Bo Hansen DI

[Pete]

With help of forum member waitup (built at the NF audio HQ) I can proudly say I made this Bo Hansen DI. I just ended up using an altronics transformer which sounds great. To use Bo's own words it has "fat and clear bottom"!

[waitup]

Don't give away the Altronics transformer secret, Pete! People will find out they sound good and Altronics will jack the prices! Also I can't take much credit for this one, Pete pretty much rocked it on his own... not bad for a first DIY eh!?

For anyone who builds this... the LED has to be installed for it to work... as we found out.

[spandex man]

Looks great! Whats the pricetag for the parts to build one of these?

[Pete]

It was about:

case - 15
parts - 25
board - 15

Not sure what the transformer cost, I'm "borrowing" it from nick. I also had access to a pretty spec'd out workshop with drill press etc etc so if you don't have that then it would be a bit more to put it all together.

That said building something to budget seems to lead to disappointment. I mainly did it because it was fun to make (and DIY is very addictive..)

[waitup]

Not sure what the transformer cost, I'm "borrowing" it from nick.

That's ok, I'm pretty sure I "borrowed" that particular one from Lach's desk drawer.

[Mac]

hey Pete, looks great - good tip on the altronics trafos. Half the price of an OEP.

For anyone who builds this... the LED has to be installed for it to work... as we found out.

you can also just use a wire link on the board instead of the led if you dont want one.

Mac

[waitup]

hey Pete, looks great - good tip on the altronics trafos. Half the price of an OEP.

For anyone who builds this... the LED has to be installed for it to work... as we found out.

you can also just use a wire link on the board instead of the led if you dont want one.

Mac

Of course. I'll rephrase. A led or a wire link needs to be installed for it to go.

[Mac]

Pete,
what transistor pair did you use? I made one tonight (self etch) and tried a couple of different transistor pair combos (mainly salvaged from old philips and RME boards i have lying about).

Wasnt much difference in the sound between the transistor combinations. I am only using an Edcor XSM 600/10K trafo (all I have here), but I noticed that the bottom end isnt as fat or tight as my JLM baby animal fet DI.

How is the the Altronics trafo in terms of bottom end? (100 - 600hz).

Mac

[Pete]

The altronics trafo might be a bit better - I have done some DI bass tracks with it and it sounded fine (DI'ed guitar actually sounded really good too.) The ultimate would be the lundahl ll1538 but it costs about twice what I paid for the whole project!

Not sure about the transistor pair, I'll have a look and get back to you.

[Mac]

hey Pete,
finally stuffed my "prototype" board in a recycled box last night....more here
http://www.prodigy-pro.com/diy/index.ph ... =36569.180

[Pete]

Looks cool! Just as importantly, does it sound cool? Sorry I still haven't had a chance to crack it open and see what transistors I used.

And what's that front panel for in background (nice VU meters..)

[Mac]

Hey Pete,
Yeah it does sound nice. The edcors sound much more open and punchy than the altronics for my ears though (just dont fit in this enclosure). The OEP sounds really smooth too, but to be honest since i invested in a pair of those - I am going to use them in a Gyraf G9 valve mic pre instead.

The panel in the background is from a build I have on the bench at the moment. It is two channels of valve mic pres. Coil meters are from old Byer Rola tape machines. One of the channels is a simple 5965 12av7 single bottle preamp based around the NYD one bottle from group diy. The second channel is still in development and to be honest I am using this chassis as a bit of a test bed while i try out various simple two valve preamp circuits. Changing layouts /transformers / circuits.
Ultimately I wanted to end up with two completely different valve mic pre flavours in one box - like "the good and the ugly" - "clean and dirty" (or something similar)....

Anyways - back to the stereo BO Hansen Di..... the courier finally delivered some extra parts I have been waiting on from Farnell
Hopefully will get that one in the box by the weekend (if real work doesnt slow me down too much)...


Mac

[gorepants]

First of all, since this is my first post, hello Turtlerockers!

