+ Reply to Thread
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 23

Thread: Amp Switch (2 amps into 1 Set of Speakers)

  1. #11
    Join Date: Jan 2009

    Location: Essex

    Posts: 31,853
    I'm openingabottleofwine.

    Default

    The only concern with your arrangement is that the amplifier that is not selected is not given a load. The danger is that this amplifier could be switched on by accident without a load. To provide 'safety' loading would necessitate the use of an 8-pole double throw 'break before make' switch, and one where the time between 'break' and 'make' is very short.

    As to the possible degradation of the signal through the insertion of another set of contacts, well provided the current rating of the switch is high enough the effect will be minimal.

    I once built a switch box to switch the output of my amplifier to either speakers or headphones. I used a military (aviation) grade, 20A rated, Cutler-Hammer 4PDT switch. When switched to the headphone position, the amp was loaded by 10W 8Ohm metal-clad resistors, with the headphones fed via series 0.5W 100 Ohm resistors.
    Barry

  2. #12
    Join Date: Jan 2009

    Location: Essex

    Posts: 31,853
    I'm openingabottleofwine.

    Default

    Quote Originally Posted by RothwellAudio View Post
    True, but most transistor amps are quite happy with no load, or should be.
    The OP's amps are a Tripath switching amp and a Quad 306. I think both of those should be ok with no load.
    Yes, I knew the Quad amp would be OK, but didn't know about the switching amp.

    So, no problem.
    Barry

  3. #13
    Join Date: Feb 2008

    Location: Middlesex, UK

    Posts: 4,481
    I'm Alex.

    Default

    Quote Originally Posted by RothwellAudio View Post
    Well, I'm guessing that the switching amp will be ok with no load. Disclaimer to the OP: don't blame me if your house burns down
    The guy that built my very good class D TPA3116 amp told me not to run it without speakers connected.
    Spendorman

  4. #14
    Join Date: Feb 2008

    Location: http://www.homehifi.co.uk

    Posts: 6,288

    Default

    Get some 100 Ohms cement resistors of 5 or 10W rating. You'll need 4 pieces. One for each RCA/PHONO connector.

  5. #15
    Join Date: Jul 2017

    Location: Kent

    Posts: 550
    I'm Paul.

    Default

    I'll do this Stanley, thanks, by one for each RCA do you mean both ends connect to the one socket?

  6. #16
    Join Date: Jan 2009

    Location: Essex

    Posts: 31,853
    I'm openingabottleofwine.

    Default

    RCAs? Is that a typo, or are you using RCA connectors for your speaker connections?
    Barry

  7. #17
    Join Date: Feb 2008

    Location: http://www.homehifi.co.uk

    Posts: 6,288

    Default

    Quote Originally Posted by Pepperamip View Post
    I'll do this Stanley, thanks, by one for each RCA do you mean both ends connect to the one socket?
    Each resistor should be connected from the signal pin to the ground pin on the same connector. If you want to, email me and I can send you a diagram back attached to the email.

  8. #18
    Join Date: Dec 2015

    Location: Leeds

    Posts: 46
    I'm ian.

    Default

    I am interested in the progress of this idea.
    I run two systems in one room; AV system and a system for stereo. I am sick of unplugging and replugging everytime I go from system to system.
    I was originally trying to figure out how to implement a home theatre bypass, but an amp switching facility would suffice.
    StanleyB I like the look of your basic unit and the idea of the dummy load. How does this work in practice?

  9. #19
    Join Date: Jul 2017

    Location: Kent

    Posts: 550
    I'm Paul.

    Default

    Morning all, just thought I'd give an update on the progress of my speaker wire switch.

    The parts I was waiting on arrived from China and seem well made to my un-trained eye. I also found the MDF I was using way too thick for the front and back panels so I cut out 2 pieces of ply wood instead.

    Here's the front and back of the front panel with the on>off>on switch wired in:
    20180408_111315.jpg20180408_111309.jpg

    And here's the back panel with the gold plated (questionable) speaker binding posts. Theres a bit too much space between each set of 4 for my liking but hopefully only an issue aesthetically.
    20180408_111407.jpg20180408_111425.jpg

    I'll post up some final pics once the binding posts are wired in and it's all been screwed together.

  10. #20
    Join Date: Feb 2008

    Location: http://www.homehifi.co.uk

    Posts: 6,288

    Default

    Quote Originally Posted by daddydj View Post
    I am interested in the progress of this idea.
    I run two systems in one room; AV system and a system for stereo. I am sick of unplugging and replugging everytime I go from system to system.
    I was originally trying to figure out how to implement a home theatre bypass, but an amp switching facility would suffice.
    StanleyB I like the look of your basic unit and the idea of the dummy load. How does this work in practice?
    You press the two switches on the TC-7210 (Left and Right speakers) to switch over between amps. That's how simple it is . It's quickly becoming popular with valve amp owners since valve amps need a load at all times.

+ Reply to Thread
Page 2 of 3 FirstFirst 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •