new "class x" transformers from Edcor

A few days ago I got a some of the XSM series transformers namely the XSM10K/600, XSM10K/10K and XSM2.4K/600 (custom order).

The 10K/10K's step response is as good as it gets and it is paired with good bandwidth. Both the 10K/600 and the 2.4K/600 had pretty good step response, but the 2.4K/600 has less of an overshoot when terminated with 600 ohms on the secondary. I got the 2.4K/600 transformers to be driven by an ECC99 based SRPP output stage (under development, oh, for months...)

The bandwidth is sufficient on the step down units and the singal is not visibly attenuated until 80KHz. I realize that none of this is accurate data resulting from thoughtful measurements, but this is all I had time for.
At $12 these are REALLY a bargain.

You really have to specify the conditions for the measurements to be meaningful--that's one thing that drives me nuts about the "specs" on Edcor's website, they tell you nothing about source and load impedances used, signal level, etc. Driving the transformer from a low-Z source with the secondary unloaded (or lightly loaded) won't tell you much that'll mean something in a real-life application.

I know the SRPP is trendy these days, but it's overrated for use as an output stage, especially when driving lower impedances. It became popular in recent years in audiophile circles, where the signal level and impedance requirements are much more forgiving (usually -8dBU and 10K-47K, typical). If you want to drive impedances below 10K with the authority needed for "pro" operating levels, a WCF operating at a high plate current is a very good choice. And I think the ECC99 would probably work very well as a WCF.

I did specify 600 ohm secondary load. :? Here, have a beer Dave. :sam:
Driving the the transformers was a cheap signal generator that has a chip output so the output is impedance is someplace between 100 and 600 ohms.

The ECC99 SRPP works fine into the 2.4K load IF it is purely resistive. When I hooked it up to the transformer it soiled itself in the pants. Maybe it is not happy with the capacitive components of the load?

I have to say that all of EDCOR's transformers are made in the USA and we do not use any ovens for the varnish. The baking of the transformer causes the varnish to turn an ugly yellow color. We air dry them in a ventilated room. As for the winder, have being in the sound industry for over 40 years we have a sound system that rocks with XM radio for the winders to choose the station. Heck we even had the comment about individual DVD player for some of the semi-automated winders. :grin: Ha ha, maybe some day. Remember EDCOR is not cheap, just inexpensive. Thanks for the good comments.

[quote author="CJ"] Don't expect to see OSHA approved ventillation systems near the varnish tank and dry out oven at the Edcor factory. Someone is busy getting lung cancer so you can have your 18 dollar x-former, so enjoy it for all it is worth.
Yes, I worked in a transformer shop for ten years, so I know what I am talking about as far as winders are concerned.

I would hate to work in a restaurant and rely on your tips to pay the rent.

Seriously though, I just swept a cheapass 5:1, 600 to 120 volt small power transformer for a product at work, and the dang thing was flatter than a pancake. This is just pri-sec construction on a cheap core, so go figure. Maybe there are other things to consider besides response, like excitation current, etc.

cj[/quote]

Hey Brian, welcome to the board. You may have noticed that Edcor transformers are becoming very popular around here. :thumb:

Heck, I have four of them I bought for experiments. I just wish I knew where I put them now.

Welcome to the boards, Brian. We'd all be pleased if you could stick around and hang out with us. :thumb:

EDCOR has, over the last few months, added nickel core to some of their transformers. We have not posted them on our web site just yet. We started out using the nickel on a few custom transformers, like the ribbon microphone transformers and a few of the matching transformers. We now are offering nickel up to EI75. It does cost a little extra. Not an arm and a leg, maybe just an arm or other extremity. :grin:

[quote author="edanderson"]chris:

all edcor transformers are made using grain oriented M6 grade silicon steel. that is the only core material they use.
[/quote]

Rock on! :sam:

[quote author="brian weston"]EDCOR has, over the last few months, added nickel core to some of their transformers[/quote]

awesome.

Yes, Rock on, EDCOR!

[quote author="edcorusa"]EDCOR has, over the last few months, added nickel core to some of their transformers. We have not posted them on our web site just yet. We started out using the nickel on a few custom transformers, like the ribbon microphone transformers and a few of the matching transformers. We now are offering nickel up to EI75. It does cost a little extra. Not an arm and a leg, maybe just an arm or other extremity. :grin: [/quote]

I don't know... maybe somebody covered this already ??
But here goes,
Are any of the Edcor xformers suitable for the line in/out stage for the LA2a build ?

That's awesome! The transformer plant I worked at was just like CJ's; winders with Walkman! And a really big Easy Bake oven! (I have more flashbacks of the MEK, though, than the varnish!) EDCOR, you are truly kings among men! :grin: :thumb:

Sice the lams are not perfectly square, and the assembler is not perfect either,

Click to expand...

They were before they got to varnish! :grin: :sam: