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I've got a Blackstar HT Stage 60 2x12 combo that I got serviced (new tubes + biasing) at The Amp shop approximately 4-5 years ago. I sold the amp and bought it back within 1 month, and I think the new owner had a mate that replaced the tubes (not sure if he biased it).
Basically my question is who here biases their own amp? Obviously it's best done by a professional, but I'm comfortable replacing the tubes (lol), but heard you can die if you touch a wrong high-voltage capacitor etc.
When I picked up my amp from Ryan he did mention these Blackstar Amps are a pain to work on

Its not a difficult job if you have some electrical knowledge. It is a dangerous job though if you don't know what you are doing.

If it sounds ok and the power tubes aren't red plating I wouldn't worry too much.

Ryan generally bias amps on the colder side if I remembered right (50-55%) so it should be relatively safe for you to just throw in a different pair of the same brand/model of tubes without biasing.

I've biased my Sovtek Mig 100 myself before (bit fiddly), and my (ex) Bogner Uberschall (really easy - external test points/pots). Easy enough, but as mentioned, lots of large voltages/currents hanging around, gotta be safe.

Guess it depends on the amp. Fender HRD for example is easy (YouTube guidance) but I wouldn't know where to start with a Marshall.

Sam Browne mentioned on facebook the other day that Ryan had just serviced his amp and all was good!

jeremyb wrote:Sam Browne mentioned on facebook the other day that Ryan had just serviced his amp and all was good!

Sorry as much as I like Ryan, servicing one amp does not make him a reformed character. Maybe reaching out to the people he's let down would be a start.

anyway, its pretty easy to bias an amp - even easier if test points and pots are provided externally - why don't all amps do this, those with fixed adjustable bias anyway.

And of course, Katana!

Bg wrote:

jeremyb wrote:Sam Browne mentioned on facebook the other day that Ryan had just serviced his amp and all was good!

Sorry as much as I like Ryan, servicing one amp does not make him a reformed character. Maybe reaching out to the people he's let down would be a start.

For sure!!! Was just commenting cause his name came up.

Bg wrote:anyway, its pretty easy to bias an amp - even easier if test points and pots are provided externally - why don't all amps do this, those with fixed adjustable bias anyway.

And of course, Katana!

Yeah, but you're biased...

All week. Veal etc.

I bias my Deluxe Reverb using a bias probe, like this https://www.ebay.ca/itm/2-in-1-Tube-amp ... Swq7JTzk5p

The DR has an external access bias pot which makes things easier.

You do need to look up the tables and do the maths to get the ideal current bias for the particular tube you're using but it's pretty straight-forward on this kind of amp.

Looks very easy to set it to Blackstar's factory settings.




Then all you'll need is a decent cab like this one.

http://nzguitars.com/forum/viewtopic.php?f=51&t=33965

The thing that confused me with Blackstar amps that isn't explained in the video is the need to have something plugged into the input before biasing. Blackstar uses an unusual switching/muting design where you won't measure any current on the output tubes if the input jack is empty. Most tube amps you bias with no signal input (ie. at 'idle').

Setting the balance pot can be important too, if the bias was previously adjusted/balanced for a well-used or nearly worn out pair of tubes and now you've installed a fresh matched pair.