Andyjr1515

[quote name='BigRedX' timestamp='1476988665' post='3159084'] The baritone circuit that I have for the Gibson 355 guitar uses 0.001µF, 0.003µF, 0.01µF, 0.03µF and 0.22µF capacitors for the 5 filter positions (the 6th is a bypass) if that helps? [/quote] That's useful info, BigRedX. I've got a 0.001 cap on order - I'll be interested what it sounds like compared with the others.

[quote name='samhay' timestamp='1476989645' post='3159092'] That's correct for the notch filter. The corner frequency will be different for a more conventional low pass filter (tone control), but vintage p bass tone controls use 100n, which most consider to be about as dark as anybody would ever need. 220n is darker. [/quote] Ah - I understand what you are saying. Yes - in normal tone position, a capacitor of .047 is about as high as I go. [url="https://soundcloud.com/andy-rogers-6/eb3-notch-comparisons"]This soundclip here[/url] is not terribly useful because somewhere along the line something is clipping, but it gives some idea of the type of sound coming out. It sounds like an old fashioned moog synthesiser to me (think The Persuaders theme). I announce each of the settings, but on the file, all neck pickup, is : no notch, tone at 10; no notch, tone at zero; notch with .011 capacitor; notch with .047 capacitor; notch with .022. You can't really hear it here, but through the amp the .22 does sound brighter and clearer. However, the .047 is noticeably louder than either of the other capacitors. I'll try and record some better quality samples next week Thanks again for all the input, folks Andy

[quote name='samhay' timestamp='1476980736' post='3158995'] 220n would make for an incredibly dark tone control on a passive bass or guitar. In any case, I have a good stash of caps and am happy to pop some in the post if you want to try other values. [/quote] If I understand the figures above, doesn't the 220n knock out the low frequency 280Hz? (It must be said that I probably don't understand the figures above )

Thanks again, samhay I've got .011uF; 0.022uF and .047 on hand. If PRS have ever fitted 0.22uF (because that is what seems to be written on the side of a cap out of a PRS circuit, then I may have one of those too I may be able to find a bit of time this eve and I'll try them out. Failing that, it'll be middle of next week. Either way, I'll let you know I'll also order a 0.001uF - it will be waiting for me when I get back

[quote name='samhay' timestamp='1476972286' post='3158922'] Great - sound like we are on the same page. Below is the simulated frequency response of an RLC filter (image a few posts above) with your transformer (1.5H inductance and 148 ohm resistance in series with this inductance) and a 22n capacitor. The top graph shows the output when driven by a perfect voltage source. The bottom graphs shows the same filter driven by a simulated guitar (not mudbucker) pickup. Notice how there is a lot more treble rolled off, and this will get worse with a bigger pickup like the mudbucker. In both cases, the resistor is varied from 1k-100k. As the resistor gets larger, two things happen: 1. The notch gets broader 2. As this resistor works as one half of a voltage divider with the volume pot (I asssumed 500k here), larger resistances give additional signal lose at all frequencies. Bottom line - less resistance is more signal. Also, the original varitones switched in a range of capacitors, and this is still a good thing to do with the rotary switch. I can suggest values if you tell me how many values to suggest... p.s. look like a resistance of about 10k would be a good choice, so it seems the computer agrees with your ears. [/quote] Brilliant! Thank you so much, samhay, BigRedX and 3below And thanks particularly for the above, samhay I have switch positions 4 5 and 6 so it would be three different capacitor values. The present one is, as you say, .022uF

Ah.....but I DO have a 25k linear pot! Just wired that temporarily and think I'm getting somewhere! With the pot about midway, it's almost same volume as the clean neck pickup, it's in the same tonal range as the neck pickup with tone rolled right off but a tad different. I think this is usable The other two switch positions, taking it through the inductor's split primary and full secondary, make very little difference to going through the full primary. As such, I might have a look to see if, instead, I can use the three positions to bring in three different values of capacitor... Still got no idea what I'm doing but it's immense fun (other than I should be doing other things today ) I will get a trim pot to replace the full size pot so I can use that in the final version. Thanks for all of the input so far, folks. I think I'm starting to clamber up some of the early foothills of the enormous learning curve mountain

