rmorris

Sounds like a paint / varnish stripper type product may be a better option to sanding ?

On 11/10/2021 at 21:59, itu said:

I did this trial a few years ago. The units I tested were Jan Rey Vemuram (for guitar, not bass), an old russian Muff (that big box weighs a ton), RAT (fun 'n' thin), Darkglass B3k (good, but not for me), Darkglass Duality (yes!), Way Huge Pork Loin (a good unit), EBS multidrive (lousy), MÖG (slightly complicated and for heavy), Overlord (tube wonder with a good eq), Spruce Effects OGF (modified for bass by the maker), RaingerFX AirField (now that's what I call strange!), Rochambeau Musical Apparatus Crustacean (just like previous), Amptweaker Bass TightFuzz (tough guy), and Voodoo Labs Sparkle Drive (this has good basic sound). On top of this I have had both IE FrantaBit and Oxide in different occasion. Franta is not actually a distortion, although there were sound possibilities that sometimes amazed me.

 

What was left after the trials? Amptweaker, because it works with various signals and has really good sound - for me. Spruce Effects is clearly a hi-Z unit, but a really good sounding one - again, our tastes vary... Crustacean is still somewhere in my house, just because it is totally different. I also loved Sparkle Drive and Duality for their basic sounds.

 

I tested a few compressors, and there are few left in my three boards: tce HyperGravity and mini, they both work well at the end of the signal chain. They do have to be adjusted quite a lot before the actual use, but the work pays off. Very good sound, and price.

 

Daring Audio Phat Beam is not at its best with lo-Z signals, but it loves hi-Z signals AND fretless basses. I have not met anything similar so far. A real keeper.

Impressive !

5 hours ago, neepheid said:

Glad you got it sorted.  I wish I had seen this back in the day - I would have suggested the headphone jack replacement route.  A few years ago my amp would regularly and seemingly randomly mute itself (although it happened more when things were loud).  Worked out that plugging a jack in and out of there a few times would provide temporary relief.  Eventually I replaced the jack socket and the problem was solved.  No obvious damage like the one which came out of yours but it was one of these types:

 

 

When the headphone jack is plugged in, it breaks the contacts shown and sends the signal down the headphone jack instead of passing it through to the speaker and the ground lift is detected by the amp and lights up a mute LED (which was very handy in piecing together what was happening).  My guess is that the socket was cheap as chips and the contact(s) had lost their spring and were lifting away causing interruptions in sound and the LED to come on.  Haven't had a problem since I replaced the socket.

As it happens I have a similar thing on a Marshall guitar combo' that I recently got free with no loudspeaker (it has one now).

Not stopping the amp working but it doesn't short the input as intended with nothing plugged in so it stays a bit noisy.

Yes - I can see that while it handles the jack plug okay, it doesn't have enough 'spring' to short when no plug there.

It's actually a 'stereo' socket configured to also short some internal points - presumably to stop the OD channel boosting internal noise when there's no input. Obvs not much use when the socket has lost its zing !

Pain to replace because of all the pcb pots etc that mount to the front panel and another socket - 'Aux Input' or similar has the same problem.

So I'm thinking to do a bit of metalwork and put in panel mount sockets in parallel.

What degree of volume change are you hearing ?

Is the amp very hot (as far as you can tell) when the volume change starts to kick in kicks in.

It seems to be time dependent ? So that sort of points toward a thermal issue.

7 hours ago, itu said:

I did not mean that they would not work, but they do behave in a different way. I have tested several compressors and fuzz/OD/dist boxes. Their behaviour as well as sound has been different with my lo-Z and hi-Z basses. No, I did not believe there would be any difference, but after quite a lot of testing I found substantial change in sound dependent on the bass' output impedance. I talked about this with a seasoned pedal maker who confirmed my findings.

I have compressors that work better in the beginning of the signal chain: I do understand that the placement in the pedal board affects effect's behaviour. When there are buffers in between, the results are naturally different.

