sandy_r

Dayyum - my profs should have been so Cool ! (...downside of doing EE)

thanks for the further detail have any of your experiences of Realist problems included distortion/noise as in Mikey's example clips - or have they been the symptoms you mentioned:- intermittent, low or no output? that's a cool idea to DIY a Realist type pickup! i guess the small piezo elements are produced for specialist technical applications in equipment where money is no object 😞 i was looking recently for backup sources for the electret condensor mics as used in my bridge pickup and found that they seem readily available - a DIY electret pickup would definitely be on the cards! (i was able to make a DIY preamp for my electrets) i wonder if you'd be able to adapt the piezo strip that you can buy for under-saddle pickup replacement? might several work as a DIY Realist type pickup, if connected together and each trimmed to short length? (i've also seen thin piezo 'cable' available that supposedly you can cut to length) apologies, Mikey - starting to go OT !

Hi, that looks like a very useful approach to try on a Realist sensor with connectivity issues between piezo layer and electrode(s) The Realist 'dot' construction sounds a little similar to the Takamine Palathetic pickup, as used in their TB10, which uses a series of piezo elements each connected by short metal rods pressed into contact in a hybrid saddle-bridge pickup, giving the TB10 a sound very close to a DB Your symptom list mentions "intermittent, low or no output at all". The symptoms here seem to be presenting more as a resonant distortion/noise - does that fit with your experience of Realist issues addressed by this method?

clarification is always welcome 👍

It doesn't take an expert to discern that the discussion about the footswitch has nothing to do with the discussion about the gain/valve issue

No suggestion above of modifying the 5 function footswitch a modified cable only needs to keep exactly the same wires as used to switch Solo, Compression, Loop, and Eq via a 5-pin DIN into the M-Pulse - the extra wires from the B-Link 1A can just be omitted (disconnected)

Yes, i think this test confirms it - you're playing more gently and still the noise (i think we can call it out as distortion now) is occuring. Most noticable in the Line In clip, hardly noticable in the DI clip, and i couldn't hear it in the Amp to Mic clip I'll let Paddy comment too, but i have to agree sadly that it appears that the Realist has degraded and needs replacing i play a travel bass as an EUB - it uses 2 electret mics in the bridge to give a nice woody, acoustic sound - the instrument is not as nice as a DB sound, but the nearest i've found apart from my uBass. I'm familiar with piezo elements through using them in oscillator circuitry and as audio sensors in sound-trigger circuitry i hope you find a reliable replacement for the Realist and achieve a suitably rich tone worthy of the instrument

Thats a B-Link 1A - 5 switches (adding Tuner Mute) - your amp version only supports 4 switches (The B-Link F/S) ...if you, or a Techie friend, are confident with checking wire continuity and making a plug-type mod, you could swap out the existing 7-pin DIN on the cable (at the Mesa end) for the relevant 5-pin plug needed by your amp, and you'd be able to use the 4 switches as expected by your amp (Solo, Compression, Loop & EQ) Or, you could make a complete new cable similarly (ie. 7-pin to 5-pin, 5-wire shielded cable?) and keep the original cable unmodded, in case you ever sell the footswitch on (personally, i'd prefer this option)

Agreed, I feel the weight of evidence is pointing to the sensor. Due to the nature of piezo sensors, however, extraneous mechanical vibration can cause electric signal, so it's preferable to check for an external cause of noise first and avoid discarding the Realist unnecessarily There are also a lot of variables in these 3 noisy recordings and the 2 stages in common are the Realist and the SSL, so again we ought to confirm that we can discount an SSL setting before buying a new sensor ...just trying to avoid unnecessary expense for Mikey by confirming things which can be tested freely - i hope this makes sense

hi Mikey thanks for the further samples - yes, there is more noise on the 1st 3 clips (and more than in the OP, too) and it sounds like the same over-driven noise from the OP, not the more acoustic 'resonant' noise - it's occuring on the higher-level, lower-frequency notes on the SSL, which switches are selected and what gain & monitor level setting? do you have a different preamp/interface (with high-Z/impedance input) from which you could record a clip, for comparison? (ie. no SSL, just Realist to Pre#2 to Logic) thanks sandy [Edit #1: its possible for signal overdrive to occur and be heard, but not picked up on a graphic level display, depending on filter time-constants ...you would hope this isn't the case with SSL gear!] [Edit #2: i don't think it is overdrive - you can hear it throughout the whole envelope of the 1st plucked note, also within the 2nd & 3rd, and in their octaves - that seems more resonant-related - could the Realist cable and/or jack be vibrating against something, however slightly, or taut?]

