Boutique blowing fuses

[Pryde]

Glad you figured it out, but bad news. Are there any numbers on the transformer or a company name perhaps? You might be able to source it from somewhere else at a lower cost if they aren't willing to help. I would definitely contact them first to see what they will do......BUT...... If they charge as much for their parts as they do their amps, I'd consider alternatives.

Not really marked from what I can see so looks like they will need to provide one, or at least specs.

[Enzo]

Specs/schmecs. It needs a 5v winding for the recto tube, it needs 6v for the heaters, which you can add up for a total. And enough high voltage for a 30 watt amp. We ought to be able to find a similar transformer in the world of Fender et al.

[Pryde]

Specs/schmecs. It needs a 5v winding for the recto tube, it needs 6v for the heaters, which you can add up for a total. And enough high voltage for a 30 watt amp. We ought to be able to find a similar transformer in the world of Fender et al.

I like the way you think sir.
What about the HV windings and bias supply lines? Anything that will feed KT66 ok. That red/white secondary wire comes to a 500m/a fuse that then terminates to a class A/AB switch. I assume that is the bias supply.

Will see what they do about it and go from there

[Enzo]

Frankly I doubt the amp is very complex, something along the lines of a Fender Deluxe, and when I am faced with such a thing, I get out a pen and pad and draw my own schematic from the circuit in front of me. It may differe in some details, but it is going to look a lot like a Fender. It may have a bias supply or may have a cathode bias output stage, but that is easy to see by looking. I don't know what the A/AB switch does exactly, but trace it out. I only see three red wires, and two of them go to the recto plates, so I tend to think the red/white would be the center tap, and the fuse is just the HV fuse. If it has a bias supply, there will be a rectifier and a cap with + end to ground. There may be a tap off the HV winding for it, but I do not see one in the photo.

[Leo_Gnardo]

I like the way you think sir.
What about the HV windings and bias supply lines? Anything that will feed KT66 ok. That red/white secondary wire comes to a 500m/a fuse that then terminates to a class A/AB switch. I assume that is the bias supply.

Will see what they do about it and go from there

They put a fuse in the center tap-to-ground apparently, that's not the bias supply.

KT66 filaments need 1.5 amps each. How many pre tubes? Add 0.3 amp for each 12AX7 or similar. Add 'em up to find what current rating you'll need in the replacement PT's filament winding if you have to go shopping for iron.

[J M Fahey]

Agree.

And 90% of booteek amps are expensive homemade clones of some old Fender or another.

A generic Bassman transformer should be an exact drop in replacement, just pick one with same physical dimensions so it fits in that chassis cutout.

FWIW the original Divided by 13 prototypes must have been built using over the counter aftermarket parts.

Speaking of the chassis, the first thing I noticed (even before the bending, go figure) , were the two puny electric soldering dots joining front panel to side wing.
Proper would be a continuous solder joint along the full edge.

Second was the bent chassis and third was the torn apart, almost pulled, 45 degree bent down puny sheet metal screw unsuccessfully trying to hold chassis wing to cabinet side (and miserably failing).
I suggest the owner drills side chassis and cabinet wood and adds 2 more side bolts and nuts, just like the visible top one.

But the Tolexing is very nice and that's what's visible, plus if somebody a little more adventurous opens the chassis , he'll feel a warm sensation in his heart when he sees tone filled cloth covered wiring inside, a certain proof of vintageness.

[52 Bill]

The bent chassis looks to me like the amp was dropped on its' back and the weight of the transformer pulled the chassis back away from the front panel and pulled out the side mount screw.

I suppose that it could have happened during shipping or it could have happened while being played quietly by the owner. It may also be the reason for the transformer failure.

[The Dude]

That's a good observation. In fact, it might not hurt to inspect the wires and makes sure none of them got mashed into the cutout, insulation cut, and are shorting to the chassis.

[mozwell]

Found this somewhere in my travels... i know its not the amp in question, as it uses 6V6, but there may be enough similarities to help in some way

I always have to ask the stupid question.... i assume you had this for a while & now it doesn't work, if its "new" to you, make sure the mains voltage on the amp matches your wall volts, (ie you have 230VAC wall volts & the amp is set for 115V, that would blow fuses for sure, even with the transformer on no load)

Does the fuse blow when the two green wires are disconnected from the amp. It looks like the green / yellow wire from the transformer is a center tap for the two green wires. A short from one of the green wires to chassis would cause your problem.

If the mains voltage is ok, and all secondaries are disconnected, & you still blow a fuse, your transformer is "toasted"

[J M Fahey]

That's a good observation. In fact, it might not hurt to inspect the wires and makes sure none of them got mashed into the cutout, insulation cut, and are shorting to the chassis.

That.
Visible wires see to come out all from the same inside-the-chassis side , so they shouldn't be "pinchable" between iron and chassis, but enamelled wire itself can.
You can see the thick filament winding enamelled wire protruding on the left, maybe some other wire (invisible in this picture) has been scratched and is shorting, enamel thickness is thin and steel chassis punching burrs are very sharp.
To boot this transformer did not use shrill cold sounding injected plastic bobbins but toneful warm copper-on-paper windings, so wire is not tightly held, at least not on bobbin ends.

Given that we have such an excellent sharp and well iluminated picture as a guide, I'd walk the extra mile (or 10) , fully pull the transformer, put it on a piece of wood, fan open wires so none touched another and connect its primary to mains, through a 60/100W limiting lamp.

