Help out Hyratel in the forums (post a comment here, Google+ or in our forums!)
I’ve been recently poking around an old stereo receiver, and have determined that the phono preamp is completely dysfunctional. now, this is ’70s era tech, and fairly high-end for the time. I need help identifying the construction and possible replacements for the capacitors on the preamp module.
Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat and our Discord!
Join us every Wednesday night at 8pm ET for Ask an Engineer!
Join over 38,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord
CircuitPython – The easiest way to program microcontrollers – CircuitPython.org
New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — New Products 11/15/2024 Featuring Adafruit bq25185 USB / DC / Solar Charger with 3.3V Buck Board! (Video)
Python for Microcontrollers – Adafruit Daily — Select Python on Microcontrollers Newsletter: PyCon AU 2024 Talks, New Raspberry Pi Gear Available and More! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi
EYE on NPI – Adafruit Daily — EYE on NPI Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey
Adafruit IoT Monthly — Halloween, WiLo, and more!
Maker Business – Adafruit Daily — The worlds largest car exporter: China
Electronics – Adafruit Daily — Are you grounded?
Sorry, the comment form is closed at this time.
They look like polypropylene film and foil type. These are pretty standard fair for a lot of audio stuff, because the frequency characteristics are generally pretty good.
I would replace any electrolytics and see if that fixes it. Those poly caps hold up fairly well.
For more info on restoration, check around the radio collector web sites like:
http://groups.yahoo.com/group/thetransoceanicfanatic/
Polystyrene and foil construction capacitors.
The tubular caps with the clear ends are polystyrene and foil. They are good quality and should be good as new. They are VERY heat sensitive so be careful if you solder near them. If you still want to replace them, there value in pF is printed on the part and you can use a mylar or polpropylene. If the polystyrene caps are used in a resonant circuit with an inductor with a ferrite core, the temperatur coefficiant of the cap cancels out the temperature coefficient of the ferrite core. You have to be careful replacing caps in those circuits. In your phono preamp, there will not be resonant circuits, so this will not be an issue.
Yes, polystyrene. Although generally a high quality capacitor as described, I’ve replaced some in audio equipment. Shorted or mechanically intermittent.
Came across my first ones in a Heathkit AR-15 stereo receiver nin 1966.
It was ahead of its time with crystal IF filters, fets, ics.