LEE JACKSON GP-1000 88 replica for sale

[phantomnote]

what would be the price for this preamp?

Cheers

 

[TheWeightedCompanyCube]

Hey,

we've got some more files. Knobs were set exactly as mentioned before. Sound was recorded using soundcard directly from preamp output.

Unfortunately, RR480 set the input level on soundcard quite high, therefore in some parts the sound hit the max level and started clipping You can hear it as muffled/distorted note. I have uploaded only the better files without much limitation (but still, second one is way too loud). If you were interested, there is a Rebel Yell cover I could upload, but sadly, it is quite badly distorted because of the loud input clipping.

@phantomnote - I don't have the exact price calculation yet. Still can't find time to sit down and look at all the bills and working hours. Hopefully it will be done during this night or tomorrow.

Aaaand the files:

 

[Rune]

Kind of a waste of recording since it got so muffered. You can here that the GP-1000 tone is there, but the soundcard or the volume level is not at it's best.

Hey,

we've got some more files. Knobs were set exactly as mentioned before. Sound was recorded using soundcard directly from preamp output.

Unfortunately, RR480 set the input level on soundcard quite high, therefore in some parts the sound hit the max level and started clipping You can hear it as muffled/distorted note. I have uploaded only the better files without much limitation (but still, second one is way too loud). If you were interested, there is a Rebel Yell cover I could upload, but sadly, it is quite badly distorted because of the loud input clipping.

@phantomnote - I don't have the exact price calculation yet. Still can't find time to sit down and look at all the bills and working hours. Hopefully it will be done during this night or tomorrow.

Aaaand the files:

 

[TheWeightedCompanyCube]

Kind of a waste of recording since it got so muffered. You can here that the GP-1000 tone is there, but the soundcard or the volume level is not at it's best.

Yep, it just felt wrong to let all of the files go to hell and don't update the thread for another few days :/

Anyway, RR480 will try to do it again, I will get together the expected price and then build another unit. This time into pro made case with push pull pots etc etc.. And I will also try to replicate the SP1000 in next week or so I'll be in touch.

//edit: and if we managed to get together GP1000, SP1000 and some nice speaker cabinet before christmas.. yum yum.

 

[aka_obscure]

Hmm.. Where is all powercords and palm muting? Only solos

 

[TheWeightedCompanyCube]

Gentlemen,

just a heads up - all the parts for the sp-1000 replica have arrived, I am now working on that. Also, parts for the second gp-1000 prototype are here for 80%, the rest is on the way.

My friend got a Marshall speaker cabinet, so the next recording session should be perfect.

please excuse the shitty photo

 

[Fastbodom]

OH MY GOD THATS Sexy !, if the Sp1000 has the wave leds in the front display il be definatly buying one

btw where are you getting all those Scematics from ?
are these all in that book that lee jackson brought out?

 

[TheWeightedCompanyCube]

Sure there will be LEDs i like LEDs. Can't live without them

For starters, I will be doing only one channel of sp1000 - as you probably know, it has two independent (but not bridgeable) amps inside. And I am planning to use the free space in the rack for gp1000 - you could have both gp1000 and half of sp1000 in one enclosure.

Also, there is a plan to produce small version of gp1000 - the circuit board has old design (well, duh - it was made in ~88), a lot of space is wasted. It does not need an entire 1U rack for itself, even half of it is way too much. I will probably use a higher box, rough dimensions 20*10*15 cm, maybe even less.

To sum up - three versions of gp1000:
-gp1000 in 1U rack - exact replica
-gp1000 in small box
-gp1000 + half of sp1000 in 1U rack
and
-full sp1000 in 1U rack

I don't have any book from Mr. Jackson. I know that there was something about him releasing it, but I don't think that it made its way into production... Did it?
I've recreated the circuit diagram from lots of detailed photos. Spent A LOT of time doing that.

 

[Fastbodom]

an combination of an GP-1000/SP-1000 is killer ! idea. your my new hero ! alto i might prefer seperated rack units, just for the benifit of using the amps on diffrent amps and not being stuck with the same preamp and poweramp

 

[TheWeightedCompanyCube]

Sure, I understand.

However, the combined unit will have jack output from preamp and jack input for poweramp. And a switch to connect them together.

It means, that you will be able to use gp1000 with another amp, sp1000 with another preamp, or connect enhancer/effects processor between them or whatever. They will just share one case.

How about that?

 

[Ben Johnson]

Not to discourage you or anything, but keep in mind that there's a pretty big heatsink built in to the chassis. Things could get pretty hot without it.

 

[phantomnote]

Sure, I understand.

However, the combined unit will have jack output from preamp and jack input for poweramp. And a switch to connect them together.

It means, that you will be able to use gp1000 with another amp, sp1000 with another preamp, or connect enhancer/effects processor between them or whatever. They will just share one case.

How about that?

think you should make them two seperate half rack units to allow for more versatility also youd sell better since not everyone wants to pay for both units when they only need one of them.

However cool idea overal.

And yeah - how will you fix the heat issue? Small fan?

 

[TheWeightedCompanyCube]

About the heat issue - there should not be any issue at all, I have ordered a heatsink with even better thermal parameters than original (but it is not on the photo I posted earlier). It will be on the side, just like the original.

