Bo Hansen DI layout

[tronnyjenkins]

Re-post from The Lab-


I finished my first of two Bo Hansen 1975 DIs yesterday. The metal work was the worst part, haha.
Anyway, I had a question regarding noise. When I plug in my telecaster through pro tools and the eleven plug in, there is a lot of noise if I take my fingers off of the strings. Is this normal for a tele or did I mess something up ground wise?
I did notice that on Bo's website he mentions using plastic 1/4" jacks, whereas I used metal...

 

[useme2305]

the plastic insulated connections are a must for this design.

 

[tronnyjenkins]

OK, so I replaced the metal TS connectors for plastic ones, and also built my second DI box. This time I tried it with my Mustang bass, and they are both still making noise. I was trying to figure out what the issue could be, and while doing so grabbed the xlr cable where it connects to the box. The noise goes away.

So- me grabbing the XLR connector or keeping my hands on the strings, no noise. Same for two DI boxes. Is it possible I have a ground issue with my preamp?

 

[Bo Hansen]

tronnyjenkins,

If you use the pc-card and you have followed my build instructions thoroughly, and done all the steps so that the grounding, metal case and connectors will work properly.
Then it should not be any interference problems that come from the DI-box.

Probably there is something in your environment, housing, studio that produces the noise/disturbance, since you say that your guitar picking up interference, and that it is better when you grab the guitar strings.

The noise can come from your sound-card, computer or computer monitor.
Try DI-box on any other equipment, as an analog studio or PA mixing console.

--Bo

 

[Classicaudio77]

Would one of these Edcor Transformers be a good fit in this DI?

http://www.edcorusa.com/p/110/mxl5cs

http://www.edcorusa.com/p/102/mx5

http://www.edcorusa.com/p/132/pcw600-15k

http://www.edcorusa.com/p/145/wsm600-15k

 

[lars78]

Hello Bo,

these are the correct versions of SA970 & 2SC2240 ?

data sheet

best

Lars

 

[Bo Hansen]

Classicaudio77,
Compare with Lundahl, Haufe and OEP versions have this MX5 poor headrom in the low end, and some other strange behavior.
We have talk about this earlier in this topic.

Lars78,
Yes, this is very nice low noise high voltage audio transistor, but a bit overkill for this application.
Watch up for different pin-out.

--Bo

 

[lars78]

...yes, but the difference is only 0,07 € to the BC550. 

 

[volker]

The 2SA970 from Reichelt is the GR version, so hFE is only between 200-400 as per datasheet. Same probably goes for the 2SC2240, but I never bought it there.

 

[tronnyjenkins]

tronnyjenkins,

If you use the pc-card and you have followed my build instructions thoroughly, and done all the steps so that the grounding, metal case and connectors will work properly.
Then it should not be any interference problems that come from the DI-box.

Probably there is something in your environment, housing, studio that produces the noise/disturbance, since you say that your guitar picking up interference, and that it is better when you grab the guitar strings.

The noise can come from your sound-card, computer or computer monitor.
Try DI-box on any other equipment, as an analog studio or PA mixing console.

--Bo

Thanks Bo!
I suspected that would be the case, and I'm very happy with the tone of the DI.

 

[turnthesoff]

I really want to make this DI, but I can't see the schematic or parts list or anything because the site is "suspended" whenever I try to get on it!

 

[lars78]

PCB´s
http://www.groupdiy.com/index.php?topic=10776.0

Partlist
EU: http://www.mentol.dk/diy/bohansen/BOM - Diyfanatic - bo DI.xlsx (made by diyfanatic)


iron
http://www.groupdiy.com/index.php?topic=39570.0

case
http://de.farnell.com/jsp/search/productdetail.jsp?sku=3824421

 

[Bo Hansen]

Sorry, my web site is temporarily shut down, because the server has been exposed to virus.
Together with my web-hotel, I am trying right now to solve this problem.

Hope it is cleaned and "on-air" sometime next week.
--Bo

 

[ksor]

Argh - I need schematics and details on Bo's DI box - can I get it somewhere else ?

 

[Bo Hansen]

ksor,

You have a PM from me.

--Bo

 

[ksor]

ksor,

You have a PM from me.

--Bo

Thx - very much !

 

[turnthesoff]

Could I possibly have those schematics as well?

 

[ksor]

Could I possibly have those schematics as well?

I only got the description - I'll try to get the schematic from Bo ig I can find his mail address.

 

[Sredna]

8)

 

[ksor]

8)

I remember reading something and seeing some PCB with a LED, but I see no LED in this schematic - is it THE LATEST version ?