Bo Hansen DI layout

[jasonallenh]

Bo-

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

 

[Bo Hansen]

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

 

[jasonallenh]

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!  :-\

 

[Bo Hansen]

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

 

[Bo Hansen]

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

 

[jensenmann]

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!!!

 

[monkeyxx]

wow those look great!  8)

 

[abbey road d enfer]

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

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...

 

[Bo Hansen]

abbey road,

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

--Bo

 

[Markus_Krippner]

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

 

[Bo Hansen]

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--

 

[12afael]

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

 

[jensenmann]

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.

 

[12afael]

No problem Jens it was just curiosity.

 

[Markus_Krippner]

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

 

[monkeyxx]

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

 

[Bo Hansen]

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

 

[Studio Mollan]

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.

 

[monkeyxx]

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

 

[Studio Mollan]

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

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