Bo Hansen DI layout

[MidnightArrakis]

Thanks for the suggestions, I'll get an order in on Monday and report back once it's installed and tested.

As for the switch, with the SPDT I get pops when switching it. For anyone following along, would a 'make before break' / non-shorting switch be the right type of switch function in hopes of minimizing pops? And if so, is a MBB denoted as On-On or On-(On)?
"Sealed" is better quality?
I'm not a penny pincher, I'd rather spend more to get something that is more rugged and robust / lasts longer than I do... so if there are any 'switch aficionados' who care to recommend a specific small footprint switch, please chime in. Otherwise, I will roll the dice come Monday morning.

[is a MBB denoted as On-On or On-(On)] -- Technically.....both switch types could be as MBB, but -- (On) -- does specifically designate a "momentary" contact type.

Should you browse around on Digi-Key and Mouser in their switch parameter listings, you will even see switches shown as being -- (On) / (On) -- types, which are "momentary contact" in both directions.

---------MOUSER--------------------DIGI-KEY-------



/

 

[Bo Hansen]

Klem,

You can rarely get everything 100% perfect when it comes to add-on features afterwards, especially on designs that are not intended for this.

You have to bear in mind that this switch sits directly on the high-resistance inputs with high sensitivity if you have a lot of gain turned up, and in this case it probably won't help with a "make before brake" function in this case, and besides, I don't think that is so easy to get hold of this function regarding toggle switches.

So instead buy a normal "DPDT" toggle switch of slightly better quality.
The two types we talked about, i.e. SPDT and DPDT are by far the most common and are very easy to get hold of in different qualities and sizes.

It is not necessary to change the switch when you have high gain on your preamp or mixer.
It is not uncommon for buttons to pop, for example on expensive condenser microphones, when you change the switches while using normal gain.
So you should probably be happy with this.

PS! the pop might be better now with these latest changes, or worse, you never know until afterwards.

--Bo

 

[klem]

The revised changes appear to have significantly quieted the buzzing, to the point that the cheap M-Audio pres appear to be the main source of any noise on the XLRs! Amp out is much quieter as well. Can't test 2 simultaneous amp outs (of Input 1) ATM as I only have 1 amp on hand. I will eventually test it every way possible with much higher-end pres and A/D. But for these initial tests, I used a cheap USB-C M-Audio pre/converter for ease of portability and quick testing.

Since the wiring in earlier pics is hard to see clearly even with my outlining/labeling the wiring in photoshop, I figured it would be helpful if I provided a clear, single diagram that summarizes the changes needed to implement this parallel vs dual 2 channel configuration. Let me know if I missed anything and I'll update it.

Only time will tell how well this may perform with the variety of guitar/pedal impedances this circuit may encounter in 'real-world' scenarios (e.g., another member had issues with fuzz pedals). But even if this works for only some scenarios, it has the potential to be a great problem solver especially for doing multi-track recordings of live performances. The whole point here is to the added functionality to eliminate the need for a splitter after a DI, so there are separate transformer-isolated outputs available for both the venue/FOH and a recording feed, with an added bonus of an additional feed to another amp via the second TS output. Thank you (once again) Bo for your assistance in helping this idea become an option for members here.

 

[Newmarket]

Only time will tell how well this may perform with the variety of guitar/pedal impedances this circuit may encounter in 'real-world' scenarios (e.g., another member had issues with fuzz pedals).


View attachment 129237

Problems with fuzz pedals are due to a specific type of fuzz circuit - fuzzface and derivatives - depending on a high impedance source. Since all outputs from this DI are low impedance the fuzz may not sound so great. This applies to any low impedance source. You can add impedance in series to help with this.

 

[Nick Silver]

Hello to all,

Here is my dual DI of my friend Bo Hansen including an external Power supply.
Both of them are completely handmade into my workshop for my best man El Rey using two great Lundahl transformers as well as Vishay Dale resistors, WIMA capacitors, Audio Electrolytic capacitors and Neutrik XLR and Jacks.
For the wooden enclosures we chose American Walnut and finished them with Danish Oil.
The DI's sounds amazing, noise free and the THD is 0.0011% at 1kHz!
Now they took their place in the Zero Gravity studios in Athens and already have made the first recordings!

