Now that the new Gaincard pictures have appeared in the recent 6moons review, I felt that the old pictures frequently shown in the web (and disapproved by the US importer of 47 systems) showed the real thing.
Therefore I had a closer look at them and tried to figure out the schematic and parts used. I came to a consistent conclusion, shown below, but there is still at least one thing I dont understand.
You may feel that this topic has been discussed too many times. In this case just disregard this thread. The information may nevertheless be interesting to some people here.
The values of the resistors are: Rg: 22k, Rf: 22k, Ri: 680.
What I dont understand is the use of R0. What is it needed for?
More pictures, more words and the sizes of the caps (probably it is possible to identify their make according to the size) are shown on my website DogBreath.de
Mick
Therefore I had a closer look at them and tried to figure out the schematic and parts used. I came to a consistent conclusion, shown below, but there is still at least one thing I dont understand.
You may feel that this topic has been discussed too many times. In this case just disregard this thread. The information may nevertheless be interesting to some people here.
The values of the resistors are: Rg: 22k, Rf: 22k, Ri: 680.
What I dont understand is the use of R0. What is it needed for?
More pictures, more words and the sizes of the caps (probably it is possible to identify their make according to the size) are shown on my website DogBreath.de
Mick
There are many questions and right now I feel that it's rather uninteresting now when I know how Sakura Systems design their stuff all pictures are confirmed to be true. Totally uninteresting besides a big WHY.
I don't understand either why the american importer is so ashamed that he can't confirm how his product looks inside. Most high-end people are really proud of the inside and don't mind showing the world.
The review if you have missed it.
http://www.6moons.com/audioreviews/47labs5/gaincard_2.html
http://www.6moons.com/audioreviews/47labs5/gaincard.html
I don't understand either why the american importer is so ashamed that he can't confirm how his product looks inside. Most high-end people are really proud of the inside and don't mind showing the world.
The review if you have missed it.
http://www.6moons.com/audioreviews/47labs5/gaincard_2.html
http://www.6moons.com/audioreviews/47labs5/gaincard.html
peranders said:
I am referring to that review in my text. It is exactly this review and the "official" pictures therein that convinced me that the old pictures show the real thing. I am not impressed by the repeated denial of Yoshi quoted in the text.
I also dont understand why the importer plays this game. Most probably, he wants to unsettle those who want to copy the Gaincard. The practice of sealing the screws on the Giancard case fits also in that view.
Mick
If I sold a product that cost thousands and it looked like something that I would have posted in the ugliest prototype thread, I don't know that I would want people to see it either 
one problem with consumers is that the expect to get something for their cash, and obviously if they knew the actual cost of the components and saw the insides with what would appear to most as extremely poor quality workmanship, they would be very unhappy indeed.
Something like Peter Daniel's Patek whilst still minimal in component count is a work of art, the picture you just posted most certainly isn't, and I don't think the people forking out big money for one (no matter how good it sounds) would be very impressed if they saw what it looked like inside!!
Tony.
one problem with consumers is that the expect to get something for their cash, and obviously if they knew the actual cost of the components and saw the insides with what would appear to most as extremely poor quality workmanship, they would be very unhappy indeed.
Something like Peter Daniel's Patek whilst still minimal in component count is a work of art, the picture you just posted most certainly isn't, and I don't think the people forking out big money for one (no matter how good it sounds) would be very impressed if they saw what it looked like inside!!
Tony.
peranders said:
Mick_F said:
Sometimes the obvious answer is the correct answer. How do they "design" their stuff? Some guy sits down with a data sheet, a soldering iron, and a piece of perf board and haywires an amp. Then he makes the simplest possible PCB so he can make a bunch of identical units. Then some marketing hack from the wine industry pushes them as something special and adds a special price tag to match the specialness of the amp. Then the audio suckers line up and plunk down big bux and rave about them, then forums like this are born.
Sealing the screws prevents people who have paid big bux from opening the amp and seeing how badly they were ripped-off. Sealing screws isn't going to stop anyone intent on copying the amp. Even ICs get opened and copied all the time. A few little screws mean nothing.
90% of the chip amps made by "amateurs" in these forums are better built and more atractively packaged that that POS in the photos.
Does that mean any of them are worth the price of a "genuine" gain card? Only if you have a hole in your head the size of the hole that will be left in your wallet.
I_F
I understandMick_F said:
You don't want people to take a peek and maybe get them disapointed of paying so much for so little, not even looking good! A good product starts from inside, good looking inside, good looking outside. At least I think a customer may require a professional look inside, meaning assembly above the ugliest chinese stuff you ever seen (sorry all you Chinese people, but some stuff China isn't a beautiful sight)
Mick_F said:
Yes, LM1875 and LM3875.
I heard the (original) 25W - LM1875 version some 4 years ago.
They had it well set up, with a pair of french fullrange speakers, those very thin dedicated speaker cables and a Naim CDSII cdp as source.
Sound was very good.
The amp is really small, cute. On the pics it's usually hard to understand their real dimensions.
