CurtPalme.com Home Theater Forum

donr · Joined: 04 Nov 2006 Posts: 153 Location: Montreal

Hi folks
Well I did the jump. Got myself a Spyder and HCFR to calibrate my Ampro 4000. I have been reading the calibration for dummies and I do, however, have a slight problem. I can't seem to find the sub contrast pots to adjust the rgb high end. I have found the sub brites on the rgb board for the low end and have tried playing around the 3 pots on the quad decoder but they did not seem to change anything. Anyone have a clue to where these pots might be to adjust red and blue high end?
Don

incova · Joined: 27 Nov 2006 Posts: 745 Location: london

AnalogRocks

donr · Joined: 04 Nov 2006 Posts: 153 Location: Montreal

I was reading up on the problems he had with his 4000G. Unfortunately, the answer to my question which is this link does not work.
http://www.curtpalme.com/forum/viewtopic.php?p=19206&highlight=#19206
Don

**AnalogRocks** · Posted: Thu Jul 08, 2010 2:37 am Post subject:

What is your question?

BTW which thread did you link from?

donr · Joined: 04 Nov 2006 Posts: 153 Location: Montreal

AR
I linked from your thread Ampro help.
My question was: where are the pots for sub contrast or how to adjust contrast on the blue and red tube?
Don

**AnalogRocks** · Posted: Thu Jul 08, 2010 4:04 am Post subject:

They are located on the top of the RGBS card

See the blue pots on the top of the RGB card in the picture here?

http://www.curtpalme.com/forum/album_page.php?pic_id=334

donr · Joined: 04 Nov 2006 Posts: 153 Location: Montreal

So there is no simple way of getting at them then without removing the card!

donr · Joined: 04 Nov 2006 Posts: 153 Location: Montreal

Sorry, I did not take the time to read your answer completely. Aren't those the sub brites?

**AnalogRocks** · Posted: Thu Jul 08, 2010 4:09 am Post subject:

That's a picture from the top down. All you need to do is take the top cover off the projector

**AnalogRocks** · Posted: Thu Jul 08, 2010 4:12 am Post subject:

donr · Joined: 04 Nov 2006 Posts: 153 Location: Montreal

Maybe there is something I am not getting here. My pj is ceiling mounted. The 5 pots on the rgb card are labeled sub brites sync on green, green, blue, red and contrast. Now I want to adjust contrast at the high end on the IRE scale. I though there were pots for sub contrast unless I am not seeing them. I did take off the cover.
Don

**AnalogRocks** · Posted: Thu Jul 08, 2010 4:18 am Post subject:

donr · Joined: 04 Nov 2006 Posts: 153 Location: Montreal

I did not find anything in the user manual. Maybe I missed it Exclamation

**AnalogRocks** · Posted: Thu Jul 08, 2010 4:26 am Post subject:

**Curt Palme** · Posted: Thu Jul 08, 2010 4:54 am Post subject:

There are no sub contrast pots on for the tubes. that's only in the later software for teh 3600/4600.

There's teh G2 controls on the CRT sockets and the RGB gain controls on the RGB board. That's it. Maybe you have low emission tubes?

donr · Joined: 04 Nov 2006 Posts: 153 Location: Montreal

Thank you guys.
I can get the low end in line but am having a problem at the high end. The G2 are adjusted to the manual spec and verified with Curt's method. Turning the drive pots next to the bnc connectors does not seem to have any effect at least while displaying a 70 to 100 IRE.
Don

donr · Joined: 04 Nov 2006 Posts: 153 Location: Montreal

I have 1 more question. Would putting up a color bar pattern from a test disk and using the scope to setup the gray scale as described in the manual work?
Don

tse · Joined: 03 May 2006 Posts: 1005 Location: Sweatbucket, Fl.

IIRR the sub contrast adjustments are right below the input BNC connectors. At least one should be at max with gray scale set correctly. Best BW that way.

Scott

**AnalogRocks** · Posted: Fri Jul 09, 2010 12:36 am Post subject:

Ahhh right Scott. I forgot about those adjustments. Been too long since I played with it

donr · Joined: 04 Nov 2006 Posts: 153 Location: Montreal

Thanks guys.
Don