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Author Topic: Trace Elliot GP7SM 200...  (Read 8403 times)

J M Fahey

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Re: Trace Elliot GP7SM 200...
« Reply #15 on: December 06, 2014, 02:07:23 AM »
Cool.
So you already got it with the TO247 plastics, I thought you'd have the TO3 metallics which of course are unobtainable.

That said, I LOVE the simplicity of Lateral Transistor power amps.

Pity they all but stopped making them.

If you decide to mod it for IRFP240/9240 remember gate legs match but Drain and Source are inverted.
No big deal, as long as you remember it.

matthias

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Re: Trace Elliot GP7SM 200...
« Reply #16 on: December 09, 2014, 10:34:03 PM »
I believe that I will go with the BUZ901/906p. The amount of re-fabricating to mount the IRF's Would eat up any savings that may be had.

J M Fahey

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Re: Trace Elliot GP7SM 200...
« Reply #17 on: December 10, 2014, 03:32:56 AM »
Cool  :dbtu:

The best solution is not universal, depends on each one's circunstance.

In my case, I'd have to order them from USA or Europe, and Customs makes my life miserable, so I always try to work with whatever's available locally, even if it involves mechanical work.

Post results :)

matthias

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Re: Trace Elliot GP7SM 200...
« Reply #18 on: December 30, 2014, 07:33:16 PM »
ok, should be able to finish up tonight... I need to verify my work and Reassemble... I dont know what the Idle Current draw for the Amp would be...
Will 800mA be enough to fire this up.
Should I use a larger Wattage bulb than 100W?


 

Roly

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Re: Trace Elliot GP7SM 200...
« Reply #19 on: December 31, 2014, 03:39:34 AM »
No!  Start small and work up is the general rule, maybe as low as 20W to start, depending...

Try, observe, evaluate, repeat.

Good luck.   :dbtu:
If you say theory and practice don't agree you haven't applied enough theory.

matthias

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Re: Trace Elliot GP7SM 200...
« Reply #20 on: January 04, 2015, 01:36:13 PM »
Of course I reassembled the amplifier bolted everything down and closed the lid....
well, I missed something....
bulb is bright
No Voltage on the rails
I just powered down the bench and locked the door.

Roly!
Thanks for the Guidance I'm Glad I didn't go ahead with the larger Wattage Bulb.
The reason I asked about the light bulb wattage is that I have a Sunn Concert Slave that Oscillates with a 100W bulb in series but operates normal on straight line voltage...and previous to this Trace Elliot, the Sunn was the largest SS amplifier I have ever worked on. I attributed the Oscillation to the 100W bulb not passing enough current to run the PowerAmp.

Ok, I hope to get back to this amp soon. Open it back up and figure out what I did wrong, or what I missed.