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Band practice yesterday and my Twin started farting ("broken fuzz" type distortion) and volume dropped a lot. Both channels are affected, so I'm presuming it's in the power section. PI and power valves are about two years old and the amp was recapped at the same time (but I know that's no guarantee). Valves are all glowing normally.

So I'll have a quick look at the valves today. Anything else I should look at while I'm in there?
(Damn, just realised I don't have any of 6L6s on hand to test - while I would rather have it rebiased by a pro if I'm going to change them, it means I can't even check to see if it's the power valves before I take it in).

As an aside, was quite proud of my band - even though it was practice, they kept comping through the chord sequence while I quickly verified it was the amp, then I just cranked the piezos, finished the song and quickly swapped in my GT-8 into the PA quickly after the song (I have an amp-only patch I use for headphone practising late at night). Just how I'd want it to go if anything went wrong in a performance. ?
    Alan Ratcliffe wrote: As an aside, was quite proud of my band - even though it was practice, they kept comping through the chord sequence while I quickly verified it was the amp, then I just cranked the piezos, finished the song and quickly swapped in my GT-8 into the PA quickly after the song (I have an amp-only patch I use for headphone practising late at night). Just how I'd want it to go if anything went wrong in a performance. ?
    yeah well done to the band alan....... you obviously cracking the whip there....yes often the difference between the top bands and the rest is only seen when something goes wrong in a show, and how they recover without letting the "wheels fall off" .....as the old showbiiz adage goes ....."the show must go on" regarless ? well done to the band

    @alan what kinda music you guys/gals playing, what genre, i know you personally tend towards some unique /experimental type techniques in your playing so are we due to see something exciting with this band ?
      I had a similar problem a few years ago with a JCM 800, i had all the valves replaced, the valve sockets etc. It kept happening and in the end the problem was the master volume pot, it didn't connect as well as it used to..
        It sorted itself out. I reseated all the valves just in case, but it was still alternating between quiet and fuzzy and sudden, clean volume swells. So I cranked the volume up to five and it suddenly came right. I think maybe she just wanted to be cranked up a little for a change ? (I usually play on 3 ...and with a Tube Tamer).

        So problem gone for now. However I'll still get her checked out soon for faulty solder joints and caps - I hate knowing there is an intermittent problem waiting to resurface at the most inopportune moment. Maybe spoil her and throw in a quad of SED Winged C 6L6s to keep her happy (me too ?).
          My ritual under those kinds of circumstances is to take out the valves and blow on them and the sockets to make sure it's not a connectivity issue due to dust. ? Sometimes the silliest things cause problems like that.
            Keira WitherKay wrote: you obviously cracking the whip there....
            Not at all. They do tend to defer to me, which actually makes me a little uncomfortable as I'm the relative young'un and musically relatively uneducated compared to the other guitarist or the keyboardist.
            @alan what kinda music you guys/gals playing, what genre, i know you personally tend towards some unique /experimental type techniques in your playing so are we due to see something exciting with this band ?
            It's actually basically a pick-up band I put together out of the local talent, specifically for the upcoming "Patatfees". Playing outdoors to a beer garden audience, so it's mostly standard crowd-pleasers that we can pull together with a couple of practices. I'm planning a solo, original show sometime this year (one of the venues is nagging me), but need some time to get it up to snuff...

            There is one thing keeping this gig interesting - we don't have a bassist, so I am often covering the bass (with my Roland GR-55) on the lower two or three strings and sometimes a lot of the keyboard stuff too, which keeps me on my toes. For instance, we do Nights in White Satin and I have cello on low three strings at the same time as doing electric and (modelled) acoustic 12-string fingerpicking parts, and fade in a full string section on all six strings with the footpedal when needed for the chorus. With the keyboardist playing piano and the other guitarist faking bass with an octaver, it's a very full sound. Another fun one is Joe Jackson's Is She Really Going Out With Him?, where I cover bass (modelled) on the bottom two strings and Rhodes on the upper four, all over the electric guitar sound. There is a nice counterpoint between the parts and some very interesting chord sequences for a pop song...
              Aha. I had a similar prob with the Bassman. Cleaned the sockets to no avail. Gave the head a light tap and all good again. In the end it was a dry joint on one of the preamp tubes. Maybe the increased vol did what my tap did. Check it out.
              Cheers
              Andy
                You've gotta love valves. ? I'm old enough to remember "percussive maintenance" of older TVs (where you give 'em a good smack upside the box to stop the picture rolling or get the colour back). Come to think of it, we had "percussive education" in those days too...
                  Alan Ratcliffe wrote: You've gotta love valves. ? I'm old enough to remember "percussive maintenance" of older TVs (where you give 'em a good smack upside the box to stop the picture rolling or get the colour back). Come to think of it, we had "percussive education" in those days too...
                  Percussive government too. All in all, the world was a drummer's paradise back then. Think about that... ??? ☹
                    This might be silly, but maybe the connection from amp to speaker?
                      Jacquesg4j wrote: This might be silly, but maybe the connection from amp to speaker?
                      Not silly at all - first thing I checked. ? Then disconnected the Tube Tamer and plugged the speakers in directly, no difference.

                      Not to worry, It's working now and I'll get it checked out properly ASAP. More than likely just a dry joint somewhere, but I don't poke inside valve amps myself - 'lectrickery loves me.
                        Alan you're welcome to bring it over next time you're in CT. I feel I've owed you a "labour favour" for a while now, ever since you set up my stratacoustic ?
                          Cool! ? Was going to bring it to you anyway, just hectic this week. Just hoping it doesn't crap out at my open air gig on Saturday. ☹
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