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Will check - I'm just lazy after work! Swapping emitter and base was a little hard on them...  I'm amazed they even got to play sound after the abuse! What you guys think - exceeded base emitter reverse bias (5V if i read the datasheet right) and they failed closed?  I mean - they did work...

It played sound yesterday.  Then I think I made a problem (probably caused a short on the speaker with my temporary connections) and blew both fuses.  Put in the other two fuses after removing the speaker, popped the positive rail fuse.  From there I couldn't power up anymore without popping the...

May I hide my head please? I need to hide. Everything works 100% as soon as you connect the big transistors the right way round...  :-[

Speaker protect works awesome.  DC to speaker out makes it go red, leave it and little later it goes back green.  And you hear the relay click back and everything.  :) I checked all the resistors. only the 22K next to TR3 measures in circuit as 3K, but I'm sure if I were to take it out of...

Speaker protect went green at 30V or something (nearly browned my pants) :) So the speaker protect is awesome.  Will check resistor values and get back to you.  But I'm really really sure I populated them as in the PCB layouts on Dropbox.

Just put on full voltage for the first time.  Only measured 11 mA with the pot at the dot (hey that rhimes) and 17 mA with the pot full clockwise away from the dot. Can't get to 34 mA. Something wrong. No smoke yet (good sign).

I'm still on the dining room table... On a path to start pushing on voltage and setting quiescent current. :) By cfbosch at 2012-01-14 By cfbosch at 2012-01-14 Only have one mono block built. I'm starving for chassis! Anyone got any plans?

So, to start tuning, we start with the pot turned farthest away from the black dot to ensure least quiescent current on starting up? This is assuming that least resistance in the bias resistor will tap more current away from the base of TR5. Assumption right?  Analysis good? Uploaded with...

I can't believe I didn't pick this up when I made the graphic - the speaker terminals looked as if they were part of the amp.  I just repaired. Uploaded with ImageShack.us

Open office she does not work that lekker at my station... Will this help? Edit - added power rails Uploaded with ImageShack.us

With that in-signal, have you got a screened pair, or are you using two single screened wires (like co-ax)?  Just a little confusing as to what to do with the 0V if you're screen is floating at the amp side.  If you run a bare line next to it for 0V, won't it be prone to the interference you're...

Ah so the 0V from the transformer is held on the caps through the 10 ohm to chassis, and the current really is only on the outside swings.  Got it.  Brilliant actually.  That may be a solution to hum on my previous designs.  I guess it would help me to study a few more designs then I can learn...

Okay, I'm supposed to be able to figure this out myself.  But I cant!  Could you please help me? The negative and positive and the two seperate grounds on the board are easy. The speaker positive and negative are easy, and also are routed through the speaker protect/psu board. My headscratch...

@tangmonster Impressive.  And pretty chassis.

Rudi and SoundAdv, How are the plans coming with the "metal plankie" design and how does it affect the enclosure? If I'm not mistaken, SoundAdv was already on the home run with getting enclosures, but if the transistor mounting changes, surely the enclosure is affected? And, I think Rudi...

We're all waiting for Santa.

Gonna have to get me a Homer Simpson avatar by the looks of things.

I must have been mistaken about the 50Hz problem then - which is most often if not always the case. Which at least means I can buy torriodals from commercial sources in stead of making them up with the most expensive option of earth screen.

The reason I'm so on about the earth screen: Used a torroidal on the other project of mine - a Linsley Hood Class A.  The centre tap had quite some AC voltage on it because of the capacitive coupling between the primary and secondary.  A 1.5 mm2 wire to earth on the centre tap would not drown...

Jan W Gardner n Son TA Torroidal 300 VA 230 V 33 0 33 V VPI  Vacuum impregnation Copper earth screen is my guess?  (From your post at 8:50 - of course, you said another great guy on the forum was looking into getting already, this I think is just info all can easily get via a search of AV...