LEE JACKSON GP-1000 88 replica for sale
- Thread starter RR480
- Start date
I hear ya. Anyways, don't let the chase drive you crazy, mixing has a huge role in it. Good luck!
Rune
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- Aug 7, 2005
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Of course mixing has a lot to do with it, but there are several clips and live shows that proove more interesting than the album tones. Plus you need the basic sound to work with, and the gp-1000 got a better stock harmonics and edge than any other amp I've played and I've tried about everything
TheWeightedCompanyCube
The Engineer
- Nov 19, 2012
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Aaallright. News:
Recording session was partially successful. We spent all day gathering all guitars, speaker cab, a laptop with a firewire connection, charger for this laptop (forgot it, dammit), then made some sound tests without recording (RR480 was fucking happy - this version 9 unit sounds MUCH better than v8. And it also played nice with the SP1000 and Marshall 1936 cab - something we did not see before.
We found a reason why - if you turn the master pot on GP to 9 o'clock (where it should be to get a good sound), you have to be very careful when setting volume on SP1000. Because you move the volume pot one milimeter and is gets loud as hell. So loud in fact, that when I hid behind the cab to save my ears and pushed the volume on SP to 30-40 percent, brick and mortar wall in my garage started shaking and some dust fell out from behind of some pipes. F***ing loud.
Anyway - RR480 suggested a mod of the SP1000 which was swiftly done. It mods the feedback resistor in op-amp section, lowering the maximum volume approximately to 1/30 of regular output. Very simple stuff and it allows to use the front volume pot on SP1000 in its entire range. Great news is, that this does not screw up the sound in any way - did measurements and it is perfect, only changes volume.
Back to why we did not think that GP plays with SP and Marshall nicely - we never gave it enough volume which resulted in a (now
) known phenomenon about potentiometers - they limit treble on low volumes. I remember RR480 saying few months ago that the tone was as good as he was expecting only after he turned the volume quite high in recording room. However, our old borrowed sound card and mic could not work with volume so high and the recording was shitty.
Right now we limited maximum power of SP1000, but got rid of the problem with the volume pot. Ideal for room level or even for recording.
Aaaanyway.. back on topic. After we found this it was already 18:30 and we got an ultimatum from grandparents living in the house we were testing in. They go to bed at 18:30 and after some minor arguing we decided to make you guys a 5 minute sound test and come back tomorrow and do the rest.
During testing we also found something very important - again, the trimpot on the PCB. Rune says that in his GP1000 units it solved issue with bad sound after he set it very precisely to around 25 percent.
RR480 likes more edgy and may I say "trebly, sharp bordering on unpleasantly sharp" That's why he set it to around 50 percent and was very happy with the sound. However, when we later listened to JonWormwood's gp1000 recording via Kemper (this one), it is clear, that his sound is not so sharp and trebly. Fortunately during the recording I played with the trimpot and you can hear what it does to the sound. And I would say that with correct trimpot setting (yes, around 25 percent as Rune has) should give the same sound. You can find exact time in next paragraph.
0:00 - 0:10 I was looking for correct volume on sound card. Few seconds went to limitation.
0:25 - 1:00 RR480's attempt at some solos
1:50 - Start trimpot test at 50 percent.
1:53 - Trimpot at zero
1:54 - 2:06 turning trimpot slowly to 100 percent.
2:07 - 2:17 turning trimpot slowly to zero again
2:21 - trimpot back at 40-50 percent (I know, way too much - will use 25 percent tomorrow)
3:00 more squeaky solos
3:24 attempt at some song
3:30 attempt failed
3:57 - 4:31 I played with microphone placement. Went from left to right in various heights and distances from the speaker.
Oh by the way - due to lack of time (and lack of mic stand which i forgot to borrow, dammit) I placed the mic on a wooden box cca 20 cm from the cab in front of one speaker. See picture for more details. If I remember correctly, the mic should be much closer to the speaker? Around 2-5 cm? And also, is it best to place it in the middle of one of the speakers, or in halfway between middle and side? Or do you have any other suggestions?
Pic of test bench with v9 GP.
