Comments on: Building an (almost) RCA OP6 Mic Preamp https://www.preservationsound.com/building-an-almost-rca-op6-mic-preamp/ information and ideas about audio history Mon, 07 Feb 2022 19:44:51 +0000 hourly 1 https://wordpress.org/?v=6.9.4 By: LEONARDO ARAUJO FERRAZ https://www.preservationsound.com/building-an-almost-rca-op6-mic-preamp/#comment-618292 Mon, 07 Feb 2022 19:44:51 +0000 http://www.preservationsound.com/?p=2576#comment-618292 Hi ! I have a remote mic preamp manufactured by RCA, the model is MI12242. And I need the electrical schematic to restore it.

]]> By: Scott Wolfe https://www.preservationsound.com/building-an-almost-rca-op6-mic-preamp/#comment-599239 Thu, 27 Feb 2020 13:26:44 +0000 http://www.preservationsound.com/?p=2576#comment-599239 This is a nice write up. How do I find the values for all the caps and resistors. There is no voltage or polarity for the caps needed, and no wattage ratings for the resistors. Also there are a few resistor ratings missing. How do I find this info? Is there a better schematic our there that will help?
Thank you
Scott

]]> By: Maynard https://www.preservationsound.com/building-an-almost-rca-op6-mic-preamp/#comment-460319 Sun, 01 Apr 2018 07:21:11 +0000 http://www.preservationsound.com/?p=2576#comment-460319 Chris,

Has any one figured out that resistor network? I d love to build an OP6 clone.

]]> By: chris https://www.preservationsound.com/building-an-almost-rca-op6-mic-preamp/#comment-429107 Wed, 06 Sep 2017 01:48:12 +0000 http://www.preservationsound.com/?p=2576#comment-429107 In reply to Andres.

looks great Andres

]]> By: Andres https://www.preservationsound.com/building-an-almost-rca-op6-mic-preamp/#comment-429053 Tue, 05 Sep 2017 17:44:25 +0000 http://www.preservationsound.com/?p=2576#comment-429053 Hi chris !!! here my build .

https://scontent-sea1-1.cdninstagram.com/t51.2885-15/s750x750/sh0.08/e35/21372258_1054375894665648_5085563916407275520_n.jpg?ig_cache_key=MTU5NjU0MTMzNDI2NTM3Nzc1MA%3D%3D.2

Greetings!!! OP6 RULES !!!

]]> By: Robert Wainscott https://www.preservationsound.com/building-an-almost-rca-op6-mic-preamp/#comment-373618 Sun, 09 Oct 2016 20:39:20 +0000 http://www.preservationsound.com/?p=2576#comment-373618 Greetings,

Quick question for you regarding the 1meg grid resistor and 1k grid stopper. If I am to understand your design correctly, you are using a 1k grid stop resistor right out of the wiper to the 1meg grid resistor?

This is, I understand, necessary to isolate the grid resistor from the 100k pot. So, if I wished, I could use a 100k pot but set the operating parameters of the next tube using the 1meg and hide it all with a 1k resistor? Sounds good to me. Would that work with other values like, say, a 5k grid stop into a 1meg? Are there any drawbacks?

Finally, with triodes, that 100k pot would be seen in parallel with whatever load I had on the plate. Is that true with these pentodes you are working with?

Thanks for entertaining a newbie.

]]> By: Victor https://www.preservationsound.com/building-an-almost-rca-op6-mic-preamp/#comment-372920 Fri, 30 Sep 2016 22:21:28 +0000 http://www.preservationsound.com/?p=2576#comment-372920 Many thanks!

]]> By: Victor https://www.preservationsound.com/building-an-almost-rca-op6-mic-preamp/#comment-372919 Fri, 30 Sep 2016 22:21:01 +0000 http://www.preservationsound.com/?p=2576#comment-372919 In reply to chris.

Many thanks!!

]]> By: Andres Luraschi https://www.preservationsound.com/building-an-almost-rca-op6-mic-preamp/#comment-372668 Wed, 28 Sep 2016 14:49:24 +0000 http://www.preservationsound.com/?p=2576#comment-372668 Hi Chis … Excelent job , majestic site !!! all my admiration for having gathered all that information. and congratulations for builds .

I try to make 2x ba2/op6 .. have more pics? need to know choke placement .

Greetings for Argentina.

]]> By: chris https://www.preservationsound.com/building-an-almost-rca-op6-mic-preamp/#comment-371507 Mon, 19 Sep 2016 15:40:20 +0000 http://www.preservationsound.com/?p=2576#comment-371507 In reply to Victor Abascal.

Hi Victor. the “Box” is a combo of a Raxxess Flanged Aluminum 2sps panel and a hammond 17x4x3 alum box+cover plate. Google ‘grid stopper resistor.” it s a basic concept. 1k (usually) 1/4 or 1/2w res b/w the grid ground-ref resistor and the grid socket. Body of the 1k res should be as close to the socket terminal as possible. Look at Marshall Gtr Amp schems, they often use this concept. good luck.

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