BOSS DI-1 ... looking for schematic

[clintrubber]

Hi,

I'm looking for the circuit schematic of that still going BOSS DI-1

Anyone got ? Or traced it ? Perhaps even the Service Notes ? (these are for sale I know, but I'm first of all curious to what just the circuit is like)

Thanks,

  Peter

 

[clintrubber]

Allow me a bump. There's one for sale here and was wondering if its circuitry is more sophisticated than the usual EU30 alternatives.

This DI-1 has been around forever already, so likely someone had a peak inside already ? Or user experiences with one of these ?

Thanks,

  Peter

 

[analogguru]

I only traced it partly years ago (missing the attenuator stuff) and have some hand-drawn notes.

It consists of a Fet-Buffer (with a 2SK246-GR) similar to the Boss FA-1, and outout buffer (with a 2SC732) for unbal. output and an balancing circuit with a M5218.

It can be powered by phantom-power, the supply voltage is catched with two resistors, diode and stabilized with a zener-diode.

Depending on the price, but I would choose the Behringer GI-100 (Ultra-G).

analogguru

 

[clintrubber]

Hi analogguru,

Thanks for responding & the info.
Aha, so nothing special, no compound buffering, just straight on single
device stages. No need to go specifically for this then. The suggested Beh. indeed a better
route, at least you get fresh caps 

Have another box upcoming, will be replacing the guts.

Bye/thanks,

  Peter

 

[analogguru]

If you get hold of a Boss DI-1 I would be interested in pictures of the guts to finish the partly schematic I drew uo during a service job.  I had not enough time for an exact schematic.

analogguru

 

[Whoops]

Why is it the Behringer GI-100 a better route?

 

[analogguru]

It would only be my personal choice, because:
1.) it costs only EUR 30,-- / I don´t know the price of the Boss DI-1
2.) it is galvanically isolated (transformer balanced) / the DI-1 is electronically balanced
3.) it has a (not so bad) built in speaker simulator / the DI-1 doesn´t have this.

The only thing I dislike is the TL064 used inside, but I think this is a problem caused by the abilty to get the supply voltage from the phantom power.

analogguru

 

[Whoops]

oh, thanks
nice to know that


What I was not getting was if you mentioned the Behringer to use as a DIY project or if someone simply needs to buy a cheap and reliable DI box.

regards

TS

 

[clintrubber]

If you get hold of a Boss DI-1 I would be interested in pictures of the guts to finish the partly schematic I drew uo during a service job.  I had not enough time for an exact schematic.

analogguru

Hi,

I won't be getting the DI-1 for sale here but I'' keep it in mind to post here if the schematic or a tracing opportunity ever pops up.

Bye,

  Peter

 

[clintrubber]

What I was not getting was if you mentioned the Behringer to use as a DIY project or if someone simply needs to buy a cheap and reliable DI box.

regards

TS

To bypass mechanical-DIY:
I just made a Thomann order and while at it I threw in their cheapest DI, to be used for the enclosure.
Before I remove the guts I'll have a listen to it stock though, otherwise the original circuit (a single cheap TX I expect)
will never have seen a signal 

http://www.thomann.de/nl/millenium_die_dibox_passiv.htm

Bye,

  Peter

 

[Whoops]

Nice Box,

its cheaper than buying the Box + switch + jacks and XLR's in separate!

Well done,
I feel sorry for that cheap transformer.

 

[clintrubber]

Nice Box,

its cheaper than buying the Box + switch + jacks and XLR's in separate!

Well done,
I feel sorry for that cheap transformer.

It's a good box for DI I think, there are also a couple of internal standoffs that can be used to fasten a small PCB to. These are now used to clamp the TX to the case. No idea about the TX and its ratio (box came 'specless') but I might measure a bit before I 're-populate' it.

Bye,

  Peter 

 

[Whoops]

What circuit are you using for your project?

 

[clintrubber]

The only thing I dislike is the TL064 used inside, but I think this is a problem caused by the abilty to get the supply voltage from the phantom power.

No idea how bad that '6'-range actually is. Seen it indeed in more DI-boxes. An opamp (say a dual) that can work well from phantom, it's indeed a universal issue: low-enough power & decent audio quality. We might start a poll on what people think would be the best type for that application.

Bye,

 Peter

 

[clintrubber]

What circuit are you using for your project?

Not sure yet, was thinking of the cntry-thing* (& adapting it for phantom-powering) or a simple straight on TX-less JFET&PNP stage with impedance balanced output.

*: http://www.diyfactory.com/projects/countryhick/countryhick.htm

Bye,

  Peter

 

[gswan]

I found a schematic for the Boss DI-1 after acquiring a couple of these for almost nothing (http://www.hh.iij4u.or.jp/~tokumi/pict/di-1.GIF).
The housing is quite nice. The circuit is pretty ordinary. It's a simple FET input stage with a M5128 dual op amp buffer. The op amp is about as good as a 741 op amp, so I think the best thing to do is to rip out the guts and design a new board that will pop in to replace the old one, with improved noise and response specs.

 

[clintrubber]

Hi,

I won't be getting the DI-1 for sale here but I'll keep it in mind to post here if the schematic or a tracing opportunity ever pops up.

Bye,

  Peter

And so it happened, this post here has the complete orig BOSS DI-1 schematic:

http://www.freestompboxes.org/viewtopic.php?f=1&t=5641#p230394


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Bye