braided shield, then a nylon braid was threaded over everything for the outer cover.  The console end of the cable splits to a large connector for high voltage\/filament and a smaller one for the lower DC voltages.<\/p>\n\n\n<div class=\"wp-block-image is-style-default\">\n<figure class=\"alignleft size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_103300-1024x576.jpg\" alt=\"\" class=\"wp-image-600\" width=\"365\" height=\"205\" srcset=\"https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_103300-1024x576.jpg 1024w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_103300-300x169.jpg 300w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_103300-150x84.jpg 150w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_103300-768x432.jpg 768w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_103300-1536x864.jpg 1536w, https:\/\/funkwerkes.com\/web\/wp-content\/uploads\/2020\/12\/20200919_103300-2048x1152.jpg 2048w\" sizes=\"auto, (max-width: 365px) 100vw, 365px\" \/><figcaption><center><em><span style=\"color: #ff9900;\">Fame Studios Engineer Spencer Coats Records Spooner Oldham&#8217;s Wurlitzer<\/span><\/em><\/center><\/figcaption><\/figure>\n<\/div>\n\n\n<p>We wanted to conjure the feel of the early UA consoles with their strange green paint.  I guess you love it or hate it&#8230; we love it!  The first use of the unit was at Fame Studios recording <a rel=\"noreferrer noopener\" href=\"https:\/\/www.rockhall.com\/inductees\/spooner-oldham\" target=\"_blank\">Spooner Oldham<\/a>&#8216;s Wurlitzer electric piano through the Fame UA 100D channels for the upcoming Aretha Franklin movie, &#8220;<a href=\"https:\/\/www.imdb.com\/title\/tt2452150\/\" data-type=\"URL\" data-id=\"https:\/\/www.imdb.com\/title\/tt2452150\/\" target=\"_blank\" rel=\"noreferrer noopener\">Respect<\/a>&#8220;.  How cool is that?<\/p>\n\n\n\n<p>&#8220;Little Greenie&#8221; now resides in Memphis and keeps busy guiding melodic electrons along their way.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I&#8217;ve built several pieces of audio gear over the years, but this one is special to me. In the late &#8217;80s I had an audio repair shop in Sheffield, Alabama (just like now). I&#8217;d been doing repair work for Rick Hall at Fame Studios in Muscle Shoals. Rick had just upgraded studio A with the [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-568","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/funkwerkes.com\/web\/wp-json\/wp\/v2\/posts\/568","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/funkwerkes.com\/web\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/funkwerkes.com\/web\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/funkwerkes.com\/web\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/funkwerkes.com\/web\/wp-json\/wp\/v2\/comments?post=568"}],"version-history":[{"count":78,"href":"https:\/\/funkwerkes.com\/web\/wp-json\/wp\/v2\/posts\/568\/revisions"}],"predecessor-version":[{"id":724,"href":"https:\/\/funkwerkes.com\/web\/wp-json\/wp\/v2\/posts\/568\/revisions\/724"}],"wp:attachment":[{"href":"https:\/\/funkwerkes.com\/web\/wp-json\/wp\/v2\/media?parent=568"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/funkwerkes.com\/web\/wp-json\/wp\/v2\/categories?post=568"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/funkwerkes.com\/web\/wp-json\/wp\/v2\/tags?post=568"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}