GC working fine!
My GC is up and running, sounds pretty good, too. After careful reviewing with a calmer set of eyes, I discoverd that I had the NFB resistors soldered to the neighbor of the intended pin, opening the NFB loop so OF COURSE the output went to rail. I was very consistent in this error, having made it on both boards.
Jimbo
Whenever I make a mistake, I try my best to make it a really dumb one, so at least it will be funny at some later date. :^P
My GC is up and running, sounds pretty good, too. After careful reviewing with a calmer set of eyes, I discoverd that I had the NFB resistors soldered to the neighbor of the intended pin, opening the NFB loop so OF COURSE the output went to rail. I was very consistent in this error, having made it on both boards.
Jimbo
Whenever I make a mistake, I try my best to make it a really dumb one, so at least it will be funny at some later date. :^P
Re: GC working fine!
I'm glad you found the problem! That sort of thing is very easy to do. I've now built only about 8 GCs and have made that exact error once and swapped other resistor values twice. (Not a great percentage I know. My only defense is that I usually find time to work on these when I'm already pretty tired!)
Like you I find that sometimes the best thing I can do is leave it and come back later. Funny how some things that seemed impossible to find just pop out with a fresh look.
One of my college professors had a poster on the wall in his office that said- "If you must make mistakes, it will be more to your credit if you make a new one each time". That's the goal I strive for- new mistakes, not repeating the old ones!!!
BTW since you did it to both channels at the same time I would only count that as one mistake! 😀
jimbo149 said:
I'm glad you found the problem! That sort of thing is very easy to do. I've now built only about 8 GCs and have made that exact error once and swapped other resistor values twice. (Not a great percentage I know. My only defense is that I usually find time to work on these when I'm already pretty tired!)
Like you I find that sometimes the best thing I can do is leave it and come back later. Funny how some things that seemed impossible to find just pop out with a fresh look.
One of my college professors had a poster on the wall in his office that said- "If you must make mistakes, it will be more to your credit if you make a new one each time". That's the goal I strive for- new mistakes, not repeating the old ones!!!
BTW since you did it to both channels at the same time I would only count that as one mistake! 😀
Smallest gainclone?
Hi All-
I am looking to find the smallest gainclone built so far.
I LOVE Peters Patak but to my knowledge he is not selling that one yet.
Has anyone built a similar unit or just one as compact as possible?
Thanks in advance,
Troy
Hi All-
I am looking to find the smallest gainclone built so far.
I LOVE Peters Patak but to my knowledge he is not selling that one yet.
Has anyone built a similar unit or just one as compact as possible?
Thanks in advance,
Troy
Its Alive!
My gainclone sprang to life yesterday afternoon.
Being brave I just plugged the little rascal in and went for it.
No problems with ps or the amp wiring. I measured ~30mV at the power supply inputs to the board(s) which I gather from other posts is satisfactory.
I started out with low volume checking for heat on the chips and the left channel seemed to run a little warmer than the right. I didn't know if was the program material or not so I raised the volume and started to get the "spike" protection mentioned in the data sheet on the left channel.
I shut it off and looked at the mounting of the chips to the heatsinks and realized that I hadn't tightened the screw on the left channel enough to make good contact with the sink on the final build. Once that was tightened everything seemed to work great.
I've got the amp connected to a pair of Snell E3's (I can't remember exactly but I think they're only moderately efficient at about 90 db/w). Anyhow, I can achieve comfortable listening volumes for my taste with the gainclone.
So far I'm very pleased with the sound. To my ears its got a very bright sound but not at the expense of bass response.
Thanks a million to BrianGT for getting me started on this little adventure and to all the advice and opinions that I've found here at diyaudio.
Mike
My gainclone sprang to life yesterday afternoon.
Being brave I just plugged the little rascal in and went for it.
No problems with ps or the amp wiring. I measured ~30mV at the power supply inputs to the board(s) which I gather from other posts is satisfactory.
I started out with low volume checking for heat on the chips and the left channel seemed to run a little warmer than the right. I didn't know if was the program material or not so I raised the volume and started to get the "spike" protection mentioned in the data sheet on the left channel.
I shut it off and looked at the mounting of the chips to the heatsinks and realized that I hadn't tightened the screw on the left channel enough to make good contact with the sink on the final build. Once that was tightened everything seemed to work great.
I've got the amp connected to a pair of Snell E3's (I can't remember exactly but I think they're only moderately efficient at about 90 db/w). Anyhow, I can achieve comfortable listening volumes for my taste with the gainclone.
So far I'm very pleased with the sound. To my ears its got a very bright sound but not at the expense of bass response.
