Dave

Someone on the EB board mentioned the foam underbelly of a mouse mat is almost identical to the material used in the original Musicman Stingray bridge string mutes, and as I examine the one currently sitting beside my computer I'd have to agree. Probably too thin to reach a string, but I assume you could possibly stack and glue a few pieces together and it should work a treat. Hope that's helpful!

I seem to recall there is a difference between the pre-amps in the 2EQ and 3EQ models. I think the 3EQs are cut and boost, whereas the 2EQs are boost only (or something like that) but I could be wrong. I actually have one of each (an '89 2EQ and a late 90's 3EQ) but have never strung them up or tuned them both identical to be able to give a definitive answer regarding differences in sound. They also have different necks (3EQ maple and 2EQ rosewood) but I guess I should do a proper comparison one day. I like them both for different reasons, but probably more due to the neck differences because of their age differences (the 2EQ has a "finished" neck) though I'd say they definitely sound different. The 2EQ seems to produce the "one trick pony" classic Stingray sound a little better than the 3EQ does, but I'm happy with that. If you want a Stingray, you probably can't go wrong with either (so I guess that would suggest you may as well save the money and buy the 2EQ). Or as others have said save even more money and buy a second hand one. I thought about selling one of mine, but knowing what they typically go for these days on Basschat and fleabay, I've decided to wait as they're worth more to me than the loss I'd take. I might change my mind once I find a Sterling5 to try.

[quote name='Cabal' post='343916' date='Dec 3 2008, 11:30 AM']Now this is what i call a selection of pickguards: [url="http://www.wdmusic.co.uk/"]http://www.wdmusic.co.uk/[/url] Anyone bought from here?[/quote] Hey Cabal. I actually have a few spare MusicMan pickguards for an SR4 (and am based in the Birmingham area), so let me know what you're looking for. I went a bit pickguard crazy back in the day, but have gone back to using the black ones my SR4s originally came with. If I remember correctly I have abalone, black pearl and tortoise shell guards going spare, so if you're interested, just drop me a PM. I also have a strange gold coloured one from one of the limited edition Stingrays. They all fit the standard single humbucker SR4 with the trussrod adjustment wheel at the bass of the neck. Otherwise if you're looking for alternative sources, I bought a clear plexi guard from Dazbootman on ebay. He's based in the US and I assume he makes them himself (and was strangely based in San Luis Obispo where the MusicMan factory is/was), but the one I bought fit perfectly and it was much cheaper than the official ones and still of good quality.

Just want to thank everyone who gave me advice regarding cleaning the potentiometers on the old Marshall amp I recently picked up. Once I'd opened up the amp I then sprayed some Servisol into the openings at the rear-side of the pots and twisted the knobs about 50 times each way and then closed her back up and left her to dry for about 48 hours. Almost all the pots were crackly before I tried this, and one gave a lot of resistance, whereas now they all turn smoothly, and only one of the pots still crackles a little (though much less than before). I twisted this one some more and it seems to be improving. I assume I could probably re-clean this one and it would be as silent as all the others. So again I'd just like to thank everyone for their suggestions, as I was clueless before I took this task on, and there's no better feeling than being able to sort out a problem "on your own" for very little monetary outlay. Love this forum, as ever a wealth of useful information.

[quote name='Mottlefeeder' post='320542' date='Nov 2 2008, 10:27 PM']If you haven't picked it up already, the WD in WD40 stands for water repellant or something similar. It isn't a cleaner and it isn't a lubricant. You need to get a can of something that says it is an electrical switch or contact cleaner.[/quote] Yeah, I assume WD stands for Water Displacement, or something along that ilk. The Servisol I bought is labelled as contact/switch cleaner, so I assume that's the stuff I need. I have seen some more expensive products on ebay (Deoxit, which a lot of the Yanks seem to prefer) but figure I'll give this stuff a try first, since a lot of the people over here seem to use it to clean out their pots with some success. As for the lack of lubricant, Thinman, I have read about that problem as well, but must admit my Marshall knobs don't feel particularly smooth even now, so if I clean out the pots and notice a detectable difference, I guess I'll need to address that problem next! Cheers!

