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

[daveweyer]

Yeah, there's a good chance it was a West Coast mod. I do remember several different colored cases, and I think we talked about some metal knobs and other non-stock knobs.
Not every wah had a TDK inductor, but the later in his career you go, the more TDK inductors you find. The 5089 transistors made the biggest difference in the wah, better highs (a lot less sucking), lower noise, more Q, and less interference from whatever it was plugged into.

There were one or two 3 transistor fuzz units out there, in old cases. If it sounds a lot different from the older units, it may well have affected what you hear out of the wah. The 3 transistor fuzz units were "always on", so there is a different quality to the wah, even if the fuzz is minimum.

The wahs with the 5089 transistors also loaded the guitar pickups less, so you get that benefit too.

[daveweyer]

It's been so long that I just had to add a new post. Xplorer, where are you?? Do you have a new girlfriend who is absorbing all your time and energy?

I hate to see this good old forum laid to rest.

[Xplorer]

It's been so long that I just had to add a new post. Xplorer, where are you?? Do you have a new girlfriend who is absorbing all your time and energy?

I hate to see this good old forum laid to rest.

Dave ! Hold on ! i'll get back here with some news for you i'm working on it ..... at last.
i'll mail you btw.

[masonbeckham]

I’ve been looking at it all day, reading about the 3 transistor fuzz. Still super anxious to get my hands on one!

[Coony]

oh ! i finaly managed to get the pdf. wow !!!! Thales certainly never imagined he would help our quest

i see that you managed to calculate, chapeau ! bravo !
if it can help, i improved the visibility of the tubes :

http://i.imgur.com/2A29Xh6.jpg

This enhancement is made of the left or right amp - looking from the rear of course?

Thanks!

[Xplorer]

Sorry, i don't remember.
if i come accross the original photo someday i'll tell you

[Xplorer]

It's been so long that I just had to add a new post. Xplorer, where are you?? Do you have a new girlfriend who is absorbing all your time and energy?

I hate to see this good old forum laid to rest.

Hi Dave ! Hi Tek !

So ... Here it is ... back to the project, after some years ... I'm deeply sorry, i had so much to do before i could put my mind back to it, i didn't expect this.

As i unfortunately broke some traces on the little pcb provided by Tek, i'm redrawing the traces my way, and i'll etch a paxoline and copper. old school way.
Here's a simulation, with the components at the correct scale more or less.

i have to verify a lot more, check every components value, redraw the schematic and compare with the one you provided before. Well ... a long preparation, so once it's time to build it, it'll avoid some bugs hopefully.

I'll show you the progression. I wanted to finish it and make a surprise at first but it could be more interesting that way.

Sorry, the forum doesn't let me post an image. so here are some links below.
( "It was not possible to determine the dimensions of the image. Please verify that the URL you entered is correct."
yet ... it's correct .... I wish George could do something about it, and introduce a way to upload images directly in the forum, this would be great ... )

https://i.imgur.com/Y5Lu8Gp.jpg

https://i.imgur.com/kc2ZgNb.jpg

[daveweyer]

That fake Marshall amp is for sale on Reverb.com. Get a good look at it and you can see it has no West Coast sticker. Lots of pics of Jimi with the real West Coast Marshall, but the amp for sale is not it.

More to come......

[Xplorer]

That fake Marshall amp is for sale on Reverb.com. Get a good look at it and you can see it has no West Coast sticker. Lots of pics of Jimi with the real West Coast Marshall, but the amp for sale is not it.

More to come......

Yeah, sorry Dave, when i received this link, i believed it, but then ...

Anyway, back to the fuzz, i may have some time next week to etch a new pcb from the new traces i linked above, i must verify it and optimize it first, in relation to the components sizes.

[Frank1969]

Hi, I'm Frank new to this forum even though I'm participating in the other forum: The 6550 Experience.
I would like to play you some clips I just recorded, I haven't done all the Dave Weyer mods yet that I will do soon ...
This is a 1969 Layout Super Lead amp with 6550 tubes and shared cathode that I just finished building.

here is the link
https://drive.google.com/file/d/10nKCXb ... sp=sharing

What do you think...

[Xplorer]

That's quite cool ! At times it really feels like listening to a different mic in the isle of wight. Well done !

but what about the voltages and the bias ? And this univibe .. which one is it ?

[Frank1969]

BIAS 72%
plate voltage 480 V
univibe: Roger Mayer

[daveweyer]

And what is the voltage across the 1 ohm cathode resistors? This will tell a lot about where you have it biased.

[Frank1969]

PLATE CURRENT: 65 mA

[FloPoeKo]

Hi Everyone, I hope you all are doing well and hopefully we´re about to exit this whole mess!

One thing: I´ve acquired a bunch of germanium transistors. I measured a few with my DCA75 Pro (all measurements were taken at 23-25°C/73-77°F ambient temperature). They all fall into to 60-100 range gainwise. As for leakeage, the range is 0.2-0.3mA. Is this too high?