lele_sakko
Member
Thanks Bo, you’re right, the strange thing is that it worked for a week.. on another pic i have it looks right..
When i’ve replaced it i think i’ve put it right.. here are another 2 pics (i’m at work now)..
Bo Hansen DI layout
- Thread starter Soeren_DK
- Start date
Help Support GroupDIY Audio Forum:
When i’ve replaced it i think i’ve put it right.. here are another 2 pics (i’m at work now)..
This is the first time I've ever had a cap in reverse.
lele_sakko
Member
Here i am with some news!
i've tried many times to change components on the pcb, and sometimes the DI works well and sometimes after che DI make the noises again..
Voltages were right, no problems with connections and ground, and i don't know where to look for identify the prolem..
this morning, after many tests, i've noticed that the led does't works well.. i've fixed it and now the di works very well! it was the only thing I havn't looked!
i've tried to replace the old components (the first one i've replaced) and they works well, i have 25.5v instead 24+-1 but DI works fine and is very quiet!
I really like that DI!
i've tried many times to change components on the pcb, and sometimes the DI works well and sometimes after che DI make the noises again..
Voltages were right, no problems with connections and ground, and i don't know where to look for identify the prolem..
this morning, after many tests, i've noticed that the led does't works well.. i've fixed it and now the di works very well! it was the only thing I havn't looked!
i've tried to replace the old components (the first one i've replaced) and they works well, i have 25.5v instead 24+-1 but DI works fine and is very quiet!
I really like that DI!
Ricardus
WILL SOLDER FOR FOOD
Interesting! Good to know that can be an issue.
Bo Hansen
Well-known member
Lele_Sakko,
Nice to hear you finally found the problem.
It is important that this LED is of normal good quality, and not some China junk.
(and that it has not been damaged when soldered with too much heat)
This LED is in series with the supply voltage which is not usually normal, to save current from the voltage rail.
In this case, it is important that the 100uF electrolyte that is after the LED is whole and of good quality, this to remove any noise that the LED can generate.
But if it's a junk LED, then it can make a lot of noise and crackle so that it goes through the supply voltage and modulates the audio signal.
And as I always pointed out, only use a normal 3 mm red LED, partly because it has the lowest voltage drop and because it lights up well at only 3.5 mA through it, and because there are usually no strange things with these.
And of course be connected with the short leg/cathode to the 100uF electrolyte.
The fact that your voltages do not match exactly with my specifications may be due to your DVM/voltage meter not measuring correctly.
But if you get 22-26 volts, it doesn't matter, as long as you have half the voltage at all the stated measuring points around the transistors.
--Bo
Nice to hear you finally found the problem.
It is important that this LED is of normal good quality, and not some China junk.
(and that it has not been damaged when soldered with too much heat)
This LED is in series with the supply voltage which is not usually normal, to save current from the voltage rail.
In this case, it is important that the 100uF electrolyte that is after the LED is whole and of good quality, this to remove any noise that the LED can generate.
But if it's a junk LED, then it can make a lot of noise and crackle so that it goes through the supply voltage and modulates the audio signal.
And as I always pointed out, only use a normal 3 mm red LED, partly because it has the lowest voltage drop and because it lights up well at only 3.5 mA through it, and because there are usually no strange things with these.
And of course be connected with the short leg/cathode to the 100uF electrolyte.
The fact that your voltages do not match exactly with my specifications may be due to your DVM/voltage meter not measuring correctly.
But if you get 22-26 volts, it doesn't matter, as long as you have half the voltage at all the stated measuring points around the transistors.
--Bo
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Yep this is Molex 2.54 - Wafer Connector 2.54mm 2 Pins
But JST XH are smaller 5I use this ones in my pedals now): XH Connectors - Wafer & Housing & Crimp Terminal - Connectors & Sockets
hayunart
New member
Hello, glad to see you guys!
it’s first time to post the Group. I’m Korean, my main hobby is building guitar stompboxes and tube amps.
I built Bo’s DI with Vigortronix VTX-101-003.
Original plan was OEP A262A3E, but it was out of stock.. so I chose it as an alternative.
Both have exactly the same spec, but I can hardly find reviews.. (I found only negative one) so there was a bit of doubt
FYI the Vigortronix one is even cheaper.
and finally, I made it.
with 1590A !
It was hard to place the XLR jack, the mounting screw almost touched bottom plate screw.. however no problem after all.
I wired the circuit around input jack. As you expect the space is very very limited..
True to its reputation, the sound of this unit was undeniably excellent.