On topic, I made a pair of these with LL1538XLs (from control devices), and generic mouser bc550s and bc560s on tag strips a couple of years ago. Love the DI, except that I need to add a pad for some louder sources. Sorry for no pics - but one the outside it looks more or less like Pete's, minus the LED.

But I do have a couple of tracks up that use it with minimal processing.

The tracks are Amusing Meiwes and Virgin Eyes, here http://www.gorepants.com/about (sorry, they are mp3s, but fairly high bit rate).

The signal path is Washburn 5-string active bass (of some sort) -> Bo Hansen 75 -> FiveFish SC-1 -> Focusrite Saffire Pro -> Tracktion -> Sonalksis EQ -> Sonalksis Compresor

I may have hit it with another compressor in a kick/bass buss, but I don't use tracktion any more so I can get the session open without a bit of effort.

I'd be interested in comparing the lundahl to the altronics, I'm thinging of digging out the drums tracks from the same sessions and can get the raw bass with that if anyone is interested. Won't be very scientific, but I'd like to know if the altronics gives a dirtier sound (which I might be looking for if it's right).

[waitup]

I wouldnt say the altronics trafo sounds dirty, but certainly less linear than more expensive ones... it is what it is: a 17 buck transformer

[Mac]

Agreed... they lose out in the bottom end...the lundahls would shine. I love my 1540's on the front end of my two 1176's - like floating glass!!

I guess that was why I was a bit shocked with the clarity of the $13 USD xsm Edcors. They punch well and truly above their weight.

[gorepants]

I know a few garage bands so a 17 buck sound might be just right. For the price it's not a biggie to chuck something together to have a listen.

@mac, glad to hear you like the edcors - I have a bunch sitting on the bench for some spectrasonics style pres I'm making.

[Mac]

Yeah they sound better than their price point - but watch them on quality control...matching them for stereo compressor input or output duties is needed...


Mac

[gorepants]

Cheers Mac, I'm building a quad pre, so I'll look out for that so the pairs line up best they can

[Mac]

Finally finished the stereo one with OEP's for a mate of mine, he is happy.
Uses a new marking technique I have been experimenting with, enamel paint, laser marking and poly film coating.

worked pretty well I think...

[harry]

Hey Friends,

Re: cheap transformers for this thing: OEP's can be had from Canford.co.uk for about 10pounds ($17-18bucks) i'd speculate that they would be better than the altronics.... might do an order for some in coming months if anybody is up for a group buy (shipping is a bit steep)

carry on

h.a.r.r.y.a.r.v.a.n.i.t.i.s

[Mac]

Hey Harry,
let me know when you do your buy. Shipping is always the killer....

[waitup]

Hey Friends,

Re: cheap transformers for this thing: OEP's can be had from Canford.co.uk for about 10pounds ($17-18bucks) i'd speculate that they would be better than the altronics.... might do an order for some in coming months if anybody is up for a group buy (shipping is a bit steep)

carry on

h.a.r.r.y.a.r.v.a.n.i.t.i.s

Do OEP not have a distributer in aus?

[Mac]

RS have them - at $40 a pop plus postage...So unless the postage for a GB is good, it may not be worth the trouble....

[Bo Hansén]

Hi guys,

Nice DI boxes you have built, glad to hear that you like them.

I have updated my DIY page, and changed the address.
http://www.hansenaudio.se/techpage.htm

--Bo

[Pete]

Hi guys,

Nice DI boxes you have built, glad to hear that you like them.

I have updated my DIY page, and changed the address.
http://www.hansenaudio.se/techpage.htm

--Bo

Hi Bo, thanks for the kind words. I have been using this DI pretty much every day since I built it. Thanks for the design and I hope you stick around here on the forum.

[waitup]

Hi guys,

Nice DI boxes you have built, glad to hear that you like them.

I have updated my DIY page, and changed the address.
http://www.hansenaudio.se/techpage.htm

--Bo

Bo, Welcome to the forum!

Now I hope you weren't googling your own name to come across this post?

Great to have you on board!

NF.