To minimize messing with the amp, I wouldn't unsolder wires , just not to mess with the others staying behind, would simply clip them , even leaving a couple mm insulation attached as a reminder.

You'd need to pull the PT anyway, at least to take proper body measurements to get another drop-in one.
And we still have a small hope that you won't
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Rant starts: as seen in the other schematic (thanks Mozwell), this is just another example of booteek designs: cut and paste (with scissors and glue or with photoshop) bits and pieces of different classic schematics and voila !!!! a new "design" I can call my own.

Just couple a VOX preamp with a Blackface one, add a Marshall power amp (with righteous KTxx), say that those British tubes are more American sounding than 6L6 (no kidding, they state so in their main page) , build a Tweed cabinet but cover it in foam green Tolex (hey, that's a slick move ) , add a Celestion speaker (a Vintage 30 nonetheless, the most un-American sounding you can find) and .... hey!!!!! nobody should notice !!!!!!!


It reminds me when my kids were very young, not long ago, and Mc Donald's was their own version of Heaven.

Every other month they came out with a new toy set (be it Shrek/Pirates/Avengers/Minions/Batman/Toy Story/my little pony/whatever) and a new approppriately named sandwich, which of course was "different" .

How many combinations and permutations can you pull out of the same old 6 or 7 elements?
Meat cheese meat , meat meat cheese , add a single leaf of lettuce , add two , and so on, whatever you do you run out of mathematical possibilities after a couple years, yet they have been pulling the stunt for decades.

Same with (most) booteek amps.

If you are interested in keeping up with the boutique scene and don't want to browse 100 pages, you have all together under one roof:
The AMP SHOW and GUITAR PEDAL EXPO site!
Quite a few of the famous ones and tons of .... "who?"
Browse that slowly, opening all galleries and versions, you'll be amazed by how many creative ways can be used to pack some Tweed or Blackface amp (as well as early Marshalls) and the odd Silvertone under a new exciting cover.

In fact, if you have some special sauce project running, you can exhibit it there, it's not expensive at all.
And you'll have a few pictures rubbing shoulders with the Royalty to show hot girls, bar buddies or grandchildren, depending on your age.

A few personal favorites:



this one is in-kreed-ih-bool !!!!!! :

[J M Fahey]

by comparison this one looks quite cool:


what about these? ... dressed in authentic Cowboy Texas Ranch original wood:

maybe they hope to sell these to ZZ Top ?

There are some rumors that amps covered in authentic sheep skin, with guaranteed 6" thick wool on them caught fire during burn in and won't be available this season.


Of course, you already know what *all* these amps have inside and how they sound .... but that's not the point, is it?

[52 Bill]

Where is this amp located, US or UK? Juan's point about the plain enamel wires made me review the photo again and I noticed a few odd things. First off, I was wrong about the direction of the fall, as I didn't notice before that this is a combo, not a head.

The ac cord is not color coded for US standards. The hot is fused while the neutral is switched (or vice versa). And there is an odd mix of filter caps in there. Has this been repaired before? How old is this amp?

[mozwell]

Power cord is standard UK / Australian colours, brown is active, blue in neutral, green / yellow is earth (IEC colour scheme)
Old UK / Australian power cords red is active, black is Neutral, Green on its own or Green / Yellow is earth
US power cords black is active, white is neutral, Green is earth

Standard UK (IEC) type power cord used here

BUT as 52Bill says, switching the neutral is NOT a safe way of doing things (if this is what they are doing). I don't know about US wiring codes, but in AU the neutral cant be switched, unless by a dpdt switch that switches active & neutral together.
Soldering the mains earth to the chassis is also not allowed in my part of the world. The power cord earth wire must attach to a bolt to the chassis (or some other approved connection). It must be the ONLY wire attached at this point. Other earthing wire can be attached to the chassis but at another earthing point.

The mains wiring (IMHO) leaves a bit to be desired (standards compliance & safety wise)

Enough rant....
Do what Juan says to do in post #25, fully pull the transformer..... etc....

[Pryde]

Where is this amp located, US or UK? Juan's point about the plain enamel wires made me review the photo again and I noticed a few odd things. First off, I was wrong about the direction of the fall, as I didn't notice before that this is a combo, not a head.

The ac cord is not color coded for US standards. The hot is fused while the neutral is switched (or vice versa). And there is an odd mix of filter caps in there. Has this been repaired before? How old is this amp?

Yes amp is in USA. I found the AC colors odd, never seen them like that. I also noticed the illinois cap among all the F&T and Sprague caps and thought it odd.
The way the chassis is bent looks like the amp was dropped straight onto it's feet as there clearly is downward force present looking at the bends.
I am going to find out if he is the original owner and if anyone has done any work on the amp.

[Chuck H]

Since DB13 won't provide a schematic... Perhaps it's appropriate post several clear shots of the entire circuit here on this public forum so that we can better asses what transformer you'll need. Much better, as a company protecting it's "secret sauce" to have several detailed pics of your circuit in the public domain than to provide one service tech with a schematic Stupid F'ers.

As an added bonus, we not only get to know their circuit but we can continue cutting up the build quality All in plain view for everyone. I wish the thumbsup emoticon could be made to waggle back and forth about now.