Behringer ADA-8000 owners: PLEASE READ!!!

[SSLtech]

Nice job.

Although if anyone were to add phantom, I'd suggest 2x22V or 2x25V, since 2x30V is too high. The 6V transformer is going to cool down the unit considerably. the 2x18V is still higher than needed, though slightly gentler than the 2x20V original. You could almost certainly get away with 2x15V I reckon, that too would cool down the unit, and render the 7815, -and particularly the 7915- less prone to failure.

-You know, the secondary may even be un-windable... I have a dead tranny here that I can try it on... I'll give it a go. I wonder how many turns you'd have to remove from the 12V secondary? -Half of them should be plenty, and would more or less halve the heat generated from the 5V rail.

Keith

 

[gnd]

I noticed this thread on ada8000 power supply voltages.

I have four ada8000, soon it will be five. So it would be lot of modding, to open each of them. So I thought about alternatives, and I got an idea for lowering voltages. I have 220 volt mains, si it may not be such a problem. But still...

What if I order a converter transformer, to convert 220V mains into lower AC voltage (say 180V or similar), then feed this to my four ada8000's. This reduced primary voltage would reduce secondaries voltages, is it?

So I could have such pre-trafo, some 100 or 200Wats, which would first lower mains voltage. Then I'd feed this reduced mains to ada8000's, through a normal power cables.

Would this work?
What would need to be the reduced voltage? 150V? 180V? Can somebody help with calculation?

thnx

 

[clintrubber]

[quote author="gnd"]What if I order a converter transformer, to convert 220V mains into lower AC voltage (say 180V or similar), then feed this to my four ada8000's. This reduced primary voltage would reduce secondaries voltages, is it?[/quote]

Or try this:

http://www.geofex.com/Article_Folders/vintvolt/vintvolt.htm

Bye,

Peter

 

[chrissugar]

[quote author="Michael Krusch"]I made a small box with cheap standard transformers (2x18V, 6V). I don't need phantom power, but a small 2x30V will also fit inside this box.
I haven't found a transformer that fit inside the Behringer case, so I went this way and it's rather easy. The box powers two Behringer.
[/quote]

Hey Michael

kind of off topic but I want to make new universal PSUs for all my vintage tube mics, and was looking for an aluminium case like the one in your picture. looks very much like the Hammond boxes, but the upper side looks like it has ventilation holes?
Please can you tell me the source for them, a product code, maybe a price.
Thanks.

chrissugar

 

[clintrubber]

Dunno if they're exactly the same, but I believe to have seen cases like this @ Conrad. Nice looking boxes indeed.

 

[SSLtech]

[quote author="gnd"]Can somebody help with calculation?[/quote]

I reckon a 20% reduction should work, so that would be a 5:4 transformer, or 1.0:0.8...

Which would give you 230V->185V.

Basically anything above 185 and less than 230 will be an improvement.

Keith

 

[gnd]

Basically anything above 185 and less than 230 will be an improvement.

Thank you, Keith.

Actually I just got another, even more funky idea! :idea:

How about if I put some light bulbs in series with ada8000 mains.

:idea: :idea: :idea: :idea:

I did this trick with 220V ventilators in my machine room, to reduce rpm.

Possibly a 100W light bulb would do. I'd need to experiment a bit with those. 100W bulb has some 500 ohm resistance when heated up. Connected in series it will light dimly, and R will be probably a bit less, maybe 200 ohm, I guess.

ADA8000 uses some 25W of power, which is some 2000 ohm at 220V. One 100W bulb with 200ohm may exactly work.

Now, isn't this a funky solution. And I could use some dim backlight in the back of my racks anyways, so this would solve it all! :razz:

What do you think? Any warnings? Suggestions? :?:

thnx

 

[Michael Krusch]

Hey Michael

kind of off topic but I want to make new universal PSUs for all my vintage tube mics, and was looking for an aluminium case like the one in your picture. looks very much like the Hammond boxes, but the upper side looks like it has ventilation holes?
Please can you tell me the source for them, a product code, maybe a price.
Thanks.

chrissugar

Yes the upper cover is perforated. It's from a local shop. Go to www.segor.de and do a search for 001.04.L.SW.