Cheers BOD2, I've bought some Servisol Switch Cleaner from fleabay with the straw attachment, so I'll definitely be giving that a go. I had a bit of a play with the solid state Marshall last night and there is NO WAY simply turning the knobs back and forth will be fixing anything (I think they are quite dirty). I have also been playing around with different valve types in the other Marshall, but the pots on that one aren't nearly as bad, so will have a go at cleaning the bad ones and maybe try your valve base cleaning method as well. I guess I just have to be sure everything is completely dry before I switch it on again. If this doesn't work then I assume I may need to sort out some new pots, and I will probably need to find a decent amp repair specialist for that (hopefully not necessary). Thanks for all the advice (everyone), very helpful indeed!

Thanks ever so much for your suggestions/help, Musky, I really appreciate it! So much conflicting info on the net, I guess I shouldn't really be surprised. Some suggest WD40 is OK, others say it definitely should NOT be used. Some say you can clean the pot by simply spraying cleaner down the stem/shaft to get to the inner workings, while others say you definitely have to take it apart. Use compressed air, contact cleaner, oil/grease-free lubricant, the options/opinions are endless. Think I'll try to use common sense, try a few obvious things first, and delve deeper as required.

Cheers for the info, Musky! I also copied this thread to the technical section and received a number of useful responses there. With regards knob removal, I assume if I don't see a visible screw holding the knob onto the stem (from the outside) then it is likely I can simply pull the knob straight off? I'm never sure if they glue these things on or how they are attached, which is why I don't want to use any excessive force for fear of breaking something (and then having one wonky knob or having to replace them all to match). I can't believe I just typed wonky knob! I must also admit I'm somewhat curious about the whole pot cleaning idea. After cleaning it to remove the crackling, where does the dirt actually go??? Seems almost mystical.

Thanks again Basschatters, as always you are a whirlwind of information! I've done some more internet searching and found quite a wide variety of ideas, but I think BOD2 seems to have supplied exactly what I was looking for (sorry, no prize). One of the Marshalls is a valve amp, and the other is solid state, so I guess I'll have fun playing/dismantling one of each. I wouldn't say I was overly adept with electronics, but am always willing to give it a go (and I don't think I need to worry about voiding the warranties on these) so I guess that's what I'm going to do. I work in a lab so have access to isopropanol, but think I may go for the more expensive can of compressed cleaner as I assume this will work better (will get inside the pots more easily). Looking forward to some crackle-free knob twisting! (I hope). Cheers!

Sorry this is a duplicate post, but I just realised my question might fit better in this area of the forum (and the more help I can get the better): Hi everyone. Before you ask I did attempt a search on this topic and didn't find anything directly relevant to my query. Basically I have a couple of old Marshall bass amps with scratchy/crackly (actual words?) pots and I want to get this sorted. After searching this site I did find out about a product called Servisol, and someone else mentioned getting some Maplin Switch Cleaner to spray on the pots, but I'd still like a little more info. If I purchase one of these products do I simply spray them on the outside of the volume/EQ knobs (should I try to remove the plastic knobs first before using) or do I actually need to do something internally to get rid of the problem? I also read how the dust/dirt can build up from lack of use (I have a feeling these amps were stored unused for long periods of time), and some people have simply twisted the knobs frequently to get rid of the crackling sound. Does this really work? I'd be happy to remove the knobs if this would allow better access and lead to improved results, though I'm not sure if I should simply try to pull them off or not (I'm somewhat worried about damaging them)? Any suggestions as to how I can make my playing/adjusting less crackle-y would be (as ever) GREATLY appreciated! If you think I need to seek a professional to sort out this problem, then any recommendations would also be appreciated (I'm based in the Midlands/Birmingham area). Cheers!

