Mullard 5-20

[david counter]

maybe because of the recent interest I have the burgeoning idea to build a 5-20
can anybody point me in the direction of an easy to understand circuit that's not too difficult for an idiot like me

[Allen]

I have the Mullard book if you want to borrow it.

[alnewall]

http://www.lundahl.se/pdfs/claus_byr...fier_30wpp.pdf

Its in this pdf file along with some good reading. A web search will reveal some variants.

[david counter]

thanks guys

[John Caswell]

Hi Dave,
The beauty of the Mullard book is that it gives all details of how to build it incl. chassis work, so you could take the drawings to a local tin basher and get two professionally made chassis etc.
If you decide to go this route get the best O/P txs you can afford as they are the final arbiter, but you may have to change the feedback R/C slightly to accomodate modern Txs.
When I built them I was able to buy the Partridge C core txs, P6878 rings a bell, but at what cost to my pocket! Two were about 3 months spare cash.
Results were well worth it though.
I still rate it as one of the best U/L applications of EL34s.

Regards

John aka Dr john

[ian_r]

Also worthwhile looking at the old Maplin magazines for the Millenium amp which is very close to the 5-20 design. Its easy to modify the front end to that on the shown on the lundahl site pdf. I have scans and PowerPoint overlay files for the PCBs for this if you want them. I was surprised how good it sounded after changing the front end.

[hifienthusiast]

Originally Posted by John Caswell

When I built them I was able to buy the Partridge C core txs, P6878 rings a bell, but at what cost to my pocket! Two were about 3 months spare cash.
Results were well worth it though.
I still rate it as one of the best U/L applications of EL34s.

Regards

John aka Dr john

Vintage Partridge transformers still worth a lot of money even nowadays, especially in internet auctions, but perhaps not as much as 3 months spare cash!

Hon