Potato Cakes
Well-known member
monkeyxx said:
For this particular transformer, the center tap is to allow phantom power to pass through when used in a microphone design. It's in the spec sheet on Sowter's website.
Paul
Bo Hansen DI layout
- Thread starter Soeren_DK
- Start date
Help Support GroupDIY Audio Forum:
For this particular transformer, the center tap is to allow phantom power to pass through when used in a microphone design. It's in the spec sheet on Sowter's website.
Paul
Bo Hansen
Well-known member
Sowter 9045, connected in 5:1 configuration.
Red to amp output/10 uF cspasitor.
Blue to ground
White cable not used (isolated)
Orange to XLR pin 2
Green to XLR PIN 3
Yellow and Grey soldered together and isolated.
Black cable to the DI-box metal case, if the transformer can are bolted in the metal case.
But if the transformer can is grounded in the pc-board electronic ground, (isolated from the metal case) the black cable shall also be connected to the PC-card electronic ground..
--Bo
Red to amp output/10 uF cspasitor.
Blue to ground
White cable not used (isolated)
Orange to XLR pin 2
Green to XLR PIN 3
Yellow and Grey soldered together and isolated.
Black cable to the DI-box metal case, if the transformer can are bolted in the metal case.
But if the transformer can is grounded in the pc-board electronic ground, (isolated from the metal case) the black cable shall also be connected to the PC-card electronic ground..
--Bo
Hi everybody,
I have completed my second DI Box with the Sowter and today, I made a very quick comparison between the first one (Haufe) and the Sowter into an Awtac Channel Amp . Third contender is the DI of the Awtac. I played a Höfner Clubbass with flat wounds .
The difference between Sowter and Haufe is mini, I couldn't tell the difference, after many switchovers from one file to the other I had the feeling, that there's a tiny bit more bass in the Sowter, which could also be the nature of the other take.
The most Bass has the Awtac, but both DI boxes have more grid, more definition, which I really like.
I made some screen shorts with DMG audio Dualism, if anybody wants, I can send the audio files
thanks again for all the participant parties !!!
I have completed my second DI Box with the Sowter and today, I made a very quick comparison between the first one (Haufe) and the Sowter into an Awtac Channel Amp . Third contender is the DI of the Awtac. I played a Höfner Clubbass with flat wounds .
The difference between Sowter and Haufe is mini, I couldn't tell the difference, after many switchovers from one file to the other I had the feeling, that there's a tiny bit more bass in the Sowter, which could also be the nature of the other take.
The most Bass has the Awtac, but both DI boxes have more grid, more definition, which I really like.
I made some screen shorts with DMG audio Dualism, if anybody wants, I can send the audio files
thanks again for all the participant parties !!!
Attachments
Humner
Well-known member
I finished a 2 channel version of Bo's DI.
My first test was fender strat through this DI and then through my racked PM1000 channels. Really happy with how this sounds - very impressive.
My first test was fender strat through this DI and then through my racked PM1000 channels. Really happy with how this sounds - very impressive.
Cade Allen
Member
- Joined
- Aug 29, 2015
- Messages
- 5
Can somebody post the link to buy the PCB?! I only saw it on PCBgrinder, but that was for an updated version called the "DI28".
Thanks! 8)
Thanks! 8)
Humner
Well-known member
Cade Allen said:
[silent:arts] - http://groupdiy.com/index.php?topic=39570.msg488632#msg488632
I have a question - I want to power one of these from a 15V DC supply. Do I need to may any changes to the circuit?
Bo Hansen
Well-known member
Humner,
Do you mean 15 volts phantom from a mic input, or feed the DI-box from a external 15 volts power supply ?
--Bo
Do you mean 15 volts phantom from a mic input, or feed the DI-box from a external 15 volts power supply ?
--Bo
Humner
Well-known member
external regulated 15v supply.
Bo Hansen
Well-known member
Humner,
Ok, remove the two 6.8 k resistors and connect a pure stabilized +15 volt directly to the point that the two 6.8 k resistors were connected together.
And of course the 15 volts -/ground to the circuit board ground rail, for example, minus on the 100 uF capacitor.
This is all you need to do, but the downside is less headroom because the electronics get 10 volts less voltage feed and and also slightly worse driving of the transformer, because less current in the output transistor.
--Bo
Ok, remove the two 6.8 k resistors and connect a pure stabilized +15 volt directly to the point that the two 6.8 k resistors were connected together.
And of course the 15 volts -/ground to the circuit board ground rail, for example, minus on the 100 uF capacitor.
This is all you need to do, but the downside is less headroom because the electronics get 10 volts less voltage feed and and also slightly worse driving of the transformer, because less current in the output transistor.
--Bo
Humner
Well-known member
How about a bipolar supply? 15 +/- and then use a 1.8k resistor to bring down to 24v
Will this work OK?
Will this work OK?
Bo Hansen
Well-known member
Humner,
Do you mean to drive the DI-box electronics with 15 volt symetrical/bipolar plus and minus with mid ground ?
