Experience with AnTek OPTs?

[torrence]

Hi,

Does anyone have any experience with the toroidal output transformers
offered by AnTek? This company seems to be more oriented towards
power transformers. I am looking for something to handle up to 20W
in PP and I can't possibly afford Plitron. For the price of the AnTek toroids
offered on Ebay, I could buy a pair of 25W CXPP from Edcor. Would this
be a better option?

Thanks

[Wavebourn]

I wanted to have, several times, but they could not answer simple questions. So I buy from Edcor.

[whitelabrat]

I've got a pair o' AT-1008's on the way and I'll report back with my findings. May be a few months though before I can cobble together something though

I would be open to letting someone borrow them if they have the equipment to test them (analyzers, scopes, etc).

[Ultima Thule]

Originally Posted by whitelabrat

I've got a pair o' AT-1008's on the way and I'll report back with my findings. May be a few months though before I can cobble together something though

I would be open to letting someone borrow them if they have the equipment to test them (analyzers, scopes, etc).

Hi whitelabrat,

long time passed, how did it go with the AnTek OPT's??
Maybe you meant AT-100L as I couldnt find what you typed in your post..

Cheers Michael

[Jeb-D.]

I'm curious too. I'll be trying some some of their transformers for my next project.

[Ultima Thule]

btw found AnTek's eBay shop:
eBay Store - Antek inc: Transformers, Enclosures, Power Supply

Whitelabrat typed correct, they have OPTs models AT-1008 and so on (not listed on their homepage) but they are without the UL 40% tap.

The ones with UL 40% tap have very low input impedance of around 2 k for their 2 largest trannies, isn't that crazy low, who would buy these??
Or maybe there are suitable projects for PP UL 40% trannies with so low input impedance...

[whitelabrat]

I've got a big backup of projects that just aren't going anywhere. The AT-1008's just sit in a box. Very sad.

My current intent is to do something Screen Drive Parallel Push-Pull with 22JF6's. At about 2k ohm these are intended for PPP with 6L6's, 6550's or similar. I just got novar sockets and big aluminum plates. The amps stuff is trumped by house projects at the moment.

I did see thisrecently. It's the only build I've ever seen with these transformers.

[Jeb-D.]

They have some other models on their website. All of which have %40 taps. I'm going to try the AT-040L (4.8k 40W) ones. Your right, the higher powered ones use low impedance. They must be intended for parallel output tubes. Or low impedance tubes. The 70W version would probably work well for a 6c33c push pull.
Antek - Products - List View[]=2

[Eli Duttman]

Originally Posted by Ultima Thule

btw found AnTek's eBay shop:
eBay Store - Antek inc: Transformers, Enclosures, Power Supply

Whitelabrat typed correct, they have OPTs models AT-1008 and so on (not listed on their homepage) but they are without the UL 40% tap.

The ones with UL 40% tap have very low input impedance of around 2 k for their 2 largest trannies, isn't that crazy low, who would buy these??
Or maybe there are suitable projects for PP UL 40% trannies with so low input impedance...

PPP EL34s would do fine with those O/P trafos.

The trafos without UL taps go with full pentode mode "finals". Regulate g2 B+ and combine NFB techniques. Short loop plate to grid around the O/P tubes will dispose of damping factor and linearity issues, for the most part. A few dB. of GNFB takes care of linearizing the "iron" and anything left after the short loop NFB has done its job.

[Ultima Thule]

Thanks Eli! But where can I use the ones with UL 40% and around 2k input, also PPP, then what's the use of the UL 40% tap??
Sorry I'm not too well aquinted with tube stuff but checked one PPP EL34 scheamtic and there's no UL 40% tap OPT, check out the schematic here: http://www.audiofanatic.it/Schemi/Ti...eticFrance.jpg

Good to hear from you labrat, sorry to hear the project is moving so slowly for you, hopefully you can tell us soon how those trannies worked, I'm gearing up for a KT88 PP, check out TubeMack's thread where I am in too as we are probably going to build the same thing. Here's the direct link btw: "Mullard 5-20 KT88 PP blocks!

Jeb, yeah I noticed the smaller core which could have been a good one regarding the input, but that frequency response looks a little bit freightening doesn't it?