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cslammy
Joined: Apr 27, 2018 Posts: 206 Location: USA
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ixtern
Joined: Jun 25, 2018 Posts: 145 Location: Poland
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cslammy
Joined: Apr 27, 2018 Posts: 206 Location: USA
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Posted: Thu Aug 22, 2019 8:05 am Post subject:
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ixtern wrote: | A curiosity. Seems that MPY100 may be replacement for 4214. Picture below taken from 1984 Burr-Brown Product Data Book. |
For sure! The 4214 is around but can be a touch hard to find. So I'd liket to see about other possibilities.
IMO this single part BM sounds as good or better than the AD533, AD633, 3080 and 13700 BM's I've built. Definitely kicks butt on AD633 and OTA, but maybe my design was crappy?
The AD533 one came out about as well but integrating the 10 pin can in Eagle was tricky.
http://www.charlielamm.com/gear/balanced-modulator/forums.html#ad533
The AD633 doesn't sound as good--to much feedthrough, at least with this design.
http://www.charlielamm.com/gear/balanced-modulator/forums.html#ad633
If anyone ever checks out a 4214 replacement and it works as well/with as little DIY effort, I'd be interested to know about it. Thanks! _________________ Visit my AUDIODIWHY blog and website |
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gabbagabi
Joined: Nov 29, 2008 Posts: 651 Location: Berlin by n8
Audio files: 23
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Posted: Fri Aug 23, 2019 2:19 am Post subject:
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nice!
and low part count as promised
i have some dificultys to fnd that thing on xbay, any help?
cheers, cu soon mate |
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cslammy
Joined: Apr 27, 2018 Posts: 206 Location: USA
Audio files: 1
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Posted: Fri Aug 23, 2019 7:50 am Post subject:
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gabbigabba!!!
I see at least four of them for sale in China over Ebay--not the exact same chip I used but it looks to be the same BB4214 w a different designation.
Does this link work for you? 8-23-19 8AM US PT.....works for me.
https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=BB4214&_sacat=0
Can't vouch for how well they will work--I am always a bit hesitent to buy chips out of China, but for older ones sometimes you have no choice.
trying to buy more myself....I will keep you posted and if I can get some good ones I'll let you know. _________________ Visit my AUDIODIWHY blog and website |
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Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
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Posted: Fri Aug 23, 2019 7:57 pm Post subject:
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Looking at that design I noticed that the inputs of the 072 is just a capacitor which will give an offset caused by the offset input current (typ. 65 pA) in combination with the (especialy with good capacitors) impedance of the capacitors C1 and C4.
This input offset current is temp. dependent to make things worse. _________________ my synth |
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gabbagabi
Joined: Nov 29, 2008 Posts: 651 Location: Berlin by n8
Audio files: 23
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Posted: Sat Aug 24, 2019 2:02 am Post subject:
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20Döllars?
Thats around 18 Coins over my WTPFAC-Limit (willingness-to-pay-for-a-chip)
But if it gives you back your beloved LazerGun - it can worth it!
i dont know about internal caps and temperature, but as far as i know the positive input of an opamp should be connectet (thru a resistor) to a potential, otherwise the input tends to drift around.
May you could move the caps just before the pots. with 100k and 1µ you would get fc = 1.591Hz, and the input would have automaticly a connection to a potential. |
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L´Andratté
Joined: Sep 23, 2012 Posts: 150 Location: Hamburg, Germany
Audio files: 5
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Posted: Mon Aug 26, 2019 1:25 am Post subject:
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Hey Cslammy!
Link is 404 for me?
This one is a nice Ad633 design by Roman Sowa that let´s trim cancellation and offsets...http://www.sowa.synth.net/modular/m_rm.gif |
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ixtern
Joined: Jun 25, 2018 Posts: 145 Location: Poland
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L´Andratté
Joined: Sep 23, 2012 Posts: 150 Location: Hamburg, Germany
Audio files: 5
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Posted: Mon Aug 26, 2019 12:45 pm Post subject:
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Thanks that works...
Look at the schem I linked to- the only difference to your schem is
there´s a trimmer at the output I think it cancels out modulator feedthrough---
(I don´t know the proper english terminology?)
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