Power Transformer Search

[Ed_Chambley]

Hi, I am trying to find a stock transformer without being something like Mercury Marshall Major replacement.  I guess I can order one fro Edcor, but let me state what I want to.


I am working up a HiFi amp to run push pull stereo, 2 KT88 pre side.  I have the OT's I need, but I cannot seem to find a Power Transformer with all is needed in the same housing.  I will be using a Rectifier tube, GZ34.  Output Transformers have UL taps at 40%.


I would like to find about 120V primary, Secondaries 380-0-70-380, 320ma or more, 6.3 8A, 5v 3A.  Looking to hit around 485 Plate Voltes, but can go higher if necessary.  Also, bias tap is not necessary, but nice.


Of course, more current handling is fine, but this is about minimum.


I plan to run fixed bias, Tetrode and Triode configurations.  Preference is standup, but I can use a lay down.   Either is fine.


Anyone seen a stocking PT.  The only one I can locate that I know will work is the Hammond 379wx, but is overkill.

[sluckey]

Take a look at the 373HX. You're gonna need two GZ34s.

I'd like to nudge you toward two PTs rather than one. Maybe even consider two Dynaco Mark IIIs.

[Ed_Chambley]

Steve,
I understand what you are getting at.  It would make things easier.


Take a look at this link as this kits get really good reviews.  http://www.tubes4hifi.com/bob.htm#ST120


Only one Rectifier Tube, but only getting 120 watts which is fine.  I would just order the kit, but that is why I got rid of my Dynaco amps anyway.  I just not a fan of the old plugs on the front and I would prefer to a better looking Chassis.  Also, I prefer the board to not be visible, but only tubes showing above the chassis.  Also, with his kits you do not get any savings if you order no chassis.  I have a stash of GEC KT88 and prefer the flexibility of some other board designs.


I have a really nice pair of James Output Transformers.  If it makes more sense, I may simply build dual monoblocks.  I do like the idea of a single unit and I prefer to not have connections on the front.

[sluckey]

You do realize that those speakers you have only need about 10 watts to blow the putty out of your windows?

[SILVERGUN]

This immediately came to mind...it is, unfortunately missing the rectifier tap
http://www.classictone.net/40-18069.pdf
 
 

[John]

I'm curious, why do you prefer a rect. tube instead of silicon for this amp?

[SILVERGUN]

I'm curious, why do you prefer a rect. tube instead of silicon for this amp?

It's going to double as a space heater.
He could maximize that effect by knocking down those 2 - 15V windings I threw at him to 5V with a couple 5ohm 25watt resistors.

[Ed_Chambley]

You do realize that those speakers you have only need about 10 watts to blow the putty out of your windows?

Sure, but you do not know what I am planning.


Those speakers are 50 watt maximum supposedly, but after getting them used to playing again I connected them to a very nice SS unit, 110 WPC RMS.  They are sounding very killer.  I could hear a little horn ring, so I have gotten rid of the ringing.  My windows have no putty, so I am safe there and it you say it is too loud, you are too damn old.


You gotta know I prefer listening in triode mode, but that is not all I am doing.  I actually have 2, tube EQ's with vocal microphones.  Very vintage.  I use for old-timers to play bluegrass, which includes me at times.  See, the VOT speakers are really nice for live performance too.  Remember me telling you I was taking the speakers to North Carolina.  Well, there I have a rehearsal room.


I will use a SS amp for the very lows, but I just prefer to have plenty of headroom cause as you know the first thing to go if distortion appears is are the horn drivers.  I really don't even want to ask Great Plains how much to repair.




Anyway, I gave it a light test this weekend and the sound is really good for miked up acoustics, but also really shines playing old rock-a-billy.  I guess you might say I am spoiled, but I really like to have a setup where others can stop by, plug in and play.


I guess what I am saying is I am wanting to drive more than the just the speakers.

[Ed_Chambley]

I'm curious, why do you prefer a rect. tube instead of silicon for this amp?

Prefer the glow, no other reason.

[Ed_Chambley]

This immediately came to mind...it is, unfortunately missing the rectifier tap
http://www.classictone.net/40-18069.pdf

I have not seen this.  It will work easily, I will just have to use 3, 5 volt rectifiers for the 15 volt taps.


It will not get any hotter than a Marshall Super Lead, but have you fun.

[Ed_Chambley]

This immediately came to mind...it is, unfortunately missing the rectifier tap
http://www.classictone.net/40-18069.pdf

Don't need a rectifier tap.


I built out a Macintosh Bias Balance circuit and it works really nice.  The bias tap will work well. Might be a winner.