Behringer MDX2000 internal pics ?

[Rossi]

Interesting how many revisions there must be...

I have several MDX2100 as well, and each of them has different chips. The basic layout is the same, though. The worst sounding are the ones with 4558 chips. It's worth swapping them for something better. I used NE5532, which worked nicely and sounded much better.

My MDX2000 has a different layout, but I think it's mostly the same circuit as the MDX2100. The MDX2100 includes the same chips you find on the MDX2000 subcircuit board. I tried to take out the board to take pictures, but it didn't work. The glue's too strong.

 

[henk]

The revisions look the same but the part on them are completly different and the buildup from the case is different too.
But when changing the 4558 to 5532 you have to do a lot of work before you have the underside of the pcb.
But when you change it do read my earlyer mail about upgrading it! Than you will know that it is better than a lot of other professional stuff!
If you would put in first sockets than you can test different opamps.
The sound of the opa2604 will change when the voltage goes up and because we still have a few opa4134 in dil we fill them in these things.
The envelope of the compressor in the mdx2000 and mdx2100 are mostly the same , the part on the pcb are a little different in place but is schematicly seem the same.
The only big differents between them is the BE2000 or 2x ca3046 , and because the be2000 has only a few connections to the schematic (the rest is on gnd) so therefor the change for the mdx2100 is only for cost reduction but the same schematic.

 

[clintrubber]

Nice things going on here, Rossi & Henk. :thumb:
Keep the good stuff going.

I have a MDX2100, can open the lid, take pics etc so if I can be of any help (in addition to the info already present here), just tell.

Bye,

Peter

 

[Rossi]

MC33078 is a good choice (the dual opamps next to the VCA chips are the crucial ones. I like the NE5532, too. Not sure which I prefer...

You might want to beef up the PSU caps while you're at it. On my unit the caps at the regulator outputs are only 4.7 u. As Henk pointed out, there's holes for additional caps, but none were used in my unit. If yours has none either, it's probably a good idea to put some into those holes.

Last weekend I did a listening test. I think I like my MDX2000 (pretty much stock) a little better than my MDX2100s (I got three in various states of modification).

 

[henk]

Hey Buttachunk nice to hear that the mdx2000 is working again , hopefully you will change the voltage of that unit to +/- 18V , then the compressor will sound completly different then the unit when it still has +/- 15V.
When the unit is unscrewed watch the front side of the pcb , put a plastic tape on the aluminium front bottem side where the pcb is laying on , this will help an lot of problems that i have had with all of the unit of Behringer.
For the mdx2100 there are only 2x 14pin dil and 1x 8pin dil too change too better ic's (opa4134 , opa404 or the one we made from two smd opa2604 =>opa4604??) , put powersupply to +/- 18V and the sound is very very good , same as mdx2000.
The rest of the envelope can stay the same , so no changes!!
Than you will hear no pumping or so anymore and the corner of the compressor is softer than with the +/- 15V unit.

 

[clintrubber]

[quote author="henk"]Hey Buttachunk nice to hear that the mdx2000 is working again , hopefully you will change the voltage of that unit to +/- 18V , then the compressor will sound completly different then the unit when it still has +/- 15V.

For the mdx2100 there are only 2x 14pin dil and 1x 8pin dil too change too better ic's (opa4134 , opa404 or the one we made from two smd opa2604 =>opa4604??) , put powersupply to +/- 18V and the sound is very very good , same as mdx2000.
The rest of the envelope can stay the same , so no changes!!
Than you will hear no pumping or so anymore and the corner of the compressor is softer than with the +/- 15V unit.[/quote]
Interesting mods Henk. You just replaced the regulators with 18V types ? In other words, has the transformer enough V_AC on its secondary for enough supply voltage headroom for those 18V regulators ?

Groeten,

Peter

 

[henk]

Yes you do need an other trafo , to put the trafo in get the old one out use a hammer to modify the metal and wait for the pictures that i have made to show you how it looks then.
The trafo is a ERA Typ UI 39/13.5 2x 21V Flachtrafo 18VA only 230V dont know how that is in the US.
You will need 4 screws to fix that in the box.
I still have some trouble getting the pictures on a server , so you have to wait a little bit.

 

[clintrubber]

[quote author="henk"]Yes you do need an other trafo , to put the trafo in get the old one out use a hammer to modify the metal and wait for the pictures that i have made to show you how it looks then.
The trafo is a ERA Typ UI 39/13.5 2x 21V Flachtrafo 18VA only 230V dont know how that is in the US.
You will need 4 screws to fix that in the box.
I still have some trouble getting the pictures on a server , so you have to wait a little bit.[/quote]
All fine, I'll await the pics. And otherwise let me know, if they're not that enormous I could host them.

dont know how that is in the US.

Groeten uit Brabant ! :grin:

Peter

 

[Rossi]

Actually, wouldn't it be easier to use a toroidal transformer? Some early MDX2000s supposedly had toroidal transformers, and there's a hole in the bottom for a big screw to mount a toroid. Some other B*ringer boxes have toroidal transformers, and they use the same housing for all their units.

