Caved and got the Marshall DSL402- but it has a couple of (hopefully very minor) problems

Dave_Mc

Hi everyone,

This will surprise absolutely no-one but I caved and got the (new) Marshall DSL402 which was on offer. It's pretty nice, sounds pretty good, but it has a couple of (hopefully very minor) problems that I hope you could help me with.

1) The little rubber (?) push-button for the tone shift switch is missing. I'm not sure whether it fell out at some point or was never there in the first place. Can I just get another one and fit it myself from the outside? The actual tone shift function does work- I managed to use a thin plastic pencil to push through the hole to activate and deactivate it.

2) Hopefully this is nothing, but when I first tried my pedalboard with the amp (with pedals both into the front of the amp and in the loop), on the same (supposedly isolated) Harley Benton Iso-12 Pro power supply, I got a pretty loud hum/buzz. It wasn't there initially, and then grew in intensity, and then I turned the amp off before it got any worse. I tried again with the loop pedals unplugged from the amp (but still plugged in to the power supply) and the pedals still going into the front of the amp, and still got the hum/buzz. I then unplugged all the pedals and plugged straight in and the hum/buzz was gone again. I turned a couple of modulation pedals (going into the front of the amp) on and off, as I sometimes feel that they can add noise and doing that sometimes seems to help (or it could be my imagination!), and then plugged all the pedals back in (both in front of the amp and in the loop) and the issue seemed to be more or less fixed. I changed the settings on the amp a bit too, lowering the gain and treble/presence a little and that may have helped too.

Is this anything to worry about? I suspect it's the power supply (as it's always a little noisy, I'm not sure if it's earthed as I'm just using the adaptor Thomann sent as it came with an EU plug), or maybe just the layout of the cables as the amp is in the middle of the floor until I figure out where I'm going to put it and the cables aren't exactly neatly routed. Or maybe even just plugging and unplugging the FX loop cables helped.

I haven't been able to replicate the hum/buzz since.

I'm tempted to keep it as apart from this is seems to be working fine and I'm not sure there's much point in sending it back for such a minor fault- the tone shift button isn't something I'd use much anyway, even if I can't get it replaced I don't think it's the end of the world, unless it means that something else could be wrong with it. Same thing with the FX problem, I'm not sure it's even a problem with the amp. And two courier trips aren't likely to do the amp any good... and a replacement (if it's even available) might not work as well!

Thanks for your help,
Dave

ICBM

From memory, the button will pass through the hole in the front panel so you can fit it from the outside. If you don't get any help from the shop, try Marshall - they're very good for aftersales service. If both options fail, I have a couple from the previous series which may fit.

The hum issue is odd - if it's anything like a ground loop I would expect it to start immediately. If the hum built up over time, it sounds more like either a stability problem, or - given that it doesn't seem to be doing it now - a purely coincidental power valve fault that's nothing to do with the pedals at all.

Dave_Mc

ICBM said:

From memory, the button will pass through the hole in the front panel so you can fit it from the outside. If you don't get any help from the shop, try Marshall - they're very good for aftersales service. If both options fail, I have a couple from the previous series which may fit.

The hum issue is odd - if it's anything like a ground loop I would expect it to start immediately. If the hum built up over time, it sounds more like either a stability problem, or - given that it doesn't seem to be doing it now - a purely coincidental power valve fault that's nothing to do with the pedals at all.

Brilliant, thanks John

That's good news about the button. Good idea about contacting Marshall, too! (And thanks very much for the offer of the older ones, hopefully it won't come to that, though!)

That's more concerning about the hum, though. It's one heck of a coincidence, though, considering I tried it twice with the pedals (I don't think the pedals were even turned on, just plugged in and powered up IIRC) and it hummed/buzzed, and yet as soon as I removed them the hum disappeared! (And also I tried it the previous day without any pedals and it didn't hum/buzz.) But you know a lot more about this than I do, and it did seem to me like it was something "wrong" (and also something building up and getting worse!), rather than just noise (which does suggest something more along the lines of what you said).

Just out of interest, when you say, "a stability problem", what exactly do you mean by that? And how serious is it? And also the power valve fault- do you just mean one or both of those particular valves? I.e. replacing the valves would fix it?

