I came across this thread ocasionally and i liked that too much, mostly because of its simplicity(I am just a beginer in constructing elecronic circuits)
Hey macka I would really like to have some more information on building that amp (the GB300 should be more powerfull?)
Can u please send me any circuit diagram with the components spesifications and PCB, if it doesn't bother u. I'd like to construct my first REAL power amplifier, all DIY. Just for better sound quality at home. Thanx.
If u need that my e-mail is: ardi_lulaj@yahoo.com
Hey macka I would really like to have some more information on building that amp (the GB300 should be more powerfull?)
Can u please send me any circuit diagram with the components spesifications and PCB, if it doesn't bother u. I'd like to construct my first REAL power amplifier, all DIY. Just for better sound quality at home. Thanx.
If u need that my e-mail is: ardi_lulaj@yahoo.com
Sorry but the design is property of the author Greg Ball.
You need to contact Greg and buy the kit and then you can obtain the schematic.
The kit is quite reasonably priced.
Greg's web address is under his profile.
Macka
You need to contact Greg and buy the kit and then you can obtain the schematic.
The kit is quite reasonably priced.
Greg's web address is under his profile.
Macka
Hi John
Greg proposed to try a 10R in place of the 2R7. Finally I did switch mine to 10R three days ago. Actually I went for a 10R//1N5407 following AndrewT's wise recommendation on post#349 (For the record AndrewT, the 1n400X managed to survive a +DC rail to 0V short right on the PSU board. The 3A slow fuse at the x-former primary, fused promptly).
The sound may be better, but it is not worse (compared to the 2R7) for certain.
There is a slight increase of a 50/100Hz buzz which can only be heard with the ear over the speaker.
I havn't done any new crosstalk measurements yet.
Regards
George
Greg proposed to try a 10R in place of the 2R7. Finally I did switch mine to 10R three days ago. Actually I went for a 10R//1N5407 following AndrewT's wise recommendation on post#349 (For the record AndrewT, the 1n400X managed to survive a +DC rail to 0V short right on the PSU board. The 3A slow fuse at the x-former primary, fused promptly).
The sound may be better, but it is not worse (compared to the 2R7) for certain.
There is a slight increase of a 50/100Hz buzz which can only be heard with the ear over the speaker.
I havn't done any new crosstalk measurements yet.
Regards
George
Hi Gpag,
the diode in the disconnecting network will carry mains shorting to earth.
It will not be stressed by a secondary short to audio ground. Mains current still flows live to neutral.
Audioaddicted,
Ampguru can be found at www.DIYhifi.org. He has a couple of threads running in the Sponsored area.
the diode in the disconnecting network will carry mains shorting to earth.
It will not be stressed by a secondary short to audio ground. Mains current still flows live to neutral.
Audioaddicted,
Ampguru can be found at www.DIYhifi.org. He has a couple of threads running in the Sponsored area.
Hi HiFiddle
The transition from 2R7 to 10R did not change anything on the crosstalk figures.
Latelly I installed the bootstrap capacitors. I prefer the sound with the capacitors installed. I would say that details are more well defined without sound turning dry or clinical.
I increased the bias from +/- 75mA to +/-130mA. I did it following my impression that the amp was sounding "warmer" for a few minutes after switch on.
Regards
George
No, I didn't. The amp is dead silent (1mVpp pure 50HZ on the output) with open or shorted inputs. It is dead silent again with only one input connected to a source. When both inputs are connected to a source, then one channel of the amplifier produces this slight buzz, the other no buzz. I havn't check with a battery operated source.
The transition from 2R7 to 10R did not change anything on the crosstalk figures.
Latelly I installed the bootstrap capacitors. I prefer the sound with the capacitors installed. I would say that details are more well defined without sound turning dry or clinical.
I increased the bias from +/- 75mA to +/-130mA. I did it following my impression that the amp was sounding "warmer" for a few minutes after switch on.
Regards
George
Hi Gp
But would need about 10db less on 100db speakers i.e. back to 0.03mVac~=0.1mVpp.
You have a hum output that is 20db above 0.1mVpp.
I think the problem is, at least partially, in the amp. That problem gets worse when two sources are connected.
0.1mVpp is dead silent on 88db speakers. I can tolerate 0.1mVac on same speakers.
But would need about 10db less on 100db speakers i.e. back to 0.03mVac~=0.1mVpp.
You have a hum output that is 20db above 0.1mVpp.
I think the problem is, at least partially, in the amp. That problem gets worse when two sources are connected.
Sorry AndrewT and all
The 1mVpp was a typing mistake.
