escholl

Have you had a look inside? Was there any indication from the previous owner about what the issue might have been caused by? How are you powering it? And do you know if the pedal is true bypass?

[quote name='fryer' post='825847' date='May 2 2010, 08:11 PM']It's the 9V one that came with it. It's a 2 pin one with a uk adaptor.[/quote] Hmm ok. Well it definitely sounds like the sort of ground hum that switching circuits tend to produce in some situations, the trick is figuring out ways around it. It could also be some sort of clocking or switching signal which is produced by the pedal, and present on the ground. Are there any other pedals connected? Do you have any other power supplies to try it with? Switch mode supplies tend not to be Earthed, which is fine as long as nothing else in the circuit is -- but when something is, they tend to hum. It's also possible that the pedal itself has a noisy ground, as is the case with some DSP effects, and is not a problem when there -is- an Earth present in the circuit (or at least when the Earth are connected, even if not to the mains Earth), but when there isn't, it presents itself on the audio signal itself. Can you try it with a battery?

[quote name='fryer' post='825595' date='May 2 2010, 04:00 PM']Hi, I have a Genz Benz shuttle 6, and have recently bought a Soundblox pro distortion pedal. The pedal works fine with other amps, but when I use it with the GB, I get a high pitched, Morse Code type sound from the speakers. This starts after the GB warms up, 5 seconds or so, then stays on. Is it something to do with the power supply the GB has instead of a transformer ? Any ideas how to stop it ?[/quote] What kind of power supply are you using for the pedal?

[quote name='Eight' post='824839' date='May 1 2010, 02:06 PM']So have I blown the input/pre-amp stage?[/quote] Yes, that is exactly what has happened. The good news is, at my best guess, it should be an easy (read: inexpensive) repair from any decent and competent tech -- you could even try getting in touch with Ashdown. I've only got one head as well -- in fact I really have none at the moment, as mine is in storage in the UK while I'm stuck back in the US for now -- so I am under-equipped too!

Given that the power amp stage of a SS amp will likely have less effective power supply filtering and regulation applied to it, giving it a larger percentage of the total circuit gain seems like reverse logic if the output desired is the cleanest, lowest-noise signal possible. For bass and guitar I always set the preamp first, then the power amp (or, gain then master).

[quote name='OldGit' post='823987' date='Apr 30 2010, 01:04 PM']This is for blues harp rather than guitar. Does that all still apply?[/quote] Well, it's not going to hurt I suppose, but if you like the sound and just want is a darker tone, seems most logical to start with the two caps that are either side of the tone control C6 and C12. No sense overcomplicating things, and if you don't generally work with circuits like the one here, as some of us do, then keeping it simple will reduce the likelihood of anything going wrong and you then having to try to fix that too...

[url="http://www.dv247.com/studio-equipment/m-audio-studiophile-bx5a-deluxe-active-studio-monitor-speakers--48624"]M-Audio BX5a[/url] Haven't heard them but they've been getting rave reviews for a few years, seem to be some of the actives out there under 200. Used to have a pair of smaller M-Audio's, turned out to be pretty trusty above about 100Hz with most material. Anyways, those ones are supposed to be really quite good for the price, my choice would be there.

[url="http://www.diago.co.uk/component/page,shop.product_details/flypage,shop.flypage/product_id,24/category_id,1/manufacturer_id,0/option,com_virtuemart/Itemid,206/"]Diago Engineering[/url] I bought some of this stuff a while back, it's cheap and really, really good.

