BVP5500 bias adjust

[JMBassist]

Found this post from some months ago:
For Sale: Bugera BVP5500-Moded-please read

Can someone teach me how can I do this bias adjust in a Bugera BVP5500?

[BassmanPaul]

Take it to a tech to have this checked. It's not something that the average user can perform.

[T-Bird]

Hi.

What Paul said.

Even if there's individual bias potentiometers and test points for every tube, You still need to know all kinds of important values, like the B+ voltage. It's not rocket science, but all sorts of things can go wrong if You don't know what you're doing, and most of those things will leave you ampless until a tech corrects the mistake.

Regards
Sam

[JMBassist]

OK, guys.

Thanks for your opinions. I'll try to find some tech to do this work to me.

[username1]

You shouldnt have to adjust the bias on that amp as it is a hybrid and doesnt have power tubes. The small pre tubes dont need biasing and wont even have a way to adjust it. Usually biasing is for power tubes and that amp doesnt use them.

[KramerBassFan]

Transistors need to be biased too.

[churchpark]

WHat about replacing with a more better 12AX7 tube?

[BassmanPaul]

Originally Posted by churchpark

WHat about replacing with a more better 12AX7 tube?

No Offence but what has a 12AX7 to do with the bias of this amp????

[Growly Lytes]

Transistor output may need biasing.My last poweramp developed a distortion at very low levels for no reason.I took it to the tech & he told me that the bias was not correct but he fixed it.

[jeff62]

Originally Posted by Growly Lytes

Transistor output may need biasing.My last poweramp developed a distortion at very low levels for no reason.I took it to the tech & he told me that the bias was not correct but he fixed it.

+1

SVT-3Pro's seem somewhat susceptible to this issue when shipped from Ampeg. Biasing the transistor's takes care of this and you end up with all sorts of headroom as compared to prior.