[quote name='samhay' timestamp='1476967398' post='3158874'] >I think the above is what could be predicted? Yes - that sounds about right. The mudbucker has considerable resisance - perhaps 30k, so you probably won't want to add much additional resistance to get this work (2 x 100k resistors in parallel are 50k total resistance). I have seen some design(s) that use a resistor to balance between pickups, but these are mixed before the signal makes it to the volume control. The transformer will have somewhat variable inductance (this varies with frequency) and non-negligable resistance. If the resistance is more than a few k ohms then the notch becomes very broad. Are you using a blue LT44 transformer from Maplin? [/quote] Hi, samhay No - its a Xicon 42TL021-RC (but is indeed blue ) I wondered about trying a much smaller resistor but don't think I have any in my bits box. Shows how much I know though - I assumed the higher the resistor the narrower the band. If the garage do some magic fixing my car later today, there's a Maplin near where I pick it up from. If so, I'll get a variety of smaller resistors to try them out. What value(s) do you reckon is worth a punt?

OK, folks I've done a few experiments up to the point that MrsAndyjr1515 has 'reminded' me that there are more pressing things to do today I've basically wired it like this (as far as my little brain can work out): ...which my newly acquired education tells me is a Band Stop Filter. The results are interesting, and I think as the notch filter has been described:[list] [*]With a 100k resistor, definitely different to the mudbucker alone. Similar to the bucker with the tone turned right down, but less boomy. Very quiet in comparison, though. [*]With 2off 100k resistors in parallel (ie 50 ohms?) it is louder - not as loud as the clean mudbucker but again bassier, fluffier but without the boom of the bucker with tone right down [*]With no resistor, similar in volume and tone to the mudbucker with the tone wound right down [/list] If I have understood the theory right of what the notch is trying to do and what the resistor is doing within it, I think the above is what could be predicted? Anyway - must go and do some other stuff!

[quote name='samhay' timestamp='1476953614' post='3158690'] Nice build! As I understand it, the varitone is a notch filter. You can get a RLC notch filter with a resistor, inductor and capacitor in [u]series[/u]. If you put the 22n cap and the transformer in series (to ground) then 22n and 1.5H will give you a notch at about 880 Hz. Any series resistance will not change the frequency, just make the notch less deep. So - I suggest you lift one leg of the 100k resistor (so it is out of circuit) and see how it sounds. Edit - just realised your transormer is parallel to the cap and resisotor too. If you disconnect the resistor and cap and then splice the cap between the volume pot and rotarty switch, you will get everything in series. [/quote] Great - it'll only take a few minutes to do that. To be honest, it's one of the reasons I decided to put the three components on a bit of veroboard so I could chop and change to try different things (and correct inevitable errors ). I'll try it later this morning I have made a mental note to do a bit more reading on electrical circuits! In our family when we were youngsters, I only understood things that moved and my brother only understood things that didn't - that's why I ended up as a mechanical engineer and he ended up as an electronics engineer

[quote name='6v6' timestamp='1476944955' post='3158620'] Well this is the first one I've attempted, but the approach I took was to make an mdf template, double stick tape the plastic to the template, then use a flush trim bit in the router table (got a cheap one from aldi!) followed by a chamfer bit to cut the bevel. Worked pretty well but I had to experiment with the depth of cut on some scrap to get the bevel looking right. I suspect the same approach would work with a hand held router, but I'd probably make a thicker template so it could be stuck securely to the bench without the bearing fouling, and possibly add a sacrificial thin mdf board on top to avoid marking the plastic with the router base. There are some pretty good tutorials of the router table method on YouTube which is how I figured it out, good luck! [/quote] In any terms, let alone a first try, I think that's a splendid job...

