Cost of producing a 20W amp with 6V6.

[g1]

Could they have mixed up the colour coding on the CT and the blue/red? It is supposed to be 45V and you said the voltages were off by 44V.

[J M Fahey]

40V difference between 2 officially equivalent windings is ABSOLUTELY UNFORGIVABLE ....... PERIOD......

It is a GROSS error, means the presumanly chinese OEM winder misread a spec or something and that Weber does NOT check what they sell, not even a single sample.

Makes me shudder about other hidden errors, as well as how on Earth other builders have not noticed that and complained.

What does Weber say about the first 2 ones?

Did they measure them?
Do they confirm or deny your findings?

Or they simply tossed it in a future "SALE !!! 2x1 offer !!!" labelled box?

We are not talking an acceptable error of 1 or 2 turns possible because of digital counter last digit resolution but some 100/200 turns.

Thatīs why I suspect a misread or misunderstood winding table or spec, the blue collar worker does not know or care about the design, why each winding uses such and such wire, turns, whatever, he just follows instructions.

Note: I calculated it to put it into numbers.

Thatīs a 3.1 Turns/volt core @ 50 Hz.
You could use 80% of that for 60Hz-only designs and save a couple bucks but itīs good practice to design for 50Hz so the transformer (and amp) work anywhere.

Back to the transformer, 40V error means 40x3.1=124 turns error.
NO WAY a modern counter will err that much.

I remember when I was poor and attached a cassette recorder counter to my winder , I *could* have 1 or 2 turns error with that crude method, but not higher (which anyway was less than 1 VAC error).

[Alan0354]

Could they have mixed up the colour coding on the CT and the blue/red? It is supposed to be 45V and you said the voltages were off by 44V.

I did, that's the first thing I did on both PT. They measure the opposite!!

Meaning if I measure Red1 at 356V and Red2 at 312V using the Red/Yellow as CT. If I use Blue/Red as CT, Red1 measured 312V and Red2 measured 356.

So there is no center tap, they both off.

[Enzo]

I don't know just which transformer this might be, but some time ago, Weber was selling a PT and it had something like two taps in the middle, but not center. You had to pick one as your "center tap" then use the other for your bias winding, leaving the grossly mismatched winding ends for your B+.

Imagine a straight 700v winding with a 45v winding in the center made with taps. In other words, if there were a center tap is would have these two middle taps 22v either side, but there isn;t one, so you have to slide the whole winding one direction or the other, and there is your 45v difference.

Imagine trying to use this one:
https://taweber.powweb.com/store/PTGPsch.jpg



Look at the diagram. I could see an ignorant winder looking at this one and thinking the 50v winding was centered and not a tap side of center. We naturally assume there is a center tap, but someone not familiar with our tube circuits, just knows winding, might interpret it different, after all hte drawing does not specify center tap, just has 50v in the middle. NO, I am not defending it, just trying to understand how it happened.
https://taweber.powweb.com/store/022756sch.jpg

[Alan0354]

40V difference between 2 officially equivalent windings is ABSOLUTELY UNFORGIVABLE ....... PERIOD......

It is a GROSS error, means the presumanly chinese OEM winder misread a spec or something and that Weber does NOT check what they sell, not even a single sample.

Makes me shudder about other hidden errors, as well as how on Earth other builders have not noticed that and complained.

What does Weber say about the first 2 ones?

Did they measure them?
Do they confirm or deny your findings?

Or they simply tossed it in a future "SALE !!! 2x1 offer !!!" labelled box?

We are not talking an acceptable error of 1 or 2 turns possible because of digital counter last digit resolution but some 100/200 turns.

Thatīs why I suspect a misread or misunderstood winding table or spec, the blue collar worker does not know or care about the design, why each winding uses such and such wire, turns, whatever, he just follows instructions.

Note: I calculated it to put it into numbers.

Thatīs a 3.1 Turns/volt core @ 50 Hz.
You could use 80% of that for 60Hz-only designs and save a couple bucks but itīs good practice to design for 50Hz so the transformer (and amp) work anywhere.

Back to the transformer, 40V error means 40x3.1=124 turns error.
NO WAY a modern counter will err that much.

I remember when I was poor and attached a cassette recorder counter to my winder , I *could* have 1 or 2 turns error with that crude method, but not higher (which anyway was less than 1 VAC error).

I wrote to them very detail like this:


> INPUT: Wall AC to Black and
> Blue.(120VAC)
>
> 1) Measure with the black probe of the meter on RED/YELLOW
> wire:
> a) Measure RED/WHITE
> wires: 242VAC and 286VAC resp.
> b) Measure RED wires:
> 311VAC and
> 353VAC resp.
> c) Measure BLUE/RED
> wire: 44VAC
>
>
> 2) Measure with black probe of the meter on BLUE/RED wire:
> a) Measure RED/WHITE
> wires: 285VAC and 242VAC resp.
> b) Measure RED wires:
> 356VAC and
> 312VAC resp.
> c) Measure RED/YELLOW wire: 44VAC

When I email to them the first time, they did not contest, they just sent me the second one. I still have the first one in my amp!!! The problem is with the wrong winding, I only get 330VDC on the 540V taps. I am using it as if I already have a little power scaled down!!!

As you can see, it's not just mixed the Red/Yellow and Blue/Red.

