Balanced F5 question

[AndrewT]

Hi,
enameled copper and stranded copper are the same to me, except that fatigue resistance of stranded is very much higher.

I do not want to have to remove insulation to expose the secondaries to attach flexible cords.

I would like flex for all leadouts. I am still provisional.

 

[EUVL]

Flex lead-outs are nothing more than stripped enamel wire soldered to a length of PVC wire before they wind the PE tape around it so that you don't see.

We'll ask for you.


Patrick

 

[_henry_]

thank you patrick

 

[EUVL]

Pleasure.

Patrick

 

[qusp]

> do remember that richard makes these custom, so if the perfect number is 504va, ask him for 504va, i'm sure he will do it for the same price

I think I can also live with an over-rating factor of 2.976 instead of 3.000.




Patrick

really? I would have thought given the opportunity 100% ideal would be better for your sensibilities than 99.206349% ideal but I am sure Richard although willing would most certainly prefer 500va

 

[EUVL]

I'll let you have the honour (and the pleasure) to talk him into making you a special 504VA, since you want specials anyway.

I have to look after the interest of the rest, so I can only go for simple, less exotic things.


Patrick

 

[massimo]

Patrick, to source heavy Xfrmrs from Canada might be not really convenient for EU Diyers. Quality and price of theese items are beyond dispute, but don't you think that shipping & duty can be much reduced/saved if sourced among EU?
The same apply for people living "upsidedown" in Australia.

 

[AndrewT]

to source heavy Xfrmrs from Canada might be not really convenient for EU Diyers

surely not from Canada.
I mistakenly presumed that if EUVL was recommending that the transformers are sourced in Europe.
I am not paying the airmail carbon to fly them across the Atlantic.

 

[massimo]

Moreover, while I agree to have not a whole potted Xfrmr, I'd rather prefer the centre half potted with a 6-8 mm diam. hole, just to avoid a long screw and a wide metal cap that might interfer with the magnetic flux

 

[EUVL]

The team is in US and Asia Pacific. So SumR or Plitron makes sense.
For the Europeans, you can organise your own group buy, if anyone has a good source.

Having said that, the US dollar is low, and surface mail to Europe is not ridiculous.
It was only an offer, not a recommendation.


Patrick

 

[EUVL]

As to centre potting, if you don't have centre pot, you can still unwind the transformer for whatever reasons.
In addition, you can use stainless steel or even plastic bolts which are not magnetic.

Again, an offer, not recommendation.


Patrick

 

[EUVL]

This is one of the many well-known European sources, but I have not used them before.

http://www.mennovanderveen.nl/eng/index.html
500VA - Amplimo

Another one in the UK :

http://www.airlinktransformers.com/audio.html

Rumour has it that Amplimo get theirs made by Avery.
Avery deals with the Audio industry and won't do small batches.


Patrick

.

 

[samoloko]

Patrick

can I use bc550 /560 as coscode transistor If I use this option

 

[EUVL]

In circuitry terms yes, but not with my current PCB layout.
And it would be too much change for the PCB to allow the use of a BJT cascode, as you need additional Vref for the base.


Patrick

 

[samoloko]

thank you

 

[EUVL]

The simulation does not indicate a significant advantage with cascode, and we want to test it first.
So don't think as yet that you must have it.

Patrick

 

[qusp]

Patrick, to source heavy Xfrmrs from Canada might be not really convenient for EU Diyers. Quality and price of theese items are beyond dispute, but don't you think that shipping & duty can be much reduced/saved if sourced among EU?
The same apply for people living "upsidedown" in Australia.

well I was one of the people who suggested richard, there arent any local custom options here in OZ as far as I know, not of any quality and as EUVL sad the dollar is low at the moment, so works out well. shipping by canada post is definitely expensive, moreso than anything from the US, but luckily we dont pay any duty unless the value is over 1000 and even then you can often avoid it. I paid nothing on over 5k worth of copper wire, if its for export market often raw materials that will be turned into product are given a bit of leeway.

so i'll be sticking with sumRs 504VA transformer

 

[ichiban]

Transformer shipping

Hi,
would SumR ship trannys to individuals separately?
I'm in the U.S. about 70 miles from Toronto.
I would like to get in a group buy to save a few $
but if I must I'll order directly for myself.

 

[Melon Head]

well I was one of the people who suggested richard, there arent any local custom options here in OZ as far as I know, not of any quality and as EUVL sad the dollar is low at the moment, so works out well.

This guy will make a transformer to any spec you want Manufacturer of toroidal TRANSFORMERS-Home page , and he is an Aussie located in sydney.
He is as good as anyone.

 

[EUVL]

> would SumR ship trannys to individuals separately?

Yes, and since AndrewT is probably not having his shipped from Canada, there might still be a vacancy for 2x.


Patrick