Unfinished WAD 300b PP kit

[cc454]

I am waiting on delivery of my ebay find of an unfinished W.A.D. kit. It appears to have all the iron install, tag boards and a few components installed.

In the mean time I have been researching the amp and its schematic and have been enjoying the results.

I am not sure if the mains transformer has export type primary taps.

Does anybody know what to look for?

Will post pics as soon as it arrives.

[John Caswell]

There were 2 types of 300B pp amplifier - one a mono block and the other a stereo version, any idea which?

John

[Pingushome]

Hi CC454,
if this is the amp with the wood surround on EBay it’s a strereo power amp, but I’m not sure it’s a world audio designs amp it may be an American clone. No doubt the circuit will be near enough identical tho. Be careful of the mains voltage if it’s the US one as you have already mentioned
No doubt someone on here will know when it arrives and you post some pix
Good luck
Martin

[cc454]

Yep, that's the very one.

I was unfamiliar with the WAD brand until I started on the research. It does have "Panacea Engineering Company" right there in the artwork. Could not find anything on them.

I have been looking to build something a little more exotic for home use.

[A Stuart]

This may be relevant. Have not read the whole thing.
See post #42, where the author heli001 appears to be, or to work for, Panacea Engineering.
https://www.audio-talk.co.uk/phpBB3/...=3542&start=30

[Pingushome]

Originally Posted by A Stuart

This may be relevant. Have not read the whole thing.
See post #42, where the author heli001 appears to be, or to work for, Panacea Engineering.
https://www.audio-talk.co.uk/phpBB3/...=3542&start=30

Oh very well detected indeed Stuart, we will have to start to call you Sherlock! 👍🤭
Yes that is what CC 454 has bought
Martin

[Richard]

Originally Posted by cc454

I am waiting on delivery of my ebay find of an unfinished W.A.D. kit. It appears to have all the iron install, tag boards and a few components installed.

In the mean time I have been researching the amp and its schematic and have been enjoying the results.

I am not sure if the mains transformer has export type primary taps.

Does anybody know what to look for?

Will post pics as soon as it arrives.

Hi and welcome.

Whilst waiting for delivery why not email the vendor to see (if he bought the parts) what mains TX is included.

AFAIK the amp was sold over here with 0-220-240V primaries, for UK or European use.

If you're in Texas and you've bought it from a US vendor hopefully it will have a US voltage mains TX.

If it were mine I'd remove all valves and run it up on a variac to check the voltages out of the secondaries then check all the parts and circuit against the diagram.

[cc454]

I am keeping my fingers crossed for a 120vac mains, but for less then half the price for a set of tubes for this amp I can install a dedicated 220vac outlet in the wall where my audio equipment lives if need be.

I am thinking the economics of the 300b will be addressed 1st.

I'm researching making something to address the cold hard starting the filaments and staging of the HT.

[A Stuart]

Originally Posted by Pingushome

Oh very well detected indeed

I recently discovered that Firefox has a "Find in Page" function using Control+F, or in the drop-down menu from the three little lines icon.
This makes it easy to locate a word like "Panacea" hidden within a large page.

I later noticed that after 275 posts in the thread, it still wasn't finished!

Alastair

[Greg.]

Originally Posted by cc454

I'm researching making something to address the cold hard starting the filaments and staging of the HT.

If the clone you have accurately follows the original WAD circuit, you already have a soft start function. Check the circuit around the GZ37 and you will find the HT is rectified by solid state diodes. The GZ37 is not used as a conventional rectifier, but as a soft start component. Of course this only applies to the HT and not the filament supply.