Jimi Hendrix' Gear and Mods at West Coast Organ and Amp

[daveweyer]

Also remember that I used a 120K pot, that AB 5103.
I actually tuned the thing by ear and in reference to what Jimi liked. But the numbers shown give a good idea of what was "ideal" for Jimi.

[niknik]

Ok Warning long post
So i did a bit more math and simulation for the wah, this time on the heel back/dark position.

Here is the stock value.
500/33k/10n
fo=711Hz
Q=14.75

Here We see that with the 530mh inductor and 13n cap, at the same frequency(wah pot setting) smooth the wah in the dark range, wich is a really really good thing.
530/33k/13n
fo=681Hz
Q=14.54

Now if we factor the 3nf in parallel with the 10nf, that make the low frequency sweep down to 606hz .
IMO putting the 3nf cap in parallel with the inductor is a better idea,(give a better range while also smoothing the heel back position)
530/33k/13n
fo=606Hz
Q=16.33

Here is what happen with my 500m/30k/15n value. range is a little bit better and the heel back position is smoother.
500/30k/15n
fo=694Hz
Q=13.74

Here is a quote from the result to the push toe/bright position from the other topic.

Tek465b wrote:
Stock value
500mh / 10n /33k
fo=2.250 khz
Q=4.666

Dave value(lower frequency a bit sharper peak)
530mH / 13n / 33k
fo=1.917 khz
Q=5.168

My Value(pretty much the same as above)
500mH / 15n / 30k
fo=1.837khz
Q=5.196

stock value with 15n(samelower frequency but peak too sharp)
500mH / 15n / 33k
fo=1.837kHz
Q=5.715

Now to push it further.
Can see that on the heel/back position the Q factor is much higher, this should result in a much more intense wah effect but it just do not happen in the simulation/real world(in effect the effect diminish at low frequency).

Reason is pretty simple...
The 100k wah pot and the 220n capacitor act as a high pass filter cutting down that intensity.
so putting in a 470k-500k wah pot will make the heel/back position much more intense/sharp and increase the dark/low frequency sweep. wich to my taste is just bad.

Ok the dunlop JH-1 wah usee a 470k wah pot and the effect is not that intense, but they use a 22n from the wiper to ground wich do reduce the heel back wah effect drastically(it also fuck with the pot taper and reduce low frequency sweep range).

I put in some 800HFe transistor in my wah and the bias measured right at half VCC Supply. it almost look like it was made to bias at this HFe loll

So to recap
530mh and 3nF cap parallel to the inductor with 100k wah pot really seem an interesting configuration.
or the 500mh / 5n(parallel to inductor) / 30k is what am gonna try(since i dont have a 530mh around)

Really interesting Tek465b!
I'm going to do some experiment with my vox wah,
at the moment the inductor installed is a 350mH with a .015 cap, and a 100k pot, purchased from chase tone.
I think it's ok, but I have to tune something else somewhere in the wah, cause it seems a little too distort, in a particolar half way position..

[niknik]

ok,
I did some changes in my 45/100, trying to solve my ghosts issue..
I paralled two in series 30uf caps to main filtering, so now I'm in the 50uf range.
I changed the balance of plate resistors in PI, lowering 82k and raising 100k (a little..)
this thing seems work, ghosts are decreased, even if not completely disappeared, but I think I can stop to work in this amp, for now.
I made another clip with same setup like in the previous clips, but this time my guitar volume goes from 4 to full (previously never set it beyond 7/8 'cause the ghosts..)

http://www.soundclick.com/html5/v3/play ... i&newref=1

please let me know what you think (about the amp, not my playing )

now I can start the 5687 driver mod in my west coast super lead

[Tek465b]

That sound very good and great playing

Ok as promised i did a small clip(forgot to Turn the vibe intensity up) anyway
Keep in mind am quite new to this song, and.. i use the wah only at the end because it hurt my hearing a bit too much. I had brain fog and dizziness because of the meniere's disease so i dont even know how i was able to just play.. anyway. this is to about the tone not my playing.

This is recorded with a cellphone in my guitar case on the side of the room, this morning at semi/bedroom level.. it has a big loss of headroom, just sound alot better in real life(except for my shitty playing). next time i try to move the phone in front of the amp(instead to have in in the corner of the room...) maby it record more of the clarity/headroom. I will practice learn the song a bit more and make a better recording on a better day, its gonna be a bit more pleasant.