Thanks a million to BrianGT for getting me started on this little adventure and to all the advice and opinions that I've found here at diyaudio.
Mike
Re: Its Alive!
Congratulations! Feel free to send me pictures and I will put them in my gallery.
--
Brian
saabie22 said:
Congratulations! Feel free to send me pictures and I will put them in my gallery.
--
Brian
Re: Smallest gainclone?
The amp in post #448 here http://www.diyaudio.com/forums/showthread.php?s=&threadid=31339&perpage=10&pagenumber=45
may be smaller than my current Patek version.😉
rabstg said:
The amp in post #448 here http://www.diyaudio.com/forums/showthread.php?s=&threadid=31339&perpage=10&pagenumber=45
may be smaller than my current Patek version.😉
a small correction
In my last post I stated that I was seeing ~30 mV at the ps inputs to the amp boards. What I meant to say was that I was reading ~30 mV at the amp outputs with no signal in.
Mike
In my last post I stated that I was seeing ~30 mV at the ps inputs to the amp boards. What I meant to say was that I was reading ~30 mV at the amp outputs with no signal in.
Mike
My gainclone monoblocks are finished!
Finally I finished mine......
This pic shows the initial testing (in the kitchen 😀) using an iPod as source. I built the clone as power-amp without volume pot, so I took the only device with volume control I had
.
Some pictures of the two together and the internals of the boxes:
As to sound, I am pretty impressed up to now. The sound is detailled, bass is deep, and the clones do a fine job driving my 91 db efficient speakers. Loud enough for me!!!
The DC offset was nice allready from the start (11 mV and 20 mV resp.), but for safety I added the zobel network, it might go lateron.
On the downside: the amps are very sensitive towards mains peaks/dips, so that even switching of a light causes a tick in the sound. The spikes caused by my fridge are simply horrible
, time for some thorough mains conditioning overhere. Connected to my home cinema receiver as pre-amp, I also hear a slight humming through the speakers, audible only when the volume is low. When volume is increased, hum stays constantly on a low level. Any idea what this could be? Grounding? I will check for ground loops etc.....
Rob
Finally I finished mine......
An externally hosted image should be here but it was not working when we last tested it.
This pic shows the initial testing (in the kitchen 😀) using an iPod as source. I built the clone as power-amp without volume pot, so I took the only device with volume control I had
. Some pictures of the two together and the internals of the boxes:
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.
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.
An externally hosted image should be here but it was not working when we last tested it.
As to sound, I am pretty impressed up to now. The sound is detailled, bass is deep, and the clones do a fine job driving my 91 db efficient speakers. Loud enough for me!!!
The DC offset was nice allready from the start (11 mV and 20 mV resp.), but for safety I added the zobel network, it might go lateron.
On the downside: the amps are very sensitive towards mains peaks/dips, so that even switching of a light causes a tick in the sound. The spikes caused by my fridge are simply horrible
, time for some thorough mains conditioning overhere. Connected to my home cinema receiver as pre-amp, I also hear a slight humming through the speakers, audible only when the volume is low. When volume is increased, hum stays constantly on a low level. Any idea what this could be? Grounding? I will check for ground loops etc.....Rob
thanx.
transformers are 120 VA each, and measure 91 mm diameter, so it's a tight fit in this casing.
Rob
transformers are 120 VA each, and measure 91 mm diameter, so it's a tight fit in this casing.
Rob
Finished My Monoblocks Too
I have finished my BryanGT GC amps and am very pleased with the results. They sound great and were a lot of fun to build.
The bottom and back of the case is constructed of 3/16” aluminum with the chip mounted on a 1” x 2” aluminum bar. The sides, top and front are teak.
The only problem that I have is with the “Parts Express Special” transformers. As soon as the primary voltage is applied, they have a pronounced hum that appears to be independent of the load. My wood cases magnify the problem and it is audible a few feet away in a quiet room. I tried to isolate the transformers by mounting them on a foam pad, but I’m not sure that it helped much. The good news is that I can’t hear it when playing music.
Thanks to Bryan, Peter and all of others who worked on the design and made this project possible.
Bill
Here are some photos:
Interior view:
Close up:
Rear View:
Front View:
I have finished my BryanGT GC amps and am very pleased with the results. They sound great and were a lot of fun to build.
The bottom and back of the case is constructed of 3/16” aluminum with the chip mounted on a 1” x 2” aluminum bar. The sides, top and front are teak.
The only problem that I have is with the “Parts Express Special” transformers. As soon as the primary voltage is applied, they have a pronounced hum that appears to be independent of the load. My wood cases magnify the problem and it is audible a few feet away in a quiet room. I tried to isolate the transformers by mounting them on a foam pad, but I’m not sure that it helped much. The good news is that I can’t hear it when playing music.
