+ Reply to Thread
Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 31

Thread: Fancy a cheap passive pre-amp?

  1. #11
    Join Date: Aug 2011

    Location: Coventry, England UK

    Posts: 419
    I'm Simon.

    Default

    Seems to be pros and cons to both. What about relay based attenuators? (this looks nice: http://www.khozmo.com/64_steps_relay...ttenuator.html)

  2. #12
    Join Date: Oct 2012

    Location: NE England

    Posts: 4,647
    I'm Jez.

    Default

    Quote Originally Posted by RothwellAudio View Post
    Light Dependent Resistor is adamant that mechanical/physical contacts are a problem from an audio point of view but personally I'm not convinced.
    I disagree with him as strongly as is possible within the way things must be worded on the forum and believe that LDR's are a bad way of doing the job as they measurably add distortion.

  3. #13
    Join Date: Oct 2012

    Location: NE England

    Posts: 4,647
    I'm Jez.

    Default

    Quote Originally Posted by Simon_LDT View Post
    Seems to be pros and cons to both. What about relay based attenuators? (this looks nice: http://www.khozmo.com/64_steps_relay...ttenuator.html)
    I have been meaning to build myself a relay one for a while... one of those round tuit things! I'm not offering to make these for customers.

  4. #14
    Join Date: Sep 2013

    Location: North Island New Zealand

    Posts: 848
    I'm Chris.

    Default

    Quote Originally Posted by Simon_LDT View Post
    Seems to be pros and cons to both. What about relay based attenuators? (this looks nice: http://www.khozmo.com/64_steps_relay...ttenuator.html)
    It is honest by admitting there is a design issue with conventional pots and signal paths, as it
    seeks a partial different solution. But it has the same problem, that the signal path still engages
    contacts. And it is more expensive.

  5. #15
    Join Date: Sep 2013

    Location: North Island New Zealand

    Posts: 848
    I'm Chris.

    Default

    Quote Originally Posted by Arkless Electronics View Post
    I disagree with him as strongly as is possible within the way things must be worded on the forum and believe that LDR's are a bad way of doing the job as they measurably add distortion.
    Prove it ! , and can I strongly suggest you use a design that properly isolates cathode ground from signal ground
    before measuring. If that takes a while to design ( years ) - so be it, And also measure a conventional pot at the same time.

  6. #16
    Join Date: Oct 2012

    Location: NE England

    Posts: 4,647
    I'm Jez.

    Default

    Quote Originally Posted by Light Dependant Resistor View Post
    Prove it ! , and can I strongly suggest you use a design that properly isolates cathode ground from signal ground
    before measuring. If that takes a while to design ( years ) - so be it, And also measure a conventional pot at the same time.
    Don't need to. I trust Lurcher's (Nick. Longdog Audio) measurements showing this... oh, and the warnings about distortion in the manufacturers data sheets for LDR's.

    And that ends my participation in the specific matter of LDR's.

  7. #17
    Join Date: Sep 2013

    Location: North Island New Zealand

    Posts: 848
    I'm Chris.

    Default

    Quote Originally Posted by Arkless Electronics View Post
    Don't need to. I trust Lurcher's (Nick. Longdog Audio) measurements showing this... oh, and the warnings about distortion in the manufacturers data sheets for LDR's.

    And that ends my participation in the specific matter of LDR's.

    http://lunainc.com/product/optocouplers/

    "Luna Optoelectronics’ optocouplers are ideally suited for high performance audio circuits. Most “design-ins” have demonstrated proven performance benefits over silicon based audio control devices such as VCAs and FETs.

    The optocoupler is a very cost-effective way to improve the performance of your audio equipment."

  8. #18
    Join Date: Apr 2012

    Location: Southall, West London

    Posts: 28,464
    I'm Geoff.

    Default

    Quote Originally Posted by Minstrel SE View Post
    That little bear product just looks a bit cheap

    Best wishes
    Martin
    That was the point. And it sounds good!
    Mr. Tact!

    Main system: MMs/ADCs/Low output MC's/One rare Japanese SUT/One scarce British phono stage/various tonearms/hefty Japanese DD TT and hefty Japanese BD TT and small British BD TT. 4 CD players/2 jitter buster/2 DACs/Valve buffer. TVC stepped attenuator or valve pre-amp or solid state pre-amp. Current dumping power-amp or either of two Class A SS power-amp or Class A EL34 valve monos or big Japanese (part Class A) integrated. Big dual concentric speakers/Smaller dual concentric speakers/Two way British compacts and full range speakers, amongst others. And too much more to list!

  9. #19
    Join Date: Apr 2012

    Location: Southall, West London

    Posts: 28,464
    I'm Geoff.

    Default

    Quote Originally Posted by RothwellAudio View Post
    BTW, Black Adder is selling a nice passive here on AoS
    http://theartofsound.net/forum/showt...y-nice-indeed)
    I Know. It's lovely, but it's not 25.
    Mr. Tact!

    Main system: MMs/ADCs/Low output MC's/One rare Japanese SUT/One scarce British phono stage/various tonearms/hefty Japanese DD TT and hefty Japanese BD TT and small British BD TT. 4 CD players/2 jitter buster/2 DACs/Valve buffer. TVC stepped attenuator or valve pre-amp or solid state pre-amp. Current dumping power-amp or either of two Class A SS power-amp or Class A EL34 valve monos or big Japanese (part Class A) integrated. Big dual concentric speakers/Smaller dual concentric speakers/Two way British compacts and full range speakers, amongst others. And too much more to list!

  10. #20
    Join Date: Oct 2012

    Location: NE England

    Posts: 4,647
    I'm Jez.

    Default

    I presume the XLR's are not balanced?

+ Reply to Thread
Page 2 of 4 FirstFirst 1234 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
  •