This is using my 3 transistor fuzzbender, wah with 30k and 5n parallel to the inductor and a modded univibe clone to my openback bluesbreaker(modded too of course).

https://soundcloud.com/mathieu-girard-8 ... led-banner

[niknik]

Well done Tek465b! Very thick and organic fuzz sound!
I would like to listen it in action with more amp volume, I'm sure it really rocks!
May you tell us more about your fuzz?
And yes, definitely the vibe is a fondamental part of the equation, I need a good one..
at this moment I have got only one vibe, a Wilson uber haze, pretty good pedal but not so Hendrixy..
I'm looking for a different vibe, but I really don't know what to choice..
And don't apologize for your playing, passion and love for the music is what keep us alive! And it never is a competition! We are all brothers!

[Tek465b]

Hey, i was thinking about your ghosting issue and when was the last time the amp was re-capped? to me it sound like it may need a recap..

Here is a link with picture of my gear
https://1drv.ms/f/s!AkAEksGZa3pXgw6TeSXiFLT5zonP

Its just a normall NPN fuzz with ac127, the 330/470 en emitter of Q2 was changed for 750ohm(trimmer value)
The first transistor is configured as a common emitter buffer and i use it for the clean too(the pedal can be wired in many diferent way of course). I do use the settings that you see on the pictures.
The PDF files for the fuzz schematic/pcb/layout are in the link.(i can sell this one and build more if needed)

I know the vibe look real funny, its one of my early prototype, it was build on veroboard with flying lead soldered together, all component got desoldered and moved to a homemade pcb loll. the depth control and chorus/vibrato switch work backward(yes i was lazy, its been like this for about 8 years) loll.
Anyway it is a neovibe clone with the bias offset mod and probably 1 another mod i cannot remember(opening it up will confirm) and probably a oddball value gain resistor for the bulb driver.

I know the inside of the amp is looking ugly. it is more like a testing platform. soo many mods got done and undone / component swap in this amp in the past 10 years loll.
I do use the amp setting that you see on the picture(assembled/in cab), but there is oddball value component in the amp and tonestack.
Tubes are mullard, rft and new prod. JJ in the preamp and chinese kt-66 in the power amp, can't remember the bias, probably around 60%. B+ is around 455Volt.
Speaker are 2x vintage 30(8 ohm wired in serie, total 16 ohm), they are connected in parallel with the 16 ohm hotplate(set to load) for a 8 ohm total load.

The stratocaster is a YJM with scalloped neck, it do sound good and sing easily, when i get in a good mood i easily fly to heaven with this setup up.

I love to give detail about my gear loll sorry for the long post

[niknik]

Tek465b,
thanks for sharing these things! I just bought a blue dunlop bc108 jh f1, and I'm gonna to perform some mods, like input res and output gain mod, but also I would like to build a 3transistors fuzz, I've got some 2n525, 2n591 and 2n527 with right hfe..
About the filter caps in my 45/100, they are F&T, 7 or 8 years old, so I think they are ok, or maybe not?
anyway now the ghosts in the amp are less pronunced than before, I raised a little the main filtering to about 50uf, and changed plate resistors in v3, 81k and 103k..
Could it be also a power tubes issue? They are new production gold lion kt66. Maybe a different brand is a better choice?

[Tek465b]

Yeah the jh-f1 look ok
They put high gain transistor in, then reduced the 100k feedback resistor to 82k(this bring back down the input impedance/look more like a low hfe transistor but increase current comsumption(bad for battery)). should put these 2n527 in it and chande the feedback for 100k
They also have a small pf cap across that feedback resistor, that is only good to stop oscillation(same thing as cap from collector to base), it can be removed in most unit.
Am not sure why they put a 100n cap on the output.. thats seem a bit excessive.

If you need help building the fuzz or any circuit, i can help with everything from circuit/pcb design to final assembly.

About your cap, i dont know. i think when they get around 10 years is starting to get old... the one in my amp are 11 years old they seem to hold up well. Electrolytic capacitor can go bad if unused/stored for a period of time too.
Dave will tell you more about that than i can, my knowledge in vacuum tube is limited.

[niknik]

Thanks Tek465b,
I will let you know if I need some help with fuzz
about the filters caps, I really don't know, I read many times that they have to be changed after 10 or 15 years, but I can say that my original Marshall super lead from 71, still has original blue daly 50uf+50uf caps, and they work perfectly even after 46 years! And in my opinion they are the best caps I tried! So really I don't know
in my collection I have got 12 Marshall amps, originals and clones build by me, seven 100w, two jmp 50w, two jtm45 and one sort of major but with only 2 kt88, so about 90w
It's my little luna park!