 

[clintrubber]

[quote author="Rossi"]Actually, wouldn't it be easier to use a toroidal transformer? Some early MDX2000s supposedly had toroidal transformers, and there's a hole in the bottom for a big screw to mount a toroid. Some other B*ringer boxes have toroidal transformers, and they use the same housing for all their units.[/quote]

I should check... I don't have the unit here but IIRIC my MDX2100 has a toroid as well. FWIW, a MX662 having a toroid also.

 

[Rossi]

My three MDX21oos of various production runs are all non-toroid. My MDX2ooo, too, but supposedly some early ones have toroids.

I have an old Ultr*gain that has a toroid, some of the older German made B*ringers have toroids, too.

 

[tony666]

[quote author="Rossi"]My three MDX21oos of various production runs are all non-toroid. My MDX2ooo, too, but supposedly some early ones have toroids.

[/quote]

I just bought a very early and total black Behringer Studio compressor (pre mdx2000, made in germania). I'll post some pictures soon to see the differences. Some people state it's a sort of Urei ripoff others say Drawner?

 

[henk]

We did change the trafo because voltage is to low for +/-18V and because powerconsumption is to much for that trafo it only gets hot.
It is a little tricky to put that trafo in , only a few mm free on every side.
Some mdx2000/2100 do have round trafo's but i only found them in the xr2000/2400 one's.
I do have some problems getting nice stuff on a server , i did thought that i had put it nicely on one , does it tell me that it deleted everyting because it wasn't use for downloading for more than 10 days.
All my work on that server is gone!!!!!!

Where is a server that i can fill with nice stuff????????????

 

[Rossi]

[quote author="tony666"]I just bought a very early and total black Behringer Studio compressor (pre mdx2000, made in germania). I'll post some pictures soon to see the differences. Some people state it's a sort of Urei ripoff others say Drawner?[/quote]
I have one of those too. I got it very cheap. It's a totally different design. It uses two impenetrable black boxes that contain the VCA circuits. So it's hard to tell if it's a ripoff of anything. It's pretty cool for compression effects, but it's no good at more usual dynamics processing. The stereo linking is very clumsy. You have to set the knobs on both channels exactly the same for correct stereo imaging. The linking function only summs the sidechain signals, the controls for the right channel remain active.

Btw: the limiter function in the MDX2ooo is unaffected by stereo linking. The MDX21oo is the fist B*ringer model that has a correct stereo linking function. I don't like the interactive gain reduction in the MDX21oo, though. The 21oo reduces overall gain for several seconds when the signal hits the limiter threshold for more than just a few ms. May be good for live use, but I find it disturbing for recording purposes. The MDX2ooo doesn't have this feature. Which makes it more desirable, IMO.

 

[nrgrecording]

I own a few studio compressors, too.

Uli liked to seal his stuff in the early days.
Under the black coat there is a dbx RMS detector (2252 if i remember correctly) and a... nah? ... 2150.

 

[Rossi]

Wow, you're a brave man! I tried to open those boxes, but couldn't find a way to do so without breaking them. You must work out a lot :grin:

I had hopes there might be something fancier under the hood, maybe one of those Aphex VCAs. Oh well, another dream gone.... DBX RMS detector and VCA chips isn't exactly stealing. DBX used to sell those, and quite a number of companies used them. It's almost funny that B used to hide those chips in a mysterious black box. I wouldn't be surprised if the circuit in there comes right off the DBX datasheet/application note.

BTW: one of the initials on the red sticker in my unit is "UB" - touched by the devil's hand? :shock:

 

[henk]

This old Be.... looks much simpleler than the mdx2000/2100 , so is it possible to make a schematic out of it?
Then we all can see what can we do better to make it very good.

 

[clintrubber]

FWIW, I lifted the lid of my MDX2100 as well.
Among others, mine has:

THAT2159
CA3046
JRC4580

BA10324A
BE037
TL074

non-toroid power-TX


Would it be worth while to replace the THAT2159 ? Come to think of it, I have 6 THAT218X-ICs around. Could put two of those in the MDX2100 and use the '2159-ICs for the sidechain in two SSLs. Bad idea ?

Regards,

Peter

 

[Rossi]

I have no idea if changing the VCA improves the sound significantly. For all I know the 2159 is a 2150 with higher THD rating - probably higher even than the 2155.

If you do want to upgrade the VCA, it might be a good idea to change the JRC4580 next to it for somehting nicer. The 4580 doesn't stink too much, but subjectively I like the NE5532 or MC33078 better.

 

[clintrubber]

[quote author="Rossi"]I have no idea if changing the VCA improves the sound significantly. For all I know the 2159 is a 2150 with higher THD rating - probably higher even than the 2155.

If you do want to upgrade the VCA, it might be a good idea to change the JRC4580 next to it for somehting nicer. The 4580 doesn't stink too much, but subjectively I like the NE5532 or MC33078 better.[/quote]

Thanks Rossi, soldering iron will first be pointed at the 4580 and perhaps later on at the VCA.

Bye,

Peter