Bo Hansen DI layout

[Newmarket]

Yeah - links can often become an issue when the stuff gets rearranged / moved host.
While I'm being pedantic  : - the bottom line in paste from webpage below should presumably start BC560C ( rather than BC550C).

Thanks again

Here are some recommending European types that fits well:
BC550C = BC550B, BC549B/C, BC548B/C, BC547B/C, BC414B/C, BC337-25/40, BC237B/C, BC184B/C
BC550C = BC560B, BC559B/C, BC558B/C, BC557B/C, BC416B/C, BC327-25/40, BC307B/C, BC214B/C

 

[Bo Hansen]

Thank you,

Yes, you are absolutely right, will change it at the same time.

It gets easy wrong sometimes when there are many digit combinations at once.

--Bo

 

[Newmarket]

It certainly is.
I have a hard disk full of specs and stuff here and a stack of (real) folders but part numbers with all the digits/letters and (often not relevant) suffixes can still get me going round in circles...
Cheers

 

[providedrailroad]

Does anyone have Gerber or Eagle files for this one, or some spare boards?

I'd like to build a couple but would like to have them manufactured or purchase the PCB's, I don't have a home etching setup right now and don't want to go down that road.

Thanks.

Wes
[email protected]

 

[Bo Hansen]

Wes,

You can order very nice DI-box PC-cards from  Silent:arts/Volker Mayer

http://groupdiy.com/index.php?topic=39570.msg488632#msg488632

--Bo

 

[speed12]

Hi, First time replyer here but have been browsing this thread for a while.

Hopefully a simple question as a first post.

I'm in the process of designing a rack system to use with a guitar modeller and audio interface and as part of it would like a rack mounted DI. All of the commerical options seem to have either features I do not need or (mainly) the jacks in reverse of what I need (I'd like input jack on the rear, XLR on the front) and seem to cost a lot.

Having looked for a DIY option (I'm a competent solderer, but not 100% up to speed with actual electronic design - I can follow instructions though!) and found Bo's great DI box, my wondering is whether making this DI into a rack would be as simple as using mutliples of the PCBs constructed as normal? In my head it would work as long as I followed Bo's advice on grounding etc. As they are phantom powered then shared power supplies aren't an issue as far as I can see.

If anyone has any thoughts on potential issues of doing this or any helpful tips (specifically on making a 'rack' version) then they would be much appreciated!

Many thanks,

 

[Bo Hansen]

Hi Speed12,

Of course, you can mount several DI cards in the same housing without any problems.

But I do not really understand how you want to do with the voltage feed.

Are there regular balanced microphone inputs that you should use these DI boxes to, or is there any other type of inputs ?

Would you like to feed each card from the microphone input with phantom power, or do you want an internal rack power supply for all cards, so they not will be feed from phantom power ?

--Bo

 

[speed12]

Hi Bo,
Thankyou for your swift reply!

My apologies - I worded the question badly. I will be using the DIs with a FoH mixer which can provide phantom power to each channel and that is how I am planning to power the units individually. What I was trying to say was that because of this there aren't any issues with sharing a power supply in the rack unit for the DIs which could cause noise issues.

It sounds as if it is all good to mount multiple units together so  I look forward to building them! Will report back with how it goes 

 

[Treb]

I've seen a few two-DI's-in-a-single-box here. Why not ask the makers of those for potential noise issues?

 

[Bo Hansen]

Treb,

It's no problem to mount many DI boxes in the same housing if you do it right, it is equivalent to stacking many separate DI boxes on each other.

But it may be a problem with ground loops if many DI boxes in the same housing have an internal PSU, and if the DI boxes are to connected to many different instruments and preamps that are grounded in different wall sockets.

There are some DI boxes on the market that are two channels / stereo and some with even more channels that are good.

During the 1980's I was dealer  for EMO products here in Sweden , they had good simple passive DI boxes, and also had a 19 "rack that was able to screw both DI boxes and mic-split boxes on small panels/ modules.
A smooth and good system that I liked.

--Bo

 

[kante1603]

I've seen a few two-DI's-in-a-single-box here. Why not ask the makers of those for potential noise issues?

Hello,


one of them was me.No issues at all.
As Bo already stated it is the same as stacking single units.Just take care of propper grounding and keep the jacks isolated where needed.


Best regards,


Udo.

 

[jbvdwal]

Just built mine, and it works great, still have to box it!

I did use some 50v 10uf elna silmic II's, and 1n4742 zeners, which i dont think are 0,5 w but 1,something.

I hope this does not affect the design? I can easily swap it anyway, put the zeners on sockets to be sure.

If not its getting boxed and probably used live on it first shows and festival allready <3

 

[Bo Hansen]

jbvdwal,

As I said many times here, this DI-box design works with almost component types and quality, and will work great.

The internal maximum voltage is 24 volts, so rated voltages for components higher than this are ok.

The recommended voltage and component values ​​are today's standard values, to give your DIY builder a benchmark when purchasing components.

Zenerdiides from 500mw to 1 watts are quite ok.

The type and brand of resistors/capasitors  is up to the builder's taste and conviction / belief.

Read ALWAYS building description and suggestions on my DIY page www.hansenaudio.se/techpage.htm, I have to try to explain all the questions you normally have regarding this project.

--Bo

 

[jbvdwal]

Had a re read and missed it indeed, sorry about that.
Thanks again for the design, and volker for the pcb! <3

Here's a little shoot out, with 2  guitar riffs (excuse the out of tune tele) between, the:

1: Bo Hansen DI
2: LittleLabs Redeye,
3: the RME Di input on the soundcard.

https://www.dropbox.com/s/ytdnyk18aqibcro/DI%20TEST_BOHANSEN%20LITTLELABS%20RME.wav?dl=0

I didnt get all the people saying it has little output, mine is louder then the LittleLabs.

 

[Bo Hansen]

Amazing, we have passed 200,000 visitors.

I also want to take the opportunity to thank you for your great interest and that you like my DI-box design.

Wish you all a Merry Christmas & Happy New Year.

--Bo

 

[andrii.konkov]

I have a question concerning transformer ratio.
I could get my hands on vintage soviet input transformer. It has ratio 1:8 according to datasheet. Is it worth trying with this schematic? Also it could be connected in 1:15 ratio, maybe I'd better use it for passive DI box?

 

[Bo Hansen]

Andrii,

A microphone transformer  that have a ratio of 1:8, connected backwards is ok, you get slightly lower output level approx.  -18 dB versus the 1: 5 original transformers around -15 dB.
(which is a suitable attenuation for an active DI box)

But 1:15 (that have aprox. 24 dB loss backwards)  fits better for a passive DI-box, and is nice for synthesizers and active instruments.

--Bo

 

[andrii.konkov]

Grateful for your reply. Then I'll  experiment with both i guess.

 

[godwin]

I'm looking for help on the Bo Hansen DI build. I have built four (4) of them. Three work excellent The fourth has a thin sound and low output from the XLR. I'm getting the correct voltages where the directions say to check for correct operation. Any help would be appreciated.

 

[godwin]

Pictures of my DI's. The cases are hand cut from stock aluminum tubing.