[daveweyer]

Summer must be here, the forum gets so quiet.
Just an update on some Jimi stuff; the Jimi Hendrix Family Foundation, and the Jimi Hendrix Foundation are interested in getting some gear made which duplicates the stuff we made for Jimi at West Coast Organ and Amp. The foundation is not to be confused with Janie's Experience Hendrix, they are at odds with each other.
Much of the equipment will have the mods discussed here over the last couple of years; As Xplorer says though, "don't make it too easy to get his sound or it will take all the mystery out of it", and we think that is a good point. We will leave room for mystery if this equipment ever gets made.
I'm trying to restore and old amp I started for Jimi in 1969 and then modified and gave to Dave Farrell after Jimi died. It was supposed to be my ultimate solution to the screen dissipation problem which plagued Jimi in his Marshalls. The circuit was developed over time by trial and error through a bunch of hot rod circuits I installed in a Fender Showman amp belonging to Sneaky Pete Kleinow of the Flying Burrito Brothers. He'd take it to try, and then bring it back blown up is a week or so, or even overnight, and then I'd try it again. It was a challenge trying to get 250 watts out of four output tubes reliably.
I'll explain how this worked out if there is a chance.

[Xplorer]

Hello Dave, that is some very interesting news ! congrats, it must be exciting for you.
yes, sometimes the forum is a bit down, things to do, girls to try to forget lol, work, elections ...
let's email, we should talk.

what i meant by saying "don't make it too easy", was that if everybody buys the stuff massively thanks to a marketing from the foundation or such, this will of course please them but at the same time it'll lose some of the mystery. but this said, i don't think that there's a good solution about it, either way. if it becomes a common mod, and sound, it could lose a bit of this "special thing" in it, on the other hand, running into this kind of "wall of sound" and demistifying it will make peoples to see how the playing is almost all : put jimi with a setup , hear it, then compare it to anybody with the same setup ... it'll always be special with jimi. so the anybody guy will maybe admire what he did even more.
i don't know, it's a special subject but anyway, you're the inventor of it, so it's up to your choices there.

[daveweyer]

For those of you who are really into Jimi, please check out the latest issue of Jimpress, issue 110, summer 2017. Lots of really good info on Jimi, little known stuff, and Xplorer, even a mention of Jimmy Halliday (sp). They also take a nice stab at figuring out if the guitar we put the Tele neck on was the same one Jimi played at Woodstock, with a new neck.
Plus, the complete rundown on the "impossible wah" I made for Jimi in '69, and tons of info on his gigs and recordings. They even start in on the subject of those notches we cut in Jimi's frets on the earlier guitars; quotes from Neal Moser too.
Really first class publication, on good paper.
JImpress UK.
Just got my copy and reading all through it.

[Xplorer]

That's fantastic news i wish i had access to this paper.
btw, it's johnny Halliday, not Jimmy, but anyway, i'm not a fan of the old french rocker he he. some are.

here is a quick clip i've made with an SM57 + an SE R1 ribbon mic.
i tried to work with some virtual version of the Tools that Eddie Kramer had, like a pultec, a fairchild compressor, an helios console preamp, things like that. but it's not easy, and it expands the possibilitys. lot to learn.
anyway, i think that it sounds chemical than my usual clips using virtual speaker.

https://soundcloud.com/xplorer80/170618 ... compressor

[daveweyer]

Quite right, Johnny Hallyday, not Jimmy. Too much Jimi on my mind.
Really great clip by the way, the vibe sounds stereo with that reverb. Keep up the fantastic work.

[Xplorer]

Quite right, Johnny Hallyday, not Jimmy. Too much Jimi on my mind.
Really great clip by the way, the vibe sounds stereo with that reverb. Keep up the fantastic work.

Thanks very much better can be done for sure, but i'm quite happy with this new approach for me.
About Johnny Hallyday, actualy i have to thank his godson to have turned me to the guitar ( AND to Jimi Hendrix ! ) back when we were twelve, after school. Sending me some tabs by fax ha ha. and at home, he had a strat that was given to Johnny by Jimi, before or during the Jimi Hendrix experience, i don't know, because they were good friends the whole time, living sometimes at their home when one was in France, or the other in UK. Johnny even put out his version of "Hey Joe" before Jimi, i think. of course it wasn't the same result