Thank you very much Bo for another one time for this amazing DI!

 

[abbey road d enfer]

Very nice build!
Have you noticed a difference in sound between Danish oil and Greek olive oil for the finish?

 

[Nick Silver]

Very nice build!
Have you noticed a difference in sound between Danish oil and Greek olive oil for the finish?

Thank you very much!

Oh yes, Greek Olive oil has a coloration in sound, it's not very transparent!

 

[Bo Hansen]

Thanks Nick, a very nice version and build of my DIY DI-box.

Ps! Nick Silver is a very good craftsman who always does neat and accurate work.
His maufacturing of guitar pickups has a very high quality and finish.

--Bo

 

[MidnightArrakis]

Very nice build!
Have you noticed a difference in sound between Danish oil and Greek olive oil for the finish?

[Have you noticed a difference in sound between Danish oil and Greek olive oil for the finish?] -- But.....if I had written what you wrote here.....I would be reported for being off-topic, racist, hijacking the thread or some other such crime!!! Nice joke, though!!!.....

/

 

[Nick Silver]

Thanks Nick, a very nice version and build of my DIY DI-box.

Ps! Nick Silver is a very good craftsman who always does neat and accurate work.
His maufacturing of guitar pickups has a very high quality and finish.

--Bo

Bo, thank you so much for your kind words about me and my work! I really appreciate them!
Thank you for being so helpful!

 

[samic]

nice build ,
what engraver reference do you use, I am in the process of thinking about my workshop
Is it a black paint that you apply before engraving?

 

[Nick Silver]

nice build ,
what engraver reference do you use, I am in the process of thinking about my workshop
Is it a black paint that you apply before engraving?

@samic thank you!
The plates are made from aluminum and I sent them for black Electrostatic paint. After that I fit them to my CNC machine and I engraved them with a V Engraved bit.
I will upload a video to see the process.

 

[Nick Silver]

Here is a video of engraving Lundahl logo on the faceplate.

 

[abbey road d enfer]

Nice!
What engraving machine are you using?
How do you clamp the workpiece?

 

[Nick Silver]

Hello,
I have a small CNC with working area of 300x200mm and I'm running it with Gecko drives and wrap9 controller.
As for the clamping, I made a jig from acrylic and I locked the plates on it with the 6 holes mounting holes.

 

[abbey road d enfer]

Thanks for your answers Nick.
Now, more questions: what software do you use to create the drawing? What fonts?
How do you set the origin when engraving? Just by eyeing or do you have a specific technique?

 

[Nick Silver]

@abbey road d enfer no worries, my pleasure to help.

I design them using Illustrator. The fonts are Sans Serif. The Lundahl logo was image so I was using Image tracing to make it vector. After that I open the file on the Cambam and to drive the CNC I'm using Mach3.

As for the origin, I reset to 0 the position on the acrylic jig then I drilled the mounting holes on it and after that I mounted each plate on the acrylic without to zero again the position. With this way you don't need to reset each time that you mount the next plate.

 

[abbey road d enfer]

OK, got it.
If I understand well, the acrylic jig is not reusable (at least not as precisely). Correct?

 

[Nick Silver]

Exactly, it's only for engrave them all at once. If you try to position it days ago would be difficult to find again the previous zero point at XY.

 

[klem]

Should anyone want to build the configuration of a dual mono or parallel box as shown here, feel free to use this front panel designer file for the face plate. Forum limitations require an incorrect file extension, so after downloading, change the filename's last three letters from ‘zip’ to ‘fpd’. Working with Frank (info at front panels.de) was refreshing - helpful, efficient and easy to communicate with, I highly recommend! (I’ve no affiliation with Frank other than being a first-time customer.)

The face plate / end plate is for a Hammond 1455Q1601BK. It’s a very tight fit for component spacing, so having it all nicely laid out on a pro looking panel is well worth the cost of the printing the panels IMHO. You can print the pdf version I've attached and use it to make a DIY faceplate on a drill press, but it’s easy, at least for me, to ruin a plate because of the tight tolerances, and then risk lifting the fragile traces on the PCB from new rounds of de/re-soldering to move the XLRs PCB to a new face plate. Alternatively, if you’re lucky enough to have Molex-type crimpers, that would be a great route. Anyhow, hope this is useful to someone now or years later.