turning a bass preamp into a DI?

[ppatchmods]

anyone ever modded a bass preamp to have an xlr out to go straight to the board? i was thinking about the flipster for this one. i think there is a company that does a mod to the vt bass (pztronics if i recall correctly). i've seen pics of the mod but would like to know how to do it. any help would be appreciated! thanks

[space_ryerson]

While I've never modded a bass preamp to have an xlr, I have used an Eden Nemesis NC-200 for DI with xlr. It works well for me, and if you look through the schematic, you will see how they do it. My old Randalls use a different method, which may be of some use as well.

[ppatchmods]

thanks! i think i have a solution but won't a second and maybe third opinion.

output jack of pedal>transformer>xlr

this way when you want to use it in a chain you can unplug the xlr and plug in a 1/4 inch plug. it is all passive so it shouldn't need anything else. right?

[ashcat_lt]

You can usually get away with an even simpler implementation.  Get a TS plug, a male XLR plug, and some 2 conductor + shield (standard microphone) cable.  Connect the Tip of the 1/4" to the + pin of the XLR, the Sleeve to the - pin, and the shield braid to the ground pin.  Leave the shield braid unconnected (insulated to avoid unwanted contact) at the 1/4" end.  This should create a "psuedo-balanced" connection which will give noise specs better than unbalanced.  The line-level signal coming from the preamp will be a little hot for a mic preamp input, but that's what volume and trim knobs are for.

[Jarno]

You could also get a signal transformer to do this 10k to 600r, but you will need a decent one, else you're going to loose low-end. I anxiously awaiting a package from Edcor, to mount transformers in a tube (bass) preamp. Those are like 13-20USD, that shouldn't be a hurdle. Standard DI box is also an option of course (or gut it to use it's transformer).

[ppatchmods]

You can usually get away with an even simpler implementation.  Get a TS plug, a male XLR plug, and some 2 conductor + shield (standard microphone) cable.  Connect the Tip of the 1/4" to the + pin of the XLR, the Sleeve to the - pin, and the shield braid to the ground pin.  Leave the shield braid unconnected (insulated to avoid unwanted contact) at the 1/4" end.  This should create a "psuedo-balanced" connection which will give noise specs better than unbalanced.  The line-level signal coming from the preamp will be a little hot for a mic preamp input, but that's what volume and trim knobs are for.

is this safe? will it sound decent? i was thinking of getting a transformer to stick in there.

[ppatchmods]

does anyone have any links to decent transformers that won't break the bank? i looked at mouser and they have a lot to choose from but i don't know enough about them. i want something that won't cut off the low end of the bass. thanks

will this one work:
http://www.edcorusa.com/Products/ShowProduct.aspx?ID=304

[ashcat_lt]

is this safe? will it sound decent? i was thinking of getting a transformer to stick in there.

Yep, I do it every week running the unbalanced out from my ancient line mixer down the snake to the mic pres on the house mixer.  You might watch out for phantom power, but I think the coupling caps at the end of the preamp circuit will probably take care of that.

[Jarno]

does anyone have any links to decent transformers that won't break the bank? i looked at mouser and they have a lot to choose from but i don't know enough about them. i want something that won't cut off the low end of the bass. thanks

will this one work:
http://www.edcorusa.com/Products/ShowProduct.aspx?ID=304

Have you read my reply?

That series from Edcor will be fine, but I think you'll need 10k or 15k to 600 ohms for a line out. For better low-end you might also use a bigger one like the PCW series. But using those PC mount trannies will imply that you are going to design a PCB. If you just want to tack it onto the output of an existing preamp chassismount will be more conventient (like the WSM). You can just order from Edcor directly.

[ppatchmods]

thanks guys. yes i did read your reply but didn't know esactly which one to use. thanks