Sourcing transformers here in the UK

[stressbaby]

Hi folks,

I'll apologise in advance of any dumb questions as i'm relatively new to this site and also to amp building- just finished a 5watt plexi kit from ampmaker (http://www.ampmaker.com/ak01x.asp).

Could I ask if someone could check out this transformer supplier:-

http://www.danburyelectronics.co.uk/ and recommend a transformer set I could use to build either an 18watter or 36watt amp using the layouts you have on this brilliant site.

To say that the UK was supposed to be the home of Partridge trannys it's like finding 'hens teeth' trying to track down a decent tranny set over here.

Your help would be much appreciated.

Many thanks
Stressbaby

[Mauri]

Barry at ampmaker sells set of transformers (made by danbury electronics) for both 18 and 36W
I think he is moving at the moment so you might not be able to order them right now but he should be back in businness shortly.
Maurizio

[Merlinb]

There's also Sowter transformers http://www.sowter.co.uk/, although they are more expensive as they as extremely high quailty.

Danbury make great trannies. From the following site I recommend: http://www.livinginthepast.demon.co.uk/xformer.html
For either an 18W or 36W the Super 20 - 30W Output Transformer (Ok its only 30W rated, but that's down to 20Hz so it should be ok for guitar)
The 50VA General Purpose Valve Mains Transformer would power an 18W, although you'd need an extra filament transformer for the preamp valves.
And the 100VA General Purpose Valve Mains Transformer would power an 18W, and also a 36W provided you also had a filament transformer for the preamp valves.

[stressbaby]

Cheers folks for the good advice... can I ask another stupid question?

What type of filament tranny would you recommend and is this simply to provide power to the heater filaments of the pre amp valves?

Regards

Stressbaby

[steveh]

You can work out filament requirements by looking at the tube datasheet. Each type of tube (valve in the UK ;o) ) draws a specific current, so you simply need to add them up for your intended build.

Barry at Ampmaker has Transformers which will suit nearly any of the 18/36w builds on this site. His prices are also cheaper than hammonds (in the UK) or custom wound.

I've also used custom wound transformers from
http://www.transformers.uk.com/contact.htm
before, and they seem good. I have had a PT from them fail, but that could have been my fault running it a bit too hot.

[Merlinb]

For three preamp valves of the ECC8x type, a 6V 1A (6VA) transformer will do- they're quite small in size.
However, if you are forced into having a filament transformer just for the preamp valves it's highly recommended that you use a 12V 0.5A (6VA)tranny instead (wire the heaters for 12.6V operation; pins 4 & 5 only). This makes wiring the preamp valves easier, and seems to improve noise perfomance too.

[zaphod_phil]

If you're not too badly strapped for cash, I would really recommend Shinrock's 18W transformers - at very least the output transformer. These are generally believed to be the most accurate reproductions of the Radiospares originals, using mostly the very same materials sourced from the UK. Shinrock is based in Germany, so the shipping costs are quite reasonable and there are no customs duties to worrry about.
http://www.shinrock.com/index.php?trans ... amplifiers
http://www.shinrock.com/index.php?marsh ... ansformers
http://www.shinrock.com/index.php?marsh ... ansformers

BTW, why did you want a separate filament transformer? There shouldn't really be a need for that.