Bo Hansen DI layout

Bo-

jasonallenh said:

Hey guys, I'm working on a smallllll PCB to use when a transformer must be wired off the board, as is the case with my jensen jt-13k6-c. It saves you quite a bit of space as it's only about 1.5" x 2.5"

https://www.dropbox.com/s/r93oktrj62eb9bj/BHDI%20Rough%20Draft.jpg?dl=0

Does this look correct? I've left six pads to use in the center for transformer connections. 

Thanks for your patience!  ;D

Click to expand...

Jasonallenh,

It seems to be connected right, but the LED is connected wrong. Compare with the original PC card, so you can see how it should be connected.

--Bo

Shouldn't I have LED + to the 6.8k phantom resistor and LED - to the + of the electrolytic? I'm not seeing what I missed!  :-\

jasonallenh,

The LED shall be connected in series with the voltage rail.
Cut up and insert the LED between the junction of the two 6,8 k resistors and the 100 uF electrolytic capasitor.
You can see the way to do it on the orginal PCB layout.

--Bo

jasonallenh,

Much better you post everything about my DI-box on the main  thread in the "Lab section" , because mostly of the DI-DIY people are there and discuss my DI.

--Bo

Since my other Bo Hansen DIs never returned back to me I had to make a few new ones.
Thanks for this great project, Bo!!!

wow those look great!  8)

Bo Hansen said:

jasonallenh,

Much better you post everything about my DI-box on the main  thread in the "Lab section" , because mostly of the DI-DIY people are there and discuss my DI.

--Bo

Click to expand...

I agree with you, this thread should be merged with the main one, but which one? 
There are about 5 different BHDI threads i the Lab...

abbey road,

This topic/thread with near 100.000 visits.
http://groupdiy.com/index.php?topic=36569.0

--Bo

Hi

Has anyone ever tried "CDIL" branded transistors for the Bo Hansen DI ?

https://cdn-reichelt.de/documents/datenblatt/A200/BC550C.PDF

Are these good enough ?
Or is it better to look for "wellknown" brands ?

...markus

Markus,

I think they can be ok, try the input BC550C transistor and compare with a good orginal brand as Motorola, National, Philips, Telefunken,  SGS/Ates, if you not can here more noise with the "CDIL" transistor, it can be ok for this project.
Test with chorted input.
--Bo--

Hey Jens do you hear any difference between Haufe and Oep? which one do you prefer?

Sorry, I didn´t do any comparison. If you desperately need to know if there´s a difference then let me know. I´ll try to make files for you.

No problem Jens it was just curiosity.

I'd be interested in sound differences....cause i'm thinking about building a Bo Hansen DI with 4-6 switchable transformers.

1 Switch Position "Clean Expensive Highend", (Lundahl?...Haufe?...or both if theres a difference?)
1 Switch Position "Cheap 5 Dollars", (just for A/B comparison for people without golden ears ;-)
and 2-4 Positions with a "Character".

I'd be interested what to choose for the Character positions.

...markus

Don't forget about the Lundahl either, I've heard said that it's very good in Bo's DI... I might try one

Amazing, we have now passed  100,000 views in this thread.

Many thanks for yours enormous interest in my active DI box, hope many of you become satisfied with your DIY builds.

--Bo

Hi,
I have built a couple of these and been using them regularly the past years. Today I tried them with a piezo contact microphone on a piano and got a huge 50hz ground loop. I used two and they both have got the same issue. I opened them up and they appear to be built according to spec. any ideas?
I'm using a white LED, case grounded only from the ground pad on the circuit board. Plastic trs jacks. The piezos are mounted on wood.

Try a ground lift.  Can really help in some situations.

monkeyxx said:

Try a ground lift.  Can really help in some situations.

Click to expand...

But not in this circuit I think? The ground is also a 0v for the 48v power. I read early in this thread where Bo advised against it.
/
Emil