LM3875 socket

[Jsixis]

Nice test box

[jackinnj]

Originally Posted by WSJ

I found a LME49830 demo board parts list, but no socket was listed.
Do you have a link for the socket?

Thanks

The LM4702 will work in a ZIF socket, the pins of the LM3875 are staggered differently. Sorry

You could check the 3M site, or Textools. Alternately there are Mill-Max pins which could be purposed for this.

[WSJ]

Originally Posted by Jsixis

Nice test box

Here is a link to my op amp test fixture.
Discrete Opamp test circuits

[Jsixis]

thanks!!

[CanAm Man]

WSJ..... I noticed the device under test in your post #23, marked Nexus.

Just went thru my old parts bin, and found four Philbrick/Nexis PP45U modules. They each have seven leads (+In, -In, +15v, -15v, common, output, and trim) They also have gummed labels on the side indicating Offset trim [16k], +I trim [331M] and -Trim [329M]. (The values in brackets [] vary significantly from one module to the next; these values have been handwritten on the with gummed label.)

All four appear to be unused.

Can you advise what these are (I'm assuming early Op Amps). Are they worth anything today? I'm old--please tell me they are priceless, so I can retire in style....

Thanks.... Just curious......... Didn't mean to hijack the thread....(!)

[WSJ]

Originally Posted by CanAm Man

WSJ..... I noticed the device under test in your post #23, marked Nexus.

Just went thru my old parts bin, and found four Philbrick/Nexis PP45U modules. They each have seven leads (+In, -In, +15v, -15v, common, output, and trim) They also have gummed labels on the side indicating Offset trim [16k], +I trim [331M] and -Trim [329M]. (The values in brackets [] vary significantly from one module to the next; these values have been handwritten on the with gummed label.)

All four appear to be unused.

Can you advise what these are (I'm assuming early Op Amps). Are they worth anything today? I'm old--please tell me they are priceless, so I can retire in style....

Thanks.... Just curious......... Didn't mean to hijack the thread....(!)

Hi Jack.....No problem….
I worked at Intech in the 70’s, only 43 years ago. We made great discrete op amps, they sold for $150 - $450, at the time gas was 24 cents. Philbrick/Nexis sold similar op amps, so we evaluated the completion, most of ours were better.

Your amps may be worth putting on ebay. Do a search for discrete Op Amps and you will find some very good audio Op Amps.

The 990 Discrete Op Amp is almost exactly the same circuit as the A148 Intech, my personal favorite.
http://www.johnhardyco.com/pdf/990.pdf

The balance resistor is a selected single fixed resistor to balance the offset. The amp was made unbalanced to avoid using a pot to balance the amp, in order to keep the cost down.

Here are some Intech 10 MHz bandwidth op amps.