[quote name='OldGit' post='823167' date='Apr 29 2010, 04:56 PM']So, got all excited, got a space and time to try this op and went to Maplins to the tech guys in the box at the back and asked for the stuff. They asked what type of capacitor and resistor I need ... er... seems there are many types.. Any idea which I need? Metallised Ceramic plate Resin dipped Decoupling ceramic disc Polypropylene Film and Foil Audio grade polypropylene Class Y RFI Metallized Paper RFI class X2 Electrolytic (of many sub types) Double Layer Variable miniature film dielectric trimmers Thanks[/quote] For resistors, their standard .6W metal film ones Maplin sell will work fine (the blue ones), assuming they fit as the schematic mentions SMT for some resistors (surface mount). For capacitors C6, C12, C9 (remember, C9 is rated at 400V, the others at 50V) and similar, anything related to either the polypropylene or polyester film (including multilayer and metallised/metal foil versions) will be fine. Don't bother with the "audio grade". Assuming they have the values and voltage ratings you need, their following ranges should work: [url="http://maplin.co.uk/Module.aspx?ModuleNo=98156"]http://maplin.co.uk/Module.aspx?ModuleNo=98156[/url] [url="http://maplin.co.uk/Module.aspx?ModuleNo=361"]http://maplin.co.uk/Module.aspx?ModuleNo=361[/url] [url="http://maplin.co.uk/Module.aspx?ModuleNo=12031"]http://maplin.co.uk/Module.aspx?ModuleNo=12031[/url] For the electrolytics, which are C1, C2 and similar, pretty much any of them will work fine as long as they are the value you need and are equal to or above the voltage ratings given (which in both cases here is 50 volts). You don't need non-polarised ones, and you don't need high temperature ones (the red ones they sell). You might want to check though if the caps you are replacing are axial lead (one wire comes out of each end) or radial lead (wires both come out the same end of the cap). Odds are they are radial. Getting the lead package wrong is not the end of the world, it's just inconvenient. Good luck!

i think the best course of action would simply be to sell it to me! it sounds though like the zoom's impedance is either too high, or doesn't have the right type of pot (linear vs logarithmic, etc) so I'm not sure that modifying it is the way forward -- unless you could put a different potentiometer in it? it's just a guess though, and I don't really know what the boss is looking for in terms of an expression pedal.

[quote name='Eight' post='819939' date='Apr 26 2010, 09:01 PM']I do when I remember... which obviously isn't as often as it should be. Perhaps it was the fates trying to tell me that I don't need two amp heads.[/quote] pfff...two is the minimum, i thought everyone knew that?

[quote name='Eight' post='818891' date='Apr 26 2010, 09:08 AM']Need to find some locking jack system for my guitars. [/quote] Have you tried looping it over the bottom strap button? I used to pull mine out all the time too until I started doing that

[url="http://www.guitarampkeyboard.com/en/83944"]I've always been partial to the VisualSound V2 Liquid Chorus, best one I've tried yet.[/url] Fully analogue, only 100 quid.

[quote name='JackLondon' post='818621' date='Apr 25 2010, 10:53 PM']I'm still having problems with my delay and I'm determined to get this working myself[/quote] If you need/want help, fill me in on the current state of it and I'll try to help as best I can. Not saying you have to, just saying the offer is there. Best of luck getting it working mate!

[quote name='Mr. Foxen' post='818778' date='Apr 26 2010, 01:53 AM']Sounds dark, like a heavily overwound pickup. Will have to take it apart and see if I can wire it in parallel. Might sort a push/pull coil tap. Not looking forward to delving into the gubbins of this bass again, had enough fun with my mono/stereo switching. [/quote] Ooh, that has a nice look to it. Did you get the mono/stereo thing sorted in the end then? I always feel that way about my bass whenever I have to go back and do something else, but in the end it is always worth it, if only for the fact that I stop thinking about it all the time -- it always just feels good knowing it's done.

