thisisswanbon Posted July 17, 2018 Share Posted July 17, 2018 Hi! So I purchased a second hand Gallien Krueger 1001Rb-II after realising class D was not for me... and after taking it out for it's first gig realised that, one of the pots was incredibly scratchy. Half a tin of Deoxit later and the scratchiness is gone, but there are some serious loud pops that make the speakers jump when the dial is turned. Anyone have any idea where I can get a replacement knob? All roads seemed to lead to polar, who haven't been much help thus far... Thanks Quote Link to comment Share on other sites More sharing options...
BassBod Posted July 17, 2018 Share Posted July 17, 2018 Take it to a good tech...chances are very good that the correct value pot is available from many other sources. Even a quick evilbay search will probably turn up a few options (although US, most likely). Quote Link to comment Share on other sites More sharing options...
thisisswanbon Posted July 17, 2018 Author Share Posted July 17, 2018 7 minutes ago, BassBod said: Take it to a good tech...chances are very good that the correct value pot is available from many other sources. Even a quick evilbay search will probably turn up a few options (although US, most likely). I had it in with a good well known local tech last week, but he suggested that he was unable to get the specific pot Quote Link to comment Share on other sites More sharing options...
BassBod Posted July 17, 2018 Share Posted July 17, 2018 In that case, be polite but persistent. Try Polar...but also get the "spec" of the part you need and search US suppliers. Its probably a board mounted pot, so its the exact size and pin location that matters. If you have to source from the US, then think about adding a second spare pot, or some knobs..or a handle to your order. The things that break or fall off! It will take some time, and cost a bit but probably worth it if you really like the amp. Quote Link to comment Share on other sites More sharing options...
Bigwan Posted July 17, 2018 Share Posted July 17, 2018 57 minutes ago, thisisswanbon said: I had it in with a good well known local tech last week, but he suggested that he was unable to get the specific pot I've heard this excuse a few times. It usually means I can't be bothered. I'd try somebody else... 1 Quote Link to comment Share on other sites More sharing options...
hubrad Posted July 17, 2018 Share Posted July 17, 2018 If Polar aren't being much help, I'd contact GK in USA. If they suggest contacting Polar, say why you've come direct to head office! 1 Quote Link to comment Share on other sites More sharing options...
The fasting showman Posted July 17, 2018 Share Posted July 17, 2018 Apologies if this seems a bit of a strange suggestion...have you put a jump lead in the FX loop? I have cured some real weirdness with GK RB heads this way, cutting out, popping, low volume you name it. I absolutely love the RB heads but alas the jack sockets and pots are a bit high maintenance. I believe there is a company in the US that supplies entire new 700rb/1001 rb preamp modules (quite cheap but that is minus customs etc) but I think that it will be something more trivial so give the jump lead a go if you haven't already. All the best, Martin 2 Quote Link to comment Share on other sites More sharing options...
BassBod Posted July 17, 2018 Share Posted July 17, 2018 Always a good idea - we never seem to use the return socket (with switch in the signal path). In this case, can’t help thinking it’s probably worth going to another tech for diagnosis and fresh opinion. 1 Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted July 17, 2018 Share Posted July 17, 2018 6 hours ago, thisisswanbon said: I had it in with a good well known local tech last week, but he suggested that he was unable to get the specific pot Maybe he doesn't have it in his parts bin, but neither G-K nor anyone else uses proprietary parts. Contact G-K, if they can't recommend a source at the very least they can tell you what's in there so you can track it down yourself. 1 Quote Link to comment Share on other sites More sharing options...
thisisswanbon Posted July 18, 2018 Author Share Posted July 18, 2018 Thanks for all of the suggestions everyone! Turns out Polar have suddenly come up good! I got in touch with a guy called jack who identified the part and it'll be here in 2-3 days which schematics if needed Only came to £7 incl VAT and shipping so not bad! Just hoping this fixes it. Still interested in this jump lead in the FX loop though! Would that have any bearing on getting a bit more growl out of the amp? With the crazy amounts of power in this head its difficult to run it hot to bring the GK growl out Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted July 18, 2018 Share Posted July 18, 2018 2 hours ago, thisisswanbon said: Still interested in this jump lead in the FX loop though! Would that have any bearing on getting a bit more growl out of the amp? No. All it does is to bypass the internal jumper. Some amps use a switching jack on the FX loop, which can over time get dirty or corroded. Using a jumper can shake loose dirt and/or remove corrosion, but so does just using cleaner on the jacks. 1 Quote Link to comment Share on other sites More sharing options...