Low noise / High definition / Wide range dynamics..
At this point, the performance of Lundhal is highly expected. I’ll try it someday..
Thank you, Bo. Thank you.
it’s first time to post the Group. I’m Korean, my main hobby is building guitar stompboxes and tube amps.
I built Bo’s DI with Vigortronix VTX-101-003.
Original plan was OEP A262A3E, but it was out of stock.. so I chose it as an alternative.
Both have exactly the same spec, but I can hardly find reviews.. (I found only negative one) so there was a bit of doubt
FYI the Vigortronix one is even cheaper.
and finally, I made it.
with 1590A !
It was hard to place the XLR jack, the mounting screw almost touched bottom plate screw.. however no problem after all.
I wired the circuit around input jack. As you expect the space is very very limited..
True to its reputation, the sound of this unit was undeniably excellent.
Low noise / High definition / Wide range dynamics..
At this point, the performance of Lundhal is highly expected. I’ll try it someday..
Thank you, Bo. Thank you.
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Bo Hansen
Well-known member
H
Nice that you liked the result of your DIY Di-Box project.
Very compact built on experimental PC-card, may be problematic for some, but you seem to have succeeded.
Vigortronix version of OEP A262A3E shall be identical to the original.
Vigortronix's owner is said to have previously been a partner in OEP company, but dropped out and started his own.
I will include this on my website, as some may have difficulty getting hold of the OEP version.
--Bo
Hayunart,
Nice that you liked the result of your DIY Di-Box project.
Very compact built on experimental PC-card, may be problematic for some, but you seem to have succeeded.
Vigortronix version of OEP A262A3E shall be identical to the original.
Vigortronix's owner is said to have previously been a partner in OEP company, but dropped out and started his own.
I will include this on my website, as some may have difficulty getting hold of the OEP version.
--Bo
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hayunart
New member
Thank you for kind reply, sir! I’m glad to hear the Vigortronix info is useful.
by the way
I have installed pin header to jumper setting for xformer parallel/serial primary connection (just for experimental curiousity)
and I tried serial connection (3.23 : 1)
(preamp is adjusted to same level)
there is no noticeable malfuction, rather, slightly? stronger bass responce.. but I’m not sure. I don’t have any test gear, just ear.
by the way
I have installed pin header to jumper setting for xformer parallel/serial primary connection (just for experimental curiousity)
and I tried serial connection (3.23 : 1)
(preamp is adjusted to same level)
there is no noticeable malfuction, rather, slightly? stronger bass responce.. but I’m not sure. I don’t have any test gear, just ear.
Bo Hansen
Well-known member
Hayunart,
This 1:1+6.45+6.45 OEP/Vigortronix transformer which is also to be used backwards, works best in my Di-Box design if both sides are connected in parallel, i.e. 6.25 kohm to 150 ohm.
You can connect the high ohm side that we use as primary in series, and you get 25 kohm to 150 ohm and -6 dB extra drop in level and somewhat poor high end response.
But leave the low ohm secondary in parallel, this is good for the mirror impedance so that the drive stage is not affected by long cables between Di-box and mixing console.
Ps! When experimenting with transformer windings in parallel and series, be sure to connect the windings in the correct phase.
--Bo
This 1:1+6.45+6.45 OEP/Vigortronix transformer which is also to be used backwards, works best in my Di-Box design if both sides are connected in parallel, i.e. 6.25 kohm to 150 ohm.
You can connect the high ohm side that we use as primary in series, and you get 25 kohm to 150 ohm and -6 dB extra drop in level and somewhat poor high end response.
But leave the low ohm secondary in parallel, this is good for the mirror impedance so that the drive stage is not affected by long cables between Di-box and mixing console.
Ps! When experimenting with transformer windings in parallel and series, be sure to connect the windings in the correct phase.
--Bo
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hayunart
New member
My experimental setup was 6.25k to 600ohm. (3.23:1) -8dB.
So.. is this even not recommanded, compared to 25k-150?
For now, I just returned to normal setup(6.25k - 150)
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Bo Hansen
Well-known member
Hayunart,
This cheaper OEP transformer passed my approval (on the limit) during my tests and measurements, when both primary and secondary were in parallel, but to be used in series on either side with good results, the transformer should be of higher quality.
I tested a number of other similar transformers in the OEP price range that did not pass my test with acceptable results.
Haven't tried Vigortronix yet, but will do so before I can recommend it.
--Bo
This cheaper OEP transformer passed my approval (on the limit) during my tests and measurements, when both primary and secondary were in parallel, but to be used in series on either side with good results, the transformer should be of higher quality.
