Newmarket
Well-known member
Higher voltage rating is not a problem. All other things being equal cap life is extended.
Bo Hansen DI layout
- Thread starter Soeren_DK
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johnchantler
Well-known member
no problem.
mathiazdub
New member
thank you guys. Unfortunetly somethings parts is difficult avilable in Europe. Finally I will use Nichicon GD fine gold capacitors.
Ricardus
WILL SOLDER FOR FOOD
Yeah, you're fine with a 50v and the larger resistor.
Bo Hansen
Well-known member
mathiazdub,
As long as the components fit neatly and practically in their places on our circuit board (if this is what you are using), it is perfectly ok to use capacitors with higher voltages and resistors with higher watts.
--Bo
As long as the components fit neatly and practically in their places on our circuit board (if this is what you are using), it is perfectly ok to use capacitors with higher voltages and resistors with higher watts.
--Bo
mathiazdub
New member
Ricardus
WILL SOLDER FOR FOOD
Your 200v resistors are fine.
Bo Hansen
Well-known member
mathiazdub,
If you are working with a tube amplifier, resistors and capacitors must withstand around 400 volts dc, but solid state gear similar to this DI-box is normally sufficient with components that withstand a maximum of 35-100 volts dc depending on the supply voltage.
In this DI box there is a maximum of 24 volts across the resistors and capacitors, so common standard components will withstand enough voltage.
As I have also pointed out many times, this DI-box design does not require any "audiophile" resistors or capacitors, ordinary good standard components will works perfectly.
Good component choices are, for example: Wima MKS2 as standard film capacitors, Panasonic series NHG or FC electrolytes, some series of Vishay carbon or metal film 1/4w resistors.
But there are many other brands with the same standard quality.
It is more important to find good manufacturers of the BC550C and BC560C transistors, such as F/Fairchild, NS/National, ON-semi/Motorola, NXT/Vishay/PH, ST/SGS, because many unbranded transistors on the market today can be fake and are very bad.
It is good to read what I write on my help page about this DI box, there is everything you need to know.
www.hansenaudio.se/techpage.htm
--Bo
If you are working with a tube amplifier, resistors and capacitors must withstand around 400 volts dc, but solid state gear similar to this DI-box is normally sufficient with components that withstand a maximum of 35-100 volts dc depending on the supply voltage.
In this DI box there is a maximum of 24 volts across the resistors and capacitors, so common standard components will withstand enough voltage.
As I have also pointed out many times, this DI-box design does not require any "audiophile" resistors or capacitors, ordinary good standard components will works perfectly.
Good component choices are, for example: Wima MKS2 as standard film capacitors, Panasonic series NHG or FC electrolytes, some series of Vishay carbon or metal film 1/4w resistors.
But there are many other brands with the same standard quality.
It is more important to find good manufacturers of the BC550C and BC560C transistors, such as F/Fairchild, NS/National, ON-semi/Motorola, NXT/Vishay/PH, ST/SGS, because many unbranded transistors on the market today can be fake and are very bad.
It is good to read what I write on my help page about this DI box, there is everything you need to know.
www.hansenaudio.se/techpage.htm
--Bo
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Ricardus
WILL SOLDER FOR FOOD
For some reason when someone posted a public Mouser BOM for this build, all of the resistors were WAY bigger (voltage and size) than they needed to be. I built my first two using this BOM. Then I fixed the BOM and posted a link here somewhere, probably 2 years ago.
egroys
Well-known member
Can you direct me to the name of (or link) to these connector pins, please? Both ends.
I know they aren't necessary but I'd like to use them for my build. It would also be awesome if they were included in the BOM!
They are 2.54mm Molex connectors. I have not ever messed with them. I trust my soldering more than a crimp connector. But that is just me.
Newmarket
Well-known member
Look like Molex KK type with Friction Lock. 2.54mm or possibly 2mm "Hard Metric". I've used/specified a ton of these professionally and for my own DIY stuff. They are really good. Small enough but not too small to allow easy removal of crimp when you get a connection wrong 
. But you do need to use a proper crimp tool and a bit of practice for reliability. So don't use a long nose pliers then blame the connector system 
Note that there are two different crimp sizes for different wire gauge ranges.
You can look up the details on the Molex site or via RS / Farnell / Newark etc.
. But you do need to use a proper crimp tool and a bit of practice for reliability. So don't use a long nose pliers then blame the connector system Note that there are two different crimp sizes for different wire gauge ranges.
You can look up the details on the Molex site or via RS / Farnell / Newark etc.
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Potato Cakes
Well-known member
Hello, Everyone,
I've built a myriad of these DIs with various transformers for myself and for others and they always worked and sounded very well with any instrument. I have recently come across a gain issue with the Sowter version with passive pickups in old Fender basses. Recently I was doing rehearsals and used the Sowter version on bass like I normally do. It was an old P-Bass and about 40dB of gain was needed at the console to get a good level. This amount of console gain introduced buzz and other noise. I had this same problem with a CAPI DI, another Bo Hansen with a Carnhill transformer, and a passive box with a Cinemag. I then used a Radial Pro48 and the output was much hotter which only needed 17dB of gain to get a similar level, which then the buzz was no longer audible. I much prefer the sound of the Bo Hansen DIs and was wondering if removing the 10k resistor at the input would sufficiently allow more signal to hit the circuit and provide more signal at the output. Forgive me if this was answered earlier in this post and I missed it.
