Behringer ADA-8000 owners: PLEASE READ!!!

[zmix]

zmix

the psu module is a JLM module, details here : http://jlmaudio.com/JLM%20Power%20Supply.htm

Rob

Thanks, Rob!

I'll check that out...

EDIT:  Wouldn't you know it? There is now a Version 2 of that triple regulator board, and it features a JUMPER to select voltage doubling or tripling to the +48v regulator...

In my case, no such jumper is present, so I'll simply need to find a suitable replacement PSU transformer...

 

[blue_thunder]

I have an ADA800 that just quit working, and I'm assuming that it's this power supply issue that caused it. I'm wanting to fix it, but my electronics skills are quite novice. I've tried replacing the 7518 & 7519 regulators that have the heat sinks attached, but the unit still won't power up. I'm now thinking that the transformer might have gone bad. I've tested it using a digital multimeter to measure the voltages of the secondary wire that run from the transformer to the pc board. I clip the black lead of my multimeter to the ground screw on the chassis and touch the red lead to each of the secondary wires. All of them are reading 1.2 VAC & .001 VDC. I don't know what the voltages should be, but it seems like the numbers I'm getting are a bit low. Does this indicate that my transformer is bad? Is there anything else I should check? If it is the transformer, where can I get a replacement?

 

[SSLtech]

Remove the power connector.

Switch your multimeter to read resistance (ohms).

With the power switch in the "on" poasition, measure resistance between the live and neutral pins at the IEC power connection on the rear of the unit.

Report your readings here.

-I'll bet dollars to doughnuts that your transformer is bad.

Keith

 

[blue_thunder]

Ok, I went home at lunch and tested the resistance between the live & neutral pins like you said. There was absolutely no continuity. To be sure that it was the transformer that was breaking the signal, I checked the power switch & the fuse for continuity, both of them passed a signal. So, I checked the continuity from the live pin of the power connector to the power switch and then between the neutral pin of the power connector and the blue wire coming off of the transformer. Both of those were passing a signal. So obviously there is a break in the circuit inside of the transformer. I guess this means the transformer is dead? Where can I get a new transformer? And, what kind of transformer do I need (specifications)? Can I replace it with a different transformer that will prevent the issues everyone seems to have with the voltage regulators?

 

[SSLtech]

You can either buy a replacement from Behringer (which will suffer the same over-volted secondary issues) and then simply replace it and it will work probably about as long as the first one did before failing in a similar manner...

Or buy the Behringer replacement and then modify the unit exactly as described here, three pages ago.

Or buy the Behringer replacement and use a "Buck" transformer secondary wired to REDUCE the incoming voltage by a useful percentage... again, described earlier here, I think.

-Or I have a couple of higher-rated toroidal transformers which are rated for a MUCH higher power rating. -They should power 2 or perhaps 3 ADA-8000s, but would be a little too large to fit inside the unit, so they'd need to be mounted externally, like in this photo:

If that's what you need, you can have the transformer for $30 plus shipping. (I'm in central Florida, you're welcome to collect if you're nearby, which will save on shipping!)

But whatever works best for you.

Keith

 

[blue_thunder]

pm'd you

 

[blue_thunder]

I found a 120V toroid transformer that has the following secondaries:

23-0-23 at 1.4 amps, 17-0-17 at 3.8 amps and 12 volts at .41 amps

Would this work with my ADA8000? Would I need anything additional to make it work (resistors, caps, etc.)?

 

[blue_thunder]

Does anybody know where I can get a transformer for my ADA8000?

 

[SSLtech]

You'll need a 5V winding as well, since this is the rail which draws all the heavy juice...

I dug mine out and weighed it for shipping. -PM sent. -I can get it off to you this lunchtime.

Cheers,

Keith

 

[blue_thunder]

Thanks Keith. You're a lifesaver. Maybe one of these days all this electronics stuff will sink in.

 

[blue_thunder]

Hey Keith, I'm having trouble getting the transformer to work with the ADA8000. It keeps blowing fuses. Any ideas. I sent you an e-mail with more info. Thanks.

