DeWick Repairs. DeWick RepairsSpecializing in the Repair of Audio Electronics Since 1962 Terry DeWick 1829 Plumb Branch Road Knoxville, TN 37932-2040 Phone : (865) 691-2446, 10AM to 10PM EST E-Mail : Terry DeWick(firstname.lastname@example.org) WILL BE CLOSED FOR MONTH OF FEBRUARY Sorry, will not be taking on any new work during February, will be in Florida. Specializing in the repair of audio equipment both Solid State and Tube, old and new. Due to overwhelming work load I am limiting my rebuilds and repair to McIntosh and Vintage tube, sorry no updates and rebuilds for Pioneer, Marantz, and Sansui at this time. STOP - read this ! New mail address, please use email@example.com or firstname.lastname@example.org Note: 1 I do not normally mind working on equipment that has been upgraded by some one else, as long as the work has been done correctly with good components.
Note: 2 Current Backlog is 90+ days (11-01-2014).Date of arrival to Today's date = Time to get on the bench. Note: 3 Extras, Trades, and Abandoned, for sale. Vintage Marantz Audio Equipment - Rebuilds & Repairs - Rebuild of a Marantz 1030 Integrated Amplifier. After rebuilding any amplifier it is necessary to adjust the basic settings for correct operation. Each amplifier will have its own particular set of adjustments which are outlined in the service manual. There are 6 sections to the Performance Verification on a 1030: Power Amplifier AdjustmentsTotal Hum and Noise TestMaximum Power OutputHarmonic Distortion TestChannel Separation To perform all of these test you will need to following equipment: Without all of this equipment you will not be able to perform all of the tests, but you can do the most important adjustment which is the Power Amplifier adjustments (also know as the Bias Adjustments).
----WARNING--- You must have the service manual to perform these tests. ---WARNING--- Performing these tests and adjustments is where 90% of do-it-your-selfers FAIL. I'm not going to do a detailed description of how to adjust the 1030 amplifier. The very first time you power up a newly rebuild unit disaster may be waiting right around the corner. Replacing old capacitors. When planning to restore old radio sets, common questions are: ‘How many capacitors should I replace?’ Or ‘Should I replace all capacitors to prevent faults?’. I read of people that dismantled their radios to replace everything inside, finding themselves with nice cabinets full of shining parts, but showing erratic operations or not working at all. In my experience the substitution of properly working parts with more or less similar components is useless, may impair the operation of the equipment and may also result in additional failures.
Original components, when still good, are stable and not subjected to infant mortality. Of course everybody has his own opinions derived from past experiences. Nevertheless answers may vary depending upon several reasons: quality of the design with proper use of right components, type and quality of materials, environmental conditions during life and storage of equipment.
I see frequent discussions tied to specific models. 1) Short circuits. Rap on Replacing Electrolytic Capacitors. NOTE PLEASE: This web page provides information only; you are responsible for assuring that your repairs are safe, and that all repairs are carried out with proper safety. Tube-based equipment operates at high voltage which can be lethal and if you aren't totally confident in your ability to ensure your personal safety and the safe operation of your repaired equipment please take your amp, radio or test equipment to a qualified tech. What's Available for Repairs Unfortunately, the selection of high voltage electrolytic capacitors today is both smaller and different from the past, so chances are you won't find an exact replacement for your original equipment electrolytics. For low voltage applications, like cathode bypass capacitors, most vintage types have an axial configuration, which is less common today but still available.
The more modern radial configuration can also be used if their leads are long enough and they don't violate your notion of aesthetics. Rap about Electrolytics. Vintage amplifier repair/upgrade manual. I thought like posting that ..... feel free to edit it ... happy regards sakis ( with sexy avatar ) Vintage amplifier repair/restore tips by east electronics part 1 1-All vintage amplifiers need recapping (most electrolytic inside a vintage amplifiers are likely to be gone. Apply not only to rectifier board but also the all device. 2-By the same logic resistors should be taken care off or at least take a look at to see for variations from the original value. 3-Often replacing electrolytic with higher quality caps will make difference in the overall performance. 4-All changes to be made have to have a symmetric effect .IE adding 100mf bypass cap next to positive rail ,next to output transistor should followed by the same on the negative side . 5- Adding bypass caps of 0.1 mfd to rectifier board electrolytic makes them faster. 7- Replacing outputs have to be done with caution .If outputs are obsolete you can go to the nearest pair that is on production today.
Power up!!!!!! Replacing Capacitors in Old Radios and TVs. Why Replace Capacitors? Second only to power cords, capacitors are the most failure-prone components in old radios and televisions. In a professional overhaul, it is common to replace all of a set's large electrolytic capacitors and small paper capacitors. This article explains how to do that. In many cases, this "recapping" is all that the radio or TV needs to be restored to health. Incidentally, tubes are much more reliable than capacitors. These photos show the underside of a Grundig 940W radio before and after recapping. The new capacitors in the second photo are colored yellow, orange, and blue. Types of Capacitors Before getting to work, let's make sure you know what to replace.
Electrolytic capacitors are polarized, meaning that they have positive (+) and negative (-) leads. Non-electrolytic capacitors are not polarized. Note that two of these types—mica capacitors and flat molded paper capacitors—look similar. Understanding Farads, Microfarads, Picofarads .47 mfd = 470,000 pf. TweakersAsylumVHAudioOIMP.pdf. Speaker Exchange | Your one stop for all things speaker!Speaker Exchange. ExcelStereo.com. Music Technology. HiFi Heaven Repairs. CD Player Troubleshooting and Repair. [Mirrors] Contents: 10.5) Types of skipping problems The general behavior will usually fall into one of the following categories: 1.
It gets stuck and repeats a fraction of a second (1 rotation). 2. 10.6) Short distance skipping This means jumping forward or backward by a fraction of a second. 10.7) Playback gets stuck (rapid repeat) This means repeating the same track or a small number of tracks (meaning disc rotations, in this case). 10.8) Occasional long distance skipping or repeating Usually, several seconds of music will play without any trouble and then there will be a skip forward or backwards by a few seconds or longer. 10.9) Player gets stuck at approximately same time on multiple discs Common causes: transportation lock engaged, gummed up lubrication on pickup tracks or worm gear, other mechanical problems like an obstruction or errant wire getting in the way. 10.10) Various tracking problems on portions of discs 10.11) Repetitive noise at disc rotation rate.