And for the combined/half rack ideas - yeah, if someone would not want a gp+sp in one case, I'd separate them. If I'll find suitable half-rack, they will go to the half rack, if not, they will have to sit in 1U case.

I am also checking with local metalworking company, if they could build me custom cases for a good price. The pro made 1U rack that is on the photo was f***ing expensive and it consists only of four bloody pieces :/ Their material costs must be around 10% of the final price....

 

[phantomnote]

About the heat issue - there should not be any issue at all, I have ordered a heatsink with even better thermal parameters than original (but it is not on the photo I posted earlier). It will be on the side, just like the original.

And for the combined/half rack ideas - yeah, if someone would not want a gp+sp in one case, I'd separate them. If I'll find suitable half-rack, they will go to the half rack, if not, they will have to sit in 1U case.

I am also checking with local metalworking company, if they could build me custom cases for a good price. The pro made 1U rack that is on the photo was f***ing expensive and it consists only of four bloody pieces :/ Their material costs must be around 10% of the final price....

If you buy alot I think you could reduce the price. Try to find out who provides rack casings to professional companies in the first place


really cool project. One thing tho that I've run into with my gp-1000 that has bothered me: no clean channel or way to turn on off distortion (but I guess they fixed this on later models, so you could footswitch the dist out?)
also - a way of boosting solos since placing a boost between pre and power amp will fuck up everything.

My resolution has been to use the two outputs and an ab box but I figure there could be something much more handy.

Cool project over all! Wish lee was doing what youre doing tho

 

[TheWeightedCompanyCube]

Definitely, If I wanted 100 racks, I'd get them for 1/5 of the regular price.. But for starters I think that maybe 10 racks should do it. If they piss me off, I will make them on my own.. just have to tune my hand made metal bender/brake and it should work wonders.

About your clean channel problem, yep, the gp1000's I've seen have the footswitch input. You turn the distortion on on the preamp and then switch between clean/dist with the footswitch.

Your way of boosting solos is actually quite good. Outputs 1 and 2 differ only in one capacitor, it is possible to make them sound the same and simply set two different volume levels on master1 and master2 and then switch them.

Another way would be to use special amp pedal after the gp1000, that would only amplify the signal, not distort it in any way.

But when comparing the work and material costs, the output switching is simpler and easier - no need to make/buy amplifying pedal.

Actually, I tried to contact Mr. Lee Jackson three times - he did not respond. I wanted to check with him, whether he is OK with me making a replica of his work. I would not do this work if they were still in production, but since they stopped making them long ago and it is quite hard to buy them... why not.

 

[phantomnote]

Definitely, If I wanted 100 racks, I'd get them for 1/5 of the regular price.. But for starters I think that maybe 10 racks should do it. If they piss me off, I will make them on my own.. just have to tune my hand made metal bender/brake and it should work wonders.

About your clean channel problem, yep, the gp1000's I've seen have the footswitch input. You turn the distortion on on the preamp and then switch between clean/dist with the footswitch.

Your way of boosting solos is actually quite good. Outputs 1 and 2 differ only in one capacitor, it is possible to make them sound the same and simply set two different volume levels on master1 and master2 and then switch them.

Another way would be to use special amp pedal after the gp1000, that would only amplify the signal, not distort it in any way.

But when comparing the work and material costs, the output switching is simpler and easier - no need to make/buy amplifying pedal.

Actually, I tried to contact Mr. Lee Jackson three times - he did not respond. I wanted to check with him, whether he is OK with me making a replica of his work. I would not do this work if they were still in production, but since they stopped making them long ago and it is quite hard to buy them... why not.

Well he didnt have any succes relaunching them himself. Because he basically hid it from the world (no advertising whatsoever - just hid it somewhere on his website) and of course the price which was higher than what you could get the old ones for used - so people just bought those instead.

Yeah - my solution doesnt work however if you want stereo. But still, this is not the 80s - most people wont run stereo

Also lee has responded to me once a long time ago. But since then silence. :/

Good luck with the problem - someone should be keeping these awesome amps alive!

 

[aka_obscure]

TheWeightedCompanyCube, this project is dead? OR You`re working on it?

 

[TheWeightedCompanyCube]

Hey,

sorry for the late reply.

I've just finished building the SP1000 (well, almost - as you can see on the shitty photo, the cooling is rather.. eh.. temporary and it is not built into the rack yet.). Everything works as expected.

There is a teeny tiny problem with the GP, though. It seems that it lacks a bit of gain/edge/agression of the sound when playing the high tones. We have narrowed it down to the tubes - they are from ebay, chinese made (as they should be), but I've found they are 12AX7B actually.

Now we are going to order original 12AX7 Groove Tubes from thomann.de (if you know a cheaper source of original GTs let me know please, they cost ~22 EUR a piece there) and make the problem go away. I did some measurements, all other parts and connections are fine, only the tubes are not tip top.

We should have them in a week or so, then we will try to get together for a recording session.

Thanks for your interest

oh.. and the shitty photo..

 

[Arystar]

as said. if u produce a professional good looking GP-1000 which is exact replica. even I would be interested...shame I dont have money right now rofl.
1 question though, ive never ahd a rack before... what do you guys mean by half rack or something like that was said?

 

[TheWeightedCompanyCube]

Half rack is an enclosure that has half the width of full 19" rack.

the one on the top.

Also, thanks for your interest