Regarding the distributors, or you know how to demo a product, or you don't.
These guys knew how to choose the right speakers for them, but others don't have any idea. I've heard reports of demoing these amps with the most absurd speakers.
These amps are as picky with speakers as SET amps.
Naturally.
Sound Quality
A friend used one with two power humpties to drive Lowthers in a factory horn cabinet. He loved it, but went back to tubes quickly.
He ended up with a Rowland amp that uses chips. Said it was better. Cheaper also.
Carlos, has you ever compared a Gaincard to any of the chip amps you have built? Unless the two amps are heard in the same system on the same day it is hard to be objective.
George
A friend used one with two power humpties to drive Lowthers in a factory horn cabinet. He loved it, but went back to tubes quickly.
He ended up with a Rowland amp that uses chips. Said it was better. Cheaper also.
Carlos, has you ever compared a Gaincard to any of the chip amps you have built? Unless the two amps are heard in the same system on the same day it is hard to be objective.
George
I_Forgot said:
This is essentialy the same thing that goes on with the Grado RA-1.
http://www.ecp.cc/ra1.html
http://www.geocities.com/rubin_jpk/rubin/page_4a.html
I don't imagine that Mark Levinson or Cary would ever seal their chassis shut.
Re: Sound Quality
No, I never had a Gaincard at home.
I listened to that system on the local distributor.
George, I'm not trying to be objective, I just said that the music I heard there coming from that system sounded good, that's all.
But it was not my type of music and it's not my type of system.
The music that was playing was slow jazz, very detailed.
I also listen to this type of music, but it's not the thing for a real test.
I'm almost sure that with a couple of my CDs I could defeat that amp, even with those sensitive speakers.
Ben Harper would kill it.
Panelhead said:
No, I never had a Gaincard at home.
I listened to that system on the local distributor.
Panelhead said:
George, I'm not trying to be objective, I just said that the music I heard there coming from that system sounded good, that's all.
But it was not my type of music and it's not my type of system.
The music that was playing was slow jazz, very detailed.
I also listen to this type of music, but it's not the thing for a real test.
I'm almost sure that with a couple of my CDs I could defeat that amp, even with those sensitive speakers.
Ben Harper would kill it.
Mick_F said:
One interesting think to learn from 47 labs is how they're grounding the amp : the transformer and diode bridge are away, the PCB uses the same plane for the power ground and for the signal ground.
In this arrangement the tricky think is how to connect every components to the ground in such a way that the hum and oscillations are minimised. I tried several "exact copies" versions inspired by this photos and what I've learned is that if even one of the resistors (or the input signal ground) is shifted as little as 1 mm you've got hum and oscillation. IIRC someone explained that the trick they're using is a re-injection of the hum in the - input (near the Ri) in such a way that CMRR of the chip helps to reject it.
If you find the exact arrangement of grounding you will find a kind of « local optimum » in which the amp play wonderful music with no hum and no oscillations. Also, in this arrangement, one bridge sounds better than two (more transparency) and ....;-).
Re: Re: Gaincard pictures revisited
Sounds like a lot of design work went into something that could've been easily solved by some proper PCB layout... You'd think that they could've at least sprung for some of the nice stuff, like PD and Brian did.
I don't think that the price would be as much of an issue if the insides didn't look someone was having a seizure when they designed and soldered the thing. The PCB work is seriously an embarassment and they should be ashamed of it. At least if they fixed it, they might be justified in asking 1/3rd of the price they are currently
vladimir said:
Sounds like a lot of design work went into something that could've been easily solved by some proper PCB layout... You'd think that they could've at least sprung for some of the nice stuff, like PD and Brian did.
I don't think that the price would be as much of an issue if the insides didn't look someone was having a seizure when they designed and soldered the thing. The PCB work is seriously an embarassment and they should be ashamed of it. At least if they fixed it, they might be justified in asking 1/3rd of the price they are currently
Re: Re: Gaincard pictures revisited
that isn't just limited to professional (marketing driven) reviews but also user / builder / designer reviews we see frequently here. Not that people intend to deceive but sometimes we want to believe we made a difference (for the better) after having spent hours researching and building our own amps.
I have breardboarded and p2ped quite a few gainclones and none exhibited such sensitivity.
I think the gainclones own a lot of its success to its exorbinant price tag. I have heard quite a few stories of how certain clothing items sold well only after their prives had been raised substantially. the high prices helped establish its superior sound quality, in the minds of their owners.
motherone said:
that isn't just limited to professional (marketing driven) reviews but also user / builder / designer reviews we see frequently here. Not that people intend to deceive but sometimes we want to believe we made a difference (for the better) after having spent hours researching and building our own amps.
vladimir said:
I have breardboarded and p2ped quite a few gainclones and none exhibited such sensitivity.
I think the gainclones own a lot of its success to its exorbinant price tag. I have heard quite a few stories of how certain clothing items sold well only after their prives had been raised substantially. the high prices helped establish its superior sound quality, in the minds of their owners.
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