Way to test current rating of a power transformer?

[shepdog]

Picked up a Peavey Deuce VT for $80 over the weekend and I have been thinking about building it into a Twin Reverb. Currently the power transformer is powering 4 6l6GC's and I'd like to know if there was a way to measure the current rating. I've also heard of using separate power transformers to power the power and preamp sections independently in situations like this. Does that sound right?

Thanks

[Cliff Schecht]

I fixed a Deuce rather recently. One of the things I remember was how MASSIVE the PT was. I think it could handle the job no problem, Peavey is known for overrating components like these for a very stiff output section. You shouldn't need a second transformer, you're only asking maybe 30-40mA more from a Twin preamp. You could probably reuse the Peavey tube socket board and some of the power section if you plan carefully..

Somebody else posted a great link that shows you how to measure the current rating with some accuracy though. Perhaps somebody can help find that link if the search button can't help you.

[shepdog]

Thanks, I'll have to do a search for it. The first thing when that I thought of when I got into this amp was the Twin Reverb. Seems like that was what Peavey was going for with this amp. The chassis even shares the same dimensions.

[tubeswell]

Easiest way is to get a schematic and look at the tube compliment and the way the heaters are wired, and you'll be able to figure it out

[shepdog]

Should I be more concerned about the heater supply current, or the high voltage winding current? One side of the heater winding is grounded and there are 4 6l6s.

[tubeswell]

Can you post a link to the schematic?

[Cliff Schecht]

C'mon, nobody bookmarked the link I was talking about? It's the one that you calculate however many Ohms/Volt you have and use the chart to find the max current with a HW and FW bridge rectifier.

[KT66]

C'mon, nobody bookmarked the link I was talking about? It's the one that you calculate however many Ohms/Volt you have and use the chart to find the max current with a HW and FW bridge rectifier.

I think it's in this thread : https://tubeamparchive.com/viewtopic.ph ... rt+current

I agree that you probably shouldn't worry about it, some guys on the Dumble side have taken Peavey hybrids and made ODSs with them. The HT draw is negligible, if there is anything to be concerned about it would be how much heater current is on tap and can it take another 1.8 amps ? So, you could just put a little filament transformer in there to be safe.

[martin manning]

C'mon, nobody bookmarked the link I was talking about? It's the one that you calculate however many Ohms/Volt you have and use the chart to find the max current with a HW and FW bridge rectifier.

I spent a few minutes searching for it and couldn't find it. Structo, did you save a copy of the page? It was a scan of an article from somewhere or other. I seem to recall you or someone else reposting it in another discussion after the original posting. That should be in the reading materials sticky thread for sure.

[Phil_S]

I think it's in this thread : https://tubeamparchive.com/viewtopic.ph ... rt+current

I posted that one, and don't know its origin and it is not particularly fine tuned.

I think, maybe, we are looking for this one: http://www.geofex.com/article_folders/x ... former.htm Click the reverse engineering hyper link at the top of the page.

[martin manning]

Phil, the item was a scan of an article that contained a plot that could be used to determine the current capability from some measurements.

[Firestorm]

Is it this one?
http://www.diytube.com/phpBB2/viewtopic ... 65&start=7

[cobalt]

https://tubeamparchive.com/viewtopic.php?t=13728
?

[martin manning]

That's it!

[Cliff Schecht]

Is it this one?
http://www.diytube.com/phpBB2/viewtopic ... 65&start=7

This one is what I was referring to. I couldn't find the damned thing in my bookmarks or with a search..