Ghost_Bass Posted July 9, 2012 Share Posted July 9, 2012 (edited) Hi, i've bought me one of these this weekend. Really nice tone, i'm not into valve goodiness but i little bit always sounds great. After a bit of fiddling and experimenting i came to the painfull realization the its DI is only post EQ and the worst part is that the master volume also affects it. I've been reading the manual and Mesa states this regarding the DI and Master: [quote] [font=courier new,courier,monospace][i][color=#231F20][color=#231F20][color=#231F20]If you must have true independence between these two [/color][/color][/color][/i][/font][font=courier new,courier,monospace][i][color=#231F20][color=#231F20][color=#231F20]controls - and cannot learn to work with the stock scheme, contact us directly and we can [/color][/color][/color][/i][/font][font=courier new,courier,monospace][i][color=#231F20][color=#231F20][color=#231F20]fax you a simple modification you can do that will remove the MASTER and its associated [/color][/color][/color][/i][/font][font=courier new,courier,monospace][i][color=#231F20][color=#231F20][color=#231F20]stage from the DIRECT signal path. However, this will result in degradation of the sweet tube [/color][/color][/color][/i][/font][font=courier new,courier,monospace][i][color=#231F20][color=#231F20][color=#231F20]character and while you will gain independence of the controls...you will trade a substantial [/color][/color][/color][/i][/font][font=courier new,courier,monospace][i][color=#231F20][color=#231F20][color=#231F20]measure of tone.[/color][/color][/color][/i][/font] [/quote] So here's a couple of questions: 1. Has anybody done this mod and can teach me how to do it? 2. Is there any way to make this DI work as pre EQ (i'm thinking about something like the jumper on markbass amps) without the obvious solution of adding a DI box? I have a limited knowledge of electronics but enought to poke around the amp without tearing it appart, if needed. Thank you Edited July 11, 2012 by Ghost_Bass Quote Link to comment Share on other sites More sharing options...
thodrik Posted July 9, 2012 Share Posted July 9, 2012 I have the amp. The post EQ thing is a bit of an issue. You can get a really nice post-EQ DI sound for recording or gigging, it just takes a little bit of work with the soundperson in terms of getting the DI level setting at the right level. This can be problematic if your band's soundcheck has to be done in 3 minutes. The easiest solution is just buy a DI box if a pre-EQ DI is essential. I already owned a Sansamp so I never really considered the mod. Getting in touch with Mesa seems like the best option, since in the blurb it states that they would fax you the mod. Quote Link to comment Share on other sites More sharing options...
Ghost_Bass Posted July 9, 2012 Author Share Posted July 9, 2012 (edited) Yeah, i'll probably send them an e-mail but it's always best to hear it from others who have done this to know beforehand of any problems/dificulties that this procedure might bring. The pre EQ isn't as essential as it might seam because i always use a fairly flat EQ on my amps but the pre Master is a must have because many times i have the need to adjust my master mid gig. Cheers Edited July 9, 2012 by Ghost_Bass Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted July 9, 2012 Share Posted July 9, 2012 I've got a copy of the schematic if you'd like it. I intended to do the mod, but the reality is I've never had a problem with it. I just let the techies know that it's post-everything, so if my signal jumps, at least they know why. Sound people can handle this kind of thing.... Quote Link to comment Share on other sites More sharing options...
Ghost_Bass Posted July 9, 2012 Author Share Posted July 9, 2012 Yes, it's a valid point, but we're a pub band and don't always travel with a sound guy but always use PA support so i don't want to get caught having to change my volume mid gig without having somebody out there listening to the changes on the PA and correcting them on the mixer. If you could send me those schematics that would be great, here's my e-mail: [i]marcorreia.bass [at] hotmail.com[/i] Cheers Quote Link to comment Share on other sites More sharing options...
Musicman20 Posted July 9, 2012 Share Posted July 9, 2012 Mesa seem, IMO, a bit stubborn, but they can get away with it because they make amps with great tone. What the world needs is a slightly more powerful Walkabout, with the same pre, a similar power but higher (eg 500-600W), with speakons and a switchable pre/post EQ with a separate DI level. It'd be £1500+, but it would sell. Quote Link to comment Share on other sites More sharing options...