Pic of mic placement (after we were done, that's why there is no cable)
Recording session was partially successful. We spent all day gathering all guitars, speaker cab, a laptop with a firewire connection, charger for this laptop (forgot it, dammit), then made some sound tests without recording (RR480 was fucking happy - this version 9 unit sounds MUCH better than v8. And it also played nice with the SP1000 and Marshall 1936 cab - something we did not see before.
We found a reason why - if you turn the master pot on GP to 9 o'clock (where it should be to get a good sound), you have to be very careful when setting volume on SP1000. Because you move the volume pot one milimeter and is gets loud as hell. So loud in fact, that when I hid behind the cab to save my ears and pushed the volume on SP to 30-40 percent, brick and mortar wall in my garage started shaking and some dust fell out from behind of some pipes. F***ing loud.
Anyway - RR480 suggested a mod of the SP1000 which was swiftly done. It mods the feedback resistor in op-amp section, lowering the maximum volume approximately to 1/30 of regular output. Very simple stuff and it allows to use the front volume pot on SP1000 in its entire range. Great news is, that this does not screw up the sound in any way - did measurements and it is perfect, only changes volume.
Back to why we did not think that GP plays with SP and Marshall nicely - we never gave it enough volume which resulted in a (now
) known phenomenon about potentiometers - they limit treble on low volumes. I remember RR480 saying few months ago that the tone was as good as he was expecting only after he turned the volume quite high in recording room. However, our old borrowed sound card and mic could not work with volume so high and the recording was shitty.Right now we limited maximum power of SP1000, but got rid of the problem with the volume pot. Ideal for room level or even for recording.
Aaaanyway.. back on topic. After we found this it was already 18:30 and we got an ultimatum from grandparents living in the house we were testing in. They go to bed at 18:30 and after some minor arguing we decided to make you guys a 5 minute sound test and come back tomorrow and do the rest.
During testing we also found something very important - again, the trimpot on the PCB. Rune says that in his GP1000 units it solved issue with bad sound after he set it very precisely to around 25 percent.
RR480 likes more edgy and may I say "trebly, sharp bordering on unpleasantly sharp" That's why he set it to around 50 percent and was very happy with the sound. However, when we later listened to JonWormwood's gp1000 recording via Kemper (this one), it is clear, that his sound is not so sharp and trebly. Fortunately during the recording I played with the trimpot and you can hear what it does to the sound. And I would say that with correct trimpot setting (yes, around 25 percent as Rune has) should give the same sound. You can find exact time in next paragraph.
0:00 - 0:10 I was looking for correct volume on sound card. Few seconds went to limitation.
0:25 - 1:00 RR480's attempt at some solos
1:50 - Start trimpot test at 50 percent.
1:53 - Trimpot at zero
1:54 - 2:06 turning trimpot slowly to 100 percent.
2:07 - 2:17 turning trimpot slowly to zero again
2:21 - trimpot back at 40-50 percent (I know, way too much - will use 25 percent tomorrow)
3:00 more squeaky solos
3:24 attempt at some song
3:30 attempt failed
3:57 - 4:31 I played with microphone placement. Went from left to right in various heights and distances from the speaker.
Oh by the way - due to lack of time (and lack of mic stand which i forgot to borrow, dammit) I placed the mic on a wooden box cca 20 cm from the cab in front of one speaker. See picture for more details. If I remember correctly, the mic should be much closer to the speaker? Around 2-5 cm? And also, is it best to place it in the middle of one of the speakers, or in halfway between middle and side? Or do you have any other suggestions?
Pic of test bench with v9 GP.
Pic of mic placement (after we were done, that's why there is no cable)
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Rune
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- Aug 7, 2005
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Sounds great, a bit too trebly yes, but that can be fixed!
So what mods is on in this test, and what settings were used for this?
And even more important, did you still use the PRS with EMG ALX setup?
That would also cause some extra harsness, since the EMG's got that sound, not to say J-50BC aren't but they are somewhat milder.
Yes you should put the trimpot back to 25% and it would be cool if you could demonstrate the amp with both outputs (or even both ouputs into an intellifex and one out to the sp-1000 part, this is kind of alexis old setup).