[quote name='3below' timestamp='1476914157' post='3158530'] Your understanding is correct in my world of Physics / Electronics, you have described a notch filter. They have a very interesting looking varitone wiring diagram for the 'CT' bass on the website. Might be useful? http://www.guitar-mod.com/wiring/ctimages/ctbass_wiring.gif [/quote] Yes - saw that and took a copy of it for my 'just in case' file. Couldn't quite work out what is going on (there seems to be some connections missing as far as my little brain can make out) but might be a better way of getting three more usable sounds than what I'm trying at the moment

[quote name='Andyjr1515' timestamp='1476912030' post='3158497'] I don't know if it has any relevance, but the outfit in the states that sell an 'improved' Eb-3 pre wired loom (can't remember their name but I'll post a link in a bit) apparently aim for a 800hz mid point...they don't say how they achieve that, though ... [/quote] Got that wrong. The site is here, Rothstein Guitars http://www.guitar-mod.com/rg_eb3.html I think what they are saying is that is is supposed to be a notch that lets all frequencies though except the target range? Their range they say they are trying to block are the frequencies around the 800hz, if I've understood their blurb correctly.

Based on the fact that I now have a feed from the neck hot to where the c/r circuit joins terminal 6, does my circuit look right in terms of getting the filter working in the first place, regardless of the frequencies it is letting through?

I don't know if it has any relevance, but the outfit in the states that sell an 'improved' Eb-3 pre wired loom (can't remember their name but I'll post a link in a bit) apparently aim for a 800hz mid point...they don't say how they achieve that, though ...

Looks splendid. I'm attempting to make a pickguard shortly. I find them a right pain! Do you have any tips and tricks?

[quote name='Paul S' timestamp='1476878343' post='3157986'] [/quote] ...which might give you a clue as to one of the other ones.....

[quote name='gelfin' timestamp='1476872419' post='3157906'] [/quote] ...which might give you a clue as to who is one of the aforementioned...

Thanks, folks Showed the progress to Pete last night - he's delighted with it (phew) He's a good player - it sounded great! It's light, it balances beautifully, the neck is the same profile as his favourite bass and it looks quite classy in the flesh Very few things to do now: - re-stain the neck. Easy job. I tried a variation on my experiments with the slurry method which didn't really work, so I'll redo it the way I did my LP junior so that the buffing doesn't start to reach the mahogany (which is what it's doing at the moment) - sort the varitone notch or alternatives for switch positions 4-6 - fit round-wounds - fit the brass nut that should be arriving in the post today - get him a hard case On the basis that there's plenty of time for those jobs before his November birthday, I've started getting my head round a couple of smaller mods and a very exciting full build, all for Basschat members . I'll kick off threads at the appropriate times Oh...and after I've finished those, then Pete wants me to build him ANOTHER bass...piccolo (c 25" scale, to boot...maybe fanned frets...)!!!!

[quote name='Andyjr1515' timestamp='1476785128' post='3157152'] In fact, have I spotted the error? Presumably the notch circuit is supposed to be a bleed off the main volume? I've realised, I have the feed from the neck p/up in positions 4 / 5 & 6 ONLY going through the capacitor/resistor circuit. Presumably I should be taking a line direct from the volume hot to the 6 \\ position on the rotary switch? It'll take 2 mins - I'll try it [/quote] OK - well I think that has worked to an extent. In position 4 (intended to be neck going through notch filter using full primary induction coil) I now have a sound that is different to the other positions, more trebly and lower volume (bit like the equivalent of putting a mute on a trumpet) but OK. The other two positions still lose most of the volume. But I'm still not convinced I've got the notch circuit right... - or if it is, I might use the other switch positions in a different way Whatever, it is an interesting diversion. Also - in all other ways - I'm really pleased how the bass is turning out. I've been playing it this morning and it sits so nicely both on the strap and on the knee and, with the neck volume at about 9 and bridge on 10, the three main position sounds are phenomenal. Can't wait to get the proper nut on and hear it through a bass amp Final tweak I might do is take the neck back down to wood and restain/reoil it....I've got it silky smooth but I've gone a little too enthusiastic with the slurry and buffing and the mahogany colour is showing through a bit through the dye. I might try Pete out with it first, because it is lovely to play and he might prefer it as it is.