The fasting showman Posted July 18, 2018 Share Posted July 18, 2018 (edited) Glad that Polar have helped you out in this instance. As BassBod and Bill have said, putting a jump lead in the FX loop causes the switching jack (FX return?) to get opened up thus breaking corroded contacts. You won't notice any difference in sound quality or gain etc but it can restore some order to the sound if things had gone erratic, crackly, fading up and down in volume, weird pops. I have experienced this problem with 400rb/800rb and 700rbii heads. If you have got a spare guitar lead just try it between FX send and return. I have also got nifty with removing the preamp board and using Servisol on the jacks and pots but out of superstition I leave a jump lead in the FX loop! To echo a point Bill made earlier, after changing my old US 400rb to a UK mains transformer, the amp tech I use thought that the parts and circuitry were very easily fixable if need be. Mind you, he managed to sort out the old '70s SVT I used to have where others had failed so he is quite a demystifier. Likewise Basschatter Nick sourced an off the shelf transformer for an 800rb after Polar dragged their feet. So the parts are out there, I think there is a pdf online with all the components for the 700rb/1001rb amps; Rean jacks, Alpha pots and so on so forth. I must add that my electronic know how is very basic but I am fairly logical and can suss out a decent amp tech. The bloke I use isn't an amp tech to the stars or even a musician but he has been a great help over the years. All the best, keep us posted, Martin Edited July 18, 2018 by The fasting showman poor syntax! Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted July 18, 2018 Share Posted July 18, 2018 1 hour ago, The fasting showman said: Mind you, he managed to sort out the old '70s SVT I used to have where others had failed Old valve gear is the easiest to work on. Point to point wiring and easily accessible parts make working on them not unlike working on a vintage car. Modern amps are a PITA, just like modern cars. They're made with everything attached to circuit boards, including the pots and jacks, and getting those boards out to work on them can require removing every knob and nut on those pots and jacks. It can take over an hour to remove a board to replace a component, if you can replace the component at all. Often the cost of repair exceeds the cost to replace the amp. It took me an hour to even find the oil filter on my last car, while changing it required pulling off a tire. Things today are designed to have the lowest possible labor cost to build them, with no regard to how difficult and expensive that makes it to fix them. 4 Quote Link to comment Share on other sites More sharing options...
Delberthot Posted July 19, 2018 Share Posted July 19, 2018 On 18/07/2018 at 13:31, thisisswanbon said: With the crazy amounts of power in this head its difficult to run it hot to bring the GK growl out This was exactly the reason that I sold my one. You have to have it so loud to get the GK growl that it's too loud - the 700RB was easy to get the growl from 2 Quote Link to comment Share on other sites More sharing options...
roblpm Posted October 27, 2018 Share Posted October 27, 2018 On 18/07/2018 at 21:46, The fasting showman said: Glad that Polar have helped you out in this instance. As BassBod and Bill have said, putting a jump lead in the FX loop causes the switching jack (FX return?) to get opened up thus breaking corroded contacts. You won't notice any difference in sound quality or gain etc but it can restore some order to the sound if things had gone erratic, crackly, fading up and down in volume, weird pops. I have experienced this problem with 400rb/800rb and 700rbii heads. If you have got a spare guitar lead just try it between FX send and return. I have also got nifty with removing the preamp board and using Servisol on the jacks and pots but out of superstition I leave a jump lead in the FX loop! To echo a point Bill made earlier, after changing my old US 400rb to a UK mains transformer, the amp tech I use thought that the parts and circuitry were very easily fixable if need be. Mind you, he managed to sort out the old '70s SVT I used to have where others had failed so he is quite a demystifier. Likewise Basschatter Nick sourced an off the shelf transformer for an 800rb after Polar dragged their feet. So the parts are out there, I think there is a pdf online with all the components for the 700rb/1001rb amps; Rean jacks, Alpha pots and so on so forth. I must add that my electronic know how is very basic but I am fairly logical and can suss out a decent amp tech. The bloke I use isn't an amp tech to the stars or even a musician but he has been a great help over the years. All the best, keep us posted, Martin Well further to my other post this has just happened to my rb800. Lost volume. Fuzzy. Putting a lead in the effects send / return sorted the problem for a minute but now doesn't! So needs a service! Quote Link to comment Share on other sites More sharing options...
The fasting showman Posted November 11, 2018 Share Posted November 11, 2018 Hi Rob, My next thing to look at would be preamp gain for scratchiness or again the dreaded Cliff type input jack. Thankfully (annoyingly though!) it will most likely be something like a pot or a jack if it reverted back to normal albeit briefly. My 700rb needs all the pots doing with Servisol from time to time, when they are crackly without anything plugged it in it's that time again. All the best Quote Link to comment Share on other sites More sharing options...
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