Building a Model-T -- Need Iron!

[kleptocracy]

Hello everyone!  I'm new to the site.  I joined because I've picked up a bit of a crazy project: A Sunn Model-T.

Ok, so it's not exactly a Model-T, because I just redesigned a pre-amp a little bit.  But from a power and voltage and current draw perspective, it's the same.

So, by my math what I'm looking at is a PT with a secondary in the 400-0-400 range, to get a rock solid 505V on the plates of the 6550's, which are biased to -55V.  At max output I'm looking at drawing around 600mA through the PT and Choke(s).  I don't know what the ratings on the two chokes are in the schematic, but I'm guessing 5H@300mA each (wired in parallel).  We're also totaling 7.3A on the 6.3V heaters.  And don't forget the bias tap aimed at -55VDC.  (If you hadn't noticed, since these are all guesses, some specs from a real Model-T would be super useful and I would be very appreciative!)

Anybody know where I can find such a PT without breaking the bank?  I think I'm going to use two Hammond 193L (5H, 300mA) chokes, which I can get on Digikey for a seemingly reasonable $44 apiece. 

As for the OT, I know the Hammond 1650T claims it's a little underpowered for the 150W output of the Model-T, but I noticed those ratings are for a hi-fi amp at 1%THD.  Even Dan Torres claims they can handle up to 180W (http://www.torresengineering.com/ham120180wat.html).  Anyone have any thoughts on this OT for this application?  I'm definitely not really a hi-fi kind of a guitarist but I do appreciate solid LOW END. 

FYI - I'm currently playing a drop-tuned '79 Peavey T-60 strung with flat-wound .013's thru a Russian Big Muff and a vintage '70s Acoustic 140 solid state bass head into a 4x12 bass cab.  The T will just replace the 140, so I can get the grinding lows but still manage some sharp clean highs.

Thanks for all your help in advance!

Matt

[kleptocracy]

Hi, I just found this sucker: http://www.antekinc.com/AN-4T400.pdf

I've never used a Toroidal PT before.  Any pitfalls I should be aware of?  I'll probably hook it up center tapped.  I also need to figure out what to do for the -55V bias supply.

[soberskipper]

Did you use those 5H/300ma chokes?

Did you end up getting a PT with 8A heaters and an OT with ultra linear taps for the screen grids or figure out how to work around these issues? Curious...

I am about to start a build and was going to get the Mercury set but would like to save some $$ if possible.

[stanner]

is this what yer building?
https://taweber.powweb.com/store/6s100_ad.htm

[soberskipper]

is this what yer building?
https://taweber.powweb.com/store/6s100_ad.htm

No, I was just gonna do a 70's red knob 5 input type deal. 4x6550 with taps on the screen grids and tonestack after V2. I dont even think that Weber build is based off of a real Model T. I mean EF86 and a 12AU7??? c'mon man. I LOVE playing my amps on 10 but you might have to turn that one up to 100 to get nasty od.

Might try to install a master volume bypass switch so that I can just play the amp normal loud.

any suggestions?

[stanner]

i just threw that example out there. nothing like a T...i have three of the red knobs...they kill

[soberskipper]

Yes, they are amazing!

I'm assuming that the chokes are under the hood. Can you post a gutshot? Any porn will be totally appreciated!

[mike_sims]

hows the build coming?