Gainclone and Lab 47 - Peter Daniel?

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Konnichiwa,

fmak said:

Can you pl post or point me to an url on the relationship beteen DIY Gainclones and the Lab 47 unit?

I'd like to read this up before making one.

Well, I am also not peter, but I think I MIGHT know the story even better than he does....

A long, long time ago, I remember it like it was the last years of the last millenium, a Amplifier maker (Jinji Kimura) astonished the world with a very expensive, very small (2 cigarette packs side by side) High End amplifier based around an amplifier chip. Reviewers fell over each other to proclaim the greatness of this little amp and eventually the DIY'ser got curious and asked "How does this work"....

Discussions in/on various boards led to this site:

http://home.ca.inter.net/~cfraser/Gainclonehome.htm

This site in turn led to a very transitory and underground forum (meaning it seems to be on some other server every other month.

http://www.ampchipdiy.com

In this forum much gaincloning was discussed, including a certain evil one suggesting "Inert da suckah" and such thing. Eventually (much later) Gainclones entered the groupconciousness of Mankind thanks to the visually stunning efforts by Peter. The rest, as they say, is history.

fmak said:

What is the best source for PCBs please?

Absolutely NON. One of the biggest compromises in the original gaincard is the use of a rudimentary PCB. Simply hardwire the thing, the circuit is so simple that PCB's cannot be justified, further, correct hardwiring will shorten all signal and PSU current loops to such a degree as is NOT POSSIBLE using PCB's.

Sayonara
 
Disabled Account
Joined 2003
Re: Re: Gainclone and Lab 47 - Peter Daniel?

Kuei Yang Wang said:
A long, long time ago, I remember it like it was the last years of the last millenium, a Amplifier maker (Jinji Kimura) astonished the world with a very expensive, very small (2 cigarette packs side by side) High End amplifier based around an amplifier chip. Reviewers fell over each other to proclaim the greatness of this little amp and eventually the DIY'ser got curious and asked "How does this work"....


I was wondering how much influence the high price had on the reviewers.

BTW, did anyone looking into the cables used on the gaincards? how much of its superior sound is attributable to the cables?
 
Re: Re: Gainclone and Lab 47 - Peter Daniel?

Well, I am also not peter, but I think I MIGHT know the story even better than he does....

Sayonara [/B][/QUOTE]
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Thanks. In your opinion, is it worth making one, sonically speaking?

Fred
 
I was particularly encouraged by the review of Herb Reichert http://www.sakurasystems.com/reviews/reviews1.html

Seeing before his SET project in Positive Feedback, I knew he was not BS about the sound, and there had to be something worth trying.

When I've built my first amp, which was basically a copy of a 47Labs chassis (but almost twice as big) with an inverted circuit, I presented it to two of my audiophile friends. Now, those guys are not amatures, but people who've been involved with audio for years. One owns an audio related store, the other doesn't spare any expense to improve his system, most of the commercial equipment went through his hands (stuff like $8,000 TT and $4,000 cartridges). When they've heard the amp, they were hooked on it. It is not reviewers that make the hype or influence people. Those two friends of mine didn't read any review, they just listened to my amp without any previous knowledge about the whole zen story.

As good as the amp was in the beginning, over the period of last year, we made many substitutions and changes. Although the circuit seems to be simple (2 or 3 resistors and a chip), it's not that easy to attain it's full potential.

I sold some of the original amps, but the main complaint from people comparing it to GC, was lack of soundstage depth. Eventually, I decided to try non-inverted configuration and I'm almost completely positive that it is better. This is also what's used in an original GainCard.

Now some people claim that regular carbon resistors are the best for that circuit. I tried them yesterday and they don't sound bad, but remind me very much of Cat5 cable when it's used as interconnect. Very laid back, without refinement and pretty much non involving. Holcos were rather flat sounding, dry and a bit dull. Rikens are very fast, with nice top extention, but again they are flat and if two of them are used in a circuit they are too bright and fatiguing. I tried tantalums, and they indeed sound like no other resistors, producing fuller sound, with very good bass and midrange, but the highs seem to be overpowered by the mids and seem to be missing (no sparkle). Vishays S102 are neutral, but to some people may seem too neutral and too soft without edge. I'm using only a small value of that resistor in series with input. Caddocks seem to be a good overall choice, not too bright, not too neutral, with nice extention and rather 3-dimentional sound. I'm sharing my views on the sound of all those resistors as yesterday we did some testing of what would be the best choices in a new non-inverted version. BTW, the shunt resistor from + to ground, setting the input impedance, seemed to be very influential on the sound. Initially I had Dale (the stuff that ML is using everywhere) and after I replaced it with Holco the sonics improve substantially. Also, what seemed strange, without any changes to the circuit, by changing only the resistors, we could get more or less of a soundstage.

