Fender Hot Rod Deluxe III - Drive Channel

CarpeDiem

ICBM said:

CarpeDiem said:

I'm glad you mentioned that as I was going to put the overdrive pedal direct into the effects loop. (There seems to be a trend for doing this at the moment.)

Guitar > pedal > FX return/power amp input is fine. It's guitar > amp input > FX send > pedal > FX return that isn't. What happens is that the pedal can have enough gain to make the signal at the FX return leak back to the FX send, either via the power supply, or in this case within the same chip since a dual IC is used for both send and return, and sets up a feedback loop. The result is that the amp will self-oscillate, often ultrasonically, and if you're unlucky it will fry something. The Hotrod is one of the amps where this definitely is an issue, I've seen several damaged like this.

Unless you know for sure that it's safe with your particular amp, the simple rule is to never run any kind of distortion (pedal or external preamp, including something like a Pod) in the FX loop, on any amp.

Thanks for your continued help, and explanations. I hadn't appreciated what sort of damage could be caused.

Danny1969

ICBM said:

CarpeDiem said:

I'm glad you mentioned that as I was going to put the overdrive pedal direct into the effects loop. (There seems to be a trend for doing this at the moment.)

Guitar > pedal > FX return/power amp input is fine. It's guitar > amp input > FX send > pedal > FX return that isn't. What happens is that the pedal can have enough gain to make the signal at the FX return leak back to the FX send, either via the power supply, or in this case within the same chip since a dual IC is used for both send and return, and sets up a feedback loop. The result is that the amp will self-oscillate, often ultrasonically, and if you're unlucky it will fry something. The Hotrod is one of the amps where this definitely is an issue, I've seen several damaged like this.

Unless you know for sure that it's safe with your particular amp, the simple rule is to never run any kind of distortion (pedal or external preamp, including something like a Pod) in the FX loop, on any amp.

You mean don't run anything with clipping \ dirt in the loop right ? delay  \ chorus etc should be fine on a Pod or similar effects unit ?

ICBM

Danny1969 said:

You mean don't run anything with clipping \ dirt in the loop right ? delay  \ chorus etc should be fine on a Pod or similar effects unit ?

Yes. Actually if you could find something that just introduced clipping with no gain (or minimal clean gain afterwards to make up the level to unity), that would be safe too. Even a normal clean boost is fine as far as I've ever seen - the only risk is with distortion devices that generate significant (I would guess at least 20dB) gain. Even at that, damage is rare, although you quite often get an oddly squashed tone which will indicate a problem before it gets to the point of cooking something.

I think the Hotrods are particularly at risk because of the dual IC - the feedback probably happens due to crosstalk inside the chip itself, so it's likely to be quite destructive quite quickly.

BintyTwanger77

Could you use an EQ pedal in the loop? 

ICBM

BintyTwanger77 said:

Could you use an EQ pedal in the loop? 

Yes, certainly. They usually only do a maximum of +15dB on the sliders, so even if you go completely nuts and max everything including the level slider you're probably only at about +30dB - and most people won't be daft enough to do that, since it will usually sound terrible. Any more sensible settings are unlikely to be over +20dB and probably a lot less than that, which isn't going to cause any trouble.

TTBZ

With my old one (might have been a mk1) I found the best drive tones to come from boosting it with a ts7 or behringer tubescreamer clone. Tightened up the flub and gave it a good mid boost. Though in the end I gave up and just used a Marshall gv2 on the clean channel.