For mic placement; after studing some old rack/amp pictures, Bodom always tend to have mic placed straigh infront of the speaker center, but to the far left of the speaker, so center hight, but far left and as close to the cab filth as possibe without toutching. And since this is the sound we're after you should give it a try
On the SP mod, well you know what I like the original, should have warned you guys how loud it can be with linear pots, it is really sudden when you use the old bodom setting at 9-10 o'clock on the master setting(s). Even at "1" on the markers it is good enough for bedroom level/might even be good for recording.
Can't believe Bodom uses the SP-1000 at 1' o'clock for recordings/live......it is brutally loud. 4 lights should illuminate on the SP-1000, at least they did for the legendary Seoul Korea 2001 gig. (But that was in stereo with the intellifex)
So what mods is on in this test, and what settings were used for this?
And even more important, did you still use the PRS with EMG ALX setup?
That would also cause some extra harsness, since the EMG's got that sound, not to say J-50BC aren't but they are somewhat milder.
Yes you should put the trimpot back to 25% and it would be cool if you could demonstrate the amp with both outputs (or even both ouputs into an intellifex and one out to the sp-1000 part, this is kind of alexis old setup).
For mic placement; after studing some old rack/amp pictures, Bodom always tend to have mic placed straigh infront of the speaker center, but to the far left of the speaker, so center hight, but far left and as close to the cab filth as possibe without toutching. And since this is the sound we're after you should give it a try
On the SP mod, well you know what I like the original, should have warned you guys how loud it can be with linear pots, it is really sudden when you use the old bodom setting at 9-10 o'clock on the master setting(s). Even at "1" on the markers it is good enough for bedroom level/might even be good for recording.
Can't believe Bodom uses the SP-1000 at 1' o'clock for recordings/live......it is brutally loud. 4 lights should illuminate on the SP-1000, at least they did for the legendary Seoul Korea 2001 gig. (But that was in stereo with the intellifex)
TheWeightedCompanyCube
The Engineer
- Nov 19, 2012
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Hey,
thanks for the mic placement suggestions, will do.
This test was done with the custom shop with EMG HZ H4.
Tomorrow the trimpot will get turned to 25 percent, it really seems it is the sweet spot. Also, good to know that it has this big impact on edgyness of the sound - if anyone wants to go sharper, it is only one turn of trimpot away
Mods on this recording - none. At this moment they are all soldered in and prepared for tomorrow's testing.
Also - no shielding on this prototype was used, not even connection to the ground and it works very nicely, no oscillation, no hiss. Only some mains hum because it was not grounded. Very promising.
I will try to use the original SP without the mod for volume control, hopefully the grandparents will cut us some slack.. they don't really like loud sounds, which is understandable, but after I talk to them we will get some time for good recordings.
thanks for the mic placement suggestions, will do.
This test was done with the custom shop with EMG HZ H4.
Tomorrow the trimpot will get turned to 25 percent, it really seems it is the sweet spot. Also, good to know that it has this big impact on edgyness of the sound - if anyone wants to go sharper, it is only one turn of trimpot away
Mods on this recording - none. At this moment they are all soldered in and prepared for tomorrow's testing.
Also - no shielding on this prototype was used, not even connection to the ground and it works very nicely, no oscillation, no hiss. Only some mains hum because it was not grounded. Very promising.
I will try to use the original SP without the mod for volume control, hopefully the grandparents will cut us some slack.. they don't really like loud sounds, which is understandable, but after I talk to them we will get some time for good recordings.
Rune
Member
- Aug 7, 2005
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Your welcome!
Wow, amazing that you guys got that sound out of just a regular wired EMG HZ H4 and stock GP-1000. Really proves that the tone is there, just need the tiny bit of gain addition from the SP-1000 and sustain from loud volume.
Yes that's what I found out as well, and it seemed to be stock on my other GP-1000 so I guess it is the right placement.
Superb that the noise, hiss and oscillation are gone! That was the main issue!
Great that you will give the original a try, might be wise to wear some ear-protection!
Wow, amazing that you guys got that sound out of just a regular wired EMG HZ H4 and stock GP-1000. Really proves that the tone is there, just need the tiny bit of gain addition from the SP-1000 and sustain from loud volume.
Yes that's what I found out as well, and it seemed to be stock on my other GP-1000 so I guess it is the right placement.
Superb that the noise, hiss and oscillation are gone! That was the main issue!
