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Toroidal Transformer Upgrade for S5 Electronics K-16LS Kit

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emretelci

emretelci

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Joined 2015
#1
Hi there,

I have bought an S5 electronics K-16LS kit and now is the time to upgrade. Simply, I want to replace the transformers with toroidal transformers. I am not an engineer so I have found found this forum to request help.

This is my first post also, I am enjoying this forum more and more every day and trying to learn from you guys. I am a hobbyist and have met the wonderful "tube world" just new.

Appreciate a lot if you could help me... Cheers...
 
#3
Hi Eli, thanks for your reply.

The reason I wanted to use toroidal transformers is, there is a place I have found here, making only custom toroidal transformers which are a lot cheaper than Edcor. (I am wondering if they can make the same quality...) I live in Istanbul and with the shipping, it costs around $300 just the transformers from Edcor. So maybe, I will try with these guys, but I could not figure out the difference between square and toroidal transformers. Are the cables same? And if give the specifications of Edcor transformers, will they able to build? We will see, I guess...

I am attaching the schematics here:
An externally hosted image should be here but it was not working when we last tested it.


Many people suggested me to use Edcor, so probably these are the ones I may use if I cannot use custom toroidal transformers.

XPWR227 for power, and two CXPP25-8-5Ks for the outputs. (I am using 220 Volts)

My plan is to take the technical specifications of these two Edcors and request the toroidal guys build same... So what do you think? My question is, "is this possible?"

Cheers...
 
#5
artosalo said:
You don't need to custom made. Toroids are available from Europe with reasonable cost.
This could fit very well to your amplifier:

TTG-KT88PP - Tube output transformer for 2xKT88 / 2x300B Push-pull or similar - Shop Toroidy.pl
Click to expand...

Hi Artosalo,

Slightly off topic..NB not PP so won't fit the circuit.

How do these compare to something like the Edcor?
I'm just thinking Toroid and SE which they seem to make..don't seem to go together.😀
http://sklep.toroidy.pl/en_US/p/TTG-EL34SE-Tube-output-UL-transformer-for-EL34-6L6-SE/560
Just wondering about the quality. (Any good source in Europe is worth looking into.)

Regards
M. Gregg
 
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#6

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#7
That's interesting,

The comparison of the toroid with the low frequencies, however its still good.
As you would expect the gap narrows as you go up the frequencies.
Could you hear any difference ?, my guess is not at these levels and in the low frequencies.

Regards
M. Gregg
 
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#8
I usually make only two tests to evaluate the OPT briefly.
At first I monitor the THD and signal waveform at the frequency range from 100 Hz to 20 Hz and next look the 10 kHz square wave reproduction with oscilloscope. Both test with some half of maximum power level.
This way both low and high end performance can be tested and quickly to see if more detailed measurement is worth to do.
 
#9
Thanks to everyone,

I have one more question. I want to replace Edcor transformers with toroidal transformers. There is a place near to me making toroidal transformers so I need to tell the guys the specifications of the Edcors. I sent them the links of the Edcor webpage, but they could not figure our what to do. Specially on the OPT

So which information should I tell my transformer guys to copy the Edcors?

Here are the links to Edcors:
power:
XPWR227

output:
CXPP25-8-5K


Thanks...
 
#10
emretelci said:
The reason I wanted to use toroidal transformers is, there is a place I have found here, making only custom toroidal transformers which are a lot cheaper than Edcor.
Click to expand...
Do they make audio transformers, or only power transformers? There is quite a big difference, which you and they need to be aware of. Unless they know what they are doing, you will be paying for a significant downgrade of performance.

You can't just take an audio EI OPT design and wind it on a toroid, because the core and winding arrangements are different. You might need different interleaving, for example. Stray capacitance will certainly be different. Of course, an experienced audio transformer designer will be able to arrive at an equivalent design for toroid - but that will cost a lot of money. So, you need to find a toroid design which does what you want and get them to make that.
 
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