[quote name='Mr. Foxen' post='818767' date='Apr 26 2010, 01:19 AM']Cause of a misunderstanding my bass ended up with a model 1 in the bridge position. Not ideally suited, being a trebly position with a bassy pickup. I wired it up the default way, not sure if that is series or parallel, is one of those configurations likely to give me some more top? Other option is coil tapping it, however, since that is the pickup that is going through my drive pedals, not sure if the resulting hum might be an issue.[/quote] [url="http://www.dimarzio.com//media/diagrams/4Conductor.pdf"]http://www.dimarzio.com//media/diagrams/4Conductor.pdf[/url] According to this, wiring in parallel will cancel hum, give you more highs, and an overall clearer sound, at the expense of lowered output sensitivity. However, the pickup seems rated as 7/5/8 for treble/mid/bass by dimarzio, which would leave me to think that it's the usual position of the pup, and not's it's inherent tonality, that gives it most of it's bassiness. So in the bridge position, it should be more treble-oriented anyways. How does it sound?

Ah, ok. Well, the following is purely speculation, but this is my best guess: Some amplifiers, including my own, have a FET input stage with no over-voltage protection. While this is usually not a problem, the input FET in my own amp once randomly began to exhibit symptoms very similar to what you describe, after being plugged in one day. My theory was that static electricity had damaged the unprotected input FET, as that was the only thing I could think of -- static electricity discharging into the input after the tip of the cable came into contact with whatever was charged. Replacing the FET fixed the problem that time and I've been meaning to install input protection, but that's another story. Anyways, if your Korg does have input over voltage protection it wouldn't have been damaged, and if it has a direct, unbuffered signal pass-through from input to output, then the tip of the cable could have passed a static charge from you, or the carpet/floor, through the tuner's I/O (as unbuffered it would basically just be a bit of wire) and into the input of your amp, possibly damaging it. The likelihood of all these factors occurring is incredibly small, and my theory is based upon several guesses as to the internal workings of equipment to which I am unfamiliar. Furthermore, my amp did not exhibit -identical- symptoms, and I only guessed at the cause of it's own failure, so again I am hypothesising here. Someone may certainly have a more likely theory! Anyways, that's the only way I can think of that the plug falling out could cause such a distorted sound upon re-powering. Did it make a massive noise when it happened? I suppose if it was up loud enough, the massive *thump* noise you usually hear when the cable is unplugged could have damaged an output transistor, or I could be wrong everywhere and it could be something totally different! Do you get a clean signal from the effects loop output? Or if you go direct into the effects return, is the amp clean then?

What did the cable get pulled out of, the Korg or the Ashdown? Sorry I'm just confused as you mention the signal was going though the Korg.

Sorry to hear that, at least it turned out ok. Get in touch with Ashdown though, they're usually pretty good about that stuff.

[quote name='OldGit' post='817221' date='Apr 24 2010, 03:04 PM']Thanks. I'll get a few caps and have a go.[/quote] Ok, let me know how it goes, if that doesn't work for some reason we can try something else. I'm sure you know this, but I have to say it anyway: remember not to touch C5, C7, and C8 right after turning it off! I usually put electrical tape over the contacts of them if I'm going to be having the amp on and off while working.

C6 is currently 10nF, change it to something larger. Should make the tone control darker. 22nF, 47nF, 100nF -- I don't know how dark you want it. I would try 22nF, and see how that goes. You could also try making C12 smaller, or getting rid of it altogether. When the tone is in the low position, C6 essentially bleeds the HF to ground. When it's in the high position, C12 enables the higher frequencies to bypass the gain reduction performed by the "Gain" control, effectively giving them full gain into the next stage regardless of where "Gain" is set. When it's somewhere in between Low and High, it does a combination of these things. Simple but effective, really. Of course, I could be totally wrong! In which case someone will hopefully correct me.

If you're going to buy from the US, go with [url="http://www.bestbassgear.com/lindy-fralin-pickups.htm"]Best Bass Gear[/url], I've used them before and they're good. They've also got not over-wound Lindy Fralin P's, I bought a pair for my bass a couple years ago and I wouldn't trade them for anything else, really amazing pickups and didn't seem to be excessively hot. YMMV, of course.

This:

That really is bloody clever. Ten points to you!

Ahh, genius. Reminds me of a 2x12...er, 12mm anyways, guitar cab that I once built... Yours is much better though, looks like a proper cab at least! I could really use something like that, if it turns out well....