Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Mors08 on March 15, 2012, 11:37:47 am

Title: AC30 meets Tweed Deluxe?
Post by: Mors08 on March 15, 2012, 11:37:47 am

I have the chassis to an old magnavox tube radio which included a good sized PT and OT that ran a quad of 6V6's
I'd like to build something like the Hoffman AC30 w/o the rev or trem but with 6V6's.
Would this work to sandwich the AC30 pre to basically a Deluxe x 2 back end?
As I understand that biasing of the output would be different than EL84's - I saw a 10 watt 150 ohm cathode resistor to cover all 4 6V6's?
I was also told there needed to be one change in the PI as to how much gain 6V6's need vs standard EL84's?

I found an old thread here that included several .sch layout files - ( http://www.el34world.com/Forum/index.php?topic=575.0 (http://www.el34world.com/Forum/index.php?topic=575.0) ) one made by a "Bruno" for 6V6's but I cannot get eagle to open the file no matter what I do.
Does anyone have a layout for a 6V6 AC30 like this or have this layout in a gif or jpg?

Thanks

Title: Re: AC30 meets Tweed Deluxe?
Post by: Willabe on March 15, 2012, 11:44:59 am

Here, you need to down load this program to open an sch file.

http://www.el34world.com/Forum/index.php?topic=11457.msg105965#msg105965 (http://www.el34world.com/Forum/index.php?topic=11457.msg105965#msg105965)


                           
                             Brad     :icon_biggrin:

Title: Re: AC30 meets Tweed Deluxe?
Post by: tubenit on March 15, 2012, 11:45:21 am

The files at that link opened right up for me.  You will need ExpressSCH to open that program or Jschem if you use a MAC.

You can also contact Bruno by PM . He is a good guy and I think he'd share info with you.

With respect,  Tubenit

Title: Re: AC30 meets Tweed Deluxe?
Post by: Mors08 on March 15, 2012, 12:33:53 pm

Aha! Foolish me - many thanks.
All web resources I found for opening .sch files pointed to Eagle first.
Think I got this loading now.

A layout like this is exactly what I need as my chassis is not as big as standard and I will need to do a bit of PTP work.
This helps tremendously just to trace things out and check off as I go.
Peace!

Title: Re: AC30 meets Tweed Deluxe?
Post by: bruno on March 15, 2012, 05:42:28 pm

Wow, I don't remember that one! But I did get to build something similar using vibrolux iron sometime ago.

Hey tubenit, I'm going to have a go at the hoso56 using the cascode circuit instead of a pentode, I'll be trying it this weekeng.

I'll be following your version with reverb, that should be a great amp.