I just email them today, it's after 5pm E.S.T. So I have not got a reply back from them. We'll see what they are going to do this time. I have the second one packed up ready for them to have UPS pickup.

Man, it would not be funny if you guys run into this kind of problem. Can you imagine customer calling and ask for their amp and you get this?

[Alan0354]

I thought Weber sell high quality stuffs. Their speakers and attenuators have received a lot of praises.

I bought a lot of caps and resistors, so far, nothing gone wrong.

Watch out when buying cloth wires, the Black and White colors are multi strands, but the Yellow, Blue, Green are solid strand.

[J M Fahey]

Alan, in post #18 you state:

If I use Blue/Red as CT, Red1 measured 312V and Red2 measured 312.

which is fine (at least itīs symmetrical):

but in post #20 you state:

> 2) Measure with black probe of the meter on BLUE/RED wire:
.....
> b) Measure RED wires:
> 356VAC and
> 312VAC resp.

Which of these 2 contradicting statements applies?
Thanks.

[Alan0354]

Alan, in post #18 you state:


which is fine (at least itīs symmetrical):

but in post #20 you state:


Which of these 2 contradicting statements applies?
Thanks.

Trust post #20 in blue color. I straight copy from the email that I sent today to Weber on the second PT. It was a typo in #18. I corrected it.
In order to be exact, this is the number I sent to Weber a week ago on the first transformer:

1) With Red/Yellow grounded:
a) Measure the two Red wires, readings are 320VAC and 366VAC resp.
b) Measure the two Red/White wires, readings VAC 250VAC and 294VAC resp.

2) With Blue/Red ( 45VAC) grounded:
a) Measure the two Red wires, readings are 366VAC and 320VAC resp.
b) Measure the two Red/White wires, readings are 294VAC and 250VAC resp.


Hey, I notice the two transformers is not exactly the same!!!! Don't ask me, I just measured that. I can only assure you that I measured both in no load condition and the same wires. AND measured by the same....one and only one meter!!! Unless my AC main is different, you might even read something into this also!!!

[J M Fahey]

Cool off, this is not a personal attack.
I wanted clarification on 2 contradicting posts, one of which showed a perfectly normal transformer (312/312VAC).
Thanks.

Trust post #20 in blue color. I straight copy from the email that I sent today to Weber on the second PT. It was a typo in #18. I corrected it.
In order to be exact, this is the number I sent to Weber a week ago on the first transformer:

1) With Red/Yellow grounded:
a) Measure the two Red wires, readings are 320VAC and 366VAC resp.
b) Measure the two Red/White wires, readings VAC 250VAC and 294VAC resp.

2) With Blue/Red ( 45VAC) grounded:
a) Measure the two Red wires, readings are 366VAC and 320VAC resp.
b) Measure the two Red/White wires, readings are 294VAC and 250VAC resp.


Hey, I notice the two transformers is not exactly the same!!!! Don't ask me, I just measured that. I can only assure you that I measured both in no load condition and the same wires. AND measured by the same....one and only one meter!!! Unless my AC main is different, you might even read something into this also!!!

[Loogie]

Any chance this is supposed to be used with a bridge rectifier?, and we're assuming the red/yellow wire is a center tap? When you look at it that way your measured voltages are close to the predicted values. If you measure across the red/whites and the reds do you get about 540v and 680v respectively?

[Loogie]

After looking at the WPTGP maybe W025130INT is supposed to be used in the same way, its just that someone screwed up the drawing. So maybe if you want 300 something volts you would choose the red and the blue/red or the red/yellow as your primary voltage and use a bridge. If you started with the red at the bottom and called that 0v what do you measure at each tap moving up to the top red? I know its labeled as a replacement and red/yellow is labeled CT, but, well, what we could have here is a failure to communicate. In other words if you threw out the drawing and just found a primary you liked, could that work?

[Enzo]

That would be fine if one of the taps were actually in the center. But none of them are here.

[g1]

Looks like they may have finally figured out they have a problem, the website is showing it as "temporarily out of stock".
I wonder how many of them got sold and put into use without the problem being noticed.
Years on down the line we could be hearing about people solving their mystery problem of low B+. These are supposed to be a direct replacement for Fender 025130, fairly common in many models.

Edit: Sorry, it's the domestic version that is out of stock, not the international.

[Alan0354]

Cool off, this is not a personal attack.
I wanted clarification on 2 contradicting posts, one of which showed a perfectly normal transformer (312/312VAC).
Thanks.

No, I did not take it as personal attack at all. I wasn't offended or anything. I made bigger fond to get your attention that there is another inconsistent in the reading even between two transformers. One has higher voltage than the other. The only thing I can think of that can make two identical transformers to have different reading is if the two phase of the AC main in my house has different voltages.( is that possible?) AND if I plugged in one phase for one measurement and the other phase for the second measurement. I measured the first one in the work room, the second one in the kitchen area.

It is a good PT according to spec, but this really kills it.

[Alan0354]

Any chance this is supposed to be used with a bridge rectifier?, and we're assuming the red/yellow wire is a center tap? When you look at it that way your measured voltages are close to the predicted values. If you measure across the red/whites and the reds do you get about 540v and 680v respectively?

Yes, You get 540 and 680. Just the center tap is not correct. In the data sheet, it called Red/Yel to be CT.