Didn't blow up my amp today

[Jacew]

Re: Didn't blow up my amp today

Huh. I just dodged same bullet last weekend at rehearsal.

I always bring my tube amp when playing with band. Except last weekend I wanted to try my miniamp board. Hooked everything up, and no sound. Went through connections and everything until thought that Mooer had bitten by frost (it spent night in my car in -12 C).

Yesterday I remembered that when putting speakers in my new cab couple of weeks back I just used stock connectors in there. I always solder them, but this time was just feeling lazy...

Well, wire had disconnected inside... Never again. You can guess how relieved I was, that just by happenstance I didn't have my tube amp to idle there through troubleshoot without a load!

[JamesPaul]

Re: Didn't blow up my amp today

Solid State, no, tube amp, yes.

+1

[devastone]

Re: Didn't blow up my amp today

So if you play your amp without the speaker plugged in, it will blow up?

Solid State, no, tube amp, yes.

[Mincer]

Re: Didn't blow up my amp today

Some amps can handle a mismatch better than others. My Mesa has this as a 'feature' for a different tone as long as you don't go too high or low. Read the manual before you attempt this, and if you still don't know, consult the manufacturer.

[JMP/HBE]

Re: Didn't blow up my amp today

So if you play your amp without the speaker plugged in, it will blow up?

You can fry your output transformer playing a tube amp with no load.
You can also fry your output transformer using a mismatched load.

If you're lucky sometimes you can get away with small mistakes.

If you have a tube problem or a tube crap out lots of times it takes out other components as well leading to costly repairs.

For best results always match impedance & have regular maintenance to Thermionic Valve Amplifiers.

[Clint 55]

Re: Didn't blow up my amp today

So if you play your amp without the speaker plugged in, it will blow up?

[Clint 55]

Re: Didn't blow up my amp today

^ Ya and there's no feedback.

[JMP/HBE]

Re: Didn't blow up my amp today

[devastone]

Re: Didn't blow up my amp today

I once forgot to connect Orange TT to speaker. Burning smell coming out of it almost right away made me realize that mistake very quickly.

Didn't break anything though.

Yeah, that's why I'm trying to be careful to say "probably", "most of the time", "most amps" (meaning not all). I've done that with old Marshalls and took me a few to figure out why there wasn't any sound, but yeah, they don't build them like they used to, or maybe I just got really lucky.

[Jacew]

Re: Didn't blow up my amp today

People on the interwebs get very worked up about this stuff (duh), but honestly, having the selector switch on the wrong setting won't really hurt most good quality tube amps. It may put a little more wear on the tubes depending on which way the setting goes, but transformers, again, good quality, should be overdesigned enough that it doesn't bother them. Can't speak to some of the MIC amps where they have cut every corner possible, but I would still bet the transformer is stout enough to be fine.

Some of the Fenders heads, the Tone Master (?), had settings of high, medium, and low on the selector and you were encouraged to experiment to find the one that sounded right for you.

That said, don't run them below 4 ohms or above 16, and yes it is best to keep things matched. But having the switch set wrong is nothing to freak out about. Running without a cab, yeah, that's bad, but still, if it takes you few minutes to figure out why you don't have any sound coming out, probably not going to smoke it, any good designer would have realized that stuff like this will happen and design it well enough to prevent "reasonable" catastrophic failure. The industry term is FMEA, Failure Modes and Effects Analysis, which is done on most products, or at least should be. If you are in the medical field, it is required and reviewed by the FDA, in aerospace, if people are involved it is highly reviewed, if it's a satellite, failure to find potential failures can cost hundreds of 100s if not millions of $. But as recent news has shown, stuff can slip through the cracks of the biggest and best companies (Boeing).

I once forgot to connect Orange TT to speaker. Burning smell coming out of it almost right away made me realize that mistake very quickly.

Didn't break anything though.

[PFDarkside]

Re: Didn't blow up my amp today

Refreshing to see a couple of people understand that tube amps and solid state amps operate differently, and that speakers impedance and amp output impedance mismatch is different for tube amps and solid state.

[jeremy]

Re: Didn't blow up my amp today

that was such a cool amp!

[devastone]

Re: Didn't blow up my amp today

From the Tone Master Manual, again, not saying this is true for all amps:

D. IMPEDANCE SWITCH - This is labeled LO, MED and HI. This switch serves two functions.
One, to set the output impedance of the amplifier to best match the speaker impedance for
maximum power. Second, to enable the amplifier to better achieve the cranked-up sound at a lower
volume. On the B CHANNEL, with a single Tone-Master enclosure, this switch should be set
according to the setting of the B CHANNEL volume knob: For volume settings of 3.5 and lower,
LO would be the appropriate setting. For settings of 3.5 to 7, MED is best. For settings above 7,
HI will produce full power and tone. This switch will not damage tubes or reduce tube life at
these settings. What it does do is increase the gain in the LO and MED settings and thereby better approximate the Full volume sound at a lower level than by adjusting the VOLUME alone.
With a single 16Ω enclosure, LO will produce 30 watts, MED will Produce 60 watts, and HI will
produce a full 100 watts. With two 16Ω enclosures, (an 8Ω load), LO will produce 60 watts, and
MED will Produce 100 watts. In the A CHANNEL, the switch has the same function, although
blues players may like running the switch on LO all the time to get that great crying tone.
Conversely, a player looking for a New Wave Strat® tone might like the sound of the A CHANNEL
on HI.

[NegativeEase]

Re: Didn't blow up my amp today

My buddy from the UK who has passed now did a whole US tour with his Marshall JCM800 2203 set accidentally to 16 on a 8 ohm cab.

On one of the very last shows of the tour, I noticed it when I shared his rig in Asheville NC

Didn't hurt anything after 40 shows -just changed the tone slightly.

[devastone]

Re: Didn't blow up my amp today

People on the interwebs get very worked up about this stuff (duh), but honestly, having the selector switch on the wrong setting won't really hurt most good quality tube amps. It may put a little more wear on the tubes depending on which way the setting goes, but transformers, again, good quality, should be overdesigned enough that it doesn't bother them. Can't speak to some of the MIC amps where they have cut every corner possible, but I would still bet the transformer is stout enough to be fine.

Some of the Fenders heads, the Tone Master (?), had settings of high, medium, and low on the selector and you were encouraged to experiment to find the one that sounded right for you.

That said, don't run them below 4 ohms or above 16, and yes it is best to keep things matched. But having the switch set wrong is nothing to freak out about. Running without a cab, yeah, that's bad, but still, if it takes you few minutes to figure out why you don't have any sound coming out, probably not going to smoke it, any good designer would have realized that stuff like this will happen and design it well enough to prevent "reasonable" catastrophic failure. The industry term is FMEA, Failure Modes and Effects Analysis, which is done on most products, or at least should be. If you are in the medical field, it is required and reviewed by the FDA, in aerospace, if people are involved it is highly reviewed, if it's a satellite, failure to find potential failures can cost hundreds of 100s if not millions of $. But as recent news has shown, stuff can slip through the cracks of the biggest and best companies (Boeing).