Hi everyone. Before you ask I did attempt a search on this topic and didn't find anything directly relevant to my query. Basically I have a couple of old Marshall bass amps with scratchy/crackly (actual words?) pots and I want to get this sorted. After searching this site I did find out about a product called Servisol, and someone else mentioned getting some Maplin Switch Cleaner to spray on the pots, but I'd still like a little more info. If I purchase one of these products do I simply spray them on the outside of the volume/EQ knobs (should I try to remove the plastic knobs first before using) or do I actually need to do something internally to get rid of the problem? I also read how the dust/dirt can build up from lack of use (I have a feeling these amps were stored unused for long periods of time), and some people have simply twisted the knobs frequently to get rid of the crackling sound. Does this really work? I'd be happy to remove the knobs if this would allow better access and lead to improved results, though I'm not sure if I should simply try to pull them off or not (I'm somewhat worried about damaging them)? Any suggestions as to how I can make my playing/adjusting less crackle-y would be (as ever) GREATLY appreciated! If you think I need to seek a professional to sort out this problem, then any recommendations would also be appreciated (I'm based in the Midlands/Birmingham area). Cheers!

[quote name='Hamster' post='303385' date='Oct 9 2008, 10:35 PM']Where do you live? - sticking it in your profile is a good idea If you are very very lucky you'll be living near Steve - [url="http://www.stevesamps.co.uk/"]http://www.stevesamps.co.uk/[/url] He will make your amp sing / cry / weep / scream / disembowel etc[/quote] Cheers for the recommendation, but I'm just south of Birmingham, so not really local for me. Plan to swap out the "no-name" preamp tubes for the Mullards sometime this weekend, so if it still doesn't sound right, I guess I'll just have to keep looking/try something else. Thanks for all the helpful responses. Always appreciated.

[quote name='obbm' post='302015' date='Oct 8 2008, 11:24 AM']There's a lot of nonsense talked about valves. It's very straightforward, simple and as easy as changing a fuse. It's not a black-art. Just use your common sense. Switch off the HT and the main On/Off. Let the valves cool down a bit and then pull the one you want to change straight out. Line up the pins on the replacement and slot it in. Switch the main On/Off back on and allow the valves to warm up, then put the HT back on. Job done. From memory there are no high voltage connections on top of the chassis. They are all underneath. You should be able to do the change easily without removing the chassis from the case. If you do have to remove it for whatever reason and have had it powered or plugged into the mains then do not pick up the chassis by hooking your fingers underneath. Pick it up by the transformers. For what it's worth I've never cleaned a valve because it might take off the manufacturer's labelling and you might end up with an expensive no-name ECC83. If the pins are bent the straighten them carefully with pair of long-nosed pliers.[/quote] Cheers for that OBBM, great advice. Valve "black-arts"... I like it! If only I knew what the HT was, I'd be sure to switch it off. I assume it's the "stand-by" switch?

Hi everyone. I started a thread almost a year ago after purchasing a Marshall JCM800 Super Bass head at [url="http://basschat.co.uk/index.php?showtopic=6872&hl=valves"]http://basschat.co.uk/index.php?showtopic=6872&hl=valves[/url] as I was looking for a particular sound and believed this was the amp I needed to reproduce it (as another bass player I'd heard was using this amp and it seemed to have the sound I have always been looking for). Unfortunately I was unable to get the distorted tone I was after at that time, and a number of basschatters provided some excellent suggestions as to what I might try in order to obtain it. Not so funnily enough I've only just got around to actually thinking about replacing the preamp valves, and so I've recently acquired a couple of Mullards on fleabay. What I'd like to know is if there are any precautions I need to take when swapping out the valves. I've read I should avoid contact with my skin in order to prevent oil deposits which can create weakspots on the valves, so that's not a problem, but then I guess I can't be sure the seller hasn't handled them with similar care. Is there any way I could/should clean the valves before inserting them? Also because I've never done this before, do I assume correctly that I simply need to pull the old ones out and insert the new ones by pushing them into the slots? The Mullards weren't cheap, so obviously I don't want to damage them when trying to insert them. Not sure how much resistance I'm going to encounter when I attempt to do the swap, so thought I should ask someone more "in the know" for any pointers. I assume using even pressure with a vertical pulling (removal) and pushing (insertion) motion should do the trick? I've done a thorough search on this site, but didn't come across any technical info with regards the procedure itself. I've also heard you need to be careful about getting shocked from the voltages stored in the capacitors, but not sure if this applies when swapping out preamp valves or not. Any help/advice/suggestions you can give me would (as ever) be greatly appreciated! Cheers in advance!

