How to Build a Balanced Stereo Line Driver for audio testing. Testing an amplifier with a balanced input is easy if you have an audio source that has balanced outputs. If you don't, then testing is still possible if you simply short the 'cold' input to ground. However, to fully test an amplifier with balanced inputs, you really need to test it with a balanced source, and this is sometimes a problem if you want to use a signal generator, or single-ended music source. This simple project is meant to rectify that problem on my work-bench. It accepts an RCA input and produces a balanced signal through an XLR socket, with relatively little distortion or degrading of the signal. Elliot Sound Products has an excellent write-up on this circuit, so have a look for yourself: http://sound.whsites.net/project51.htm See a series of 'Restoration Building Blocks' videos on detailed steps in the restoration process of tube radios and amps: https://www.youtube.com/watch?v=7xvTGd4ysRE&list=PLy5M_tA9ux7JSYx8z2mw303vx287LHpzf See also playlists on some other completed restoration projects. PHILIPS BX750A: https://www.youtube.com/watch?v=i8U9Lteja5o&list=PLy5M_tA9ux7IG6XgctidGO0u0DeT3_CxF TELEFUNKEN OPUS 2114: https://www.youtube.com/watch?v=_HO2bjY5vuw&list=PLy5M_tA9ux7LhcZ9h9plfTFmjaM1mcifu SABA UW-175-Z 3D: https://www.youtube.com/watch?v=cca4i60ZLw4&list=PLy5M_tA9ux7IWL18nsrSf4RnjsuPjHC-p GRUNDIG 1070: https://www.youtube.com/watch?v=i4J5l0fwhko&list=PLy5M_tA9ux7JgnyYPRWOK763aJ8bg3iCI SCHAUB-LORENZ GOLDY 58 type 3020: https://www.youtube.com/watch?v=RSbt7qVed78&list=PLy5M_tA9ux7IBse5G--Kl89SPS9sATXfZ BUSH VHF64: https://www.youtube.com/watch?v=U--6JymkQ1M&list=PLy5M_tA9ux7KsvN5M48cX6cxN4jSz0s3X GRUNDIG 3060A: https://www.youtube.com/watch?v=7x2sK2GSYeE&list=PLy5M_tA9ux7L8e9h8lrHGREPqcgWO-YQm TELEFUNKEN OPERETTE 8: https://www.youtube.com/watch?v=5IsACM0mPzs&list=PLy5M_tA9ux7K3SXDv8Hu4uAyl1O7NE5dc GRAETZ SUPER 171W: https://www.youtube.com/watch?v=MhG-CH0gqm4&list=PLy5M_tA9ux7IjUykGE8neJSI6GUxMl2YG LOEWE-OPTA MAGNET 3737W: https://www.youtube.com/watch?v=ZSZBJ5sKQm8&list=PLy5M_tA9ux7J_hzDhnF8rs2c7wmgGfRlK BRAUN ATELIER 3: https://www.youtube.com/playlist?list=PLy5M_tA9ux7L3k5nPRvrk1aH764QRCTqE LOEWE-OPTA TRUXA STEREO 4741W: https://www.youtube.com/playlist?list=PLy5M_tA9ux7KhVk0KqPx0Wkh2KO_5f2fQ GRAETZ COMEDIA 616: https://www.youtube.com/watch?v=fwmW9k3TwNE&list=PLy5M_tA9ux7L5sAApLzV6xoYzmRNJpMW5 SABA FREIBURG W2: https://www.youtube.com/playlist?list=PLy5M_tA9ux7IqvS-LshUGpE1D_WY6mrZe GRAETZ MUSICA 4R417: https://www.youtube.com/playlist?list=PLy5M_tA9ux7Ios98E59dWjwc2SRJyxwIn You may also be interested in ... CAPACITOR LEAKAGE TESTER: https://www.youtube.com/watch?v=0pySErvzUIY&list=PLy5M_tA9ux7KWexvEjLB0SANSxQXi0zTS ... https://www.youtube.com/watch?v=SG9SgAz_H8I

PCBWay Call for PCB Design Tutorials: https://www.pcbway.com/activity/call-for-pcb-design-tutorials.html See the Promo video: https://youtu.be/nfq13jI5UkA This Philips tube radio looks really messed up at first glance. However, it also presents a few contradictions, like the bakelite chassis and back cover that is in really good shape. Time to even out the condition with a full restoration. It is an AM only set, with Long wave, Medium wave and two Shortwave channels. This was very typical in Madeira, where FM took a little longer that usual to arrive. The economics of the era also contributed to many FM-less sets on the island. The apparent shortcomings in no way detract from the emotional attachment that some people have to their old radios, so this one deserves as much resect and attention as any other set, no matter how advanced. Hope you enjoy the video. You can now support the channel: https://www.patreon.com/mcaldeira https://paypal.me/macaldeira TimeStamps 00:00 Philips F3X69A Tube Radio Restoration pt 1 - Not too pretty on the outside. What about the innards? 