Engl Savage 120 Biasing - Cold Biasing?

Sacrimon

New member
QQ: Anyone Bias an Engl Savage before? Does anyone know what's up with the cold biasing. I noticed the bias quite cold and the range is limited on the bias pot when I went to change out my 6550's to KT88's last night. I did some research, and looks like this is by design not only on the Savage but several other Engl model amps too, but wondering if there is a recommended percentage ENGL suggests, since you clearly can't bias up to 70% Are most people having to do resistor mods in their Engls or using some sort of standard percentage to bias their power tubes running them a bit cold all the time? I went ahead and set them for 50% for now, which is a bit hotter than was default. It seemed like the amps bias pot was all the way down to the minimum or very close. This is a brand new old stock Savage I picked up, so it's never had tubes changed. I just wanted to throw in some KT88s instead of the 6550 Engl Sovteks, which I prefer a bit more.
 

MetalHeadMike

Well-known member
I never messed with power tubes or biasing when I owned my Savage. Wish I had, because what your saying makes me think had I switched to KT88s and maybe biased a little hotter, that maybe would have "warmed" the amp up a touch. It is one of my all time favorite amps, but it was just a touch too stiff in response in the end, and I traded it. I can't help but wonder now based on what your saying here if those changes would have yielded the character I was after. I've found on a few other amps after trading the Savage, that I prefer tubes other than 6550s.
 

Sacrimon

New member
I can say this, I had owned another Savage 120 with KT88's in it previously and the resistor must of been modded. I threw in the same exact power tubes that were in it, and I'm biasing this new one at about 50% which is running them a bit cool, and it is a lot tighter, stiffer, not as much break up, but the other Savage I had with the same exact tubes, had tons of breakup, was more brutal sounding, so must of been running them a lot hotter. I sent an email to Engl asking them about this and why they are limiting the range when the stock tubes are 42W 6550 Engl Sovteks. I do notice that the 6550's break up a lot more running them cool, so maybe that is the case with the Sovteks not needing to run them as hot as the KT88's. I'm just looking for a technical answer to this, because it seems from searching, Engl does this quite a bit with other models of their Amp also by design. If I need to have the resistor changed to open up the bias more, I can do that, but want to do my research before I take this into a tech to have that done.
 
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