EDIT: I'm just thinking as well, I didn't check the valves were seated properly or anything like that (it came by courier). I just plugged it in and turned it on, after leaving it for a while to get up to room temperature as it was pretty cold here. I guess it might not hurt to take the back off it and just check the valves are seated properly?

noisepolluter

If you’ve got a multimeter maybe you could also try checking the bias using the bias points on the underside of the chassis? 

Marshall told me each side should be running at 35mV +/-1, (double check this with them), but when my DSL40 first arrived one side was above 40 and the other was in the low 30’s, and this was causing increased background noise as well as presumably not being great for the valves. Fortunately it was very easy to adjust. 

Dave_Mc

Some good news on the missing button- I thought I'd better look in the box again, just in case I'd missed it. I found it in the bottom of the box- a bit squashed, but I managed to get it in more or less ok. So fingers crossed that it'll stay in!

Any thoughts about the hum @ICBM ? I tried the amp again today (with pedals) and still wasn't getting the hum/buzz. I think I have a 3-year warranty with the amp, so if I don't hear it again I'm tempted to just keep it and hope that either nothing goes wrong, or that if it does it'll happen when it's still covered by warranty.

noisepolluter said:

If you’ve got a multimeter maybe you could also try checking the bias using the bias points on the underside of the chassis? 

Marshall told me each side should be running at 35mV +/-1, (double check this with them), but when my DSL40 first arrived one side was above 40 and the other was in the low 30’s, and this was causing increased background noise as well as presumably not being great for the valves. Fortunately it was very easy to adjust. 

That's a good idea (which I hadn't thought of for some reason!) and some great info, thanks! I do have a multimeter so I should be able to try that. I am getting a little bit more background noise than I would ideally like, so maybe mine's the same as yours was.

ICBM

I don’t know - if the hum doesn’t return I would still suspect something intermittent with the power valves rather than an inherent fault with the pedals.

Just plugging an amp in after it’s been couriered, without a full internal inspection first, makes me nervous… they can, and do, cause a lot of damage which is not always obvious from the outside.

Dave_Mc

ICBM said:

(a) I don’t know - if the hum doesn’t return I would still suspect something intermittent with the power valves rather than an inherent fault with the pedals.

(b) Just plugging an amp in after it’s been couriered, without a full internal inspection first, makes me nervous… they can, and do, cause a lot of damage which is not always obvious from the outside.

(a) Oh yeah absolutely, I'm not saying it's to do with the pedals. I'm just saying it seems (admittedly that's based on very little!) to be ok again.

(b) Just to clarify, what do you mean by "full internal inspection"? I'm happy enough to take the back off to look at the valves, and probably even check the bias with the external bias points, but I wouldn't be confident going inside the thing in case I, er, die. 

ICBM

Dave_Mc said:

Just to clarify, what do you mean by "full internal inspection"? I'm happy enough to take the back off to look at the valves, and probably even check the bias with the external bias points, but I wouldn't be confident going inside the thing in case I, er, die. 

Personally I would always take the chassis out before powering up any amp that’s been couriered. You won’t necessarily spot any damage easily, but it will give you a chance. There’s no risk of dying if the amp *hasn’t* been turned on first. I do understand that most people may not be as happy dismantling an amp as I am though .

Dave_Mc

ICBM said:

Dave_Mc said:

Just to clarify, what do you mean by "full internal inspection"? I'm happy enough to take the back off to look at the valves, and probably even check the bias with the external bias points, but I wouldn't be confident going inside the thing in case I, er, die. 

Personally I would always take the chassis out before powering up any amp that’s been couriered. You won’t necessarily spot any damage easily, but it will give you a chance. There’s no risk of dying if the amp *hasn’t* been turned on first. I do understand that most people may not be as happy dismantling an amp as I am though .

Thanks

What if you were sent an amp that had been turned on (either someone else bought it or someone in the shop had turned it on to check it was working) before you got it? Couldn't that still zap you? A lot less likely (presumably?) as it would be several days since it was last switched on, but still not sure I'd want to take the chance.

Also I'm really bad at DIY, even aside from the electrical safety I'd be a bit worried about taking an amp apart and then not being able to put it back together again! Or drop a screwdriver on it and take a big chunk out of it or something. (I mean before I was sure I was keeping it, my strategy with anything I've bought is to look after it as well as I can until I'm sure I'm keeping it. I'm happy enough to swap speakers etc. once I know I'm keeping the thing.)

