Sparky Mark

In my experience, one thing a heavy bass does well is expose poor playing posture quicker than a lightweight.

John uses ebony mostly on basses it seems, so I reckon it'll be ebony. I'd definitely seek advice from Jaydee before adjusting the truss rod.

True, but it was a weird 60s looking thing that seem to sell for a small fortune in Denmark Street nowadays.

1976; I was 14 years old and used my savings to buy a dreadful Kay bass with flatwounds from a mate (drummer) for £25, a Sound City 120 (much better than I appreciated at the time) from Rockbottom in Croydon (can't remember how much but probably the cheapest amp they had) plus an 18" folded horn cab that probably came from a larger theatre/PA system. Crap tone with no definition at all but could be heard half a mile away from the school music room where my first band practiced in our lunch hour. Soon after got a Shergold Marathon and Carslbro Stingray head; still s#@t!! but I was hooked by the low end.

Tom bought my ABM with no hassle and extremely prompt payment. Great communication throughout and I wouldn't hesitate to trade with Tom again. Many thanks Tom.

RMS is the only half useable measure. Peak, music power, etc are pretty meaningless. Markbass are RMS.

If it's power you want then you may be better looking at the TH500 that'll give 250 watts max into a single 8 ohm cab rather than the 175 watts max of the TH350. The class D 500 watt Markbass heads are rated at 300 watts into 8 ohms.

When you say 'enough drive' do you mean overdrive or simply enough power? If you are using fuzz and/or gain pedals you'd be better off with an amp that is capable of being both loud and clean (Markbass are good for this). If you want the amp itself to generate fuzz or overdrive then don't go Markbass. If you use overdrive pedals plus hi gain overdrive on the amp you will lose a lot of definition and low end.

My experience with Markbass heads is that they are quite neutral sounding. They tend to amplify whatever goes in at the front end fairly accurately without imposing too much of a brand or signature tone as some amps do. Because of this relative accuracy they will expose both strong and weak points in your signal chain, including inconsistencies in playing technique, rather than smooth over them. It's fairly simple to get whatever you want from them especially now that Aguilar, Ampeg, Mesa, Tech 21, etc., all produce preamp pedals to flavour the input. A selection of £100ish pedals is a more cost effective way of having several brand's basic tones available to you rather than paying £500+ for each head.

I rarely stray from EQ controls at noon position on my LM heads. The EQ curves show that each control does affect quite a wide band of frequencies either side of the stated frequency.

I would recommend NEVER flexing printed circuit boards, especially relatively old ones, as you can crack the copper tracks and damage previously good solder joints and/or components.

The fact that the noise stays at the same level indicates it's the noise floor of the amp. By including the noise reduction switch on earlier models Trace Elliot acknowledged noise was a factor at low volume or in studios. This is also why setting the input gain as high as possible using the three LED system is important to maximise the signal to noise ratio. What you need is a totally silent (relatively) AH200 GP11 Mk5 head! 😉

I'm not sure that a dry/open solder joint would contribute to noise? I have read accounts on here before about aSMX heads with hum and noise issues. It may be a design issue. Someone posted that changing the orientation of the transformer helped reduce hum (but that could be building location specific). Noise or hiss might be down to ageing components just drifting out of spec with age? I'm sure that at playing volume it makes no difference. Earlier versions did have a noise reduction switch but I guess with all the new features on the SMX something had to give?