HRD - Volume loss - New valves?

Tone71

Playing last night, loud and there was a loss of volume almost like a rolling off the volume then a rolling back up again, first time I've had any issues with it and gets played loud pretty much weekly.

Having looked I found an old thread on here saying it was probably the preamp valve or socket connection, and not being overly keen on wielding a soldering iron thought it best to start with replacement valves, they are the original ones in there now so regardless a change of valve will be a good thing so not necessarily a waste of money.

Best place or recommendation for buying replacement valves online?

Also is it absolutely necessary to check the bias?

Cheers all

ICBM

Karltone.

It's not absolutely necessary to check the bias if you're replacing the power valves (not preamps) but it is a good idea - it's easy in these if you have a multimeter.

It's arguably more important to reset the voltage connection from 230V to 240V if it hasn't already been done, which is also straightforward once you've got the back off.

Tone71

Thanks @ICBM it was your comments earlier that I referred to, I have a multi meter so maybe it's worth getting a bias probe, will also look at the voltage reconnection, any tips?

Cheers

ICBM

Tone71 said:

Thanks @ICBM it was your comments earlier that I referred to, I have a multi meter so maybe it's worth getting a bias probe, will also look at the voltage reconnection, any tips?

You don't need a bias probe, the amp has a test point anyway - it's on the front left-hand corner of the valve base PCB.

The voltage change is simply reconnecting the white/black-stripe wire on P4 and the black wire on P10 the other way round - you may need to undo the cable tie on the wiring bundle, but it's otherwise totally straightforward. Do that before you check the bias.

Philtre

Thanks to @ICBM 's expert advice I've changed the voltage on my HRD to 240v and bias it with a multimeter.

See this thread:

https://www.thefretboard.co.uk/discussion/204659/fender-hrd-iii-changing-to-240v-confirmation-needed

Also, +1 for Karltone.

Tone71

Cheers both, will have a look

Tone71

Brilliant, changed it to 240v no probs, changed all valves and the 6L6's to Jan Philips, biased to 68 and it sounds fantastic, taking it out tonight to give it a crank and see how it sounds at studio levels.

Really surprised how easy this stuff is and it has made a huge difference in sound, really really clean now.

Philtre

@Tone71 Good to hear that. The 240v change is a doddle, isn't it? Referring to your OP, I was getting a mysterious dropout on my HRD (thread here) and reseating and replacing some of the valves cured it. Hope yours remains fixed!

Tone71

Philtre said:

@Tone71 Good to hear that. The 240v change is a doddle, isn't it? Referring to your OP, I was getting a mysterious dropout on my HRD (thread here) and reseating and replacing some of the valves cured it. Hope yours remains fixed!

Yes, really easy and tonight it sounded really great at volume, very happy