Hi All

Hi all - Ive just got a wad Kat 6550 with EH kt88s couple of questions really.

1 can i get a valve cover for it ? dead scared the kids will touch it at some point and fry themselves ?

2 What type of transformers do i need by way of a power supply upgrade ?


3 I notice three points where it gets really hot almost to hot to touch so would some kind of internal cooling / external heatpipe arrangement be advisable ?

http://www.hydro-powered.co.uk/catal...roducts_id=250

something like that front middle left and right ?

Thanks for looking and taking the time to answer !

[Mike G]

Hi Chris,

I too have a WAD KAT 6550, before the demise of WAD they did sell dedicated valve covers specifically designed for their amps, but I've not seen any of these advertised for quite awhile now. I think one supplier bought up some Ex WAD stock, cases, transformers etc, maybe another member here might remember who that was.

For now you best hope is that someone here may have one they are prepared to sell, failing that make one yourself or find a local engineering firm that may help you.

Transformers have been well discussed on here, so I'm sure you maybe able to find threads regarding this. I myself have not considered a mains transformer upgarde for my amp. I maybe wrong but thought the WAD ones were specifically designed, so repalcements (upgrdaes) can be costly.

Is your amp a standard build? - Do you have or know any history? It maybe worth looking to tweak / upgrade the power supply in other ways. Richards heater / bridge mod in the FAQ is a good place to start, along with capacitor changes, maybe different rectifier valves etc, even a decent plug and DIY built mains lead. There is plenty to try.

The KAT 6550's are well known for running pretty hot (almost too hot to touch) so i'd not be unduly concerned about that, the mains Tx in particular.

As for heat sinks, in my view and for this application, they are not really practical or asthetically pleasing, as they really need to be mounted on the items generating the greatest amount of heat, ie the transformers and valves. Bolting them to the case will certainly help disapate the heat, but overall I don't think the operating temperature would be reduced that much.

I have tried a silent running Papst type cooling fan, this was quite sucessful, the amp was cooler, but the room warmer. All I created was a fan heater!! The fan was difficult to mount effectively as the air needs to be circulated across the top of the amp to make a worthwhile difference, I was also unhappy with the noise (even though it's sold as silent running) that the fan made.

Ultimately, I now have no cooling - the most practical answer for me, is siting on a rack allowing plenty of air circulation.

I'm not sure if this really helps, but hopefully my experiences may contribute to you finding a workable solution to your heating issues!

Regards

Mike.

Hi Mike

Thanks for that info :-)

The amp has had several upgrades - Black Gate electrolytics,Mundorf silver/oil coupling caps and Audyn caps. Not sure about other upgrades though.

The rectifiers are now EH 54UG Front set are now Mullards.

I know what you mean re Fan heater I have for now mounted a small slow pc fan at its side ( wondering if 2 mini fans inside would help ) as you say a noise issue though.

The Amp is placed under an open vent so plenty of circulation around all the components.

The Pre Amp is an icon audio LA4.2 - headphone Amp a Little dot mk111 lots of valves lots of heat.

Chris

[John T]

Hi Chris,

My son has a WAD valve cover on his amp. It was quite expensive - c.£70. It was made of perforated steel and personally. I was not impressed because it inhibited air circulation around the valves. Hot valves and young children have never been compatible and so I suggest you site the amp out of reach of inquisitive fingers!

John.