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Welcome to the Test, Measurement and Repair Forum

Posted: Tue Oct 23, 2018 11:33 am
by mediatechnology
I decided to create a new sub-forum where we can post about test, measurement and repair topics.

Re: Welcome to the Test, Measurement and Repair Forum

Posted: Thu Nov 15, 2018 8:59 am
by emrr
Good idea!

Re: Welcome to the Test, Measurement and Repair Forum

Posted: Thu Nov 15, 2018 9:03 am
by mediatechnology
Thanks Doug!
I'm moving some topics posted in other threads that may be more relevant and visible here.
In many cases I'm leaving shadow topics in the old sub-forums to prevent broken links.

Slowly I'm converting the entire site to https for embedded image links which is causing me to revisit each and every thread.
Though I could have written a script for that, by doing it manually I rediscover some old friends and broken links.

Re: Welcome to the Test, Measurement and Repair Forum

Posted: Tue Feb 05, 2019 7:16 pm
by Audio1Man
Hi All
I worked for Audio Precision for many years as and Analog Engineer, now semi-retired. I service /older AP’s and have been to answer some questions. I have a web “sound-logic-la.com”.
Duke

Re: Welcome to the Test, Measurement and Repair Forum

Posted: Tue Feb 05, 2019 7:30 pm
by mediatechnology
Duke - Thank you for joining us here! I'm aware of your work. Wished I still had my old System One.

I recently downloaded the System One manual and have enjoyed going over the front-end schematics in particular.

Real links here are fine: http://sound-logic-la.com/

Re: Welcome to the Test, Measurement and Repair Forum

Posted: Wed Feb 06, 2019 1:18 am
by JR.
Hi there and welcome... I've seen you around the WWW...

JR

Re: Welcome to the Test, Measurement and Repair Forum

Posted: Mon Apr 01, 2019 12:28 pm
by Audio1Man
I was listing to my music system this mourning and it failed. My system consist of Electro-Voice SP13.5RBXWK Rearaxial Softspeaker driven by a Crown Belchfire BF6000SUX with the Rane P1 14 Pseudoacoustic Infector preamp with the Jensen's JE-EP-ERs Multi-denomial Transpedance Informer input stage (I got it as the last of the Zeta metal stock was depleted). The system spit out smoke and them no sound. After looking into fixing the problem, I found that the National LM0901A1411090451C Polish Opamp had failed and I need a replacement or data sheet to make a substitute. Thank god the Signetics 25120 Write-Only-Memory (WOM) is still working.
Duke

Re: Welcome to the Test, Measurement and Repair Forum

Posted: Mon Apr 01, 2019 12:51 pm
by JR.
You should consider replacing the whole rig with a TL431, I hear they sound magical. :lol:

JR

PS; Happy april phools

Re: Welcome to the Test, Measurement and Repair Forum

Posted: Mon Apr 01, 2019 1:09 pm
by mediatechnology
I have the 25120 datasheet.
It was a great part but not widely used.
It had a long write time requirement but there were work-arounds not widely known.

Re: Welcome to the Test, Measurement and Repair Forum

Posted: Mon Apr 01, 2019 1:40 pm
by Gold
It is very picky about power. Since you are in CA it should be no problem to drop a electrode in around San Pedro and another one in around Malibu and get some power out of the salt water.