Effect loop informations needed for a Marshall

[MKibanez]

Hey, I would like to install an effect loop on a DSL15 head. I have a tech here that can do it but I would like your recommandations to buy a good one that would be as much transparent as possible and a place to buy it, cheap if it's possible

Thanks to you RT

 

[Dave L]

I guess the Metro is still the industry standard.
http://www.metroamp.com/store/index.php ... cts_id=499