FX loops is another story with their varying levels etc.

Understood. But the 'driving a 'Fuzz-Face' type circuit with a lowish source impedance is the big thing that arises.

Beyond that - yeah - it's all in the circuit details. Amongst other issues a 'box' may be designed with an input impedance more suited to 'line level' sources that is generally regarded as too low for passive Hi-Z pickups - although, of course, sometimes that will be a sound that people like and want as it will, for example, go towards less sustain. At the other extreme a very high input impedance can result in resonances that over emphasise particular frequencies.

Would be interesting to hear what differences you found with Ho/Lo Z on specific pedals/boxes.

Cheers.

On 08/10/2021 at 23:39, Boodang said:

 it will have a low impedance output (normally 600 ohms) courtesy of the opamp used and because they need magnets that are not as strong as passive p/u's they have less pull on the strings.

Passive pickups normally have an impedence of 10k ohms, will have a narrower frequency r...

Just a note to say that 600 Ohm is on the high side for a 'Low Impedance' Output although still an order of magnitude below that of a standard Hi-Z pickup. A 'real' low impedance output has an impedance below, say, 100 Ohm. Typically 68 Ohm. In the simplest case simply set by a resistor in series with the OpAmp output. It primarily serves to keep the output stable with a capacitive load - basically cables.

It also limits the current if the output is shorted. So in some battery powered pedals etc it can be 1 kOhm or so to protect the battery. But higher resistor value does increase noise.

The '600' Ohm standard is something of a legacy thing from old electronic gear where power transfer and hence impedance matching was important. With modern solid state kit it's voltage transfer that is the issue.

If I'm understanding what you propose correctly I'd say:

• Won't affect the tone since (afaik!) poly' resin has no magnetic characteristics
• I wouldn't do it since it would appear to prohibit any future height adjustment of pickups (or replacement) ?

On 02/10/2021 at 21:33, itu said:

Bass signal path looks like this:

pickup(s) - blend (or vol2) - vol - tone circuitry - output

 

If there is even one battery powered part in the signal chain, the whole system has low impedance (lo-Z) output. Understood?

 

If the pickups are true lo-Z (buffered output, battery operated), the following adjustments (pots) have less effect to the pickups. Here this can be compared to a hi-Z system...

 

"Passive" system usually consists of pickup(s) and vol(s) and tone. No batteries. Here pots - even vol - affect the sound by cutting some of the highs and output slightly.

 

Usually an "active" bass has a battery operated preamp for tone tweaking. Now get to the beginning of my post and repeat the first chapter: there are (passive) pickups affected by blend and vol, which load pickups and reduce highs and signal level (although slightly). So actually many of these so called "active" basses are passive with an added battery powered tone circuitry.

 

There are few battery powered pickups available like MEC and EMG. They have built-in buffers and thus a lo-Z output.

 

There are also few mixers like John East, and certain Audere, EMG and Noll preamps. These mixers do not load pickups.

 

I am not sure, what do you actually meant with "active" pickups, so hopefully you can refine your question after my answer.

 

One thing you should be aware of, is that the output type has effect on the following units, too: A hi-Z output drives a fuzz/OD/dist effect in a different way than its lo-Z counterpart - even when the output levels are exactly the same. 

 

I also want to point out that some hi-Z outputs are actually "hotter" than lo-Z ones. "Active" does not equal higher output level.

Nice explanations there.

If people ask me I usually go along the lines of:

If an 'Active Bass' has Hi-Z Pickups then it has a powered buffer or a more featured preamp with active tone controls and whatever.

It's basically putting some or all of the functionality of your preamp section into your bass.

Advantages:

Your pickups are not directly loaded by the capacitance of the cable to the amplifier.

The output signal has a lower impedance. This good because lower impedance signals are less susceptible to interference.

Additionally low-Z signals are not as troubled by cable 'handling noise' as Hi-Z signals. You may not need 'Low Noise' instrument cable that has the semiconducting layer in it to reduce this noise.

* See note on impedance below

If you prefer to have EQ etc controls on your bass then there you go.

Disadvantages:

The circuitry is generally battery powered - one or two PP3 batteries. So if your batteries run out of steam then you have a problem (although there's sometimes an option to switch to passive operation to get out of trouble). And in most cases accidentally leaving the bass plugged in will run down the battery.

Players love to have a long battery life for obvious reasons. But this doesn't always go hand in hand with the highest audio performance so there can be a trade off compared to your mains powered preamp.

Also if you then plug your active bass into your preamp then you are sort of duplicating functionality and increasing noise by going through more amplifier stages.

*Impedance - worth noting that 'Active' basses  might have a lower output impedance than passive basses. But often it is not really 'Low Impedance' in pro-audio terms as it's just the unbuffered output directly from a potentiometer wiper. The output impedance will vary with the wiper position. (This is similar to the case with many fx pedals).

Don't be fooled by the use of an XLR socket - they are often (though not always) used for security of connection but the signal is not necessarily a proper 'DI' signal in terms of level / balance / impedance.

re: A hi-Z output drives a fuzz/OD/dist effect in a different way than its lo-Z counterpart.

I'll just note that applies to "Fuzz Face" type circuits which basically depend on the signal source having a highish impedance for their operation.

Other OD/Dist/Clipping fx work fine with lo-Z signals - they often have a buffer so that the pickup doesn't see the bits that produce the effect directly.

4 hours ago, Delberthot said:

 

 

I've increased loads of tuner holes in the past but they have all been on wooden necks - 

What is your technique for doing that ? Do you fill the existing holes before drilling ? or clamp to a supporting piece and use that to align/centre the drill ? Or...

What songofthewind said.

If anyone is going to have the tools/technique to do this then it should be Status.

Otherwise I can see it all going wrong !

On 20/09/2021 at 21:34, MrWriter said:

Anybody know if the techs at The Bass Gallery in Camden Town, London are decent for setting up a bass?

Yes.

3 hours ago, Al Krow said:

 

If it's in the band mix, then not being able to hear the nuances of the bass tones when in competition and overlap with the rest of the band is not unusual.

So True !

On 18/09/2021 at 21:17, Ander87 said:

oh! This is something I want to learn more on! The bass is REALLY quiet now but this could make it zero noise? The gain I use can be quite hissy so maybe that would help yet further although I’m not sure that it can get quieter!

If you are referring to a constant highish frequencies hiss (ssss...white/pink noise) then that isn't interference  It's inherent noise bring amplified. The noise  comes from the pickup itself, the preamp/amp and interaction between the two.

Normal passive pickups are High Impedance and regarded as a noisy source in electronic terms. Actual noise level will depend a bit on the preamp/amp it is plugged into.

Try low pass filtering / treble cut to reduce audible noise. How much you can do much depends on your desired tone.

But bear in mind that there's little signal from a bass above a few kHz.

On 17/09/2021 at 12:53, Ander87 said:

Aha, got it, all clear now @rmorris, thanks!

 

I guess the route to isolate the pickups further would be wax potting etc...

Potting doesn't affect interference noise. Wax has no RFI shielding properties. It can help to minimise microphonic effects where the pickup magnets/coils move in relation to each other.

2 minutes ago, Ander87 said:

 

 

 

I have heard about using clear nail polish for the poles to try and isolate a bit more, thoughts? Having said that the bass is really quiet now, especially by comparison!

That's a bit different - to stop you making skin contact with exposed pole pieces and causing noise. Depends on playing technique whether it's an issue. Any colour will do the job !

Although real solution is to have pickups with non-exposed pole pieces / rails.

I was meaning that the pickups themselves are usually not themselves shielded by design.

Nice. It would have been easier to check the bridge continuity with a multimeter rather than remove/refit.

