Need a schematic for quad 6aq5 power section

[sean_thornton]

Well, my external hard drive is FUBAR, my wife dropped it down the stairs while moving the laptop. It contained ALL my schematics (plus a lot of other data). I know i had a schematic on it for a power amp using 4 - 6aq5's, I think it might even have been done by Geezer, and I was going to use it for ideas on my next build. I have a bunch of NOS 6aq5's and even more NOS 12aq5's and i was going to use them with the mini-mesa preamp i have been trying to design. Anybody remember seeing a schematic like I mentioned? Any help is appreciated.

[tubenit]

Look at the Gibson 17RVT Scout for ideas.   NOTE voltages and component values around the 6AQ5.

http://el34world.com/charts/Schematics/files/gibson/Gibson_ga17rvt.pdf

I quickly drew this up for you based on an old schematic of an amp I built that was push/pull 6AQ5's  (dual not quad)

You may need to VVR the amp to get the PA lower voltage while getting high enough preamp volts.

With respect, Tubenit

[kagliostro]

May be the schematic that you remember was the Double HoSo56 (quad of 16GK6) ?


http://el34world.com/Forum/index.php?topic=10933.msg100965#msg100965






K

[sean_thornton]

Oh man, thank you Tubenit, thats going to be a huge help, i appreciate it a great deal. I shouldn't need a VVR, with a bridge rectifier and the 220v 160ma PT my voltages should be pretty good. Using Duncan's PS Designer it looks like no problem. I tend to stick to SS rectification on my builds.
I am going to still keep looking for the other schematic too, if for no other reason than reference, I lost THOUSANDS of files and I am going to try my best to hunt them all down again. She didn't drop the HD on purpose and she feels really bad about it but she doesn't have a clue what to look for on the web so she can't really help. Never mind, love makes forgiveness easy, right?
Thanks again my friend, you're amazing.

[sean_thornton]

No, it was a quad 6aq5. I think it was one Geezer used, might even have been posted on TAG, but it was 6aq5's for sure.
Thanks for posting that one though, thats another good one, i appreciate your help Kagliostro.

[tubenit]

OK,  here is an idea for you.   Tweed BluezMeister with quad 6AQ5 and FX and VVR.  You'd have to experiment with the dropping resistors on the VVR B+ rail, but these would be a reasonable starting place.

Note the editable SCH version attached also.

With respect, Tubenit

[tubenit]

I shouldn't need a VVR, with a bridge rectifier and the 220v 160ma PT my voltages should be pretty good.

220v X 1.4 (solid state rectifier) =  308v. 

So that might work?   Watch the preamp voltages.  If using 12Ax7's ................. I'd want around 160v on the preamp tube plates.

With respect, Tubenit

[sean_thornton]

Tubenit, i might put the mini-mesa on the back burner, that TBM with quad 6aq5's is a hell of a nice idea. I am actually thinking of using 12aq5's in that one because i have a 220v PT with a 1.5A 12.6v tap and a 2A 6.3v tap. Also, the 12aq5 only draws half the heater current (225ma) of the 6aq5 (450ma). This would allow me to keep power section heaters separate from preamp heaters, i have found this helps to lessen "noise".
That schematic is a work of art, LOL, mine are much more primitive.

[tubenit]

Hey man, I think you should build whatever amp you want. Honestly!

I simply was drawing up a schematic to illustrate how one could approach it.  Truly did not have any agenda for you. The schematic was more for illustration purposes then anything else.  I posted the editable SCH along with the GIF so you could change it to whatever you wanted.  The ExpressSCH is a FREE download, BTW.

The mini-Mesa could be a cool idea if that is a sound/tone you really like.

With respect, Tubenit

[John]

Nothing to do with your amp, but you can probably get your data back. These guys are in Balmer. Good luck with everything!


http://www.diskdoctors.com/data-recovery-baltimore.asp

[sean_thornton]

no problem there Tubenit, I still have a lot of troubleshooting to do on the mini-mesa, lots of noise turning up in it when I run it through my SS power amp. I am going to just sit and think on that one, I am guessing more shielded wire in a few spots and somebody mentioned ferrite beads a while back so I may have to try that. I am taking a look at the TBM that you posted and I like the idea of it, especially as I also have a 25w Fender output tranny sitting here doing nothing.

John, thanks for that post, I will have to check them out, some of the data is really important.