In fact, have I spotted the error? Presumably the notch circuit is supposed to be a bleed off the main volume? I've realised, I have the feed from the neck p/up in positions 4 / 5 & 6 ONLY going through the capacitor/resistor circuit. Presumably I should be taking a line direct from the volume hot to the 6 \\ position on the rotary switch? It'll take 2 mins - I'll try it

[quote name='BigRedX' timestamp='1476725506' post='3156696'] What value choke are you using? IIRC the Gibson circuit diagrams only give a Gibson part number rather than the actual value of the choke. When I built my first electric guitar in 1979, I fitted a varitone that used every version I could find circuits for because I wanted to use all 11 positions on the speed knob I had. TBH most of them sounded crap and there was a significant volume loss on all but the most subtle variations. [/quote] [quote name='3below' timestamp='1476725918' post='3156703'] A further element of subterfuge / chicanery was alleged on the part of Gibson: The inductance values were stated incorrectly on the circuit diagrams to mislead other manufacturers. I have picked up this statement from internet research so it may have no credence whatsoever. Do you have a multimeter that will measure inductance? [/quote] My head goes squiffy when I try to get it round the difference between henrys and ohms inductance value It is a 1.5H induction coil with induction values quoted at 4k ohm primary (presumably therefore 2k ohm tapped) and 600 ohm secondary coil. In terms of resistance, they are quoted as 148 ohms primary and 64 ohms secondary. I've got a 100k resistor and 0.022uF capacitor making up the rest of the circuit I think I need to check my components wiring diagram against the original circuit diagram before I do anything else (and double check I actually physically wired it up that way!). This is the components diagram I used: If one of you can give it a glance for a quick sanity check that would be great

I should explain, by the way, that the sound clips are through my 6-string electric practice amp...it serves only to illustrate the sound differences rather than the absolute!

[quote name='FuNkShUi' timestamp='1476703726' post='3156389'] Cracking job mate. I shall remember they're Swifts from now on too! [/quote] No problem The brass nut arrived this morning................. but it was a 6-string electric. Hopefully a replacement is on the way. Two bits of further progress: Popped a strap button on the back and did a few checks. Great news - a more conventional strap button position is fine and it balances and sits beautifully Second bit of progress, I did a few quick soundclips - [url="https://soundcloud.com/andy-rogers-6/eb-3-style-custom-bass-sound-files"]this is Bridge; Both; Neck[/url] No point in trying the notch settings yet - you would hear my breathing louder than what's coming out of the amp

OK - the 'almost finished' shots. Please forgive the self-indulgence :

Well, I award myself the honour of Andyjr1515's neatest wiring job ever (you need to see some of my others to realise how significant this is ). This is it, fully wired up and ready to play: OK - that's some of the good news out of the way But wait! There's more good news. It works! Moreover, the Model One neck pickup is unbelieveable! The 'cheap as chips but looks right' Artec also is really and seriously not bad at all. OK - hmmm - the notch filter. The good news here is that it does make three different sounds. But the volume is c 10% of the clean pickups. I'm not sure whether that is how I've wired it up or the values of components I've used. I'll double check the I've actually wired it to diagram and then consult with folk (3below springs to mind ) what understand these things a lot better than what I do... Overall, though, with a month to go before Pete's birthday and just the notch circuit and nut to sort (plus I might re-dye and finish the neck), well pleased. I'll post a few 'almost finished' shots soon