Ghost_Bass Posted July 9, 2012 Author Share Posted July 9, 2012 [quote name='Musicman20' timestamp='1341847424' post='1725034'] Mesa seem, IMO, a bit stubborn, but they can get away with it because they make amps with great tone. What the world needs is a slightly more powerful Walkabout, with the same pre, a similar power but higher (eg 500-600W), with speakons and a switchable pre/post EQ with a separate DI level. It'd be £1500+, but it would sell. [/quote] Yep, you've got it all covered, just missed the mute button . It's almost impossible to understand why in these days a manufacturer would build an amp with these "flaws". I love its tone, i can get a tone very faithfull to my bass sound but richer in harmonics and low end than my shuttle but as a working tool the shuttle has everything you'll ever need. I'm a bit torn betwen both amps, i'll give both some time on stage and then decide wich takes the spot. Quote Link to comment Share on other sites More sharing options...
peteb Posted July 9, 2012 Share Posted July 9, 2012 [quote name='Musicman20' timestamp='1341847424' post='1725034'] Mesa seem, IMO, a bit stubborn, but they can get away with it because they make amps with great tone. What the world needs is a slightly more powerful Walkabout, with the same pre, a similar power but higher (eg 500-600W), with speakons and a switchable pre/post EQ with a separate DI level. It'd be £1500+, but it would sell. [/quote] You mean like the old mpulse 360 (except for the speakons)?? Quote Link to comment Share on other sites More sharing options...
thodrik Posted July 9, 2012 Share Posted July 9, 2012 [quote name='Musicman20' timestamp='1341847424' post='1725034'] Mesa seem, IMO, a bit stubborn, but they can get away with it because they make amps with great tone. What the world needs is a slightly more powerful Walkabout, with the same pre, a similar power but higher (eg 500-600W), with speakons and a switchable pre/post EQ with a separate DI level. It'd be £1500+, but it would sell. [/quote][quote name='Musicman20' timestamp='1341847424' post='1725034'] Mesa seem, IMO, a bit stubborn, but they can get away with it because they make amps with great tone. What the world needs is a slightly more powerful Walkabout, with the same pre, a similar power but higher (eg 500-600W), with speakons and a switchable pre/post EQ with a separate DI level. It'd be £1500+, but it would sell. [/quote] My guess is that they don't make it out of fear that nobody would buy the 300 watt version. Also the Walkabout has more than enough volume for any gig I have done. The 1x15 combo is plenty enough to keep up with a half stack and can easily be heard above two full stacks if played through an 8x10. All in all, I'm not sure what practical benefits upgrading the power section will actually bring. But yes, a pre/post EQ switch, mute/standby, speakons would be handy. Mine already has a DI level, though knowing what the 'right' level is is usually down to guesswork. Quote Link to comment Share on other sites More sharing options...
Opticaleye Posted July 9, 2012 Share Posted July 9, 2012 Has anyone compared a Walkabout to a Markbass TTE500? Are they in the same tonal postcode ? Quote Link to comment Share on other sites More sharing options...
TPJ Posted July 9, 2012 Share Posted July 9, 2012 [quote name='thodrik' timestamp='1341854239' post='1725178'] Also the Walkabout has more than enough volume for any gig I have done.[/quote] +1 I have a DI before the Mesa when playing live. I never use the Mesa DI unless I'm in the studio where I can EQ for the recording, most of the time I need the eq to make the the bass sound good in the room and that would equate to a lousy DI tone to the PA. Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted July 9, 2012 Share Posted July 9, 2012 Yip.. the Walkabout is plenty loud, and the DI is to die for. Quote Link to comment Share on other sites More sharing options...
Ghost_Bass Posted July 9, 2012 Author Share Posted July 9, 2012 WoT, when you have the time could you send me the schematic for the mod (or link it in this thread)? I could put some pics of my progresses here to help someone in the future with the same question. Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted July 9, 2012 Share Posted July 9, 2012 [quote name='Ghost_Bass' timestamp='1341874442' post='1725645'] WoT, when you have the time could you send me the schematic for the mod (or link it in this thread)? I could put some pics of my progresses here to help someone in the future with the same question. [/quote] [url="http://www.jollybeggars.co.uk/bassforum/wadi.zip"]Here ye go[/url]. Actually, looking at it, you might want to get a better copy from Mesa, It'll give you an idea, though... Quote Link to comment Share on other sites More sharing options...