 

[nrgrecording]

Anyone accidently measuered the current drain of the 18V and 5V rails? :?: :?: :?:

I received 6 boxes from Walter and i don't know if I should buy replacement transformers or one big transformer for all.

Thanks,
Frank.

 

[bernbrue]

Hi Frank,
drop me a line, when you buy replacement transformer. I need two. Maybe a good job for M.Müller, our new RKT supplier.

regards
Bernd

 

[emtee]

[quote author="gnd"]

Basically anything above 185 and less than 230 will be an improvement.

Thank you, Keith.

Actually I just got another, even more funky idea! :idea:

How about if I put some light bulbs in series with ada8000 mains.

What do you think? Any warnings? Suggestions? :?:

thnx[/quote]

Bit of a pisser when the bulb pops half way through 'the' take... :razz:

 

[gnd]

Bit of a pisser when the bulb pops half way through 'the' take...

Yea... But luckily bulbs last much much longer on lowe voltage. There are some calculations arround regarding lifetime of bulb vs voltage. It can go for houndreds of years with undervoltage. Surely 20 years with no problem.

 

[nrgrecording]

Aha.. the new replacement transformer has the following specs:
17-0-17V/ 450mA
10V/760mA
51V/230mA

By the way... the 7805 datasheets says Vi=10V. Is "Vi" the input voltage?
So the 7805 is made to work with 10V input voltage? I thought Output Voltage + at least 3V is good point to start?

Frank.

 

[SSLtech]

Yes. 8V is a working minimum for happy operation without regulation dropout, 10V typical, probably a safe maximum of about 15V...

Frank, you could possibly run about 4 or 5 from one of my transformers if you're interested... -I just sent one to Idylldon, in case you want to see what he thinks. Two would EASILY run all six, I'm sure.

Keith

 

[tomcat]

Reg. the high Voltage nowadays. My whole studio is running over USVs, these are dual conversion units where i can configure the output (Voltage, Frequency). Im running the output on 220V setting (input is here also around 240 volts)

 

[nrgrecording]

Thanks Keith.
I think I would like to have two of your transformers. Would be nice to know the approx. shipping costs... ?

Iam thinking about removing the preamp pcb completeley and use a simple input stage instead of the "invisible mic preamps". I don't need preamps or phatnom power.

Can anyone recommend a simple input/buffer circuit for symm. and non.symm. inputs? I think the SSM chips are too expensive - I would need 48 of them. :sad: It was hard enough to get free samples for an original ssltech 9K. :green:
I thought about making a small pcb, maybe with +4/-10dB switch/jumper or so. Any well-tried designs out there?

 

[okgb]

Hey Keith [ my middle name ] thanks for your info on upgrading
the psu , i passed it on to a friend who was starting to have problems with his and after completing your mods has no problems , likely better than ever eh ?

He did use power resisters that come in a T0-220 for increased heatsinking

regards Greg

 

[Emperor-TK]

I love this place. What a great repository of information. This weekend I hooked up my ADA8000 in a small 4-space travel rack and noticed for the first time that the outside of the chassis was too hot to touch. I'm surprised the the unit has lasted as long as it has. I used the external transformer method (21VAC) to step down my input voltage. I got it wired up in a nice powder coated chassis with a power cord, fuse and AC outlet. These are my before and after DC voltages feeding the regulators:

5V regs
119VAC input = 12.7VDC
98VAC input = 9.6VDC

15V regs
119VAC input = 23VDC
98VAC input = 18.2VDC

48V reg
119VAC input = 75VDC
98VAC input = 61VDC

The 5V regs still run a little hot, so I might use a dropping RC section as well.

Thanks to everyone who contributed to this work. If anyone is still running one of these unmodded, I strongly advise considering one of these mods. They run REALLY hot otherwise.

-Chris

 

[RedNoise]

:sam: :guinness: :sam: :guinness: :sam: :guinness: :sam:

 

[natek]

I just saw this post and I will definatly have to do this to mine! Thanks Keith and everyone who has been working out this flaw! :thumb: