owen said:
From his few posts, it seems as though he made a balanced "gainclone", or a differential amplifier: http://www.diyaudio.com/forums/showthread.php?s=&postid=629920#post629920
This is an instrumentation "gainclone": http://www.diyaudio.com/forums/showthread.php?s=&threadid=89753&highlight=
😉
Yup, I certainly do, though I find that it drops the damned log-in cookie, and I'm too lazy to fix it, so I have to log in every time I need to do anything here-abouts..
The Instrumentation clone was on the other site. It did get completed, and had a net gain of 10 - matched to the pro-level output from the Behringer.
I really do need to get building again, but work.. there's always so much work 🙁
Email addy hasnt changed, so drop me a line.
Brian... you'll find I dropped in on that thread too 😉 🙂)
Owen
The Instrumentation clone was on the other site. It did get completed, and had a net gain of 10 - matched to the pro-level output from the Behringer.
I really do need to get building again, but work.. there's always so much work 🙁
Email addy hasnt changed, so drop me a line.
Brian... you'll find I dropped in on that thread too 😉 🙂)
Owen
Heres a quick layout question.
In the non-inverted LM3875 design on DD http://myweb.tiscali.co.uk/nuukspot/decdun/gainclone4.html
Should the 1000uf caps be soldered directly to pins 1 and 4 or could I get away with a short length of solid copper wire between the pin and the capacitor? They would only be 15mm long and in an 10mm thick aluminium enclosure.
This would mean I could use a pair of old PC heatsinks I have which are tall and skinny but ever so pretty rather than having to buy others.
Many thanks
John
In the non-inverted LM3875 design on DD http://myweb.tiscali.co.uk/nuukspot/decdun/gainclone4.html
Should the 1000uf caps be soldered directly to pins 1 and 4 or could I get away with a short length of solid copper wire between the pin and the capacitor? They would only be 15mm long and in an 10mm thick aluminium enclosure.
This would mean I could use a pair of old PC heatsinks I have which are tall and skinny but ever so pretty rather than having to buy others.
Many thanks
John
15mm shouldn't cause a problem but why copper wire links when the cap lead-outs should be long enough. Or are you recycling caps?
PS Here is a picture from my VBIGC where the chip amp section is built on to a computer heatsink.
An externally hosted image should be here but it was not working when we last tested it.
That's good news. The caps I have are Vishay with a snap in type length of lead on them.
Also while you are here, is C4 DC blocking or is it part of a filter on the input? Could it be omitted if the preamp has dc blocking capacitors on the outputs?
The enclosures are a bit on the tight side so the less I have to fit in there the better
John
Also while you are here, is C4 DC blocking or is it part of a filter on the input? Could it be omitted if the preamp has dc blocking capacitors on the outputs?
The enclosures are a bit on the tight side so the less I have to fit in there the better
John
I am maybe not a victim of Nuuk, per se, but the DIY bug.
I finished my first 3996 chip amp from BrianGT/chipamp.com's design and PC boards.
I started reading about the chip amp/class D phenom, and initially bought a couple of Tim Rawson's amps. I was super impressed by the detail and sound stage - it smoked my Carvin SS (not audiophile, but not garbage), my McIntosh 240, an ASL 15DT, and a Jolida 202.
Now I have finished my first 3886. It sounds a lot like Tim's amps - very crisp, super detailed - in some ways, more detailed than Tim's amps. I have noticed more bass, but less detail in the bass.
I did not use the standard resistors in the chipamp kit - I used a carbon 1K in place of the metal foil 1K - r1, maybe?
Anyway, the amp is black quiet (when it is supposed to be), and very detailed, authoritative in the bass, and I am pleased.
Something I noticed on the amp I built and on Tim's amp is that there is some low level electrical trash - I heard it when I jammed my ear up to my Swan Diva 4.1 tweeter on top - it is probably anomalous noise in that outlet.
Anyway, my cherry is popped, and I feel a bit like a slut!
I finished my first 3996 chip amp from BrianGT/chipamp.com's design and PC boards.
I started reading about the chip amp/class D phenom, and initially bought a couple of Tim Rawson's amps. I was super impressed by the detail and sound stage - it smoked my Carvin SS (not audiophile, but not garbage), my McIntosh 240, an ASL 15DT, and a Jolida 202.
Now I have finished my first 3886. It sounds a lot like Tim's amps - very crisp, super detailed - in some ways, more detailed than Tim's amps. I have noticed more bass, but less detail in the bass.
I did not use the standard resistors in the chipamp kit - I used a carbon 1K in place of the metal foil 1K - r1, maybe?
Anyway, the amp is black quiet (when it is supposed to be), and very detailed, authoritative in the bass, and I am pleased.
Something I noticed on the amp I built and on Tim's amp is that there is some low level electrical trash - I heard it when I jammed my ear up to my Swan Diva 4.1 tweeter on top - it is probably anomalous noise in that outlet.
Anyway, my cherry is popped, and I feel a bit like a slut!
A quick comment on the service from audiosector.com, superb!
The kit that was ordered arrived from Canada in 6 days, thanks for a second to none service.
What more can I say? Let the solder burns to the carpet begin.
MJMIII
I was drawn to the chipamps by the relative simplicity of the build, I'm new to this as well.
When I first turned it on (with lightbulb in series) I was initially pleased it made a sound at all which turned into amazement at the sound it made.
I had a denon pma250 amp before this so I wasn't judging it against high end stuff but I was hearing sounds come from the wall between the speakers and not the speakers themselves. I turned it on just to see if it worked and reluctantly turned it off 3 hours later.
Anyway I'm delighted with the chipamps but do have an urge to find out what a good discrete amp sounds like as well, then theres valves.............
John
The kit that was ordered arrived from Canada in 6 days, thanks for a second to none service.
What more can I say? Let the solder burns to the carpet begin.
MJMIII
I was drawn to the chipamps by the relative simplicity of the build, I'm new to this as well.
When I first turned it on (with lightbulb in series) I was initially pleased it made a sound at all which turned into amazement at the sound it made.
I had a denon pma250 amp before this so I wasn't judging it against high end stuff but I was hearing sounds come from the wall between the speakers and not the speakers themselves. I turned it on just to see if it worked and reluctantly turned it off 3 hours later.
Anyway I'm delighted with the chipamps but do have an urge to find out what a good discrete amp sounds like as well, then theres valves.............
John
I was somehow lured to the Dastardly Devilish Decibel Dungeon and much to the Dismay of this Dashing DIY'er, I soon found my wallet Drained, prior projects Derailed and family time Disrupted and while I couldn't exactly hear her over the test in progress, my lip reading is good enough to recognize the word DIVORCE peeling from my Wife's lips...
7/10
7/10
Guys,
I built mine same as on the first page of the NS datasheet. I used 100uf caps. I see people all over using 1000+uf and I dont get it. I have wonderful sound with really impressive bass. What am I missing here?
I dont know if my supply makes a difference here but its kind of massive for this. I am using this guy:
It has 144,000uf on it but I know its overkill, but could this be allowing me to get better bass since it always has a good steady stream of power no matter how small my CM and CS caps are?
Uriah
I built mine same as on the first page of the NS datasheet. I used 100uf caps. I see people all over using 1000+uf and I dont get it. I have wonderful sound with really impressive bass. What am I missing here?
I dont know if my supply makes a difference here but its kind of massive for this. I am using this guy:
It has 144,000uf on it but I know its overkill, but could this be allowing me to get better bass since it always has a good steady stream of power no matter how small my CM and CS caps are?
Uriah
If you are using 144,000 uF in your PSU then you can get away with less than 1000 uF on the pins of the chip. The people that you see using 1000 uF often don't have any other capacitors in the PSU! 😉
and the resulting amp is incapable of properly reproducing frequencies below 160Hz or so.Nuuk said:
But reputedly great for mids and tops.
Expect to see an argument on this, but at least go back and search for other views.
Thanks Guys. Glad to know I am still getting from my amp what many others are. I really like it, it sounds great and its such an easy build. I bought one of those Playstation PS1 units off of craigslist a few days ago and WOW what a difference. I fell asleep listening last night. The soundstage really got larger as far as depth and width but it also seemed much more, I dunno, real. Before with my Technics player it sounded good but something sounded a bit constrained and it could almost make you feel a bit uptight listening to it. The PS1 is much different and listening fatigue doesnt happen. Although I did fall asleep, but thats another fatigue 🙂
Owen, what is low frequency IMD?
Thanks again guys,
Uriah
Owen, what is low frequency IMD?
Thanks again guys,
Uriah
udailey
I've got a modded playstation also, for the cost I think they are fantastic. It's done as per the MickF site with linear power supply and is rather lovely.
I assume you are aware of MickF and his site? It's here if not...
http://dogbreath.de/PS1/index.html
Be aware though that he is a superb photographer and makes really tiny parts look much larger!
John
I've got a modded playstation also, for the cost I think they are fantastic. It's done as per the MickF site with linear power supply and is rather lovely.
I assume you are aware of MickF and his site? It's here if not...
http://dogbreath.de/PS1/index.html
Be aware though that he is a superb photographer and makes really tiny parts look much larger!
John
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