Just out of interest, what would you do with the amp if it were you? As I said, I'm a bit loath to return it if there's not that much wrong (an extra couple of courier trips won't help it, and I don't think they have any more so I'd just have to take a refund rather than a replacement), but I'm equally loath to keep it if it's a ticking time-bomb and might die just outside warranty! I'd also probably need to contact the shop fairly soon about this- I contacted the shop on the day it arrived about the missing button, but I didn't mention the hum/buzz as it hadn't happened by that point. I guess I could just mention the hum/buzz and ask them what they think and suggest.

ICBM

Dave_Mc said:

I'd also probably need to contact the shop fairly soon about this- I contacted the shop on the day it arrived about the missing button, but I didn't mention the hum/buzz as it hadn't happened by that point. I guess I could just mention the hum/buzz and ask them what they think and suggest.

I would do that, but I would be reluctant to send it back unless they're really sure it has a non-valve fault - because if it doesn't, and they send you the same one again, then that's another two courier trips.

Dave_Mc

ICBM said:

Dave_Mc said:

I'd also probably need to contact the shop fairly soon about this- I contacted the shop on the day it arrived about the missing button, but I didn't mention the hum/buzz as it hadn't happened by that point. I guess I could just mention the hum/buzz and ask them what they think and suggest.

I would do that, but I would be reluctant to send it back unless they're really sure it has a non-valve fault - because if it doesn't, and they send you the same one again, then that's another two courier trips.

Thanks

Yeah that's why I'm reluctant to send it back too! 

(When you say the valve fault, you mean that swapping to a known working valve will sort the problem i.e. there's nothing wrong with the amp, just the valve, right?)

I'll contact them and see what they say.

(EDIT: Tried it again today and it's still working fine, with no hum/buzz.)

ICBM

I'm wondering if it was just an intermittent poor contact between one of the valves and its socket. It wouldn't hurt to give them a gentle wiggle and push them into the sockets just to be sure they're seated properly.

Dave_Mc

ICBM said:

I'm wondering if it was just an intermittent poor contact between one of the valves and its socket. It wouldn't hurt to give them a gentle wiggle and push them into the sockets just to be sure they're seated properly.

It could well be. I've certainly had an amp before which was couriered which was cutting in and out, and it was the valves which had probably got unseated when the courier threw it down in my hall! Maybe plugging the pedals into the loop unseated an already slightly dodgy valve or something like that. And unplugging them gave them another slight jolt which reseated them. I'll give that a try tomorrow if I get a chance. Thanks again for all your help, John

Dave_Mc

So I tried the valves. The preamp valves were fine (well I didn't manage to get the shield off V1, it was sort of hidden behind the power valves and the transformer and I was in a bit of a rush, but I figured the shield was hopefully holding it in anyway). The power valves weren't obviously hanging halfway out or anything, but one of them looked out by maybe a mm or so, and the other one a bit less. I pushed them in as well as I could, they looked and felt a bit straighter and in tighter.

I could be imagining it but I think it sounds a bit "better-behaved", for want of a better word (bit less noisy etc.), and maybe even sounds better too!
 
Fingers crossed that sorts it!

Thanks again @ICBM ;;

(I didn't get as far as checking the bias @noisepolluter , I forgot to email Marshall and I thought I'd better check how tight they were first without wasting any more time.)

Yorkie

I’m sorry you’re having to jump through all these hoops to have a well behaved Marshall, Dave. Hopefully things will go smoothly now that the valves are attached a bit more firmly. 

Dave_Mc

Thanks very much @Yorkie I think it's probably ok now. Fingers crossed, anyway. I haven't noticed any strange noises since I tightened the valves.

@ICBM (or anyone else) can I just check I've got the speaker wiring correct? I swapped the speakers and had to change from series to parallel because of the impedance of my speakers.

As long as I have one of the negative terminals on one of the speakers connected to the negative spade connector of the speaker cable (the cable which plugs into the speaker extension socket on the amp, I mean), and the positive spade connector from the speaker cable connected to one of the positive terminals on one of the speakers, and a cable going from one negative terminal to the other negative terminal, and another different cable going from one positive speaker terminal to the other positive speaker terminal, it shouldn't matter which order it's all connected, right? I had to use a bit of lateral thinking to get all the cables to reach and also had to contend with a terminal which didn't want to accept a spade connector, so I had to kind of jimmy it together in a way which I hoped worked electrically...

I hope so anyway. It sounds "right", at any rate...

