there's is also a Pspice model, that can be used in LT-spice, but as a sub-circuit, It's beyond my skills to build a working model from that. LTspice has a lot of op-amps built in also differential ones and sub-circuit ones, but finding the right "similar" one can be a hassle.
Juma, the guy who created this opamp also suggested the meed for a buffer
That opamp can push more then 100mA so why the need of a buffer ?
Can you show me the creators response ?
Juma did that opamp ? Unlikely.
This is new to me.
I have under certain circumstances experienced that this chip can get quite hot, that can be solved with a copper trace in the MOPS version and with a cooling profile in the regualr SMD version.
Can you show me the creators response ?
Juma did that opamp ? Unlikely.
This is new to me.
I have under certain circumstances experienced that this chip can get quite hot, that can be solved with a copper trace in the MOPS version and with a cooling profile in the regualr SMD version.
I probably misread or misunderstood. Wouldnt be the first time.
http://www.diyaudio.com/forums/pass...clotron-jfet-input-buffer-opa1632-2sk135.html
http://www.diyaudio.com/forums/pass...clotron-jfet-input-buffer-opa1632-2sk135.html
Yeah kind of arc to convert from PSpice to LTSpice.
I will have to find a suitable part to create a model for the circuit.
FYI: Joachim sorry I have to catch back tomorrow morning with your posts as I was busy until now trying to prototype the older differential input stage as I was curious to see how it performs.
Good that you try the differential input. That can be for the benefit of the Paradise community.
Concerning the Masterpiece from my side there is no rush.
Concerning the Masterpiece from my side there is no rush.
Ricarditto,
easier to find if you google punch Philips 60pF.
e.g. : Teflon trimmer 60PF van Philps -hf-electronics
or 2222-809 (-05xxx to -09xxx ,are the ptfe series of Philips/BC components)
e.g. : https://www.elfa.se/elfa3~tr_en/elfa/init.do?item=68-798-03
Or http://www.newark.com/vishay-bc-components/bfc280908002/capacitor-trimmer-4pf-38pf-300v/dp/98K7134
Same routine at ebay.
Or be a teflon cheapo : adjust a polyester trimmer cap to value, then exchange for http://www.diyaudio.com/forums/pass-labs/156397-pearl-two-8.html#post2251685
(as a part fetishist, my religious beliefs forbid such activities)
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There are some really cheep NOS air trimmers that do the job as well.
Air is even better then teflon but i refuse to use NOS parts in my professional products.
Air is even better then teflon but i refuse to use NOS parts in my professional products.
Oink to you (phonebooks find it hard to remain sane)
The ptfe trimmer caps are no longer manufactured, so whether it's Vishay BFC, BC components or '80s Philips 2222-809, it's all NOS to me.
Joachin,
I have creted a schematic with the differential input stage you had proposed on Paradise thread and used folded cascode to have a fully DC coupled differential in/out.
I thought this would have been worth posting it here on the Masterpiece.
It simulates great and everything.
The only problem I was unable to solve so far is the servo for differential.
I have been thinking and playing around but I cannot come out with something that works symmetrically.
I hope someone here will have some idea.
I have creted a schematic with the differential input stage you had proposed on Paradise thread and used folded cascode to have a fully DC coupled differential in/out.
I thought this would have been worth posting it here on the Masterpiece.
It simulates great and everything.
The only problem I was unable to solve so far is the servo for differential.
I have been thinking and playing around but I cannot come out with something that works symmetrically.
I hope someone here will have some idea.
Attachments
OK, so this is more or less a Paradise with the new input stage.
Yes, i know. making a servo for this is a major challenge.
I did not find the time to look deeper into it.
Yes, i know. making a servo for this is a major challenge.
I did not find the time to look deeper into it.
You can not make a single servo for a balanced circuit, you need to use 2 servos. R12 must be split for this.
it is more less a differential input with mirrrors 😉 anyway....yes servo there is a challenge.
Don't you however think that this could reserve some good surprise over the OPA's approach or you still think the other way will yeald to a better result?
If we could design a servo here I could try it and see how it sounds and then report!
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