The correct is 0.1mVpp.
This is the lowest signal I can really see on my oscilloscope.
Regards
George
The 1mVpp was a typing mistake.
The correct is 0.1mVpp.
This is the lowest signal I can really see on my oscilloscope.
Regards
George
Well guys, i have all my modules ready, now i need to put it on the heatsinks, in argentina is like impossible to get good ones, i found this used heatsinks.
i purchased 8 of these heatsinks....
I ordered the box too (to put all the stuff inside)....
now im trying to fit all these HS inside the box but is like impossible 😀
btw you think that these HS will be enough for this modules?
the 150Watts can be mounted in that way
the 300Watts in that way
and to save some space can do something like this
another way is this.... the box that i ordered allow me to put 2 hs verticaly
and the best way (to save a lot of space) is to use the 2 modules like i display into the 4th pic but at the top of these HS put anothers, so will be like pic 5th but with 2 300W and 2 150Watts.
what do you think? these HS will be enough for this amp?
🙂
An externally hosted image should be here but it was not working when we last tested it.
i purchased 8 of these heatsinks....
I ordered the box too (to put all the stuff inside)....
now im trying to fit all these HS inside the box but is like impossible 😀
btw you think that these HS will be enough for this modules?
the 150Watts can be mounted in that way
An externally hosted image should be here but it was not working when we last tested it.
the 300Watts in that way
An externally hosted image should be here but it was not working when we last tested it.
and to save some space can do something like this
An externally hosted image should be here but it was not working when we last tested it.
another way is this.... the box that i ordered allow me to put 2 hs verticaly
An externally hosted image should be here but it was not working when we last tested it.
and the best way (to save a lot of space) is to use the 2 modules like i display into the 4th pic but at the top of these HS put anothers, so will be like pic 5th but with 2 300W and 2 150Watts.
what do you think? these HS will be enough for this amp?
🙂
well after think a few diferents places to put the kits, i think that its the best choice, tellme what do you think...
i will cut the side panels of the box and will glue the Heatsinks to the holes that i made.
so will looks something like this.
the 3 transformers inside and the 4 PSU in the center, at the sides will use in one side 2 300W kits, (using 2 Heatsinks for each one) and in the other side 1 300W + 2 150W (using 2 Hs for the 300W and 1 for each 150W), so will have 4 Ht / Side.
Will looks somthing like this 🙂
What do you think?
Edited... i think that will be better to put the transformers where are the PSU right now., so will have the 220V wires close to the chasis.
i will cut the side panels of the box and will glue the Heatsinks to the holes that i made.
so will looks something like this.
An externally hosted image should be here but it was not working when we last tested it.
the 3 transformers inside and the 4 PSU in the center, at the sides will use in one side 2 300W kits, (using 2 Heatsinks for each one) and in the other side 1 300W + 2 150W (using 2 Hs for the 300W and 1 for each 150W), so will have 4 Ht / Side.
Will looks somthing like this 🙂
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
What do you think?
Edited... i think that will be better to put the transformers where are the PSU right now., so will have the 220V wires close to the chasis.
Hi Sam,
I think you've got it well worked out; the heatsinks look about ok, but you'll find out when you test it 🙂
The only issue I see is that the EI transformers may cause hum if they are too close to sensitive inputs/wiring, and you may want to experiment with their position before you bolt everything down too permanently.
Good luck buddy, it's worth the effort!
I think you've got it well worked out; the heatsinks look about ok, but you'll find out when you test it 🙂
The only issue I see is that the EI transformers may cause hum if they are too close to sensitive inputs/wiring, and you may want to experiment with their position before you bolt everything down too permanently.
Good luck buddy, it's worth the effort!
Hi,
I do not recomend you stack the sinks vertically. The dissipation of the upper sink is seriously compromised by the warm air passing over it. Side by side is OK.
A double length sink has about 41% (sqrt2-1) extra capacity. The stacked pair will mimic this.
To achieve rated dissipation the backplate of the sink should transfer heat effectively to all parts of the fins.
If you mount the output devices near the bottom edge then the top of the sink will run cooler than manufacturer's rating and the dissipation is reduced.
The GBs run high quiescent for good performance (at least 50mA per device) and it would be cooler to mount the devices about 40% up from the bottom.
I do not recomend you stack the sinks vertically. The dissipation of the upper sink is seriously compromised by the warm air passing over it. Side by side is OK.
A double length sink has about 41% (sqrt2-1) extra capacity. The stacked pair will mimic this.
To achieve rated dissipation the backplate of the sink should transfer heat effectively to all parts of the fins.