(I put a greenback and g12h30 into it, not heritage, just the standard ones. Sounds pretty good, there's still  a wee bit of a boomy bass which I think is either the particle board or maybe just the bigger cab from being a combo. But it was a lot worse with the stock speakers, and it sounds a lot better now.)

ICBM

Yes, that’s correct. As long as both positive terminals are connected to the jack tip and both negatives to the jack sleeve, the physical arrangement of the wiring doesn’t matter.

Yorkie

Dave_Mc said:

Sounds pretty good, there's still  a wee bit of a boomy bass which I think is either the particle board or maybe just the bigger cab from being a combo. But it was a lot worse with the stock speakers, and it sounds a lot better now.)

Definitely the cab. I tested DSL40 into Bandit cab (ply) and Bandit into DSL40 cab (MDF) with roughly the same speakers and the DSL40 cab had a bass response that wasn’t there in the Bandit’s. When I had to shift a big amp in order to accommodate my brother and fam, I chose to let the Bandit go because, while that extended bass doesn’t really register a lot in recordings, the sound in the room is just bigger with the DSL40. I nearly cried, but needs must and now I’m getting those sounds with a Super Champ XD in a much smaller size anyway. 

Jon

Dave_Mc

ICBM said:

Yes, that’s correct. As long as both positive terminals are connected to the jack tip and both negatives to the jack sleeve, the physical arrangement of the wiring doesn’t matter.

Brilliant, thanks John. That's what I thought/hoped, but I figured it couldn't hurt to make sure!

Yorkie said:

Dave_Mc said:

Sounds pretty good, there's still  a wee bit of a boomy bass which I think is either the particle board or maybe just the bigger cab from being a combo. But it was a lot worse with the stock speakers, and it sounds a lot better now.)

Definitely the cab. I tested DSL40 into Bandit cab (ply) and Bandit into DSL40 cab (MDF) with roughly the same speakers and the DSL40 cab had a bass response that wasn’t there in the Bandit’s. When I had to shift a big amp in order to accommodate my brother and fam, I chose to let the Bandit go because, while that extended bass doesn’t really register a lot in recordings, the sound in the room is just bigger with the DSL40. I nearly cried, but needs must and now I’m getting those sounds with a Super Champ XD in a much smaller size anyway. 

Jon

That's very interesting- you have the 1x12 DSL40, don't you? That does sound a bit like it might be the material then- unless the 1x12 is also a bit oversized because it's a combo! I guess it could also be how much bracing (is that the right word?) etc. there is- certainly in the DSL402 there's a lot of space, and just one big panel to cover the back with only 6 screws holding it in IIRC. That makes it really easy to get at the speakers and valves, but it also might mean it doesn't sound as good...

(I'm not sure I'd say it's a "bigger" bass response with mine... more a "too boomy" or "not tight enough" bass compared to my speaker cabs which still have plenty of bass but which also are a lot tighter. Granted... I should probably try rolling the bass down a little! I do already have the resonance on zero, though...)

That sucks you had to get rid of one of your amps, I saw you already posted that in another thread recently I think, I'm really sorry to hear that Jon Glad to hear the Super Champ is covering those sounds though, it's ages since I tried one but IIRC they sounded pretty great!

Yorkie

That's very interesting- you have the 1x12 DSL40, don't you? That does sound a bit like it might be the material then- unless the 1x12 is also a bit oversized because it's a combo! I guess it could also be how much bracing (is that the right word?) etc. there is- certainly in the DSL402 there's a lot of space, and just one big panel to cover the back with only 6 screws holding it in IIRC. That makes it really easy to get at the speakers and valves, but it also might mean it doesn't sound as good...

Correct. The cab is very large indeed. Here's mine:

 

That sucks you had to get rid of one of your amps, I saw you already posted that in another thread recently I think, I'm really sorry to hear that Jon Glad to hear the Super Champ is covering those sounds though, it's ages since I tried one but IIRC they sounded pretty great!

I do miss the Bandit sometimes, but I don't regret selling it because now my niece can sleep where the amp was and that is pretty fantastic. I'll get my territory back when this is over, but for now I'm just living in the moment :-)

Jon

ICBM

You can always buy another Bandit, quite likely for the same or less as you sold the last one for. They're not rare, bombproof, and for some reason don't seem to go up in price at all either with the passing years or the increasing new price... a second hand Bandit has always been about £100, and it wouldn't surprise me if it always is.