[Soeren_DK]

 
I'm planing making a proto for Bo in the christmas vacation and when he has tested it I'm sending the gerbers for Gustav.

Cheers
Soren

[Bo Hansen]

Between Christmas/New Year I will try to do a transformer test/evaluation and compare Lundahl, Haufe and OEP in the DI-Box electronics.

But Just now I wait for a sample of OEP A262A3E from UK, so I will start when I receive that.

--Bo

[lcaudio]

This will be really cool, i would definitely buy some pcbs! I did my first build from Bo's schematic and it sounds great, but it seems to have pretty low gain. Is that the nature of this di or did I possibly do something wrong? Thanks.

[Bo Hansen]

Icaudio,

If everything is ok, and you have connected the transformer fore 5:1 configuration you shall have around 15 dB loss from instrument input to XLR balanced out. (no loss, 1:1 from instrument input to monitor amp out)

Because you use a microphone transformer backwards you get "loss" negative gain, and a 1:5 ratio transformer have approx. 15 dB step-up gain, or loss used backwards.

You want loss in a DI-box, because the level from a guitar or bass, (after a 1:1 impedance converting) are to high to match a console microphone input.

I will guess that mostly of active DI-boxes on the market have approx. 5-15 dB loss, and passive have approx. 20-30 dB loss.

If you after all need more gain, use the 2,5:1 configuaration instead for the 5:1 configuraton on the Lundahl LL-1538 transformer and you get only 10 dB loss instead for 15 dB, and have 5 dB more gain out from the DI-box.
(but the best transformer match in this circuit are the 5:1 configuration)

--Bo

[lcaudio]

Thanks for responding Bo. That was a much more involved response than i had anticipated and appreciate it greatly. A lot of great information! I use the DI mainly for live use and it does sound great. I was only conerned that I may have wired something wrong because it was seemingly lower gain than other actives i've used. I don't think i'll alter for more gain and stick to your design. I'll also have something to compare it to once the PCB's are released to the community. Thanks for your great design, it was a pleasure to build.


logan

Icaudio,

If everything is ok, and you have connected the transformer fore 5:1 configuration you shall have around 15 dB loss from instrument input to XLR balanced out. (no loss, 1:1 from instrument input to monitor amp out)

Because you use a microphone transformer backwards you get "loss" negative gain, and a 1:5 ratio transformer have approx. 15 dB step-up gain, or loss used backwards.

You want loss in a DI-box, because the level from a guitar or bass, (after a 1:1 impedance converting) are to high to match a console microphone input.

I will guess that mostly of active DI-boxes on the market have approx. 5-15 dB loss, and passive have approx. 20-30 dB loss.

If you after all need more gain, use the 2,5:1 configuaration instead for the 5:1 configuraton on the Lundahl LL-1538 transformer and you get only 10 dB loss instead for 15 dB, and have 5 dB more gain out from the DI-box.
(but the best transformer match in this circuit are the 5:1 configuration)

--Bo

[justanalogue]

Very nice work gentlemen!!!

Ready for PCB's.

Willem.

[juanjovincenzo]

Hi  Bo,  Soren and Guys !!

Exelent work!!
I´m thinking to put together in a single box the Bo hansen DI and the Green PREamp. I create a new topic about this here http://www.groupdiy.com/index.php?topic=36987.0      I love to make my own PCBs (with Lazer Print and the transfer method on a virgin copper PCB) because the DIY thread feels much "ARTESANAL"¡¡¡¡.

Soren, if it is posibless, please, post (upload) the Copper Layout (only botton layout) of your Bo Hansen´s PCB??? Only the cooper tracks in black, ready to transfer like Gyraf´s PCBs proyects.  It´s only for personal use and for the people that like to make the own PCBs.

Thanks for the patience I am beginner.

Juanjo

Here is my first PCB, Its the KROC´s PCB (Kev Ross Opto Compressor, Dual compressor based on LA-4) I´m working in this proyect, while I wait for the arrival of the parts that I bought to make the Kroc, I am making the Green MKII V14 PCBs.

The copper botton side

,

[juanjovincenzo]

and this is the Top Side or Components side..... mmmm How I can insert the images directly!!!!!!! without use the attach form! I am a bad "cyberboy" jeje

[lcaudio]

Any progress on this? 

[[silent:arts]]

Any progress on this? 

I don't want to be leaky, but I know Bo did some transformer testings over the weekend

[ChrisPbass]

Excellent news, looking forward to this.   

Glad I put off buying any 'off the shelf' brands as I've heard great things about this design.

Chris

[Soeren_DK]

I had to make some test pcb for Bo in the christmas holliday but the plans went totally wrong but thats an other story. I'm trying to get it done by the end of this week.
Sorry for the delay

Cheers
Soren

[TheGuitarist]

I know active and passive DIs have their advantages, but is this design a bridge? Or just another good one.

[Soeren_DK]

Anyone have the time to etch a proto pcb for Bo so he can test the design before we make a bunch of them.
I will provide the layout in a pdf filer here?

Cheers
Soren

[[silent:arts]]

contact Lukas
I will pay for it.

[juanjovincenzo]

Hi,
a PDf file is a good idea thanks for that, so the people that  they want can etch their own pcb, in the other hand the option to buy a profesional pcb , helps especially when the guys dont have time. Its a good contribution.

thanks Soeren
regards

[Soeren_DK]

contact Lukas
I will pay for it.

I have send an email to Lukas but I will of cause pay for it. Thanks for your kindness but you don't have to pay.


The latest design:
http://www.mentol.dk/diy/bohansen/print.pdf
http://www.mentol.dk/diy/bohansen/pcb.JPG
http://www.mentol.dk/diy/bohansen/silk.JPG

Cheers
Soren

[juanjovincenzo]

Thanks !!!!!!
Muchas Gracias!!!!! Soren, Bo, Torben

I will etch the pcb on this weekend and I can test it , but I don´t have a tranfo right now, I can buy a OEP today but I think that the transfo. will arrive to Ecuador in 4 weeks.


again thanks for
a great contribution

Best regards

[Soeren_DK]

Thanks !!!!!!
Muchas Gracias!!!!! Soren, Bo, Torben

I will etch the pcb on this weekend and I can test it , but I don´t have a tranfo right now, I can buy a OEP today but I think that the transfo. will arrive to Ecuador in 4 weeks.


again thanks for
a great contribution

Best regards

 
I look forward to hear about your experience

Cheers
Soren

[juanjovincenzo]

Hi Soren!!

I don´t have a lot experience but I can etch the PCB and try it , so if You or someone want test the layout  I can etch and send a PCB  .

Best regards
Juanjo

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