Thanks!
Paul
I've built a myriad of these DIs with various transformers for myself and for others and they always worked and sounded very well with any instrument. I have recently come across a gain issue with the Sowter version with passive pickups in old Fender basses. Recently I was doing rehearsals and used the Sowter version on bass like I normally do. It was an old P-Bass and about 40dB of gain was needed at the console to get a good level. This amount of console gain introduced buzz and other noise. I had this same problem with a CAPI DI, another Bo Hansen with a Carnhill transformer, and a passive box with a Cinemag. I then used a Radial Pro48 and the output was much hotter which only needed 17dB of gain to get a similar level, which then the buzz was no longer audible. I much prefer the sound of the Bo Hansen DIs and was wondering if removing the 10k resistor at the input would sufficiently allow more signal to hit the circuit and provide more signal at the output. Forgive me if this was answered earlier in this post and I missed it.
Thanks!
Paul
Potato Cakes
Well-known member
I took apart the Sowter version to start testing my above post and to my surprise (not really as it seems I do this crap all the time) and I had the transformer wired 10:1 instead of 5:1. I know at some point I had rebuilt this DI as it was an early DIY project. When doing so I must have wired it incorrectly. I knew when I first build it I had no troubles with it whatsoever. Anyway, I rewired it and did a before and after test with a different passive bass that was in the studio (the one from rehearsals is in vault on a semi truck) and as everyone here could guess the signal output was significantly increased.
Still doesn't explain the issue I was having with all the other DIs I tried before I used the ProDI. The testing procedure was done with a bit of pressure added so the troubleshooting process might have been a little rushed and something else was overlooked.
Also, jumping 10k resistor at the input did not yield any increase in gain. I had seen on a JFET DI that the input went directly to the gate so I thought I would give this a try on this circuit. Curious to see if anyone has been successful getting a little more gain out of this circuit.
Thanks!
Paul
Still doesn't explain the issue I was having with all the other DIs I tried before I used the ProDI. The testing procedure was done with a bit of pressure added so the troubleshooting process might have been a little rushed and something else was overlooked.
Also, jumping 10k resistor at the input did not yield any increase in gain. I had seen on a JFET DI that the input went directly to the gate so I thought I would give this a try on this circuit. Curious to see if anyone has been successful getting a little more gain out of this circuit.
Thanks!
Paul
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Ricardus
WILL SOLDER FOR FOOD
I think you and I might have the record for Bo Hansen DI builds!
lele_sakko
Member
Hi everyone! I'm Daniele from Italy!
i've build a Bo Hansen DI with a Lundahl transformer, the di sounds really good and i'm really happy and impressed about it!
but i've noticed a thing, so i ask you to made a test on yours to solve my doubt:
If i try to record a loop with a loop station, and i send it directly to my audio interface, i have a level that, for example, at -17 RMS, if i play the same loop through the parallel out of the DI i have the peak around -22 RMS, so the level is a little lower with the DI.. Is that normal for that or i have something to check inside mine? it sounds great, very silent and rich on the XLR out, i only have that small volume drop through the parallel aout..
thank to everyone!
I will try to attach a file so maybe it's easier to understand what i'm talking about. .
i've build a Bo Hansen DI with a Lundahl transformer, the di sounds really good and i'm really happy and impressed about it!
but i've noticed a thing, so i ask you to made a test on yours to solve my doubt:
If i try to record a loop with a loop station, and i send it directly to my audio interface, i have a level that, for example, at -17 RMS, if i play the same loop through the parallel out of the DI i have the peak around -22 RMS, so the level is a little lower with the DI.. Is that normal for that or i have something to check inside mine? it sounds great, very silent and rich on the XLR out, i only have that small volume drop through the parallel aout..
thank to everyone!
I will try to attach a file so maybe it's easier to understand what i'm talking about. .
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ruffrecords
Well-known member
On the schematic there is a 10K resistor in series with the monitor output (see post #1). If your interface has an input impedance of about 10K then the level would drop by 6dB. At the moment your level has dropped by 5dB so it looks like your interface input impedance is a little higher.
Cheers
Ian
Cheers
Ian
lele_sakko
Member
Thank you Ian!
From an answer from you on another thread on this forum, the input impedance should be around 2Mohm..
https://groupdiy.com/threads/scarlett-i2-instrument-input-impedance.68459/Thank you for your answer and for your help!
From an answer from you on another thread on this forum, the input impedance should be around 2Mohm..
https://groupdiy.com/threads/scarlett-i2-instrument-input-impedance.68459/Thank you for your answer and for your help!
Be sure to get the gold or selective gold versions. The tin is not that good for low voltages. The Molex crimp tool is 638112200. Use the "B" slot.Look like Molex KK type with Friction Lock. 2.54mm or possibly 2mm "Hard Metric". I've used/specified a ton of these professionally and for my own DIY stuff. They are really good. Small enough but not too small to allow easy removal of crimp when you get a connection wrong
Note that there are two different crimp sizes for different wire gauge ranges.
You can look up the details on the Molex site or via RS / Farnell / Newark etc.
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