Behringer ADA8000 modifications..

[smallbutfine]

reg. Opamp desoldering by Govinda:
This can be taken approved definitely. Every heavy desoldering I did on newer (post red) Behringer PCB's was a matter of nailbiting and cursing. consider the traces to come off and get crackled more easily than the hair-fine traces from a computer mainboard when working too long. SMD is even worse than thru-hole double layer.sometimes chips seem to be glued to the pcb. Sometimes fine work like a cell phone repair.

 

[smallbutfine]

Well, I am interested as well, Govinda...
Which OPA did your tech use?

 

[bitman]

Here is a good way to remove smds.

Get an x-acto knife and push it down on the "shoulders" of the leads right up against the chip carrier plastic.
The leads will cut right in two with a pop. Then brush away the leadless smd chip if it's not glued down. If it is that's another thing.

You can thne whisk away the leads with a soldering iron leaving clean pads.
I was taught this technique when removing 48 pin plccs at a place I worked at in the 80s.

 

[tomcat]

What is a x-acto knife ???

 

[jdbakker]

What is a x-acto knife ???

See here or here.

JD 'UTFS' B.

 

[smallbutfine]

Yep bitman, good tip. Hehe, but as you said....it does not help that much if the chip is glued down. (Well, ok, at least you instantly know that it's glued.)
Glueing is widely used with ic's on pcb that is not supposed to be serviced, to simplify/secure positioning of the parts and cut manufacturing cost. Since most pcbs are done in south asia today, it applies also to servicable pcbs, unfortunately.
(Because service is done in the customer countries and doesn't bother the asian factories until the customer complains about it...what he does not, because prices might go up due to the change.)
Leg cutting is also a good tip for the thru hole chips in Behringer gear, because the pcb material is quite thick compared to the ultra-thin copper traces that might come up instantly when removing the very thight fit legs all at once in a wrong angle.
Cutting legs here helps because you can push out every single leg thru the pcb afterwards, with help of a resister leg or similar, and without applying too much heat and force to the pcb.

If you *need* to keep the ic parts...well, you might have a problem with modern factory pcbs already....

 

[maria2010]

Hi there !

This is a LONG topic, I couldn't read all 25 pages, but I must tell you that I got an ADA8000 and I started modding the toy. I've posted some pictures from inside and some notes on http://noisehome.dmz.ro/hardware/
I hope this will be useful.

M.

 

[kepeb]

really surprised by the comparisons the rme stuff.
i have the ada hooked up to a focusrite as my interace but favoured the FR pre's on the belief that the belringer was possibly somehow inferior.

gotta have a go with that rmaa thing soon too, thats an eye opening tool.

 

[maria2010]

Hi guys !

I've been reading about a "jumping gain modification" on this site, but I couldn't find the page  ???... the "Google custom search" on the forum is just a pain, I can't find anything useful.

Can someone point me to the right place to read about?
I'll be happy to read about other people experience just before I'll perform the surgery 

Thanks,
M.

 

[Govinda Doyle]

I can't believe i missed this!
The op amp ic we changed was a version of a OPA604, it really changes the sound of the unit in a very positive way!
more upper extension tighter bottoms, wider soundstage.
G

 

[torreznor]

Hello everyone. This is my first post. My ADA8000 has died on me for the second time. Same problem as the first time, but first time it was in warranty period and it was repaired by Thomann. Now I have to do it myself and I don't have much of a clue.

It's a rev G model. I switched it on and the lights shined dimly, with half of the usual brightness. I thought it was just my impression but I tried to record throught it and it wasn't working. I tried to find some info in the internet and found this post.

I brought the device to an uncle of mine who is very technically skilled. We have opened the thing this afternoon and checked the voltages of the regulators. Every tension seems to be ok but one, the +5va, which measured at the phantom led indicators is reduced to 3,39v. We have followed the tracing and arrived to the T19 transistor in reverse of the main board, but we are not able to find such component in the schematics we own.

Thanks in advance for your time!

 

[AUDIO FREQ]

Forgive me friends, but looking at my model...it seems it has Cirrus Logic CS4270 converters in them. Not the Wavefronts

Also, can anyone point me to where the microphone preamplifier circuit is? Looking at the board, I don't see anything aside from the TL072c op amp, a comparator, and the converter section. Along with the TL074C op amp chip near the output.

 

[ccaudle]

looking at my model...it seems it has Cirrus Logic CS4270 converters in them. Not the Wavefronts

That sounds like you actually have an ADA8200, not an ADA8000.

 

[AUDIO FREQ]

That sounds like you actually have an ADA8200, not an ADA8000.

No it says ADA8000 and it's black/silver. I think it's a revision of the same model.

 

[Tubetec]

The transformer cooks itself in those ,
its well documented ,
I ripped out the mic pre front pcb , wired direct to the A/D stages line level , without any gain control .
Runs nice and cool now ,
These things will also run at 96khz with external clock , only four inputs are active in that mode though.

 

[AUDIO FREQ]

The transformer cooks itself in those ,
its well documented ,
I ripped out the mic pre front pcb , wired direct to the A/D stages line level , without any gain control .
Runs nice and cool now ,
These things will also run at 96khz with external clock , only four inputs are active in that mode though.

Yikes. You just detached the front panel cables on each channel? Then solder the XLR pins directly to the + - of the 072c op amps?

 

[Whoops]

Yikes. You just detached the front panel cables on each channel? Then solder the XLR pins directly to the + - of the 072c op amps?

If you use the search engine in this forum and also google you will find detailed explanations about doing that mod.
It’s pretty well documented and was done by many people

 

[Tubetec]

I was one of the people who contributed to that thread .

I ditched the front pcb entirely , put in new metal xlr connectors .
I wired directly into the A/D by lifting one leg of the coupling caps , I also changed the polarity of one coupling cap per channel on the basis what I was using to feed it wouldnt have any dc at the outputs .

If you want to keep the possibility of unbalanced input you might want to keep the TL072's , I ditched them because I only ever feed it from balanced studio line level outs via short patch cables .

The ADA8000 , the REV2496 and the truth monitors were some of Uli's best ever products . I was in the hifi and DJ equipment trade for a few years in the early 2000's , I did loads of install jobs using truth monitors in pubs and clubs , for the money , the sound , reliabillity and the SPL regular hifi boxes didnt even come close .

 

[AUDIO FREQ]

I was one of the people who contributed to that thread .

I ditched the front pcb entirely , put in new metal xlr connectors .
I wired directly into the A/D by lifting one leg of the coupling caps , I also changed the polarity of one coupling cap per channel on the basis what I was using to feed it wouldnt have any dc at the outputs .

If you want to keep the possibility of unbalanced input you might want to keep the TL072's , I ditched them because I only ever feed it from balanced studio line level outs via short patch cables .

The ADA8000 , the REV2496 and the truth monitors were some of Uli's best ever products . I was in the hifi and DJ equipment trade for a few years in the early 2000's , I did loads of install jobs using truth monitors in pubs and clubs , for the money , the sound , reliabillity and the SPL regular hifi boxes didnt even come close .

Like you, I only use balanced 99.99999% of the time. I just got done swapping all of the op amps to experiment. I left everything else alone, even the capacitors from 1569 A.D...though I will be order replacements of equal value from digikey here soon as I run into some more money.