Jump to content
Why become a member? ×

Transformer DI


MoonBassAlpha
 Share

Recommended Posts

Or, you could just buy one. https://www.studiospares.com/Microphones/DI-Boxes/Palmer-PAN-01-Passive-DI-Box_602860.htm?CAWELAID=120173110000146033&CAGPSPN=pla&catargetid=120173110000154407&cadevice=c&gclid=CjwKEAiA3Ou1BRDso5XyhduuwFASJABP3PED2MF679pRXvdSk2t7gjHPJoVhcvg_9FJcJs0dCyo9XhoChkrw_wcB#rtabs1

Link to comment
Share on other sites

[quote name='bertbass' timestamp='1455112739' post='2976011']
Or, you could just buy one. [url="https://www.studiospares.com/Microphones/DI-Boxes/Palmer-PAN-01-Passive-DI-Box_602860.htm?CAWELAID=120173110000146033&CAGPSPN=pla&catargetid=120173110000154407&cadevice=c&gclid=CjwKEAiA3Ou1BRDso5XyhduuwFASJABP3PED2MF679pRXvdSk2t7gjHPJoVhcvg_9FJcJs0dCyo9XhoChkrw_wcB#rtabs1"]https://www.studiosp...hkrw_wcB#rtabs1[/url]
[/quote]

Does that have the correct attenuation for feeding a speaker level output?

[url=http://www.emosystems.co.uk/Products/Passive_Direct_Injection_Boxes.html]These from EMO definite do[/url].

Link to comment
Share on other sites

Yes, the Palmer one does too:

Passive DI box. Jack input with paralell "THRU" output, transformer balanced XLR output. Attenuable input sensitivity, can handle both line level and speaker level signals.

Thanks for the suggestions guys, I'd like to build something in, but this looks like a good starting point.

Link to comment
Share on other sites

  • 3 weeks later...

Just spotted this one on sale today with a tenner off, and it's a dual, which might be handy at some point. It says it takes speaker level signals, and has 3 levels of attenuation rather than 2 that the Palmer box has:
https://www.studiospares.com/Sale/2016/Flash-Sale/Studiospares-Dual-Passive-DI-Box_449300.htm#rtabs3

Offer finished 2nd March, 3pm.
I think I might just have to @ <£20

Link to comment
Share on other sites

[quote name='Passinwind' timestamp='1456860581' post='2993013']
Take a look at how Fender taps a line level signal off the speaker out signal in many of their old tube amps. All you need then is any old decent isolation (1:1 ratio) trafo.
[/quote]
Thanks, any links?
I've bought the passive box now, but always interested to see how others have done it. Are the Fender ones balanced though?

Link to comment
Share on other sites

[quote name='MoonBassAlpha' timestamp='1456910687' post='2993367']
Thanks, any links?
I've bought the passive box now, but always interested to see how others have done it. Are the Fender ones balanced though?
[/quote]

Here's how they did it in my guitar amp: http://ampwares.com/schematics/fender_30.pdf

As I said, balancing it would just be a matter of adding a line level 1:1 output transformer. I have one in a separate box, comes in handy for all sorts of things.

Link to comment
Share on other sites

[quote name='Passinwind' timestamp='1457337399' post='2997386']


Here's how they did it in my guitar amp: http://ampwares.com/schematics/fender_30.pdf

As I said, balancing it would just be a matter of adding a line level 1:1 output transformer. I have one in a separate box, comes in handy for all sorts of things.
[/quote]

That's very similar to the method used in the tubetown link above, though one uses 47K/5K for the divider and the other uses 100K/10K. I'm not sure what the purpose of the capacitor in parallel with the pot on the first example is - it looks like it could bleed some highs to ground, but I haven't tried calculating the corner frequency.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...