00:12 Introduction. 00:21 A first look. 02:20 PCBWay. 02:49 A look inside the back. 05:58 Looking under the hood. 07:29 Testing the PT. 10:25 Testing audio output. 13:07 Reception test. 16:25 IF alignment. 23:30 Closing. #tuberadios #antiqueradio #radiorestoration ______HUNDREDS OF OTHER VIDEOS TO CHOOSE FROM_____ DIY TEST GEAR: The title says it all: https://www.youtube.com/watch?v=7buNHf6HoDw&list=PLy5M_tA9ux7KkjmWX0I0zNocg6NF33EfL RESTORATION BUILDING BLOCKS: A series of videos showing detailed steps used the restoration process of tube equipment: https://www.youtube.com/watch?v=7xvTGd4ysRE&list=PLy5M_tA9ux7JSYx8z2mw303vx287LHpzf HowTo's: Various videos on some simple techniques and projects: https://www.youtube.com/watch?v=lgr-J_D6pSU&list=PLy5M_tA9ux7K3B77iUGyLPai3RIvJOrkO See also playlists on some other completed restoration projects. PHILIPS BX750A: https://www.youtube.com/watch?v=i8U9Lteja5o&list=PLy5M_tA9ux7IG6XgctidGO0u0DeT3_CxF TELEFUNKEN OPUS 2114: https://www.youtube.com/watch?v=_HO2bjY5vuw&list=PLy5M_tA9ux7LhcZ9h9plfTFmjaM1mcifu SABA UW-175-Z 3D: https://www.youtube.com/watch?v=cca4i60ZLw4&list=PLy5M_tA9ux7IWL18nsrSf4RnjsuPjHC-p GRUNDIG 1070: https://www.youtube.com/watch?v=i4J5l0fwhko&list=PLy5M_tA9ux7JgnyYPRWOK763aJ8bg3iCI SCHAUB-LORENZ GOLDY 58 type 3020: https://www.youtube.com/watch?v=RSbt7qVed78&list=PLy5M_tA9ux7IBse5G--Kl89SPS9sATXfZ BUSH VHF64: https://www.youtube.com/watch?v=U--6JymkQ1M&list=PLy5M_tA9ux7KsvN5M48cX6cxN4jSz0s3X GRUNDIG 3060A: https://www.youtube.com/watch?v=7x2sK2GSYeE&list=PLy5M_tA9ux7L8e9h8lrHGREPqcgWO-YQm TELEFUNKEN OPERETTE 8: https://www.youtube.com/watch?v=5IsACM0mPzs&list=PLy5M_tA9ux7K3SXDv8Hu4uAyl1O7NE5dc GRAETZ SUPER 171W: ... https://www.youtube.com/watch?v=pQG8rBoYSNA

Loewe-Opta Truxa 4741W Stereo tube radio restoration log part 5. The job is done and the result is a pleasure. Should work for another 50 years (I hope). If you missed it, see the preceding parts of this restoration at: Part 1: https://youtu.be/4LFAleeriSM Part 2: https://youtu.be/a8dvvpa95_0 Part 3: https://youtu.be/nN-tZa809_Y Part 4: https://youtu.be/GdJe1TEoZeM All info on this model at: httphttp://www.radiomuseum.org/r/loewe_opta_truxa_stereo_4741w.html See also my playlists on other complete restorations. Graetz Musica 4R417: https://www.youtube.com/playlist?list=PLy5M_tA9ux7Ios98E59dWjwc2SRJyxwIn SABA Freiburg W2: https://www.youtube.com/playlist?list=PLy5M_tA9ux7IqvS-LshUGpE1D_WY6mrZe Graetz Comedia 616: https://www.youtube.com/watch?v=fwmW9k3TwNE&list=PLy5M_tA9ux7L5sAApLzV6xoYzmRNJpMW5 You may also be interested in ... Re-stuffing filter capacitors in this tube radio: https://youtu.be/WVn9k13nXvo Replace Selenium rectifier with silicon diodes: https://youtu.be/NkKOe0YU2_I Repair rig for Tube Radio or Tube Amp repair: https://youtu.be/bVXWUMCujNE ... https://www.youtube.com/watch?v=pi9Ow7wMBV4