Bear in mind that you can't totally eliminate noise pickup as some will 'get in' via the pickups themselves.

1 hour ago, franzbassist said:

 

I think D5 is the cleaner and the first choice.  F5 the lubricant.

Also be aware that the D5 comes in flushable / non-flush versions.

As it happens I recently picked up a Marshall Guitar Combo.

All pots were crackly or unusable.

A first round of D5 sprayed into the 'hole' on the pot casing and a good exercise of the pots made a huge improvement with only two pots showing some crackling these were the 'Driver' channel

treble and contour potrs so maybe greater audible sensitivity.

A bit more twisting of the pots next day and crackling almost, but not quite gone.

second round of D5 and all good since.

Still seems to me that they were ungenerous with their offer to take it back but at your packing/postage cost.

8 minutes ago, EdLib-3 said:

 

Thanks - the tuners are regular chrome Gotoh tuners nothing atypical in the finish. There is definitely something askew shielding wise here; if you could hear the buzz and crackle, you'd agree with me. Here is what we're working with regard to the control cavities:

 

 

Is this normal looking for the control cavity? I don't want to mess with the pickups so I haven't removed them to check out the pickup cavities - plus I don't really know what I'm looking for. I think I'm going to have to grit my teeth and get to my local guitar repairer. Hope it's not too expensive.🤪

Mmmm..looks like metallic Alu screening on the control plate with conductive paint to interface to that - but not clear if that has continuity to 'Ground'. And lots of cavity looks to be unscreened.

I see you might be in / near Brighton ? As am I.

Will PM but tomorrow as getting late here now.

1 hour ago, EdLib-3 said:

Just tried the bass with a new battery but it made no difference unfortunately. The buzz with treble control all the way up is pretty loud as usual and the crackle noise when I tap the tuners is still there. Anyone had a similar situation where the buzz is brought on my having certain tone knobs up on full?? I'm happy to be provide any additional detail that may assist.

Having Tone Control Open or boosting treble (in the bass guitar sense) usually emphasises buzz.

It's not unusual to get a transient when you go from not being in contact with the grounded metalwork to being in contact. The machine heads may have a surface finish that doesn't give a great connection when touched and the partial intermittency can give a problem.

I have a similar thing on a bass where I have some coated strings and the contact is variable and results in transients / crackles.

The problem does imply that there may be a screening issue where you are acting as an antennae for noise and the bass isn't adequately screened.  What screening is there in the control / pickup cavities ?

12 hours ago, Rubbersoul said:

I filled it with good wood glue and clamped it. But the clamp was crap and slipped without me realising and the gap didn’t tighten up properly but set about a mm apart in places. Solid as a rock but not right, which probably was the reason I had to set the E saddle so far back for intonation. Adds to the mojo lol.

Yes - mojo indeed.

It shouldn't affect the intonation setting on the bridge assuming the strings run properly from bridge saddles to nut.

1 hour ago, Rubbersoul said:

... because there was a big crack through the headstock. So I thought I’d get medieval with it and set it on fire, 

What did you do to fix the crack ? A good wood glue/filler, properly applied, should be stronger than the wood itself.

Nice. And just describe it as "Genuinely Relic'd" 🙃

The bridge intonation looks a bit odd but maybe that's down to the strings ???

+1 for the black pro eneloops. Also Fujitsu 'black' pro type but can't see them available atm.

For charge and test the BL7000 charger in the link below has facilities to charge / test / refresh . May be successful in bringing some 'worn out' cells back to being more useable.

https://www.batterylogic.co.uk/nimh-aa-rechargeable-battery.asp

On 16/08/2021 at 19:07, itu said:

 No moving parts, just two contacts.

Yes - but the absence of movement can be a problem where there is not a gas tight connection (as will be the case here). Surface contamination / oxidisation may occur. But that's a different issue to the loss of 'springiness' of the conductor in a jack plug.