Thanks to Bryan, Peter and all of others who worked on the design and made this project possible.
Bill
Here are some photos:
Interior view:
An externally hosted image should be here but it was not working when we last tested it.
Close up:
An externally hosted image should be here but it was not working when we last tested it.
Rear View:
An externally hosted image should be here but it was not working when we last tested it.
Front View:
An externally hosted image should be here but it was not working when we last tested it.
Re: My gainclone monoblocks are finished!
Hello Rob, the unshielded input cabling is too close to the rectifiers which very probably causes the hum. Use shielded cable instead or twist the wires in a tight way.
MIB said:
Hello Rob, the unshielded input cabling is too close to the rectifiers which very probably causes the hum. Use shielded cable instead or twist the wires in a tight way.
Thanks, I will try this. I am surprised though that the hum does not increase with increasing volume (and current, I would say?).
Rob
Rob
Rob,
Could you share where you picked up those chassis? I've been looking for something along those lines and the only thing I've found that's similar are the ones from Fair Radio that are already drilled up...
Could you share where you picked up those chassis? I've been looking for something along those lines and the only thing I've found that's similar are the ones from Fair Radio that are already drilled up...
chassis
The chassis comes from conrad an online electronics store, order # 522953. The brandname of these boxes is Isel, detailed info, and they are available in three sizes.
Rob
The chassis comes from conrad an online electronics store, order # 522953. The brandname of these boxes is Isel, detailed info, and they are available in three sizes.
Rob
Hi everybody. 
Another newbie joining this forum. I just finished my first NI GainClone. Small recap of the prototype; basic kit from BrianGT, 300VA potted toroid from Talema, RCA chassis plugs and binding posts from Vampire and a mains filter from Schaffner. As source I'm using my Samsung discman, incase something goes wrong on the first test I wont screw up my Rega Jupiter/Io combo. It's playing for about two and a half hours now, to wake up all the components, and I must say that I'm pleasantly surprised by the overall sound. To judge the amplifier is a bit to soon, first because it needs a break in period and second the mediocre source. I already ordered a premium kit so in the future I can evaluate the pro's and con's of both kits. And after that some regulated power supplys, who knows maybe I get hooked on the litlle sucker as so many of us.
Happy listening
WalterG
Another newbie joining this forum. I just finished my first NI GainClone. Small recap of the prototype; basic kit from BrianGT, 300VA potted toroid from Talema, RCA chassis plugs and binding posts from Vampire and a mains filter from Schaffner. As source I'm using my Samsung discman, incase something goes wrong on the first test I wont screw up my Rega Jupiter/Io combo. It's playing for about two and a half hours now, to wake up all the components, and I must say that I'm pleasantly surprised by the overall sound. To judge the amplifier is a bit to soon, first because it needs a break in period and second the mediocre source. I already ordered a premium kit so in the future I can evaluate the pro's and con's of both kits. And after that some regulated power supplys, who knows maybe I get hooked on the litlle sucker as so many of us.
Happy listening
WalterG
Attachments
Just came in from feeding the mosquitos, been listening to my newly finished GC out in the backyard, playing jazz through a discman and psb alpha-minis, watching the satellites buzz past. It's in a temporary home, an NAD [not again dangm-it] amp chassis that I got tired of fixing. I only burned one fuse while figuring out the powersupply wiring!
Thank-you Brian, and all the forum users who posted answers to the questions that I didn't know to ask!
Thank-you Brian, and all the forum users who posted answers to the questions that I didn't know to ask!
bzdang said:
I am glad to hear that everything worked out well for you. Feel free to post/e-mail me pictures and I will put them in my gallery. I am quite a bit behind at posting pictures of finished amplifiers, but will get them all up in the near future.
Enjoy your finished amp!
--
Brian
At long last (most of the time was practicing dovetails, as this is my first go at those).
Cherry face with maple, and clear acrylic top and bottom. Finished with Tung oil.
I may see about getting some better shots of the inside if anyone is interested, otherwise... 😉
And my wife is probably not too happy with this deal, since this is now another hobby which I probably will work with for a while. 🙂 How many amps do I need? No idea. But the kits gave me the confidence that I can do this, and from here I'll be having more fun doing my own stuff.
C
Cherry face with maple, and clear acrylic top and bottom. Finished with Tung oil.
I may see about getting some better shots of the inside if anyone is interested, otherwise... 😉
And my wife is probably not too happy with this deal, since this is now another hobby which I probably will work with for a while. 🙂 How many amps do I need? No idea. But the kits gave me the confidence that I can do this, and from here I'll be having more fun doing my own stuff.
C
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