Great that you will give the original a try, might be wise to wear some ear-protection!
TheWeightedCompanyCube
The Engineer
- Nov 19, 2012
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Aaand we have news again, today's recording session was 4 hours long
Firstly I turned the trimpot down to ~25 percent. And let's cut to the business, we have two videos and one audio file.
Audio file is about mods only.
First part no mods except for the mid pot which was changed from 10k to 50k (adds lot more mids) and turned to maximum.
Second part - gain mod.
Third part - Gain mod and first tone mod.
4th part - gain mod, first and second tone mod.
5th part - gain mod, first and second tone mod and cap mod on tube board with special trimpot set to 50 percent. (on hundred percent it muds signal a lot - unusable)
First video file - only mod was gain mod and mid pot mod (that one is active all the time) this video is based on this one. It shows various pot settings and their influence on the sound. I fucked up a little with the mid pot - forgot that it has 5 times bigger value (and therefore can give more mids), so this recording should have more mids than the mentioned video. But it should not be a big deal.
Second video shows the influence of 2nd EQ on the tone. And it is quite a bit as you can hear
And now to describe what we did not do: Place the mic off axis. I thought it is the same thing as Rune's described "in center but to the left". So I pointed it straight somewhere 2/3 on the way between center and side of the speaker. Only now I found that off axis means to point it under an angle. But it was as close to the mesh as possible.
Second thing we did not do - the 1 o'clock SP volume test. I have to wait until everyone is out of the house, because it is insanely loud.
Firstly I turned the trimpot down to ~25 percent. And let's cut to the business, we have two videos and one audio file.
Audio file is about mods only.
First part no mods except for the mid pot which was changed from 10k to 50k (adds lot more mids) and turned to maximum.
Second part - gain mod.
Third part - Gain mod and first tone mod.
4th part - gain mod, first and second tone mod.
5th part - gain mod, first and second tone mod and cap mod on tube board with special trimpot set to 50 percent. (on hundred percent it muds signal a lot - unusable)
First video file - only mod was gain mod and mid pot mod (that one is active all the time) this video is based on this one. It shows various pot settings and their influence on the sound. I fucked up a little with the mid pot - forgot that it has 5 times bigger value (and therefore can give more mids), so this recording should have more mids than the mentioned video. But it should not be a big deal.
Second video shows the influence of 2nd EQ on the tone. And it is quite a bit as you can hear
And now to describe what we did not do: Place the mic off axis. I thought it is the same thing as Rune's described "in center but to the left". So I pointed it straight somewhere 2/3 on the way between center and side of the speaker. Only now I found that off axis means to point it under an angle. But it was as close to the mesh as possible.
Second thing we did not do - the 1 o'clock SP volume test. I have to wait until everyone is out of the house, because it is insanely loud.
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Rune
Member
- Aug 7, 2005
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Wow, sounds awesome, good job guys! Really shows the difference between mods and how everything works.
Just too bad that the ESP you're using just have a HZ H4, kind of misses a gainbooster such as JE-1000/MM-04/ALX ABQ so that you've got the same setup as most of us. It sound great anyways!
I really liked part 4 of the first clip, it is proabably as close to the bodom sound that you could get with a EMG HZ H4 straight hookup.
My sound on my original(s) semi modded GP-1000 has the same characteristics as part 2 and stock is about the same as part 1, but of course with a tad less gain and mild midwah sound because of the lack of gainboostee, but I'll guess that would be fixed for a later test? ;-)
Also really enjoyed the last video with the 2'nd EQ demonstration (of course the first video as well demonstrating all the manual settings and what every regular stock knob does). The second EQ really shows that you could play more harsher and bassier types of metal/rock with the same gain structure. So lamb of god tones or metallica tones should be on range easily.
Mic placement:
Off axis is a tilted mic (to one side) infront of speaker. Ive seen it being used on some of the earlier cob tours, so it is a good idea. Have no idea if that improves the sound/quality of the recording because I'm also a complete noob when it comes to micing guitar cabinets.
Also I ment far to the left of the speaker, right at its corner, and off axis inwards the speaker I pressume.
Haha watch your ears on the 1 o'clock setting, it is already painfully loud on 11 o'clock. It is kind of hopeless if you've got neighbours. Ment for soundproof rooms or large clubs/arenas.
