A good digitally controlled resistor pot

[lineup]

Re: Jfet

Trusting an op amp model for distortion measurements is self delusion of the highest order.

Op amp models are usually macromodels and do not even use the models for actual transistors in the device. Also Spice circuits using identical models for the transistors in a differential pair will give much better results than in real life, due to differences parameters in the two actual devices. Spice is just not a good indicator of distortion as Mr. Pass has indicated elsewhere.

* AD797B SPICE Macro-model 10/92, Rev. A
* AAG / PMI
*
* This version of the AD797 op amp model simulates the worst case
* parameters of the 'B' grade. The worst case parameters used
* correspond to those in the data sheet.
*

I see there are 'worst case' GRADES
Grades can be: A, B, S
Those are the different models I got when download MutliSim Spice models
from Analog Devices
for thier 'Audio OP-Amps' today.


I have tried to find out what these 'grades' means. But did not find much info on web

- 1. Can anyone explain, further?

- 2. What worst case grade you recommend, to arrive closer to reality?

- 3. What worst case grades, does PMA use?
He is the leader in this field (spice sims) here in www.diyaudio.com
He is the one posting most many Sims and also Very interesting ones. Thank you!

 

[lineup]

Re: Re: Jfet

I have tried to find out what these 'grades' means. But did not find much info on web
- 1. Can anyone explain, further?

 

[Nordic]

Hi Hugh, I just spend the morning at a TI hands on workshop with the eZ430 development tool.... basicaly a usb stick with a detachable microprocessor that you can program.... we did some interesting things like useing it as a temperature sensor....., useing the onboard LED as a switch/sensor etc...
Relatively easy, much nicer than working with PICs, and can send itself into a sleep mode while still waiting for an interupt to start processing again...so you don't have to bother decoupling it with relays etc from your audio stuff...

Their processors have some realy neat features, and are not shy of built in periferal devices like opamps etc.. leading to minimal external parts, in fact we needed none for the projects we did...
They have free software ( with memory limitation) and a killer good price on the full version.... about $250

I have two of these sticks with f2013 processors (I was at the 430-day earlier in the year), if you look through the online materials and it looks useable, give me a shout and I'll send you one.

You have to love TI, we were only 3 guys and the trainer and all for free including lunch.!!!!!!! Thanks TI, I think I love you now.
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