The Amp Garage

any sugestions on a good model to buy? I have an old general radio W5mt only 5 amp and no meter.

would this be ok? http://www.circuitspecialists.com/variac-tdgc2-2.html

thanks for all the info - I have a plexi and 18 watt clone and this will be perfect for the variac.

I've used the Variac and attenuators (many attenuators) I like the Variac best but have always backed off from using it because of the warnings on the internet. Who really knows? I just read this Variac warning-- shortens heater life and can lead to cathode stripping. Lowering voltage, depending on ...

what about adding a tone pot? why they don't put one on all the attenuators? Because the tone pot would have to be able to handle (almost) as much power as the whole attenuator. The Weber MASS Lite attenuators actually has this (labled Mids-Highs). It is a 50W pot for the 50W version. Thanks for th...

what about adding a tone pot? why they don't put one on all the attenuators?

so the screen resistors were good?

If you have to change the screen resistors. you can unsolder them and let them drop out, then replace them on top of the board. Saves a lot of time with the rivets. Have you checked them yet?

yea that's right that would mess with the heater voltage - not good

Can achieve the same results using a variac? I have an old general radio w5mt laying around. I figured I could dial this down to 100 ac an get the same results. Bad idea?

Yea just 2 uf to 5uf with 5 watt 8 ohm inline

LOUDthud wrote:I think you are going to need something in the 10 to 20uF range. Shop for a non-polarized electrolytic typically used in crossover networks. It might be wise to install an 8 ohm 5W resistor in series with the cap so it won't damage the pot at low volumes.

Thanks- how high a voltage for the cap?

I like to add a bright switch like the ones found on other attenuators (HP weber-rivera) is it possible to do on the airbrake? would changing the value of the .1 cap do it? thanks Update: it seems I have to go with cap values no higher then 5uf - 1 to 2 uf sound best for the full range attenuation I...

sounds like its in the power amp. check the filter caps.

Mark wrote:Good to hear you've solved the problem. The other thing to consider is the screen grid resistors. The 1K valves offers the output tubes real protection but there will be less bass response as a result of the 1K resistors.

Thanks what are other values to try? I think I saw 100 ohm here. Thanks