AMZ FX ANALOG ALCHEMY GEOFX MEF ROG MEF DIY WIKI

Deluxe Electric Mistress V4 or V5

Started by Govmnt_Lacky, August 29, 2012, 08:11:19 PM

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Govmnt_Lacky

#80
November 27, 2012, 07:58:29 AM
@Jazznoise

Were you able to look over my layout?

Any feedback?
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Jazznoise

#81
November 27, 2012, 11:59:14 AM
Quote from: Jazznoise on November 20, 2012, 09:39:53 AM
What program did you use to generate the .pcb? It's not opening in Ultiboard!

Did you try increasing the clock?
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Govmnt_Lacky

#82
November 27, 2012, 12:08:23 PM
Quote from: Jazznoise on November 27, 2012, 11:59:14 AM
Quote from: Jazznoise on November 20, 2012, 09:39:53 AM
What program did you use to generate the .pcb? It's not opening in Ultiboard!

Did you try increasing the clock?

I used ExpressPCB to gen the layout.

I have NOT attempted the clock increase yet. I will need to remove the existing 25K trimmer and/or series 3K9 resistor to do this and I am a bit weary  :-\

The board I etched was not the "best quality" and I have already had signs of traces lifting during mods (nothing I couldn't fix on the spot and shore up) so if I go in with a trimmer change, it will most likely need to stay permanently. Or, until I re-do the layout with thicker traces and re-etch  :icon_eek:
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Jazznoise

#83
November 27, 2012, 01:14:58 PM
I don't see much space for crosstalk between the 4013 and the R5106. Pin 8 maybe, but the cap should be helping there. A scope on the V rails of the R5106 would tell you how dirty they are, but they should be fine.

It seems fine, I'd use your layout but we're 5 pages of stumped in on this one.
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Govmnt_Lacky

#84
November 27, 2012, 01:27:27 PM
Well, like I mentioned before... the layout I sent you DOES have some errors that have since been corrected (220uF cap backwards between schematic and actual PCB pics, transistors backwards, wrong input cap value, etc.)

Bottom line is that these R510X chips (I have 6s, 7s, and 8s) were "found" at my work in a discard pile. I really hate to say it but, it might just be that ALL 18 of them are just plain noisy!  :'(

If you look at the factory schematic, it calls for RD5106A (which could only be RD5106ANP-011) I have since raised the question if whether there was a difference in tolerances between the RD510XA series and the plain old R510X as far as audio quality.

I REALLY DONT want to face the fact that this awesome find was really a bust!  :icon_redface:  :icon_evil:
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
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Jazznoise

#85
November 27, 2012, 02:00:53 PM
Hmm, it's a reasonable question. I think the clock mod might be the next thing, and at that point if there's no luck then I think blaming the BBD stage becomes a meritable answer.

How to deal with that will have to follow, I guess. Learning experience!  :P
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Govmnt_Lacky

#86
March 15, 2013, 10:16:08 AM
Just to follow up on this thread for reference....

Using a charge pump configuration with the circuit (LT1054) was causing the problems. Once I connected a usable transformer to feed the proper voltages, practically ALL of the noise disappeared.  :icon_cool:

I dont know if was due to "sewer ground" cross talk or if the circuit was just drawing a bit too much current from the pump but, it works great with the transformer as per original spec from EHX.
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

Jazznoise

#87
March 27, 2013, 11:35:58 AM
Ah ha!  ;D

Glad you got it working! I'd love to hear it if you make any clips!
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