Help with transformer IDentification

[1blueheron]

I have a monster set of transformers out of a Baldwin Orgasonic 51P.

Have come up empty on finding a proper schematic.

Number stamped on the top of the PT is as follows: F-C512-023757C


It has a 4U5 Rectifier, 2 6L6 for output, 2 12AX7 and 2 12AU7 in the amp chassis but it also ran about 50 other 12XX7 tubes.

What I believe to be the output transformer is stamped C512-17584C

Ohmed OT out and came up with the following:

Brown/Blue= 248
Brown/Red=133.7
Blue/Red= 115.5
Yellow/Black= 1.3

Considering using to build a Fender Bassman 50.

Google turns up that the PT was reportedly 315-0-315?  Cannot verify.  No manufacturer info or specs.

[jjasilli]

The monster size 9f the PT is probably to supply lots of fitment current.  To me this cries out for a studio rig powering every cool preamp you can think of.

[1blueheron]

The monster size 9f the PT is probably to supply lots of fitment current.  To me this cries out for a studio rig powering every cool preamp you can think of.

What is a "studio rig"?  Can you elaborate?

Here is the glassware it supported, plus another 4 or 5 tubes in a different section not listed on this chart.  I'm counting almost 60-12XX7 tubes besides the 4 in the amp chassis section.

And a couple pictures of the PT and OT.  have some chokes as well.

[1blueheron]

more

[shooter]

What is a "studio rig"? 

a great sounding amp that weighs more than the car you have 
take it in the studio, leave it

[1blueheron]

But then I would have to build a studio first to put it in!

My church needs a bass amp right now so that is my motivation in building the Bassman clone.

I like your idea though.  The next organ I pick up that will be a strong consideration.   The Baldwin and Conn organs both have "modular" units within a common chassis.  Each of these modules plug in.  Got me thinking, what would it be like to build an amp with a power supply and output power and then have easily swapped preamp modules.  Similar to plugging breakers into a panelboard.  Has any manufacturer ever experimented with modular amps?  I know some of the studio console makers have done modular consoles.  I have seen some old broadcast gear that used modular boards.

[shooter]

here's a good start on "modular" concept;

http://sluckeyamps.com/vox/vox.htm

[davidwpack]

Randall MTS series had modular preamps that plugged into the amp. I don't think they're in production anymore.

[Ed_Chambley]

Just a guess, but I believe that Output Trans will probably have a higher reflected impedance than 4K, which is generally what is used in a Bassman.  Doesn't mean it will not sound good and may be preferred.


I love Baldwin Iron simply because it seems they used overbuilt components just like Hammond, maybe even more overbuilt.


You could simply build an amp that uses LTPI and 2 6L6 or El34 according to how you setup the OT then have a Fender Pre, a Marshall, A Soldano, An Ampeg (I like the B12 and B15)  I know they are bass, but really sound good with guitar too.  A much more less expensive way to get a variety of tones and I believe your Power Trans will do probably 10 different ones.

[1blueheron]

Just a guess, but I believe that Output Trans will probably have a higher reflected impedance than 4K, which is generally what is used in a Bassman.  Doesn't mean it will not sound good and may be preferred.


I love Baldwin Iron simply because it seems they used overbuilt components just like Hammond, maybe even more overbuilt.


You could simply build an amp that uses LTPI and 2 6L6 or El34 according to how you setup the OT then have a Fender Pre, a Marshall, A Soldano, An Ampeg (I like the B12 and B15)  I know they are bass, but really sound good with guitar too.  A much more less expensive way to get a variety of tones and I believe your Power Trans will do probably 10 different ones.

I like that idea, not sure how ready I am for the complexity. 

I'm picturing a lot of different tube sets, a lot of different voltage requirements and a bevy of knobs.  Could it be done with a common set of knobs and a common input with just a selector switch?

[PRR]

Is this the same lump you had last November?

Wudda been nice to measure voltages before you broke it up.

Yes, it was, and could be, a 35W audio power amp. However you have no use for *sixty+* little tubes. So you will be carrying-around about 130 Watts of idle heater windings/core. The "liberated" B+ from all the little tubes is not really enough to power two more 6L6; also your OT is scaled for just two.

[1blueheron]

Is this the same lump you had last November?

Wudda been nice to measure voltages before you broke it up.

Yes, it was, and could be, a 35W audio power amp. However you have no use for *sixty+* little tubes. So you will be carrying-around about 130 Watts of idle heater windings/core. The "liberated" B+ from all the little tubes is not really enough to power two more 6L6; also your OT is scaled for just two.

I've got two "lumps".  One from a Conn and one from a Baldwin.  The Conn amp is intact and I can power it up.  Voltages and schematic are known.  It is slated to become Reverberocket R212R.  Working on layout and schematic.

The Baldwin I just broke up this week.  You are correct it would have been good to measure voltages but when I pulled the amp plate from the chassis, all the insulation on the power cord and remote turn on cord just disintegrated leaving exposed wires.  I wasn't feeling real daring to be poking around in it with those bare wires, so I just removed it.  Plan to get some measurements today. 

It really doesn't matter to me if it weighs a lot.  It will pretty much just sit on stage at the church full time.  It's not a big auditorium so a single pair of 6L6 tubes should be plenty of power.
I had planned to use some of the 12AX7 tubes as substitute for the 7025 in the Bassman 50 schematic and pretty much replicate the circuits shown there.

[PRR]

Sounds like a plan.

When wired, check the VAC on the "6V" lines. Without all those tone generator bottles it may be over 6.5VAC. Figure the over-voltage and the nominal current, figure a pair of dropping resistors to get near 6.3VAC.

[1blueheron]

Had a chance to check the PT voltages this AM

Here's what the meter had to say about it.

HT/Red>>Red=737VAC
Red>>CT(yellow red striped)=372VAC
Brn>>Brn = 6.6VAC
Grn>>Grn = 13.6 VAC

No Center tap for low voltage.

Fine for the Bassman project?