[sdiy] LM394 vs MAT-02

[Scott Stites]

Just curious - I see that on the stompbox forum, RG Keen made reference to the DMMT3904 and DMMT3906, matched 3904's and 3906's in six pin SOT packages.  They sell at Mouser for $0.50 each.  Spec sheet says matching to 2% for the 3904 and 2% with 1% available for the 3906 by contacting the manufacturer.  Is this kind of matching anywhere in the range required of VCO expo converters? 

-----Original Message-----
From: mark verbos <mverbos at earthlink.net>
Sent: Nov 17, 2005 2:33 PM
To: Peter Grenader <peter at buzzclick-music.com>
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] LM394 vs MAT-02

what are their minimum order requirements?


mark




Peter Grenader wrote:
> I was originally using the LS312 (it's slightly more tightly matched -
> spec'd at .2mV, but the units I got were much better than that).
> 
> I found the LS site while I was looking for ua726's once.  Didn't think
> anything of them, bookmarked the site, blah --  but didn't try them until a
> few months later as the LS312 was recommended by a tech named Julie
> Yarlborough as a replacement for the AD811 when I was putting together a the
> parts to build a Buchla 259 kit for Guido (which I was VERY fortunate to
> squeak out of). 
> 
> The 312's were great, but it was Linear System's Don Howland (GREAT guy) who
> then recommended  the higher gain 318 as he felt it was better suited for
> VCO stability due to having half the sheet resistively of the 312 (basically
> it turns on easier) which would make for better tracking across the audio
> range.
> 
> Did it make a difference?  Honestly...I'm not  sure as any gains were
> deluded by a major error found about that time in my expo converter -- I was
> starving it's current which had my tracking at 2.7 octaves max.  Three
> resistor value changes later, I was up to 7 octaves. In any event, I
> continue to use 318 for a plethora of reasons, mostly due to a "if it works
> don't screw with it" mentality but above that the guys at Linear Systems are
> really terrific.  They're a low volume foundry themselves and therefore
> really support the small guys.
> 
> Now, until recently when the VCO backlog was finally blown out, i WAS using
> MAT's on my own VCOs - not because I felt they were better, because I got
> them as samples and I was saving the LS devices for customer's units.  When
> I finally switched them I did notice a sonic difference between the two,
> particularly with expo FM.  The LS sounded a lot smoother than the MAT.
> 
> I apologize for the (for me, typically) non technical response here.  I'm a
> hack as you know and in lea of technical chops I use my ears more than
> anything else in component selection.
> 
> hope this helps -
> 
> - P
> 
> 


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