Cheap project competition

[andrew ivimey]

It is soooooo hot!

[Martin213]

Originally Posted by andrew ivimey

It is soooooo hot!

Turning your 'Tractor' off may help a little to help reduce the temperature Andrew

[Paul Barker]

I'm geting all hot 14 hours a day trying to fit all the central heating folk are having round here, which at the moment they don't need. Go figure!

[Martin213]

Originally Posted by Paul Barker

I'm geting all hot 14 hours a day trying to fit all the central heating folk are having round here, which at the moment they don't need. Go figure!

Perhaps it's not the central heating foremost on their mind's Paul,maybe they are bored housewifes who need 'warming up'

[James D]

I'm having real trouble sourcing components for an amp under £100...

Probably need to simplify the designs around the psu or rethink how I do it. Two chokes eat up the budget

Over £200 is a doddle and got some nice ideas for that group :-)

James

[Paul Barker]

Yes,

I went through rs catalogue and discovered buying new it costs over 100 less than 200 to produce anything at all.

As a result I decided to use parts from my scrap bin. Most of these were gathered foraging radio rally's, which anyone here can do. I'll put a price on them as close as I can remember was right.

As I said before it's possible to get a tape player with a mono amp built in for a fiver. Cheapest amp is a pair of these. The valves are usually in great condition because most people play with a tape player for a day or two and forget it for the rest of it's life.

My first power supply was a failure, I stuck a Black Gate in it. Just couldn't hold myself back.

[Stuart Dean]

Hi Paul
I think that Dansette type record players are easier to find than tape players especially if you want 2.
Earlier models will probably have an ECC83,a EL84 and possibly a ez81.
Later ones usually have an ECL82/86.
I make a point of never paying more than £3 for these but they are becoming more difficult to find.
Another possibility is a Hacker Gondolier.
This has a sweet little ECL86 P/P amp and sometimes you can find the matching stereo conversion amp.
I think it would be a shame to limit the competion to 6EM7's why not have classes for EL84/ECL82/6 etc.Perhaps James could come up with some designs and a competion held for the best implementaion of these.
I have to admit I.ve never bought any new components for builds with the eception of
resistors and caps.
I have loads of salvaged power transformers and chokes and I doubt I could find one that was less than 50 years old some more like 70 years.All sourced from radio rallies and car boot sales. I can't remember any of these overheating or buzzing. I'm afraid I don't buy the claim that modern power TX's have superior insulation and can be made smaller and are designed to run hot.To me a hot TX is under spec.
STU

[andrew ivimey]

Was there ever a decision made that we could only use 6EM7s?

That would not be the point, surely.

I cranked my 6DN7 champ / SEX amp up yesterday. Didn't even bother bowing the dust off. Not bad ....

I have none of these wonderful Hacker criterions or anything like that I am afraid.

It will be nice to see lots of difference, IMOtHO, Just how many ways could we use a 6EM7?

[pre65]

Hi - i would like to have a go at building a cheap amp.I now have both the MJ valve books and i find the "big" one a hard read on the theory side.
i have a project in mind,but the circuit diagram i have is lacking in certain details.would any of you "experts" be prepared to look at the circuit for me and advise ?
i hope to learn as i go with this project,but having no "bits box" i will have to buy most bits new (or e-bay).is it still a requirement for the project to have a working MM phono stage ?
Anyone who can help please PM me with your e-mail address.


Philip

[Paul Barker]

no doesn't have to be 6em7 that was a suggestion of one possible way.

no doesn't have to have a phono that was a moment of lunacy but me, then I forgot all about it.

Philip put the scheme up here we'll all chip in. Dr John will probably instantly recognise it anyway. Can you scan it and attach it here?

Andrew, no sex please we're British. Trust you!