L-pad 15W/8ohms ok with M15MK1 ?

gepetto1001

I built a l-pad (like: http://www.ampmaker.com/vr02x.asp) 15w/8ohm some time ago and have not been using it yet
but started wondering if it's too small for M15MK1?
I have no intention to use the amp at max volume with the l-pad but I was merely interested in the clean channels sound at higher volumes.

d95err

Re: L-pad 15W/8ohms ok with M15MK1 ?

I think that a 15W L-Pad is not enough for the M15Mk1. At the point of clipping, I measured my M15Mk1 to 17W RMS. With a little crunch, it's more than that, perhaps 20-25W.

Even with a fairly small volume decrease the L-Pad has to take a lot of power. E.g. at -6dB, the L-Pad takes 75% of the power.

One simple solution is to get two power resistors and build a fixed -3dB and stick it infront of the variable L-Pad. This means the variable L-Pad will only have to handle half the output power.

You can learn more about how much power an L-Pad needs to handle using Weber's L-Pad calculator:
http://www.webervst.com/lpad.htm

You can always try the 15W L-Pad. Just make sure to check it often to see how hot it gets. If it gets too hot, lower the attenuation level.

gepetto1001

Re: L-pad 15W/8ohms ok with M15MK1 ?

What I'm mostly afraid is that I blow the output transformer. And I do get very good distortion on channel 2 at low volume level.

Jetzt mitmachen!