Behringer ADA8000 modifications..

[Rochey]

Back to the Behringer box mod - is there any way i can help in modding this over to the PCM4204? It'd be v.v.v.nice to squeeze the higher performance from the box

PM or reply here if there is anything I can do.

Chrz

R

 

[Sleeper]

Yes. back to AD8000 mods :grin: :grin:

I'm tracking the package and mine should be here in the next few days.

I like the chip swap idea, as well as a bit of upgrade where possible, caps, check resistor matching on diff inputs etc...Tl074 to LM387 idea was suggested. OP471, AD713 also looking pretty good

Has anyone tried any of these. In particular the chip swap...
from the data sheets it looks like this is more or less a no brainer.
I have to place an order in the next few days and am going to mess around a bit with some of these, just wondering what anyone else has done.

Thanks
Sleeper

 

[thedug]

Anybody have any insight into which chip would be a better replacement for the TL074? MC33079 vs. LM837?

Also, anybody have any specific instructions on how to bypass the mic pre? It might be nice to still make use of the volume pot for setting input gain? Or have a pad?

PS: Does the PSU need any work?

d./

 

[rafafredd]

Jakob always talks about the MC33079...

 

[andre tchmil]

are you guys planning to bypass the preamps , and using only the convertors.
Then I'm in.
Who needs these preamps anyway ?

 

[synthi]

Who needs these preamps anyway ?

Sure mate!

I preffer to hit the vocalist with a hammer for singing louder than use those Bcrap preamps!

Synthi

 

[thedug]

Anybody have an official mod on how to bypass these mic preamps?

I think keeping the vol. knob or adding a pad might be cool, cuz my api 3124s can really spit out some gain!

d./

 

[evil grill]

[quote author="thedug"]Anybody have any insight into which chip would be a better replacement for the TL074? MC33079 vs. LM837?
[/quote]

OPA 4134, EL 2444, OP 484 seem like good op-amps.
I´ve got no personal experience with these though.

 

[thedug]

Hmmm... More opamps in the equation..

I just meant between the 2 that were already mentioned...

MC33079 vs. LM837?

 

[gyraf]

I think they're the same, but from different companies. Have you compared the specs?

Jakob E.

 

[thedug]

Has anybody successfully bypassed the preamp?

Also, if you bypass the preamp, will the peak meter circuit still work right?

d./

 

[DrFrankencopter]

Anybody have any insight into which chip would be a better replacement for the TL074? MC33079 vs. LM837?

I've successfully used OPA4132's there (replacements for TL074s), and with proper bypassing they sound great. Is the chip a SOIC or a DIP? Digikey has the SOICs available.

Cheers,

Kris

 

[Bauman]

OPA4132 do sound very good, it'd be my first choice...

cheers!
Fabio

 

[thedug]

Will teh OPA4132 be better than teh LM837?

Any suggestions on how to bypass the mic pre? I see comments about feeding straight into the diff. input of the chip.

Have the pot of input level wouldn't be bad, but I'd prollly always be using the line level input...


d./

 

[tmbg]

I bought one of these cheap bastards last night... havent had it apart yet.

I may buy another for modding purposes, I actually want to USE this one!

so far, it really doesn't sound all that bad.

 

[thedug]

I replaced channels 3/4 & 5/6 with input & output chips -> MC33079

Unfortunately I didn't have time to A/B. I'll listen to it when the holiday season passes...

Next step will be to by-pass the mic pre amp on the inputs.

d./

 

[synthi]

Hi Dug,

Have you AB´ed the modded channels?
Any news on bypassing the mic pres?

Happy 2005!

Synthi

 

[thedug]

Not yet. I am gonna try to do that this weekend.

d./

 

[thedug]

I finally got around to checking this guy out.

All I've done so far is replace the chips.

Let me just start by saying that with the unit sync'd to my lucid it sounds pretty damn good. It is a bit harsher and less tight in the low end than my rme but overall it sounds good.

The 2 channels with the new op amps sound better for sure.

I also ran some tests on the A/D, the one thing I noticed is that you have to attenuate the signal quite a bit to avoid overs. I wonder if bypassing mic pre will be doable without some sort of pad.

d./

 

[Sleeper]

Hi Dug,
So you changed the chips and there's no oscillations or wierdness to deal with?

are you using the line input, because according to gyrafs schematic theres already a pad on those... although that is still going through the transistor section of the amp. just curious coz I've got my chips now. trying to think through this mod a bit, letting the box settle in to day to day use to see what I really need before having a go.
Still have to finish my 4ch. green pre first. almost done though.

Kelly