Ghost_Bass Posted July 9, 2012 Author Share Posted July 9, 2012 Thank you, that's great, even though it is of poor quality i can still see the diagram (i can't read the hand written text on the bottom, is this of any usefull information?). Anyway, i've sent a mail to Mesa asking the diagram and i'll post that one here too. Luckily this seams an easy mod for someone with my limited knowlege of electronics. Just one question pops into my mind, why removing the 10uF cap and replace for an equal one? Wouldn't it be easier to just remove the top pin of C26 from the PCB (i'm assuming that the top pin is positive, if not both pins should be removed and cap inverted) and simply solder a wire from it to the C21? Just add a bit of heat shrink to avoid any short circuit and presto! I'll look in to it tomorrw, now it's too late to pull out the solder. Cheers Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted July 10, 2012 Share Posted July 10, 2012 [quote name='TPJ' timestamp='1341871067' post='1725565'] I never use the Mesa DI unless I'm in the studio where I can EQ for the recording, most of the time I need the eq to make the the bass sound good in the room and that would equate to a lousy DI tone to the PA. [/quote] It's a fair point. Most of my EQ'ing involves rolling off the low lows, which brings out the low mids, calms the boomy rumble and helps avoid 'death by sub-bass' - something far too many engineers revel in. It generally makes for a tighter signal to the desk. Quote Link to comment Share on other sites More sharing options...
Ghost_Bass Posted July 11, 2012 Author Share Posted July 11, 2012 Just to keep this post from sinking on the 2nd page This afternoon i'll take the lid off the walkabout and do a preliminar check on the thing, I'll take some pics and post here while i'm at it, keep tuned! I'll see if i can get a way to record something on my computer before and after the mod. Cheers Quote Link to comment Share on other sites More sharing options...
Ghost_Bass Posted July 11, 2012 Author Share Posted July 11, 2012 I've got to work on my amp, after 17000 screws (are the guys from Mesa affraid that the lid comes off with vibration?!!) i removed the top of the head and identified the C21 and C26 caps for the mod, as described on WoT's schematic. This is a simple mod and all you have to do is to unsolder the positive side of C26 and connect it using a wire to the top of C21. Here's a pic: [attachment=112892:Drawing1-Model.jpg] After seeing this o got another idea, why don't i add a switch to make this mod reversible? I can apply the switch on the back pannel. At the same time and having the head opened i can also replace the noisy fan for a noiseless one. Luckily i already have all the parts i need knocking around: [attachment=112893:DSCN1235.JPG] [attachment=112894:DSCN1233.JPG] Next step is to remove the valves for safety, unscrew the PCB so i can have acess to the lower solders and remove the C26 cap (i'll explain later why i'm removing it). I'll report back soon, cheers Quote Link to comment Share on other sites More sharing options...
Ghost_Bass Posted July 11, 2012 Author Share Posted July 11, 2012 Removed the cap and build an amatorish PCB to mount the switch and the cap so it won't be hanging by just one lead. Soldered it to the PCB and added the wires that'll go to the main board: [attachment=112901:DSCN1237.JPG] [attachment=112902:DSCN1238.JPG] [attachment=112903:DSCN1242.JPG] Sorry for the quality of the pics, my camera isn't the best... On to solder the wires to the main board and give ir a try before starting to mount it all. Quote Link to comment Share on other sites More sharing options...
Ghost_Bass Posted July 12, 2012 Author Share Posted July 12, 2012 (edited) All soldered and hooked up, a very deep breath and turned it on... it works!!!! phew!!! switch working properly, no noises when switching, master volume definetly out of the DI. First impressions are that the sound in fact looses some of that valve warmness but i want this amp to run clean so that's just fine. [attachment=112904:DSCN1243.JPG] [attachment=112905:DSCN1244.JPG] On to replace the fan whilst i gather the nerve to punch a hole in the chassis to apply the switch... edit: i've just looked at the time ... i got to get to bed, i'll finish the job tomorrow! Edited July 12, 2012 by Ghost_Bass Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted July 12, 2012 Share Posted July 12, 2012 Wow.. that's so cool. Thanks for the commentary. I like the idea of the switch, as the pre-master signal might be handy sometimes. I'm completely cack-handed so I'd ask someone who knows what they're doing to do it... let us know how you get on! Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted July 12, 2012 Share Posted July 12, 2012 Incidentally.. like me, you have experience of the Streamliner and the Walkabout. I'd be interested in hearing your thoughts... Quote Link to comment Share on other sites More sharing options...
Ghost_Bass Posted July 12, 2012 Author Share Posted July 12, 2012 Sorry but i only have the Shuttle, never had the chance to try the Streamliner. Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted July 12, 2012 Share Posted July 12, 2012 Ah - I read 'STL' as Streamliner.. The Walkabout is a great amp... Quote Link to comment Share on other sites More sharing options...
Ghost_Bass Posted July 12, 2012 Author Share Posted July 12, 2012 [quote name='wateroftyne' timestamp='1342083880' post='1729120'] Ah - I read 'STL' as Streamliner.. The Walkabout is a great amp... [/quote] In deed it is, i never thought i could get such a clean tone out of anything with two valves. Quote Link to comment Share on other sites More sharing options...
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