If you mount the output devices near the bottom edge then the top of the sink will run cooler than manufacturer's rating and the dissipation is reduced.
The GBs run high quiescent for good performance (at least 50mA per device) and it would be cooler to mount the devices about 40% up from the bottom.
New GB150 build
Hi,
Here's some pics of another GB150 build in progress.
I've heard this amp in action (Greg's very own) and am utterly impressed with it. DIY fantastic value / bang for the buck at it's finest.
Here's my build particulars:
- Dual mono config
- 300 VA trafo for each side
- Flanged HS
- Thinking about a '3 case' design - with one each for the trafos, and one for the heatsink. Greg tells me this might not be the best idea due to wanting the PSU supply lines to be as short as possible, but i think i have an idea...
- All pure silver 30AWG wiring (i have a bunch, why not)
- To be part of a 'As DIY as possible' audio setup, also using the RAW Accoustics HT8 speakers: http://www.robotbreeder.com/photography/v/projects/RAWHT8/
Here's my desk-less setup:
Greg's kit was really well organized and the instructions are easy to follow. The only weak link in the chain was me! I put the mosfets pairs in the wrong way around on one side... blarg!
Entire build project here:
http://www.robotbreeder.com/photography/v/projects/GB150/
More updates soon, i plan to get the modules all finished this weekend.
Cheers,
/Adam
Hi,
Here's some pics of another GB150 build in progress.
I've heard this amp in action (Greg's very own) and am utterly impressed with it. DIY fantastic value / bang for the buck at it's finest.
Here's my build particulars:
- Dual mono config
- 300 VA trafo for each side
- Flanged HS
- Thinking about a '3 case' design - with one each for the trafos, and one for the heatsink. Greg tells me this might not be the best idea due to wanting the PSU supply lines to be as short as possible, but i think i have an idea...
- All pure silver 30AWG wiring (i have a bunch, why not)
- To be part of a 'As DIY as possible' audio setup, also using the RAW Accoustics HT8 speakers: http://www.robotbreeder.com/photography/v/projects/RAWHT8/
Here's my desk-less setup:
An externally hosted image should be here but it was not working when we last tested it.
Greg's kit was really well organized and the instructions are easy to follow. The only weak link in the chain was me! I put the mosfets pairs in the wrong way around on one side... blarg!
Entire build project here:
http://www.robotbreeder.com/photography/v/projects/GB150/
More updates soon, i plan to get the modules all finished this weekend.
Cheers,
/Adam
Hi Robot,
just as well you live in Vancouver and not Australia.
Else the Moderators and some members would think you had a commercial link with the designer/retailer and accuse you of veiled advertising. Next thing the Moderators delete your posts.
Not sure what the advantage of putting the two amps in one case but the transformers in two cases.
I would go with either a stereo unit or a pair of monoblocks with VERY short cables. Or better still a pair of stereo units with VERY short cables each amp located just beside the speaker terminals.
just as well you live in Vancouver and not Australia.
Else the Moderators and some members would think you had a commercial link with the designer/retailer and accuse you of veiled advertising. Next thing the Moderators delete your posts.
Not sure what the advantage of putting the two amps in one case but the transformers in two cases.
I would go with either a stereo unit or a pair of monoblocks with VERY short cables. Or better still a pair of stereo units with VERY short cables each amp located just beside the speaker terminals.
Hi AndrewT:
Robot may claim to be from Canada but I bet you a good ole stout that the IP address of his post ain't. Lookie here:
inetnum: 202.155.160.0 - 202.155.175.255
netname: CHILLI
descr: Chilli Internet Solutions,
descr: Internet Service Provider, Sydney Australia
country: AU
Regards,
Milan
Robot may claim to be from Canada but I bet you a good ole stout that the IP address of his post ain't. Lookie here:
inetnum: 202.155.160.0 - 202.155.175.255
netname: CHILLI
descr: Chilli Internet Solutions,
descr: Internet Service Provider, Sydney Australia
country: AU
Regards,
Milan
Maybe this Robot breeder -
http://www.audiocircle.com/circles/index.php?topic=32072.0
He lives in Brisbane now.
Mods better cut his posts like they did with mine.
http://www.audiocircle.com/circles/index.php?topic=32072.0
He lives in Brisbane now.
Mods better cut his posts like they did with mine.
HiFiddle said:
I agree, all people living in Queensland should be banned. 😀
Oops, just remembered I have a townhouse in Brisbane, don't hold that against me.
BTW: I'm still constructing my SKA.
regards
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