diytube.com

can i use just about any transformer?? for example one like this? http://www.summitsource.com/product_info.php?ref=1&products_id=9639


and do i need 3 of those?? and why? is there an alternative?

Those transformers couldn't possibly be more wrong. They will not work.

You must have at least three, one for each output channel (left/right) and one for the power supply. If you could the choke, that's four.

The power transformer is being discussed here:
http://www.diytube.com/phpBB2/viewtopic.php?t=4890

The output transformers should be any variety that are roughly a 5000 ohm to 8 ohm ratio (5K:8), unless your speakers are nominally rated four ohms. Then use a 5K:4 transformer. They should be air gapped for single ended operation, and must tolerate ~25 milliamps standing DC current.

hrmm thank you, those ppl know what they are talking about . but i don't know lol, what i mean is, what would be the cheapest option of transformers to buy for me? and what kind of example would i need for power and what kind for each channel? im a complete newb. but very interested. and the problem i have is im located in japan and they don't make it easier here to get those transformers.

ah i just found something
http://page13.auctions.yahoo.co.jp/jp/auction/r82598102

would 3 of those do the job?

You need ONE transformer fro making the AC voltage from your wall outlet (be it 100, 115 or 230V) into the voltages used by the amplifier, which means one HV around 230V and one 6,3V for heaters.
Then you need TWO transformers that convert the high impedance, high voltage low current AC signal from the output tubes into a low imp, low voltage and high current signal that can make the loudspeakers sing.
I know nothing about Japanese sources but near you, there's the www.vt4.com which sells good components for few dollars.
I'd recommend a pair of this transformer LM-2014U as OP transformers.
An this transformer cuold go for mains power transformer - LM-048A

Other useful transformers for output are these: http://www.analogmetric.com/goods.php?id=211
This transformer for mains power would work as well:
http://www.analogmetric.com/goods.php?id=287

All of those available from China.

how about this? would this work? any of those 3?
http://page.auctions.yahoo.co.jp/jp/auction/104473686

http://page11.auctions.yahoo.co.jp/jp/auction/n96254840

http://page.auctions.yahoo.co.jp/jp/auction/151355985

im sorry i know im asking to many questions, i hope somebody can help with a simple yes or no.

also is it ac-ac? or ac-dc or dc-ac??? and what if the transformere has 3A??? i mean more the required, is it bad then or.....??

thanks in advance

Anything that has the phrase "duty cycle" is no good, unless it says the duty cycle is 100% on all the time.

What is your line voltage over there? You want a power transformer with a primary winding that matches your line voltage. You need two secondary windings. One should be rated for 400 volts center tapped (400VCT, sometimes listed as 200-0-200). It must be rated for at least 50 mA. The other winding should be rated for 6.3 volts. It must be rated for at least 1.5 amps. All voltages are AC. I've assumed you are planning to build the 1626 version Darling Clementine. Otherwise, a different power transformer would be required.

One of the output transformers you listed above was on the right track, except it was specified as 10K to 8 ohm. You would rather find something closer to 5K to 8 ohm, unless your speakers are rated 4 ohms. In that case, the 10K:8 would be ideal.

If you are located near Tokyo, the "Akihabara" district is the electroic hobbyist's "Mecca" - it is a DIYer's paradise, electronics parts, tubes and transformers of all kinds, from modest cost to unbelievably expensive, high-end items. As well as the most modern high-tech devices and "toys" of all kinds. I may have the spelling (Akihabara) incorrect, but I am sure that it is close enough to help you do some on-line research.

HTH

/ed B in NC (North Carolina)

The original threads mentioning the transformers are getting buried, and I see no mention (until I edited it just now) of what transformers to use in the main schematic thread. Here's the scoop:

Darling build: Power transformer is the Hammond 269EX (universal is 369EX). Output transformers are the Edcor GXSE15-8-5K (these are for 8 ohm speakers).

6L6 build: Power transformer is the Edcor XPWR005-120. Output transformers are the Edcor GXSE15-8-5K (these are for 8 ohm speakers).

You can use the Hammond 156R 1.5H choke or Triode's C354 or a similar Stancor. 1.5 henries is A-OK.

Shannon

I have a strong feeling even an easy project like this one is too difficult for you, but why not check with your friends or in forums close to your place (Japanese forums) if someone could help you get all the parts needed assemble an amplifier for you.
Else take a bite in the bitter apple and order the transformers Separks suggests from EdcorUSA.

I'm curious about the suggested use of the Edcor 15 watt transformer when they make a 10 watt 5k/8 ohm and a 5 watt 5.5k/8 ohm output. The 5 watt does not have end bells but it can nicely fit inside a chassis box.

I don't know a lot about transformers but I thought a model closer to the power of the tube in use was more desirable for some reason. Or, is bigger always better?

miker wrote:I'm curious about the suggested use of the Edcor 15 watt transformer when they make a 10 watt 5k/8 ohm and a 5 watt 5.5k/8 ohm output. The 5 watt does not have end bells but it can nicely fit inside a chassis box.

I've got a set of those cute little 5 watters, and I meant to try them out on my Clementine. As luck would have it, a friend of mine came over for a listen and it followed him home. If I get it back any time soon, I'll try to hook them up and see what I think. If not, I guess I'll have to build another.

miker wrote:I'm curious about the suggested use of the Edcor 15 watt transformer when they make a 10 watt 5k/8 ohm and a 5 watt 5.5k/8 ohm output. The 5 watt does not have end bells but it can nicely fit inside a chassis box.

The 15W outputs represent a sweet spot: decent performance with around a 17H primary (see Ed Brown's posts) and a cheap price at $37 each. Your primary inductance will drop dramatically with the smaller outputs, hurting your low frequency reproduction. The flip side is going with a better output means *much* more money and bulk. Also, I'm doing all my measurements and feedback tuning with the 15Watters, so I don't know how transferable that data would be with other outputs.

Nutshell: Certainly if you have some outputs on hand, you use what you have. And if you want to build a super small Darling Clementine, the smaller outputs make sense. But if you are making an Edcor order, go for the 15Watters.

Shannon