Only $5 for 10 PCBs and every new member get $5 bonus. + Express 24 hour / 48 hour service on https://www.pcbway.com/ ➠ ➠ ➠ Respecting foil capacitor 'polarity' in the restoration of vintage electronics gear is a much-debated topic these days. Some say it's crucial, while others say that it makes no difference as modern capacitors don't have the same issues as those of old. While I personally am a little on the fence on the subject, I always do a test to determine which lead is connected to the capacitor's outer foil. Can't hurt, right? The oscilloscope has been my tool of choice to date. The process is easy, but a little cumbersome, so I decided to design and build a self-contained device to do the identification for me. It also represented an opportunity to build it as another of my 'under the shelf' units, which are incredibly useful. So, if this sort of thing interest you, stick around and enjoy the video. If you wish to order your own PCBs from PCBWay, the link is below: ➠➠ https://www.pcbway.com/project/shareproject/Capacitor_Foil_Side_detector_c384be11.html Other Creators mentioned in this video: @MrCarlsonsLab ? Want to support the channel? ●●●●●● https://www.patreon.com/mcaldeira https://paypal.me/macaldeira #tuberadios #antiqueradio #radiorestoration ●●●● HUNDREDS OF OTHER VIDEOS TO CHOOSE FROM ●●●● ✿ DIY TEST GEAR: The title says it all: https://www.youtube.com/watch?v=7buNHf6HoDw&list=PLy5M_tA9ux7KkjmWX0I0zNocg6NF33EfL ✿ RESTORATION BUILDING BLOCKS: A series of videos showing detailed steps used the restoration process of tube equipment: https://www.youtube.com/watch?v=7xvTGd4ysRE&list=PLy5M_tA9ux7JSYx8z2mw303vx287LHpzf ✿ HowTo's: Various videos on some simple techniques and projects: https://www.youtube.com/watch?v=lgr-J_D6pSU&list=PLy5M_tA9ux7K3B77iUGyLPai3RIvJOrkO ✿ DIY CAPACITOR LEAKAGE TESTER PROJECT: One of the most viewed projects on my channel, with full design description and build instructions. https://www.youtube.com/watch?v=0pySErvzUIY&list=PLy5M_tA9ux7KWexvEjLB0SANSxQXi0zTS ✿ DIY TUBE TESTER PROJECT: Complete design description and build instructions for this really handy device. https://youtu.be/3fCE4uaw_cU?si=BhCnTKKN2NQUDe6v ●●●● Plus full Playlists on some other completed restoration projects on this Channel ●●●●   ? PHILIPS BX750A: https://www.youtube.com/watch?v=i8U9Lteja5o&list=PLy5M_tA9ux7IG6XgctidGO0u0DeT3_CxF ? TELEFUNKEN OPUS 2114: https://www.youtube.com/watch?v=_HO2bjY5vuw&list=PLy5M_tA9ux7LhcZ9h9plfTFmjaM1mcifu ? SABA UW-175-Z 3D: https://www.youtube.com/watch?v=cca4i60ZLw4&list=PLy5M_tA9ux7IWL18nsrSf4RnjsuPjHC-p ? GRUNDIG 1070: https://www.youtube.com/watch?v=i4J5l0fwhko&list=PLy5M_tA9ux7JgnyYPRWOK763aJ8bg3iCI ? SCHAUB-LORENZ GOLDY 58 type 3020: https://www.youtube.com/watch?v=RSbt7qVed78&list=PLy5M_tA9ux7IBse5G--Kl89SPS9sATXfZ ? BUSH VHF64: https://www.youtube.com/watch?v=U--6JymkQ1M&list=PLy5M_tA9ux7KsvN5M48cX6cxN4jSz0s3X ? GRUNDIG 3060A: https://www.youtube.com/watch?v=7x2sK2GSYeE&list=PLy5M_tA9ux7L8e9h8lrHGREPqcgWO-YQm ? TELEFUNKEN OPERETTE 8: https://www.youtube.com/watch?v=5IsACM0mPzs&list=PLy5M_tA9ux7K3SXDv8Hu4uAyl1O7NE5dc ? GRAETZ SUPER 171W: https://www.youtube.com/watch?v=MhG-CH0gqm4&list=PLy5M_tA9ux7IjUykGE8neJSI6GUxMl2YG ? LOEWE-OPTA MAGNET 3737W: https://www.youtube.com/watch?v=ZSZBJ5sKQm8&list=PLy5M_tA9ux7J_hzDhnF8rs2c7wmgGfRlK ? BRAUN ATELIER 3: https://www.youtube.com/playlist?list=PLy5M_tA9ux7L3k5nPRvrk1aH764QRCTqE ? LOEWE-OPTA TRUXA STEREO 4741W: https://www.youtube.com/playlist?list=PLy5M_tA9ux7KhVk0KqPx0Wkh2KO_5f2fQ ? GRAETZ COMEDIA 616: https://www.youtube.com/watch?v=fwmW9k3TwNE&list=PLy5M_tA9ux7L5sAApLzV6xoYzmRNJpMW5 ? SABA FREIBURG W2: https://www.youtube.com/playlist?list=PLy5M_tA9ux7IqvS-LshUGpE1D_WY6mrZe ? GRAETZ MUSICA 4R417: https://www.youtube.com/playlist?list=PLy5M_tA9ux7Ios98E59dWjwc2SRJyxwIn ... https://www.youtube.com/watch?v=pemhjIltmU4