Just too bad that the ESP you're using just have a HZ H4, kind of misses a gainbooster such as JE-1000/MM-04/ALX ABQ so that you've got the same setup as most of us. It sound great anyways!
I really liked part 4 of the first clip, it is proabably as close to the bodom sound that you could get with a EMG HZ H4 straight hookup.
My sound on my original(s) semi modded GP-1000 has the same characteristics as part 2 and stock is about the same as part 1, but of course with a tad less gain and mild midwah sound because of the lack of gainboostee, but I'll guess that would be fixed for a later test? ;-)
Also really enjoyed the last video with the 2'nd EQ demonstration (of course the first video as well demonstrating all the manual settings and what every regular stock knob does). The second EQ really shows that you could play more harsher and bassier types of metal/rock with the same gain structure. So lamb of god tones or metallica tones should be on range easily.
Mic placement:
Off axis is a tilted mic (to one side) infront of speaker. Ive seen it being used on some of the earlier cob tours, so it is a good idea. Have no idea if that improves the sound/quality of the recording because I'm also a complete noob when it comes to micing guitar cabinets.
Also I ment far to the left of the speaker, right at its corner, and off axis inwards the speaker I pressume.
Haha watch your ears on the 1 o'clock setting, it is already painfully loud on 11 o'clock. It is kind of hopeless if you've got neighbours. Ment for soundproof rooms or large clubs/arenas.
Sounds really good!!
As far as the loudness issue for the SP.....this was my fear from the beginning for those of use who only play at home. Would making a 50 watt power amp help with this? Would I be able to crank the SP past 1 o'clock to push it more and it not be as loud since it is only 50 watts? I am thinking it would as I have a Blackstar 20 watt head that I use now and I don't even turn it up past half way as it is just loud. Not sure if 20 watts solid state would be the same as 20 watts of tube power.
Just an idea to be able to crank this thing without it destroying your walls.
As far as the loudness issue for the SP.....this was my fear from the beginning for those of use who only play at home. Would making a 50 watt power amp help with this? Would I be able to crank the SP past 1 o'clock to push it more and it not be as loud since it is only 50 watts? I am thinking it would as I have a Blackstar 20 watt head that I use now and I don't even turn it up past half way as it is just loud. Not sure if 20 watts solid state would be the same as 20 watts of tube power.
Just an idea to be able to crank this thing without it destroying your walls.
TheWeightedCompanyCube
The Engineer
- Nov 19, 2012
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Oh good, you make my tired myself a little bit happier
Rune - yes I will be making gainbooster clone as soon as i can get all the parts. (which can be in worst way 2-3 weeks if the FET transistor will have to be ordered from Asia/US)
srob7001 - loudness issue is solved with our mod, which lowers the signal volume right before final amplification in the SP. It is the exact way to make it sound as it should sound without shaking walls However, I understand your need for lower power amp - if not for other reason, surely for price.. There is no need for huge almost 150W transformer and 4 transistors when you can have two and small transformer. I will think about it and modify another SP PCB I have built to have only half of transistors. And order new transformer. I am 98 percent sure it will work as intended - lower volume but no change on sound.
By the way - with our mod on SP it is even possible to turn SP on max without getting deaf Maybe something for users who want to use it both for studio/room level and for gigs etc. Little switch solves everything.
Rune - yes I will be making gainbooster clone as soon as i can get all the parts. (which can be in worst way 2-3 weeks if the FET transistor will have to be ordered from Asia/US)
srob7001 - loudness issue is solved with our mod, which lowers the signal volume right before final amplification in the SP. It is the exact way to make it sound as it should sound without shaking walls
However, I understand your need for lower power amp - if not for other reason, surely for price.. There is no need for huge almost 150W transformer and 4 transistors when you can have two and small transformer. I will think about it and modify another SP PCB I have built to have only half of transistors. And order new transformer. I am 98 percent sure it will work as intended - lower volume but no change on sound.By the way - with our mod on SP it is even possible to turn SP on max without getting deaf
Maybe something for users who want to use it both for studio/room level and for gigs etc. Little switch solves everything.