Sure, it can be done, but too much changes on the PCB as the earth system must be changed completely.
I recommend that you use 15 volt that we talked about earlier, or use 24-volt power supply.
Can you explain for me why you should use DI-box without 48-volt phantom power, and how you intend to use it.
Perhaps there is a better solution for you ?
--Bo
Do you mean to drive the DI-box electronics with 15 volt symetrical/bipolar plus and minus with mid ground ?
Sure, it can be done, but too much changes on the PCB as the earth system must be changed completely.
I recommend that you use 15 volt that we talked about earlier, or use 24-volt power supply.
Can you explain for me why you should use DI-box without 48-volt phantom power, and how you intend to use it.
Perhaps there is a better solution for you ?
--Bo
Humner
Well-known member
hi Bo,
Thats right, I have an existing microphone preamp circuit I built using a 15v +/- supply. I never built in phantom power as its used primarily for dynamic microphones. I wanted to retro fit one of your DI boards inside the enclosure to include a switchable DI option.
I think I was just worrying that I might not get the full potential out of your DI.
My PSU starts with a 15v AC transformer, so maybe I build a separate supply with a voltage multiplier circuit to generate 24volts. Your DI only draws a small current so it shouldn't strain the transformer.
but really, I am probably just over thinking and I should just use the 15v supply I have and keep it simple.
Thanks for your help.
Thats right, I have an existing microphone preamp circuit I built using a 15v +/- supply. I never built in phantom power as its used primarily for dynamic microphones. I wanted to retro fit one of your DI boards inside the enclosure to include a switchable DI option.
I think I was just worrying that I might not get the full potential out of your DI.
My PSU starts with a 15v AC transformer, so maybe I build a separate supply with a voltage multiplier circuit to generate 24volts. Your DI only draws a small current so it shouldn't strain the transformer.
but really, I am probably just over thinking and I should just use the 15v supply I have and keep it simple.
Thanks for your help.
Treb
Member
Hi all!
Thinking of building one too. Question about those caps in the signal path, is there any benefit from spending a bit more money and use quality caps here instead of whatever there's in my parts bin? The 10 MFD electrolytic between Q2 and the transformer in particular, would the sound quality benefit from using a foil capacitor (like the ones found in loudspeaker crossover filters) in this location? I know these can be pretty big...
Thinking of building one too. Question about those caps in the signal path, is there any benefit from spending a bit more money and use quality caps here instead of whatever there's in my parts bin? The 10 MFD electrolytic between Q2 and the transformer in particular, would the sound quality benefit from using a foil capacitor (like the ones found in loudspeaker crossover filters) in this location? I know these can be pretty big...
Bo Hansen
Well-known member
Treb,
In this design it is not necessary to use better than standard components as Jamicon 85 degree electrolytes or the like, and the standard carbon film resistor as Firstron or similar brands.
But if you want to increase the component quality, use 105 degree Panasonic FC or Elna RJH electrolytics , Wima film capasitors, Vishay metal film resistors or similar good brands.
Never use the Hi-Fi world imaginative components such as "super or wonder" caps and the like, we are in the real world.
The most important thing is to use good transistors not substitute fake types from China, use brands like Philips, SGS/Ates, Motorola, National, Fairshild.
And of course, that you use one of the three transformers I have recommended.
Carefully follow all the advice on assembling, connector types, grounding, and much else, then you will get a good quality and results when you're done with your DI-box DIY.
You'll find all the advice on my website www.hansenaudio.se/techpage.htm
--Bo
In this design it is not necessary to use better than standard components as Jamicon 85 degree electrolytes or the like, and the standard carbon film resistor as Firstron or similar brands.
But if you want to increase the component quality, use 105 degree Panasonic FC or Elna RJH electrolytics , Wima film capasitors, Vishay metal film resistors or similar good brands.
Never use the Hi-Fi world imaginative components such as "super or wonder" caps and the like, we are in the real world.
The most important thing is to use good transistors not substitute fake types from China, use brands like Philips, SGS/Ates, Motorola, National, Fairshild.
And of course, that you use one of the three transformers I have recommended.
Carefully follow all the advice on assembling, connector types, grounding, and much else, then you will get a good quality and results when you're done with your DI-box DIY.
You'll find all the advice on my website www.hansenaudio.se/techpage.htm
--Bo
Bo Hansen
Well-known member
G-Sun,
Thanks, Tack, for your raport,
verry glad ti hear that.
Best from
--Bo
Thanks, Tack, for your raport,
verry glad ti hear that.
Best from
--Bo
Treb
Member
Another DI sees the light of day! Worked right away, the red led is working but is rather dim. Is that correct? For the nerds, Lundahl 1538, Vishay-Dale resistors, Wima, Panasonic and Vishay-Roederstein caps. Hammond 1455N1201 case, Neutrik connectors, 2mm frontpanel from Schaeffer AG.