Must admit I had always wanted to try flats, so a little while ago I decided to string one of my Rays with EB flats and was instantly impressed. I was actually a little surprised that they didn't sound THAT different from their roundwound nickel Slinkys (still quite bright, which wasn't what I was lead to believe flats would sound like). At the same time the "out of the packet" tone of these strings seems to be lasting much longer than I've noticed the roundwound slinkys last (before going "dead"). I've even tried playing this bass with a pick, and it doesn't sound that different from my other Ray strung with nickel rounds. Another added bonus is the fact I can down-tune this bass without needing to adjust the trussrod, and because of the high tension of these strings compared to roundwounds they don’t feel anywhere near as floppy as the roundwounds I’ve had on my down-tuned basses in the past. With respect to friction burn on flats (as someone else mentioned earlier) I too had a problem with this, but after someone suggested I use my string cleaning wipes on them, I tried this and it has worked wonders. Not sure what the wipes have actually accomplished, but my flats are now much slicker and I have no problems sliding around the fretboard anymore. So the long life issue is definitely worth the offset in price. I'd like to try some other brands of flats, but don't anticipate needing to replace these for quite a while.

[quote name='brycebites' post='75148' date='Oct 16 2007, 05:01 PM']I have just corrected my link and it is the same diagram as your link. To remove the chassis you probably have some bolts underneath that hold it to the case. Looking at those pics it looks like the preamp is on a PCB which doesn't make things so easy to trace. I would make an educated guess and say V1 is the valve furthest away from the EL34's.[/quote] Unless the previous owner sorted this out which might explain why the only Mazda valve is in the centre surrounded on both sides by the Micron valves? But from what I understand, one should be able to swap the valves around and see if there is a significant difference in sound with the use of a different valve in either V1 or V2 compared with how it sounds before the interchange? Cheers for all your help everyone, I'm enjoying this gradual education in the ways of valves.

Your link didn't work. I have two different looking diagrams, one shown at: [url="http://www.drtube.com/schematics/marshall/1992.gif"]http://www.drtube.com/schematics/marshall/1992.gif[/url] And the other looks like this: I don't know how to interpret either of them. I tried to see if I could remove the main part of the amplifier from the outer casing, but not sure how this is accomplished, so I guess I'll have to take a better look at the attachment screws. This photo doesn't show the types of valves I have, but it appear to be the same amp as the one I bought (and it was made in the same year). It is the one on the right here (if this helps at all): [url="http://www.amparchives.com/album/Marshall/JCM%20800%20Series/1992%20JCM%20800%20Super%20Bass%20100W/index.html"]http://www.amparchives.com/album/Marshall/...100W/index.html[/url] Cheers for your input!

[quote name='brycebites' post='74986' date='Oct 16 2007, 11:15 AM']The Mazda valve [i]could[/i] be a rebadged Mullard. Possibly. Micron are a rebranded valve as well, possibly Chinese. Can you post a pic of them? V1 is the all important valve where much of the preamp sound is crafted. Change this to a decent valve and you'll be onto a good start. The EL34's could be East German RFT's (rather good I believe) or some Japenese valves. Watford Valves have done a very useful comparison on EL34/6CA7 valves. The valves will make a lot off difference in the overdriven sound so this would be the best place to start. If there were pedals being used they would have an impact - especially the Sansamp! Also playing technique can play a big part in the sound.[/quote] Cheers Brycebites, I was hoping you might chime in! I did take some photos of the valves while the amp cover was off (for future reference) so I will try to upload them tonight. As for the valve located in V1, I must admit I've no idea which position this would be. I've downloaded a couple of circuit diagrams for this amp, and have located the valve positions, but must admit I really don't know how to read these circuit diagrams. I was actually thinking of looking for a book on this to edumacate myself. The pre-amp valves are all in a row, as are the power-amp valves, so would it be correct to assume V1 is at the far left of the pre-amp valve section, or is it quite possible that this will not be the case? I actually used to have a Sansamp, but found with the set-up I had at the time it didn't do much to add anything to my sound, so I sold it on. I'm kind of wishing I'd kept it now, as I've changed amps/guitars/speakers quite a bit since then, so perhaps now it WOULD make a difference. I wish there was some kind of "valve-trading club", so valve amp users could try a number of different ones in the quest for "the sound".