Rune
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Good about the JE-1000 clone assembly! Too bad shipping times are so crazy sometimes, lets hope it will just take a week or so.
Got every part straighted out from the pictures/schematic?
SP-1000 mod: is there a switch between original and homefriendly? If so that would be awesome, then I'm in on it
Got every part straighted out from the pictures/schematic?
SP-1000 mod: is there a switch between original and homefriendly? If so that would be awesome, then I'm in on it
TheWeightedCompanyCube
The Engineer
- Nov 19, 2012
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Yep, I have the partlist from the files you have provided. Finding the correct parts is however... hard
SP mod at the moment has a form of a jumper inside the chassis. However, that can be easily taken out on front panel. Or rear panel, whichever is preferable.
Oh one more thing - I believe I have to tone down the tone mod no.2 a bit. It adds a little mains hum to the sound when you have no guitar input. I don't know if that is a problem - when you start playing the mains hum goes away, but on idle you can hear it. I am asking because you liked the part 4 where there was this mod turned on.
..maybe will have to make you a recording with ~10 or so mod part values and you can pick later?
SP mod at the moment has a form of a jumper inside the chassis. However, that can be easily taken out on front panel. Or rear panel, whichever is preferable.
Oh one more thing - I believe I have to tone down the tone mod no.2 a bit. It adds a little mains hum to the sound when you have no guitar input. I don't know if that is a problem - when you start playing the mains hum goes away, but on idle you can hear it. I am asking because you liked the part 4 where there was this mod turned on.
..maybe will have to make you a recording with ~10 or so mod part values and you can pick later?
Rune
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- Aug 7, 2005
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Figured it would be hard to get the excact parts, and thats where 99% of all the JE-1000 cloners fail, the right parts are so important for the overall sound on this little thing that replacing a cap with a cheaper chinese one would alter the sound a lot. There is probably different sounding originals out there because of this.
That is probably a mod that should be a hard to push switch on the back of the amp so you don't just push it without intending and blowing your ears and maybe speakers away, if that is too hard then inside is also an option. since I almost always play electric guitar at my rehershal cabin, a 10-12 setting on the original SP-1000 isn't that big deal for me, but if I would bring it with me to a small club show or a friends house or even my house it might come in handy, and therefore it is some button/switch I would push maybe once a month or less.
Well the original got mains hum when idle too, but not much, you might have to turn it just a littlebit down. Give me a couple of demonstration clips and I could probably decide. Might even demonstrate one myself in an email if necessary.
That is probably a mod that should be a hard to push switch on the back of the amp so you don't just push it without intending and blowing your ears and maybe speakers away, if that is too hard then inside is also an option. since I almost always play electric guitar at my rehershal cabin, a 10-12 setting on the original SP-1000 isn't that big deal for me, but if I would bring it with me to a small club show or a friends house or even my house it might come in handy, and therefore it is some button/switch I would push maybe once a month or less.
Well the original got mains hum when idle too, but not much, you might have to turn it just a littlebit down. Give me a couple of demonstration clips and I could probably decide. Might even demonstrate one myself in an email if necessary.
Good to know that JE-1000 is also along the way
then i can atleast install my J50BC...
since amp wont be ready yet for a couple of months at this pace(no pun, quality should be good, so time is no problem)
I have no idea about half the things you guys talk about here its really funny to read though.
So far I have no idea at all anymore whats all on/in/around the thing or whatever
as far as i knew its regular amp with another section of gain,treb,mid,bass knobs which u call 2nd EQ and a gainmod.
the idea of a home-friendly switch is priceless...really its best so far imo, its atleast genuinly usefull for everyone
then i can atleast install my J50BC...
since amp wont be ready yet for a couple of months at this pace
(no pun, quality should be good, so time is no problem)I have no idea about half the things you guys talk about here
its really funny to read though.So far I have no idea at all anymore whats all on/in/around the thing or whatever
as far as i knew its regular amp with another section of gain,treb,mid,bass knobs which u call 2nd EQ and a gainmod.
the idea of a home-friendly switch is priceless...really its best so far imo, its atleast genuinly usefull for everyone
ah yes alright!! now we´re talking! kick ass sounding
thank god you guys exist and are doing this!
posted at same time troll
nunofrg
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- Dec 23, 2009
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