[sdiy] [AH] U726hc Real deal?

[Rick Jansen]

Use a mat04.. Two transistors as the matched pair, one as heater, one as sensor. One external transistor as a clamp. See the circuit at the bottom of http://dropmix.xs4all.nl/rick/Emusic/Moog/moogvcf_schematic.gif

Rick

> On 09 Sep 2015, at 15:19, Tom Bugs <admin at bugbrand.co.uk> wrote:
> 
> I wondered before why no-one seems to have done a clone of the ua726.
> 
> Doesn't *SEEM* all that complex?!
> A nice matched pair (eg LS318) is the main core.
> 6 transistors (I presume general purpose?), 2 x 6V2 zeners and 6 standard resistors.. - those parts being for the heating element.
> 
> Get the pin placement right, encapsulate it in goo.. 
> 
> What am I wrong on? 
> 
> [I don't want to fully take on such a project, though could potentially do a design up for initial testing with a view to someone running a production in a friendly open-source-ish manner]
> 
> Tom
> 
> 
> 
>> On 09/09/2015 14:00, . . wrote:
>> Wow don't pay 90$ for that!
>> 
>> I've bought a few fakes some years ago for about 10-15$ each iirc  They worked according to my tech at the time.   It's hard to say if they perform exactly the same, I ended up putting in a real one in just to be sure.
>> 
>> 
>> 
>>> On Wed, Sep 9, 2015 at 7:42 AM, Synth Parts <synthpartsdotcom at gmail.com> wrote:
>>> Also very suspicious is the pic of the one with the year 2000 date code and that there's no pics showing the pins (they were gold on the real ones)...
>>> 
>>> Doug 
>>> synthparts.com
>>> 
>>>> On Wed, Sep 9, 2015 at 4:34 AM, Kenny Balys <kenny at beatkamp.com> wrote:
>>>> 
>>>> I doubt that these were ever shipped to, or made in China so I would look elsewhere. Its hard to imagine that in the 1970's, Fairchild, in the height of the cold war, would be manufacturing vital components such as these in China.
>>>> 
>>>>> On 09-09-15 09:29 , Synth Parts wrote:
>>>>> I recognize that sellers name as one selling fake SSM2040s a while back.
>>>>> Lots of feedback regarding fake parts -
>>>>> 
>>>>> http://feedback.ebay.com/ws/eBayISAPI.dll?ViewFeedback2&userid=polida2008&iid=400613597638&de=off&items=25&which=negative&interval=365&_trkparms=negative_365
>>>>> 
>>>>> Doug
>>>>> synthparts.com
>>>>> 
>>>>> On Tue, Sep 8, 2015 at 10:30 PM, Larry Dee <mintlake at bctonline.com> wrote:
>>>>> 
>>>>>> Is this the real thing?
>>>>>> 
>>>>>> 
>>>>>> http://www.ebay.com/itm/1PCS-CONTROLLED-DIFFERENTIAL-PREAMPLIFIER-IC-FAIRCHILD-TO-100-CAN-10-UA726HC-/400613597638?hash=item5d466e61c6
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> I’m so burned out on this issue – sheeeesh for $90 it better be NOS.
>>>>>> Tried searching the AH archives for recent content on this subject but did
>>>>>> not get anywhere.  Sorry to be redundant, but what is the latest word on
>>>>>> this part?
> 
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