converting line-level FX loop to "stomp box level" ?

Discussion in 'Amps and Cabs' started by rh, Nov 22, 2005.

  1. rh

    rh Robo Sapien Noise Maker Gold Supporting Member

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    Is there a way to convert the line-level FX loop (tube driven 1 volt RMS) into something I could use with stompbox effects? Some sort of converter box or something?

    I've had a Flexloop already, and wouldn't want another one.
     
  2. hw2nw

    hw2nw Member

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    hmm. yeah, I'm interested too. My Shiva has this problem.

    Anyone?
     
  3. avenerjimmie

    avenerjimmie Member

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    Here's another lad interested. Shiva owner as well.
     
  4. ZiggY!!

    ZiggY!! Member

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    You could try using a passive DI in reverse. You'll need to use one before returning to the amp as well to bring it back up to line level.
     
  5. StompBoxBlues

    StompBoxBlues Member

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    I've gone into this a little lately because my Prosonics' effectlopp is +10db.

    Problem with any passive solution (i.e. resistors, etc.) it that the other side of the loop, the RETURN is expecting, and optimized to receive also the same level that was sent out.

    So, a low-cost "solution" would be like...I have a cable with resistors that drop it down -6db from what is put in.

    But that means also a lower volume on the output.


    What you really want is something that drops the signal to pedal levels (-10db I think) through the pedals, then cleanly or without coloring brings it up again back to the original level after the pedals into the return.

    I recently bought (but have not had the chance to try it yet) a Nobels SPX-31 I think it was called. This has two effects loops, is a very small (slightly bigger than a boss pedal) and lets you adjust the level in (from the send on effects loop from amp) the levels sent to the loop...the level back, and even mix it, as well as an output level (hopefully enough to bring up the level close to where it was).

    I emailed Nobels, and they were iffy if it would tackle this high a level (+10 is big)...but others I read on a Fender site recommended it. The Nobels takes a 15Vdc supply.

    There is another unit out there that might work, and it is designed to match impedances, but from their site I couldn't tell if they also can bring the signal up again after the effects. Sorry, I don't have the info right now though.
     
  6. cvansickle

    cvansickle Supporting Member

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    This is what my Vox Valve Effects Loop Buffer does. It uses a 12AX7 tube to buffer the effects in a loop, and has level controls at the input and output. I've got a couple of Ibanez Power Series pedals, delay and chorus, that sound great in an amp loop when buffered with this device.

    Vox made these for only a year or so in the early 90s. I first saw it at the 1994 summer NAMM show, but never saw one again. In 2001, I realized the need for one, and had to do an extensive web search to find one. With the continuously growing pedal market today, I can't believe that somebody hasn't licensed this design and started making them.
     
  7. StompBoxBlues

    StompBoxBlues Member

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    Sounds great. I did a search on Ebay, no dice (of course) but the search led me to another similar product also:
    http://cgi.ebay.com/DHA-VT1-Bob-the...ryZ22669QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

    Though I know nothing more about it than what is written in the ad.
    There is one review for this on Harmony Central, but it is mostly a pretty badly written, useless review. No good information.
     
  8. hw2nw

    hw2nw Member

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    hm, i think your link is broken.
     
  9. StompBoxBlues

    StompBoxBlues Member

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    Sorry, don't have the time at the moment, but just go to Ebay and search for DHA VT-q and I am sure you'll find it...or "bob-the-blender"
     
  10. sws1

    sws1 Member

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    I thought there is a page on the Bogner website showing how to do it. I think you create a special cable, then use the special effects amp on back to raise the signal back up.
     
  11. rh

    rh Robo Sapien Noise Maker Gold Supporting Member

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    My specific app is for a Naylor amp -- but I'll check the Bogner site too.

    Thanks for the hint.
     
  12. rh

    rh Robo Sapien Noise Maker Gold Supporting Member

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    Just got a reply from Naylor about this:

    You can make (or buy) an attenuator box to dampen the FX SEND into the stomp box, then use the stomp box's level to juice the signal going to FX RETURN.

    The attenuator's just a 100K pot.

    out-jack-tip --------------------/\/\/\/\/\/\------------------- in-jack-tip
    out-jack-shaft ----------------------------------------------- in-jack-shaft
     
  13. Beam Tetrode

    Beam Tetrode Member

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    The Naylor Superdrive and Duel 60 heads sound amazing ! ! ! ! However, the effects loop is a major dissapointment when stompboxes are involved.

    I think Zinky uses some sort of Swedish-made line-matching transformer in their FX circuit. The loop in the Superfly sounds amazing with stompboxes.
     

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