[ClickVoodoo]

Hi,

I've recently purchased the 5150 III - its awesome. I have a concern tho: The valves are running extremely cool. They're working OK (glowing nicely) and the sound is great, but I'm surprised that they're not really hot. I own a VC 50 and an Ashton Viper 100 - both run almost too hot to touch. Certainly the cooler they run will likely prolong valve life, but should they be running so cool?

If anyone has had similar experiences with the 5150 III, please share, or if you know why its running so cool then shout out.

Cheers!

CV

[bonedish]

Hey,

It's nice to see a fellow 5153 owner here! I've read on other forums that the 5153 does come from the factory quite cool. I think I've read that some of them come at 18ma? Don't quote me on that, though!

I am getting a Weber Bias Rite next week and plan to bias the head myself. I've also read that most people who have biased the 5153 can only get it up to 26-28ma.

Like you said, it still sounds great, but I'd like to see if maybe the sound will improve after a good bias.

[drolaw]

Yep, it's normal. The amp was designed to use the preamp tubes to get the tone and use the power amps to drive that sound. If you get too hot you'll end up with mixed results.

It's pretty much the same with the 5150 and 5150II.

How is your 5153 holding up? I got mine and within a month I took it to a repair shop because of a bad wire. Turned out to be a known issues and Fender knew about it all along but didn't tell the owners.

Oh well, it's back in my possession and it sounds great.

[gto1968]

I own a new 5150 III also and would like to know, since you say it comes stock with 18ma would it do any harm bring it up to 22ma or so and would you notice a difference or do any harm??
_________________
Pete

[drolaw]

You will be fine. I would recommend that you contact Fender and see what this bias range is. I haven't opened my 5150 III yet but if it's like the 5150 II it has a bias range that is set and you can only set the bias in that range.

Also, if you know how to fingure out your plate voltage you can get a better understanding at what you bias should be.

Remember that the designer had a range in mind when developing the sound of this amp. If you go outside and make changes you're making changes to the amp that wasn't intended by the designers.

Some changes are good but others are not. Trust your ears!

[gto1968]

Thanks for the info! I would like to pick your brain again if I could? Is the V1 slot on this amp the phase inverter slot or did they make it a differnt slot? The book doesn't say, and I always thought it was the closest one to the input jack?
_________________
Pete

[drolaw]

The PI is the preamp tube right after the Power tubes. Peavey calls this the V4.

Such as....

Power tubes, V4, V3, V5, V2, V1, V6.

When you use the Clean/Crunch channel you are only using the V4, V3, and V6 preamp tubes. The V4 is the PI and I believe V3 is the effects.

When using the Lead channel you're using

V4, V3, V5, V2, and V1. The V4 is the PI and again I think the V3 is the effects loop.

Hope that helps.

[gto1968]

I'm sorry but I was speaking of the 5150 III, not the II.
I was able to talk to someone @ Fender, here is the correct info!

V1 - Channel 1,2,3
V2 - Channel 1,2
V3 - Channel 1,2
V4 - Channel 3
V5 - Channel 3
V6 - Channel 3
V7 - Effects Loop Drive/Recovery
V8 - Phase Inverter
V9, V10, V11, V12 - Output Tubes
_________________
Pete

[drolaw]

Doh, I should read the heading more. lol. Sorry. Thanks for posting though.

For more info on the 5150III go here.

http://www.evhgear.com/support/

[donho]

adjust the bias to 120 around 30 per tube.
warms the girl rite up. mine ran around 18 per tube which is way too cold.
the higher bias settings actually seems to warm up the tone of the amp a bit too.
definately a must.