I tested a number of other similar transformers in the OEP price range that did not pass my test with acceptable results.
Haven't tried Vigortronix yet, but will do so before I can recommend it.
--Bo
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hayunart
New member
Oh I see.
I'm guessing maybe my test result that ‘slightly stonger bass response’ was not a good sign.
(maybe it was loss of highend)
Again, Thank you very much for your kind answer!
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Newmarket
Well-known member
Can you share what results / parameters you apply wrt transformer approval in this context. Many thanks.
Bo Hansen
Well-known member
Newmarket,
It's been more than 10 years since I did this test, and if I remember correctly, the result of the comparison between the finally selected transformers which became Lundahl, Haufe and OEP is somewhere here in this huge forum thread.
The comparison measurements I made were level and distortion at 1 kohm load, frequency response and square wave response, with 20 and 100 feet microphone cable.
The measurements were made with my Audio Precision, but have probably not shown any printed curves or tables, but have reported the most important results.
--Bo
It's been more than 10 years since I did this test, and if I remember correctly, the result of the comparison between the finally selected transformers which became Lundahl, Haufe and OEP is somewhere here in this huge forum thread.
The comparison measurements I made were level and distortion at 1 kohm load, frequency response and square wave response, with 20 and 100 feet microphone cable.
The measurements were made with my Audio Precision, but have probably not shown any printed curves or tables, but have reported the most important results.
--Bo
Good morning,
I am new member...
I am passionate about sound.
I like to build alternative devices.
I want to make a DI box that supports bass well.
I want to make the Active DI box 1975. I ordered the PCB plates and I want to order the quality components, where can I find the parts list and where to buy them?
Are there components to change for optimum use, especially in the bass?
Thank you so much
Ronan
I am new member...
I am passionate about sound.
I like to build alternative devices.
I want to make a DI box that supports bass well.
I want to make the Active DI box 1975. I ordered the PCB plates and I want to order the quality components, where can I find the parts list and where to buy them?
Are there components to change for optimum use, especially in the bass?
Thank you so much
Ronan
Ronan,
Have you read the first post?
You need to read it before posting.
Have you read the first post?
You need to read it before posting.
Bo Hansen
Well-known member
Roban,
As we have previously talked about many times, this DI-box design is in no need of special components, such as hocus-pocus HiFi resistors/capacitors or cables, to achieve its appreciated sound quality.
Common standard components of good manufacture will do just fine.
There are dozens of posts here in the thread with such recommendations, but are also described in detail on my DIY help page www.hansenaudio.se/techpage.htm
--Bo
As we have previously talked about many times, this DI-box design is in no need of special components, such as hocus-pocus HiFi resistors/capacitors or cables, to achieve its appreciated sound quality.
Common standard components of good manufacture will do just fine.
There are dozens of posts here in the thread with such recommendations, but are also described in detail on my DIY help page www.hansenaudio.se/techpage.htm
--Bo
Bo Hansen
Well-known member
Please do me a favor, don't buy any pirated copied circuit boards for my "Bo Hansén Active DI-Box 1975"
As example, there is a French company that sells pirated manufactured PCBs for my DI-Box on its own website and also on eBay without permission to do this.
Two reasons why I do not accept this.
1. It gets confusing and takes more time from us here in the group who spend a lot of time and work troubleshooting and helping DIY people to solve problems with their builds that for various reasons don't work.
Therefore, there must only be one type of this circuit board that is sold, and it must be functionally tested and approved by me personally.
2. It is extremely bad and selfish of people who make a decision to steal someone else's design, who also know that this is not accepted in the specific case.
So please, just buy the PCB/printet circuits boards from 51xAudio.com, Volker Meyer is a nice guy.
51xAudio by [silent:arts]
Many thanks.
All the best from
--Bo
As example, there is a French company that sells pirated manufactured PCBs for my DI-Box on its own website and also on eBay without permission to do this.
Two reasons why I do not accept this.
1. It gets confusing and takes more time from us here in the group who spend a lot of time and work troubleshooting and helping DIY people to solve problems with their builds that for various reasons don't work.
Therefore, there must only be one type of this circuit board that is sold, and it must be functionally tested and approved by me personally.
2. It is extremely bad and selfish of people who make a decision to steal someone else's design, who also know that this is not accepted in the specific case.
So please, just buy the PCB/printet circuits boards from 51xAudio.com, Volker Meyer is a nice guy.
51xAudio by [silent:arts]
Many thanks.
All the best from
--Bo
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