Cost of producing a 20W amp with 6V6.

[Alan0354]

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?

I kind of prefer CT. Maybe I am not correct, I think it is easier for transformer to run as CT as each side of the winding only work 50% of the time ( the negative half of the cycle does not drive anything). But maybe that's not important.

Ha ha, I don't think they are interested in getting the transformers back. They never asked to send back the first one. I might just do that using it in a new build. I am not selling it, it's just my pretend play business!!!

[big_teee]

They cost a little more, but wouldn't the ClassicTone PTs made near chicago be a better investment?
I've had real good luck with the ClassicTone Transformers.
Fender Power Transformer, Deluxe, Deluxe Reverb, Tweed Tremolux, 125P23B, 025130, 041316, 120V
T

[Alan0354]

They cost a little more, but wouldn't the ClassicTone PTs made near chicago be a better investment?
I've had real good luck with the ClassicTone Transformers.
Fender Power Transformer, Deluxe, Deluxe Reverb, Tweed Tremolux, 125P23B, 025130, 041316, 120V
T

At the time, Weber has the highest current spec of 150mA and 540V and 680V option. If it is correct, it's better. But at this point, yes, you are right.

Also, I read a lot of raving reviews of Weber speakers and attenuators. I guess that doesn't imply to their other stuffs.

[big_teee]

I bet you get it all worked out.
I put this one in the converted 18 watt chassis, was a near drop in.
Fender Power Transformer, Vibrolux, Vibrolux Reverb, Tremolux, 022723 & 125P26A, 120V
It really did a nice job with 2 - 6L6s. I ended up with about 450v loaded.
I used the bias tap, I didn't need the 5 volt tap, so I used it to power the 6 Volt pilot lamp.
That worked out slick, and the lamp was still bright enough, but not too bright, and didn't put any additional load on the 6v tap.
Don't know if anyone else here has tried running the pilot on 5v or not?
T

[Alan0354]

I bet you get it all worked out.
I put this one in the converted 18 watt chassis, was a near drop in.
Fender Power Transformer, Vibrolux, Vibrolux Reverb, Tremolux, 022723 & 125P26A, 120V
It really did a nice job with 2 - 6L6s. I ended up with about 450v loaded.
I used the bias tap, I didn't need the 5 volt tap, so I used it to power the 6 Volt pilot lamp.
That worked out slick, and the lamp was still bright enough, but not too bright, and didn't put any additional load on the 6v tap.
Don't know if anyone else here has tried running the pilot on 5v or not?
T

That would be my choise the next go around. I use the 5V winding for relay and pilot light. But I did use Schotky rectifier to get 6V DC.

I my Bassman platform, I use a few 5W zeners to drop the +B to 400VDC to adapt to 6V6, then bypass the zener for 6L6.

I should have gone to Classic Tone. I have good experience with their Vibrolux OT. My amp would have been all buttoned up already.


You have experience with the Classic Tone Marshall 50W OT? My next project will be to rip out the Marshall JCM900 Dual reverb and put in something of a modified 2204 ( definitely with slightly more gain, the original one barely break up). Or do you think the 100W OT in the Dual Reverb is good enough?

[big_teee]

The PT I listed, I put in the 18w chassis is a 2204.
I used that PT and used 6L6s, but built it like a 2204 Cascade Hi Lo amp.
I voiced it kind of in between the fender and marshall tones.
I tweaked on it a month or two, waiting on the Mojo cab, before my friend picked it up.
I used Short Bottle TAD 6L6s, and He just loves it.
I used the Deluxe heavier duty OT.
Fender Output Transformer, Super Reverb, Bassman, Concert, 4/8/16 with M-6 Upgrade
If I do another one I would probably use this one.
40-18092: Output Transformer for 50W / 60W General Purpose / Project Amps with 4.2K to 4 / 8 / 16 Ohms
Same OT, just different lower mounting brackets, and a few bux cheaper.
T

[J M Fahey]

This is weird because in the example posted by Enzo, yes , there´s no center tap, the amp is meant for a bridge rectifier and it clearly says so in the wiring diagram

But on Alan´s, the end to end voltage used with a bridge would be close to 1KV supply, then it´s not the case.

I *guess* that here we have a 2 pronged error:

1) the OEM winder didn´t understand a poorly written spec (pencil drawn on the back of a napkin?)
2) Weber, happy with the killer price quoted, ordered a ton, didn't worry too much about retesting .

Funny thing is that the transformers still "work", sort of.

There must be at least a couple guitar players out there happily wailing with their homemade amps, built around this iron.

[Alan0354]

There must be at least a couple guitar players out there happily wailing with their homemade amps, built around this iron.

Absolutely, the amp is quiet, everything works. The only thing that prompt me is the +B is down to 330VDC instead of about 370V. That prompted me to probe the voltage and find the problem. It is not going to be 20W like the Deluxe, but I bet it is close to 15W of good sounding amp here. I love the amp.

If they really cannot get me a good PT, I might just go up to the Red taps to get about 420VDC, then drop it down by zener, or even go to 6L6 and call it a day.

[Alan0354]

The PT I listed, I put in the 18w chassis is a 2204.
I used that PT and used 6L6s, but built it like a 2204 Cascade Hi Lo amp.
I voiced it kind of in between the fender and marshall tones.
I tweaked on it a month or two, waiting on the Mojo cab, before my friend picked it up.
I used Short Bottle TAD 6L6s, and He just loves it.
I used the Deluxe heavier duty OT.
Fender Output Transformer, Super Reverb, Bassman, Concert, 4/8/16 with M-6 Upgrade
If I do another one I would probably use this one.
40-18092: Output Transformer for 50W / 60W General Purpose / Project Amps with 4.2K to 4 / 8 / 16 Ohms
Same OT, just different lower mounting brackets, and a few bux cheaper.
T

Thanks.

I have a question, I have a believe not to use an OT that has a lot of iron. Because if I want compression sound, smaller OT will start compress sooner. Is this true or it does not matter. I never compare, but I did change out the huge OT from the Bassman 100 to a Classic Tone Vibrolux OT.

[gui_tarzan]

I don't see Heyboer mentioned very often, don't they make good transformers for amps?

[JoeM]

Yes,Heyboer makes very good iron, so does Hammond.

[Alan0354]

I looked at the pricing of Heyboer transformers on Weber site. Price is not bad, closer to Classic Tone than MM or hammond. How does Heyboer compare to Classic Tone?

[Alan0354]

Update:

They tested the others they have, they are all wrong also!!!

Guys, buyers beware.

[Alan0354]

Ok, while waiting for their response on whether the W025130EU model has the same problem, I want to weight my option. So far, I have been very happy with running the transformer on the 540VAC taps and get 330VDC as +B. I have no noise problem, the amp sounds beautiful.

My question is what is the down side of going to 680V taps? I can put two 5W zener diode to take up part of the imbalance on one side. OR simply ignore the imbalance and use the 680VAC. Is there any down side of leaving it imbalanced? Is there any reliability concern here? My first guess is it should be fine. Please advice.

[Alan0354]

Update

Finally!!!! They shipped the WO25130EU, it is more expensive........AND IT'S RIGHT!!! I think they are happy to get rid of me, they did not even ask for the difference in the price, they just want to get rid of me!!!!

I am going to put it in, getting rid of the extra resistors and diodes and see whether I get back the missing power. I have it in the other thread that I only get about 17W max no matter what I do. The sagging is too much. We'll see how this one work out.