 

[SSLtech]

Ah! -I just replied.

Send me the info and -schedules permitting- we'll get this cracked tonight!

Keith

 

[blue_thunder]

I haven't gotten your reply yet. What info are you needing?

 

[SSLtech]

Email me your phone number and maybe a few opportunities when you might be able to sit down with the lid off the unit in front of you.

-Schedules permitting, I'll have one open in front of me, and we'll take a look at how it's all being wired up. -It sounds to me as though you may have the primary wired a bit screwy... but I don't know until I pop the lid and refresh my memory.

Oh... don't forget to let me know your time-zone relative to Eastern US...

-Keith

 

[SSLtech]

Joe,

Another Email sent... check your inbox when you get a chance.

-Keith

 

[starfish]

Had my eye on this thread for a while and knew the unit ran hot, but never did the mod. Guess I got lucky, cause I got some distortion in the pre's, but the transformer didn't fail. Replaced the 7915/7815's and it worked fine. Found a 115/97v transformer and an isolation transformer box already wired up at a surplus store for $10. Now i'm getting 9v into the 5v regs, 60 into the 48v, and 17.7 into the 15v regs. The data sheet I looked at said 17.5 min voltage for the 15v regulators. Is this too close to the minimum? Thanks to Keith and everyone for the info. I love diy, and to be able to fix something that I rely on in my studio is very satisfying indeed.

 

[andre tchmil]

Interesting thread.
But I must say I have an ADA powered up 24 hours a day since 2004. Never had a problem with it (touch wood).
In fact , I never looked at it, it's hidden in the back of a rack , so not much cooling down there. I use all 8 channels for headphone mixes.

 

[SSLtech]

Andre,

European installations run HALF the current through the primary, since it's 240V. The US installations run DOUBLE the current, through HALF of the primary, and so they tend to fail somewhat more frequently.

-that being said, European users are STILL at risk: The modification costs a few Euros, and makes SURE that it doesn't happen, by running the regulators MUCH cooler (particularly the 5V regulator) so I'd honestly suggest that it's still worthwhile.

Keith

 

[nisios]

Hello everyone.
My first ADA8000 fried and i sent it back to warranty. I then looked on the net and found this thread.
My new unit arrived today. I opened it right away and measured the secoundary voltages.
These were my results:

Primary (Europe)
235VAC ( i think, i just checked it and didnt bothered writing down the value)

Secoundary
10.8VAC
19.5VAC
59.5VAC

I need to use the unit right away and i dont have time to do the most time expensive mods so i tried the LIGHT BULB MOD.
I tried different light bulbs and these were the results:

Secoundary 100W Bulb:
10.4VAC
18.7VAC
57.2VAC

The bulb only got a little hot, the fillament didnt even got red.

Secoundary 50W Bulb:
9.9VAC
17.9VAC
55VAC

The lamp got a little hotter than the 100w and the fillement got barely red.

Secondaqry 40W Bulb:
9VAC
16.5VAC
50VAC

The fillament lighted up a bit. Not much, and you could easyly touch the bulb all the time.

Secoundary 25W Bulb:
12.9VAC
39VAC
6.5VAC

The bulb lighted up considerably, comparing to the others, but you could barely light the inside of a rack in a very dark room.


So, i think this is a very cheap and usefull method. I migh go for the transformer lowering the primary method in the future because of the added stability, but for now ill stick with the 40W bulb for the sake of protection.
When i got the new unit i hoped they had already made a change on the next batch of converters, but they diddnt.
I think this is plain stupid from them. They must have piles of these cooked units.

Abraço

Nisios

 

[nisios]

Ok......just a major flaw to this aproach: as current goes up (loud sounds on multiple microphones) the lamp fillament gets brighter and resistance goes up, dropping the voltages too low.

So, basically, the light bulb method doesn't work!

I never thought there would be so much difference in current on loud signals. I thought it would be just a very small change, but i was wrong....