Jump to content

ME850 mods designed by Art Vandelay


Recommended Posts



Guest jakeyb77
1 hour ago, muzzagruzz said:

Oh for sure, we’ve only got one of those. 

 

This is thread is REALLY, REALLY, REALLY making me miss my 850. 

Don’t miss it they are garbage. Look at all the work you have to do to get them to sound good. ?

Link to comment
Share on other sites

George invited me down for a quick listen this morning, and I'm able to report that his big ML's are definitely sounding better than ever. As George says, there's so much space around instruments that you feel as though you could walk around them between the speakers. 

 

The presentation is very natural and very inviting too, and there's a specificity and depth to the sound stage that raises the bar on what I heard previously. (though not in the literal erotic sense fortunately, but I was slightly concerned before I sat down on George's couch having heard what he and his wife get up to in there, with all equipment turned on so to speak. 

 

   

  • Like 1
Link to comment
Share on other sites



21 minutes ago, Art Vandelay said:

I was slightly concerned before I sat down on George's couch having heard what he and his wife get up to in there, with all equipment turned on so to speak. 

Wonder if Barry White is playing at the time...

  • Like 1
Link to comment
Share on other sites



6 minutes ago, Art Vandelay said:

 

There's a nasal spray for that now anyway that can probably turn a George Lightspeed into a Johnny come lately. 

 

The 'Art' of one hand clapping perhaps? Well maybe with that nasal spray, there'd be no need for hands at all.?

  • Like 1
Link to comment
Share on other sites



34 minutes ago, Alex58 said:

 

The 'Art' of one hand clapping perhaps? Well maybe with that nasal spray, there'd be no need for hands at all.?

That's why you need to be careful not to use the wrong spray, or risk a 'spray n' wipe' situation. 

 

Ftr, I was never a Daihatsu Applause owner, and I've never been diagnosed with hand clap. The latex helps of course. 

 

Edited by Art Vandelay
  • Like 2
Link to comment
Share on other sites

@georgehifi

 

Live test of module with new trannies. 

10kHz square wave with 1.5uf across the output.

 

I tried 0.1uF but couldn't see any change at all, so it doesn't get any better.  

However, there is a problem with the other channel. When I connect the generator with any waveform the module draws lots of current. Some sort of stability issue that will need FF'ing. Probably a fault that was pre-existing, because all I've done is change output resistors and servo caps.   

 

image.png.6514238c7e02350e6328e8fadb6f4dc3.png

Link to comment
Share on other sites



1 hour ago, Art Vandelay said:

Live test of module with new trannies. 

10kHz square wave with 1.5uf across the output.

Quite different to what I got with the MJ-15003/04's output transistors, with similar capacitive loading, my initial overshoot is a little higher, but settles much quicker, you have up to six cycles of overshoots, where mine were only 2 maybe three, this could be that MJE15003/4's are 2mhz bandwith, where your are faster and need more time to settle, don't know what's better to have, six of one 1/2 dozen of the other to me.

 

BTW Arty, were your compensation caps in the old or new spot?

 

Also what were getting now is quite different and far more stable to what they were and that was with .1uF not 1.5uF (pictured 2014).

 Cheers George

 

 

 

 

 

 

  

post-121842-0-76322500-1393561974_thumb.jpg

Edited by georgehifi
Link to comment
Share on other sites

1 hour ago, Art Vandelay said:

@georgehifi

 

Live test of module with new trannies. 

10kHz square wave with 1.5uf across the output.

 

I tried 0.1uF but couldn't see any change at all, so it doesn't get any better.  

However, there is a problem with the other channel. When I connect the generator with any waveform the module draws lots of current. Some sort of stability issue that will need FF'ing. Probably a fault that was pre-existing, because all I've done is change output resistors and servo caps.   

 

image.png.6514238c7e02350e6328e8fadb6f4dc3.png

There is a thing I do when possible if the product is still working:  For printers, we take test copy and test areas b4 we pull it apart to ensure we didn’t put a fault in.

Next time b4 you go stripping things apart.  Take some measurements to ensure you didn’t introduce any faults into the product...  it helps with fault finding and also tells you if any pre-existing  conditions exits....  Those F....g unstable ME amps, I swear!   ?. Just kidding about the last but!  

Link to comment
Share on other sites

33 minutes ago, georgehifi said:

Quite different to what I got with the MJ-15003/04's output transistors, with similar capacitive loading, my initial overshoot is a little higher, but settles much quicker, you have up to six cycles of overshoots, where mine were only 2 maybe three, this could be that MJE15003/4's are 2mhz bandwith, where your are faster and need more time to settle, don't know what's better to have, six of one 1/2 dozen of the other to me.

 

BTW Arty, were your compensation caps in the old or new spot?

 

Also what were getting now is quite different and far more stable to what they were and that was with .1uF not 1.5uF (pictured 2014).

 Cheers George

 

Ftr, that was 1.5uF with no resistor in parallel, so we should run the tests using a standardised RC combination. Usually it's 1 or 2uF // 8R. 

 

Yes, I'm using the standard compensation method atm, and it's very stable, but I'll test with the alt scheme in due course.

19 minutes ago, Addicted to music said:

There is a thing I do when possible if the product is still working:  For printers, we take test copy and test areas b4 we pull it apart to ensure we didn’t put a fault in.

Next time b4 you go stripping things apart.  Take some measurements to ensure you didn’t introduce any faults into the product...  it helps with fault finding and also tells you if any pre-existing  conditions exits....  Those F....g unstable ME amps, I swear!   ?. Just kidding about the last but!  

Sure, I know the right methodology but sometimes I like to take risks and give myself a challenge.  

 

Link to comment
Share on other sites

1 hour ago, georgehifi said:

 

Also what were getting now is quite different and far more stable to what they were and that was with .1uF not 1.5uF (pictured 2014).

 Cheers George

 

 

  

 

Keep in mind that was a ME75 single layer.  

 

edit..

Here's my screen pic for 0.1uF, 10kHz.

 

Nothing to see here. 

 

image.png.748c9d9be70deef9d55b77dfd0c61651.png 

Edited by Art Vandelay
  • Like 2
Link to comment
Share on other sites



  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...
To Top