Simplistic NJFET RIAA - Page 780

Rush · 15th July 2012, 12:48 PM

Quote:

Originally Posted by Salas

Had anybody tested this kind of gadgets? A 200X or something wand type a friend got was grainy enough.

USB microscope gadget.

You can't hand hold anything over 10x (without the vibrations and motion blurring the object), so the stiffness of the scope's mount and the relationship of the object to the scope becomes more important than the optics at 200x. Every time you touch the scope to adjust the zoom or focus or snap a photo the scope will vibrate and blur the image. Think of why a microscope is built the way it is.
If the scope was purely software driven, focus, zoom, snapshot, would go a long way to make this better.
It is probably not useful for more than the minimum 20x to 30x, but that maybe enough and it looks like a fun toy. You could certainly fabricate a better mount and a way to move the image across the field of view smoothly.

Rush

Salas · 15th July 2012, 01:54 PM

Quote:

Originally Posted by merlin el mago

Connected today the Simplistic Low MC pre-pre left channel big buzz right channel without sound

, no music

Wich steps have I to follow to fix the issue?

N.B. MM where is connected the MC pre-pre is going on OK is tested before.

You had shown perfect signal with scope tests. Test again that way to see if something got broken meantime.

merlin el mago · 15th July 2012, 02:02 PM

OK I will test all connections & I will check the pcb.

merlin el mago · 15th July 2012, 02:15 PM

Salas just opened I see the left output signal wire desoldered

that was the cause of high buzz in the left channel, I connect again to MM to see what's happen.

merlin el mago · 15th July 2012, 02:50 PM

No noise & no sound right channel, left channel still buzz. Voltages are OK between Q4 BC550C & R1 +7,30V aprox in both channels, now time to inspect the pcb.

merlin el mago · 15th July 2012, 02:58 PM

Because long time without use the MM pre I tested the Rotel MM with my step-up Partridge 977 & isue is the same so the isue is in the Rotel MM

so I have to wait until Itch is finished to test the low MC pre-pre

vgeorge · 15th July 2012, 04:15 PM

Put the scope on your Rotel MM to see what is going on.
Debug stage by stage.

merlin el mago · 15th July 2012, 04:55 PM

Rotel RA-02 is an integrated amplifier with MM, where have I to measure the output at the headphones output?

vgeorge · 15th July 2012, 06:43 PM

If it has a tape out, measure there.

merlin el mago · 15th July 2012, 07:06 PM

Yes have tape out, also have pre out.

15th July 2012, 04:15 PM	#7797
vgeorge diyAudio Member Join Date: Mar 2004 Location: poros island	Put the scope on your Rotel MM to see what is going on. Debug stage by stage. __________________ "Without deviations from the norm, progress is not possible" - Frank Zappa

15th July 2012, 06:43 PM	#7799
vgeorge diyAudio Member Join Date: Mar 2004 Location: poros island	If it has a tape out, measure there. __________________ "Without deviations from the norm, progress is not possible" - Frank Zappa

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15th July 2012, 02:02 PM	#7793
merlin el mago diyAudio Member Join Date: Sep 2009 Location: Catalonia new Europe state	OK I will test all connections & I will check the pcb.

15th July 2012, 02:50 PM	#7795
merlin el mago diyAudio Member Join Date: Sep 2009 Location: Catalonia new Europe state	No noise & no sound right channel, left channel still buzz. Voltages are OK between Q4 BC550C & R1 +7,30V aprox in both channels, now time to inspect the pcb.

15th July 2012, 02:58 PM	#7796
merlin el mago diyAudio Member Join Date: Sep 2009 Location: Catalonia new Europe state	Because long time without use the MM pre I tested the Rotel MM with my step-up Partridge 977 & isue is the same so the isue is in the Rotel MM so I have to wait until Itch is finished to test the low MC pre-pre

15th July 2012, 04:55 PM	#7798
merlin el mago diyAudio Member Join Date: Sep 2009 Location: Catalonia new Europe state	Rotel RA-02 is an integrated amplifier with MM, where have I to measure the output at the headphones output?

15th July 2012, 07:06 PM	#7800
merlin el mago diyAudio Member Join Date: Sep 2009 Location: Catalonia new Europe state	Yes have tape out, also have pre out.