thanks for the kind words, Chris, i'm just a small cog on a big wheel of experience on this site - it's great that we're all able to share something, across so many topics, bass-related or otherwise. i've learnt so much in my few months here - and had a lot of fun, too ! hope you folks manage to get the M-pulse sorted and back er, ...on the road again

The noise in the 1st 2 phrases is very faint - hard to identify the nature of the cause. It seems to occur on some notes and not others, as if a resonance - could it be a positioning/mounting issue? The apparent signal overload at the end may be unrelated - is there a preamp between sensor and Amp? The Gain or Volume may need winding back slightly, if the overload isn't related to the possible 'resonance'

If it helps towards answering your peripheral question, Chris, the Mar 2001 schematics for both the 360 & 600 M-Pulses employ the same 5-pin 180-degree DIN connection for the footswitch (the 5 wires give Gnd + switching for Masters, Loop, Compr & EQ) (each switching path is a passive circuit of switch, resistor and LED in series to Gnd, protected on the Amp side by opto-isolating chips)

hi, i can't see any obvious extraneous impulse noise (static/crackling) in the waveform - there is a slight sound (zoomed in) near the start of the repeat of the plucked phrase (...could just be string/finger noise?) there are 2 instances (+possible 3rd, dotted) of what sounds like signal overload (mike? recording level?) at the end of each bowed phrase the audio signal there looks a bit asymmetrical about the 0 line (+ve peaks have greater |abs| value than -ve) - not sure if thats relevant (if mic/recording chain uses batteries, might be worth checking if they need replacing?) [Late Edit:] repeat listening later, i revise my comments - the noise in the plucked phrases seems more evident in the 1st, 4th and 6th note of the 1st phrase (but more acoustic than static/crackle - ie. more like a faint rattle), and i'd say now that only the final note in the 2nd bowed phrase seems to have some signal overload type noise hope this helps!

.That link has been 'disappeared' currently ...try this one (live at 09:00 Jan 7): Zio Analog Bass Premp DI Pedal

Oooh - that grain looks quite usable - maybe you could get some idea of the grain quality on your bass by looking in the pickup &k control routs? (if not obscured by shielding or paint)

... but a slightly 'sunburst' stain finish from dark green into slightly yellowish could still look cool

...oh, i don't know - it could look worse! 😨

Both valves listed as 12AX7 (a standard valve ...but genuine parts preferred!) 🤔

...ok - Keep existing colour scheme and apply whole-body decal, two-tone (ie, white hilite, black shadows), moody headshot of your fave player -

Should be easy to confirm then, 'cause that valve is the driver to the Power Section and it is located after the Send/Receive Loop So, whichever of you gents is going to do any follow-up checking, do the FX Loop A/B test suggested above (2 Amps, 1st as Pre, 2nd as Power) to confirm which half is faulty then switch off, let cool, and swap the 2 valves (which are the same type), repeat test - if the fault follows the valve, that confirms that valve has failed and no other issue

...when everything is working correctly! 😉

might be an idea also to report all your toggle-switch settings on front and rear panels - and are you/ have you been using a footswitch and the Solo control (try varying this, in case its working with no footswitch)

ok, thanks - well, you could try 2 other quick tests, if you wished, to narrow down the problem; try the chains:- A) bass - i/p of Big Block - Send Out from BB - Return In on M-Pulse; B) bass - i/p of M-Pulse - Send Out from M-Pulse - Return In on Big Block Do you get full volume o/p from M-Pulse in A) and quiet o/p from Big Block in B)?

ok, to clarify then: when you say the power section is "ok" (when feeding a bass into the Return jack), are you saying that the power section produces the expected ouput volume? And, also, were you feeding the bass in direct, or through a separate preamp/pedal? thanks