Once again cheers for all the suggestions. I DID have another look inside the amp and found the 3x ECC83 valves underneath protective metal cans in there, so at least that much has become clear. It's got 2x u Micron valves and 1x Mazda "foreign" valve so I guess I may need to look into swapping these out for something else which may better approximate the sound I'm looking for. Man, this "sound in my head" search is NEVER ending! As for the amp inputs, there are indeed 2 of them, but none of them are marked as being either high or low gain for active/passive basses, so not sure if they are different or not, but I could try plugging them into each and see if there is a difference. I would assume they must be different otherwise why would there be two of them? Marshall have said this amp is MONO and NOT stereo. And with a rating of 100W, when I heard the other bassists amp it could well have been turned all the way up and therefore maybe it WAS power tube distortion that I was hearing. I'll have to give that a go at my next rehearsal when I can actually crank the amp up. The power amp valves are ITT Lorenz EL34's, but I THINK from my readings the brand of power valves should not make much of a difference with respect to tonal quality? The Mazda preamp valve sits between the two u Micron valves and have tried to do some research (there's always something!) on preamp valves to see what I can do to change the tone of the amp, and from what I can tell it looks like I simply have to try a bunch of different valves/combinations until I chance on the right ones. Apparently the first one or two pre-amp valves add most to the tonal quality of the amp so for more distortion I assume I would need some "higher gain" pre-amp valves? I sure wish there was an easier way, but I guess it's all part of the "fun".

[quote name='cheddatom' post='74632' date='Oct 15 2007, 03:33 PM']Yep. Apparently it's what Tom Morello does. Maybe i'm just confused. I think I should stop posting before someone who knows about valve amps embarasses me.[/quote] Don't stop posting, I need all the help/suggestions I can get! And never be embarassed if you're wrong, it's only a suggestion and can never hurt to try different things I may not have thought of (which is quite likely knowing me). I really appreciate your input. AND this thread has helped increase my status to "no longer a newbie". Though I don't actually FEEL any less newbie-ish.

[quote name='cheddatom' post='74620' date='Oct 15 2007, 03:13 PM']Do it have an effects loop? You could use this to drive the power amp, creating power amp distortion, which is apparently better, but, like I say, not much experience.[/quote] By this do you mean insert a volume/power boost (eg. one of my overdrive pedals) into the effects loop to better drive the power amp?

Well I've just found a schematic for the sweet sweet innards of this amp, and it suggests there should be 3x ECC83's inside, so maybe I need to look into this further. I did open up the back of the amp when I purchased it, but obviously I don't really know what I'm looking at, as the EL34's were obvious and clearly marked (and appeared easy to remove as there were held in place by spring-loaded plates) so I can only assume the ECC83's are well covered/hidden because I didn't see any other glass-valve-looking components within the amp when I removed the backplate. I guess I was hoping for instant Marshall valve-tone goodness when I plugged in my bass and it simply wasn't there, so am looking for any suggestions what I can do to get it. Maybe this is simply the wrong amp for the job or maybe I need to get it looked at by a professional who may be able to help. A couple of places in the Birmingham area have been suggested to have valve amps serviced, so maybe I need to give someone a call and book her in for a checkup. But if you DO have any other suggestions of things I can try, then please let me know. Would the use of an active bass make that much of a difference in comparison to a passive one playing through an overdrive pedal with the volume set to 11?

[quote name='Musky' post='74563' date='Oct 15 2007, 01:02 PM']What pre amp valves have you got in there? It might be that fitting some higher output valves might sort you out. Take a look at the Preamp valve comparison sticky - judging by brycebites comments, maybe Groove Tubes 12AX7M's might do the trick.[/quote] I don't think it has ANY pre-amp valves, only power amp valves. It's got 4x EL34 power amp valves, but as far as I'm aware no pre-amp valves. If it did have pre-amp valves, would these glow like the power amp ones? I must admit I don't know very much about valves (apart from the size differences and lifespans of pre/power amp valves), and there's very little info on this model on the internet, but from what I can tell there are no pre-amp valves (and no gain knob) so is it possible I won't be able to get it to distort?