Bo Hansen DI layout

[boji]

Mr. Hansen, just wanted to say thank you for making public your API mod and DI stuff.  Your web pages are something I return to often!

 

[Bo Hansen]

Many thanks Boji.

—Bo

 

[Newmarket]

This PC card must be mounted in a metal box, and especially in this case where the OEP transformer is used, since it does not have a mu-metal screen.

But you can get a MuMetal can for the OEP.

The metal needs to be ferrous - ie steel (not aluminium) to provide any shielding of a transformer against magnetic fields

 

[Bo Hansen]

Of course it is best with the option mu-metal screen, but even if this was already mounted on the transformer, the PC card must be mounted in a metal box.

—Bo

 

[Newmarket]

Of course it is best with the option mu-metal screen, but even if this was already mounted on the transformer, the PC card must be mounted in a metal box.

—Bo

Oh yes the case is best a metal case in any err... case.
Just pointing out that there is an optional can for the OEP transformer.

 

[Max51]

Hi everybody !

Does someone still have the self-etching papers  ?
Links in this topic and in the Bo's website seams to be dead...

It would be helpful !

Thanks !

 

[pushbroom]

Good day to everyone.

I noticed that there are two issues with the Mouser project list, namely that 512-1N4004 is discontinued and 71-RN60D3901F is backordered until 9/2019. 

Will it be a problem to replace the rectifier with Mouser's suggestion? https://www.mouser.com/ProductDetail/863-1N4004RLG?&bdprt=1&projectguid=E23CB3E7-9EF8-4003-898F-8416D6654D75&projectid=87542205

Unfortunately I am not very knowledgeable about specific components, so can someone recommend another resistor to avoid waiting until September to complete this project? I've checked a few other distributors but haven't found RN60D3901FB14 available anywhere yet.

Thanks in advance for your help!

 

[JohnRoberts]

1N4004 is a rectifier diode, you should be able to substitute another brand 1N4004 without problem.

I assume this is a through hole PCB layout... I didn't see spec sheet data on the other part.  If they are the same package the electrons will not care.

JR 

 

[Potato Cakes]

I will confirm what JR said from building several of these. Any through hold 1N4004 will do. I would just do a part search on Mouser (or whomever you prefer to use) and which ever one came up that was in stock and inexpensive I would use that.

Thanks!

Paul

 

[Mylithra]

I cant imagine the voltage swing in this being more than 100v. Is there a particular reason 1n4004's were used vs 1n4001-4007 or will any of these do in this application?

 

[pushbroom]

1N4004 is a rectifier diode, you should be able to substitute another brand 1N4004 without problem.

I will confirm what JR said from building several of these. Any through hold 1N4004 will do. I would just do a part search on Mouser (or whomever you prefer to use) and which ever one came up that was in stock and inexpensive I would use that.

Thanks for your guidance!

 

[Potato Cakes]

I meant to say "through hole" not "through hold," but I think you get it.

 

[Bo Hansen]

Pushbroom,

As many have already said, you can use the 1 amp. diode of any of 1N4001 to 4007 series, why I just chose 1N4004 is that it is most commonly used.

—Bo

 

[Mylithra]

I wish there was a like button.. Thank Bo.

 

[pushbroom]

Sowter 9145 - If it is a bass, I only use this. It's the more expensive option and requires a larger case, but I have never had a bass guitar have as much clarity from the top to the bottom of its range with as little processing than with this DI configuration. It gets noticed with other bass players and engineers, which is really nice because it allows me to bypass all the Avalon and other gear that you typically see in a bass rig that cause problems more often then they should.

By the way, I just got back from a tour where I was using your DI on bass and keys. The bass player was using mostly a pick and using a radial Pro DI, which are solidly built and does a pretty good job. However, there wasn't much of a comparison to your DI with the Sowter 9045. All the low end that one tends to miss when a bass player uses a pick was back and the clarity of the notes was exponentially better. I was able to keep the EQ on the bass pretty much flat, occasionally bumping the high mids if the PA or the room was being difficult. And I liked that the level difference from a passive DI wasn't extreme, making A/B comparisons much easier.

Paul,
I'm curious if you have any thoughts about the 9145 vs 9045. It appears that you used the 9045 initially with great success yet later switched to the 9145 for bass exclusively.  As I'm building a few of these for different purposes I'm interested in hearing your thoughts. Thanks in advance!

 

[Potato Cakes]

It must have been a typo. I've only Sowter transformers I've used are the 9045. That is what I use for bass. Every player and engineer that I have let use one agree it's amazing on bass. I had one engineer borrow one of the 9045 versions for a session and was comparing it to a REDDI and Mr. Hansen's DI was keeping up with no problem. I think they wound up going with the REDDI because the bass player wanted the "tube sound" or something, which translated into "I want to play through the fancier looking commercial looking product and not the unpainted project box with Sharpie labels." The engineer wound up just buying the DI from me as I have another one.

Thanks!

Paul

 

[pushbroom]

Thanks for clarifying. Your comments about the transformer's size led me to believe you were indeed referring to the 9045, but since the 9145 is a Neve replica I wasn't certain. Maybe I should build one of each and compare them to the 1538XL  8)

 

[Bo Hansen]

Sowter 9145 (replacement for Neve 10468) is a nice transformer with many impedance and ratio options, but it is only in 1:4 ratio/300 ohm to 4.8 kohm configuration as it fits in my DI box design.

Sowter 9045 in the 1: 5 ratio configuration is probably a much better transformer, especially in the low end because of the much larger core, and probably sounds better for bass guitar.

As I mentioned many times before, I have optimized the DI-box electronics for Lundahl LL-1538 or 1538XL for best headroom and good load and mirror impedance behavior regarding long cables and various preamps and mixing consoles input impedances.

But even a microphone input transformers with a 1: 5 ratio that have extremely good specifications, may still have some influence on the DI box's electronics load capacity, if the transformer's secondary "reflects" a long cable's capacitance or a microphone input with extra low impedance on a less advantageous way.

It is important that you check and make measurements on the DI box electronics when you test different transformers, so that it provides a nice and symmetrical clip and good frequency response.
Unfortunately, it is not always a guarantee that a large and expensive transformer is better in this case.

Why not a better drive from the DI box electronics so that it is possible to use a larger range of transformers, for example with a lower ratio ?

It is always a compromise that has to be made between heedroom, load capacity and output transformer signal loss of the Phantom powered DI boxes or condenser microphones output amps, becsuse it is the total Phantom powering current supply that determines it all.
I chose a combination where I pull 3,5 mA from the Phantom line and then get +24 volts as an internal drive voltage to the electronics.
I found that this matched perfectly to a well-designed 1: 5 ratio transformer as LL1538 used backwards, which has a signal loss of approximately -15 dB and is a suitable attenuation of the level from the DI box's instrument input to a mixing consoles microphone input.

Of course, there are a lot of types from Haufe, Sowter, Cinemag, Jensen that can replace LL1538 with similar results.

—Bo

 

[Ricardus]

Are any pre-made PCBs available for this aymore?

 

[iturnknobs]

Are any pre-made PCBs available for this aymore?

Volker/Silent Arts:

https://groupdiy.com/index.php?topic=39570.0