Ashdown combo possibly picking up interference, what's the cause and can it easily be fixed?

[Hellzero]

9 minutes ago, Osiris said:

I'll probably go with a set from here as they claims ot be a matched pair for the specific model - 

https://www.ampvalves.co.uk/product-category/choose-your-amp/ashdown-amplifiers/ashdown-220-touring/

That's perfect. 👍🏻👌🏻

[JapanAxe]

I occasionally gig with a local singer-songwriter. On one such gig, I was to be on lead guitar and when we rehearsed in the BL’s front room, the bass player was getting noise through his old-school Class AB combo (can’t remember what, but not Ashdown). After our rehearsal I volunteered to take a look at it, so we heaved it into the kitchen so that I could get the chassis out and onto the table.

 

The amp worked fine in the kitchen. We identified the source of noise as the BL’s wireless router.

 

There are plenty of old bass amps either designed or built in the 90s that are still being gigged today because of their perceived sonic heft, and despite their physical heft. Far fewer people back then had WiFi at home, so it wasn’t something designers had to address.

 

Also I think getting your gain staging right may help to reduce background noise.

[basstone]

It would be worth servicing the amp if it's not been done for may years. Over time connections can deteriorate and the cumulative effect can cause increased noise pickup, particularly if the grounding is not totally effective. I've made improvements to several amps by improving screening in critical places, such as unscreened input jumper cables. Some designs are more susceptible to noise pickup than others should not be so bad as to make the amp unusable.

[ghostwheel]

8 hours ago, Osiris said:

 

Thanks, that's very helpful. I'll probably go with a set from here as they claims ot be a matched pair for the specific model - 

https://www.ampvalves.co.uk/product-category/choose-your-amp/ashdown-amplifiers/ashdown-220-touring/

 

But I'm going to contact Ashdown first and see what they have to say and will likely book it on for a service as it's probably long overdue. 

FWIW, there are two 12AX7 according to the manual for 220 Touring. In the schematic I've got, there are two 12AX7 as well. Apart from that, the design is rather typical for 12AX7.

[itu]

12AX7 = ECC83. 

[Hellzero]

ECC82 = 12AU7.