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Well, since just about everything (perhaps apart from a cold solder joint?) has been ruled out, that would seem to be the case...
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Drawing Board / Re: Neve 2254 build with ba185, ba191, ba192, ba283
« Last post by Rob Flinn on Today at 09:17:26 AM »
Ah I get ya now, external or separate Psu connector

Not really.  All the i/o & power are done on the same connectors as are on the back of a 1073 etc

Remember these compressors were not really designed as stand alone units.  They were designed to be plugged into slots on a desk, & as such have the same female 18pin edge connector that all the modules of this era have.
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Drawing Board / Re: Active ribbon-mic
« Last post by Winston O'Boogie on Today at 08:56:41 AM »
 
Checked headroom and THD...
 
...After all it's not so bad for a circuit with so little NFB. Doing what I can to comfort myself...  :D

Those specs are very good, there's no need for comfort and you know it  ;)
I expect  clipping is a very graceful affair and limited to  quite benign low orders, and you could also argue that if output levels are anywhere near +4 to +15dBu then there's not much need for an additional gain stage anyway.   
Thanks for the details  :)

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I have just replaced the four rectifier diodes D7 to D10, they seemed working normally, but I replaced them anyway. Still nothing, heater voltage drops to 0.3V under load. Does that mean that the transformer is the culprit?
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Ok, i see...So, combining circuits in series, is like adding an order to a lowpass filter...N circuits is n filter order...

Jay x
Yes if each circuit block has a one pole roll-off, the combined path will exhibit N poles.

JR
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Drawing Board / Re: Active ribbon-mic
« Last post by abbey road d enfer on Today at 08:21:14 AM »
Checked headroom and THD.
Max input at onset of clipping is -11dBu. It should withstand the kick drum mic (hopefully).
THD is not terrific with about 0.1 to 0.2% for output level between +4 and +15dBu. Goes down with level but hard to measure cause noise interferes.
After all it's not so bad for a circuit with so little NFB. Doing what I can to comfort myself...  :D
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Yes right, "left" meant "the only things in the heater supply circuit that I haven't replaced" are Diodes D7 to D10 and the transformer itself. These are the only stock parts in that part of the power supply.
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Yes, you can generally hear the difference of polarity. 

Generally?
No you can't. Generally you can't hear any difference at all when you are soloing 1 track and flip it's Polarity.

Lennie's problem is not related at all to the people that discuss they can hear absolute polarity, he complained of low end loss.
The problem is somewhere in the circuit don't chase ghosts
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"Left" in the sense of "not replaced", right? Not "the only things left in circuit apart from the regulator".

If replacing the diodes doesn't do the trick either, then the only remaining suspect is the transformer...
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Hi Khron, hi everyone!

I've just replaced EVERY component after the rectifier diodes and the problem persists (as soon as the load is connected the voltage goes down to 0.3V. (By the way, voltage after rectification is about 12VDC)

No there is only the transformer or the rectifying diodes D7-D10 left. What would you recommend trying next? I would really really appreciate your help.
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