12vdc in heaters

[johnheath]

I am sorry if this has been discussed before but I cannot find proper info on this... and I mean just a graphic decription.

I have made a fifthteen or so guitar tube amps and never used dc in the heaters, but now, planning to build a mic pre with 12vdc in the tube heaters, I cannot seem to find a proper explanation on how to do this.

Please... can anybody in a simple way explain how to wire the heaters for 12vdc...not how to get the 12 vdc but rather just how to wire the tubes. It is two ECC82 or 12AU7.

I am also thinking about fixing that in my la2a clone and need explanation on how to wire the 6AQ5A in series with those 12AX7's and the 12BH7.

Let me just say that I have an idea on how to do it but of course I need confirmaton or just be enlighted.  :-\ 

Thanks

/John

 

[analogguru]

Here you go:

http://www.drtube.com/schematics/marshall/4001m86.gif

 

[johnheath]

Analoggurau: Thanks... it seems to me that I should connect 0v to either the 4th or the 5th pin and the 12 vdc to the other. Question is... do I ground the 0v at v1?

 

[buildafriend]

does this help?

There is some DC heater info in here.
http://www.valvewizard.co.uk/heater.html

 

[johnheath]

Yes, I found that website before and frankly the only major issue I have with all this is to... where to ground the series coupling... that is not mentioned in the article.

/John

 

[buildafriend]

It seems like one side go's to ground ( 0v ) and the other takes the +12v DC lead. so look at the datasheet for your tube, and see what pins are the heater pins. I don't think it matters which side gets ground or 12vDC. That would be my guess, but im not the most experienced member here. 

Look at this:

http://www.gyraf.dk/gy_pd/g9/g9_sch.gif

this project also includes DC and AC heater options. maybe you can pull info from this:
https://www.dropbox.com/sh/g6n57y9ju6hwknz/AACtNb49WJryoEAlNp1Zw0QKa/Directions.pdf

 

[johnheath]

Buildafriend... thank you. Yes like you said one to 12vdc and the other to 0v. Well as you know I am not the most experienced member either =)

 

[Gus]

DC heater supplies need to be designed.
A simple AC heating circuit can sound better than a not well designed DC heater power supply.  Things like ticks in the background when the diodes start to conduct