Another very influential area of the amp is chassis construction. Depending how rigid it is, and what materials are used, the sound will change. Aluminum will produce more brighter sound, while copper and wood will dampen the sonics more. In some instanes, I actually achieved overdampening and the air produce by the amp was lacking.

PS and rectifiers are important as well, and transformer influences sonics as much as any other part. I got good results with Plitron toroids and bigger size created bigger sound, but a bit edgy, while smaller was smoother, with less air.

At the moment I'm using batteries and I like them so far. This is one amp that doesn't put big strain on the cells and after 3 days of usage I still didn't have to recharge them. The sound produced by bateries is very effortless, with no glare at all, harmonically right and with amazing detail and clarity. It also seems that silence betweeen the notes is more silent.

As to the pot, I got good results with 50k Noble, but the old production. I tried series/shunt configuration, wher I got 10K tantalum and pot was only as a shunting element, but after few tries pot by itself sounded better. I also didn't like much Alps Black Beauty (too dark in character)

One other area to investigate is PS 1000u filter caps. To tell the truth, I only tried BG (STD and N) version. I'm ordering them directly from Japan, so price is a bit lower than what locals ask. I like them and although type N is 3 times more expensive, it may be a disappointment to some people. The comparison is like between Rikens and Vishay S102. STD are rather bright and forward, while N are laid back and very refined, with all the detail although not noticable right from the beginning. In my current system the N type seem like a very good match. I tried using parallel caps (2000u) and adding 10000u at the bridges, but those took the magic and the intimacy out of the music. Bass is very good with just 1000u so why look for more? And the bridges have to be definitely separate with MUR860 being a good overall choice. I also tried MSR860, but in a long run they were too bright.


I was building other amps before, and the quality of parts was always top notch. I'm currently concentrating only on GC, as they truly sound better that whatever I was using before.

My current circuit is non-inverting with 22k in feedback, 680 setting gain and 22k from input to ground. I'm also using 224 in series with input, but this is probably optional and depends on the whole system. In some systems I noticed a hum, when series resistance is not present.

All the parts choices are not set in mortar and will greatly depend on the rest of a circuit and ea. designer is suggested to experiment on his own for best listening satisfaction;)
 
As a mainstay member of "the underground forum"i believe we can accomplish a bit more because of the open attitude present in the forum.All or most of the members there have build different configs. and analized them to near death.
When a question comes up or a different approach to a particular problem we all pitch in and eventually there is an answer.
Nothing bad about this forum, it accomplishes things, but i have seen so much flack and mini wars that its hard sometimes to really progress.
Keep an open mind, i always say,you never know where a worthwhile idea comes from.Once when i was employed at Boeing we were grappling with with a fit up problem on a high velocity exaust (but cool gases).Had a janitor suggest a ring made out of 1.5" rubber to make a proper seal.Well we basically changed the material but it worked.
ron
 
Peter Daniel said:
At the moment I'm using batteries and I like them so far. This is one amp that doesn't put big strain on the cells and after 3 days of usage I still didn't have to recharge them.
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Peter

Batteries? What supply voltage are you using and what VA?

Other questions:

The non inverted circuits is the one in the spec sheet?

Have you tried LM3886? This seems to have better drive for lower impedance although S/N is a little less.

What about heat sinking; doesn't this have as much an effect as the case itself?

Fred
 
Disabled Account
Joined 2002
There is a Chip Amp section where all this has been discussed several times.

LM1875,3875 or 3886 ? Transformers or batteries ? Inverting vs. non-inverting. What resistors to use ? What caps to use ? What material to use for the case ? To Zobel or not to Zobel. What schematic to follow ? PCB or hardwiring ? What heatsinking and which material to use for the heatsink ? Even what isolation pad to use has been discussed. Just to name a few...

IIRC only what screws to use for the case is an unbeaten path....
 
fmak said:
Peter Daniel said:
At the moment I'm using batteries and I like them so far. This is one amp that doesn't put big strain on the cells and after 3 days of usage I still didn't have to recharge them.
---------------------------------------------------------------------------

Peter

Batteries? What supply voltage are you using and what VA?

Other questions:

The non inverted circuits is the one in the spec sheet?

Have you tried LM3886? This seems to have better drive for lower impedance although S/N is a little less.

What about heat sinking; doesn't this have as much an effect as the case itself?

Fred


I don't really see a problem with answering those questions again.

I'm using 4 Panasonic 7.2AH batteries for +/- 24V supply (it's actually more at full charge). When using regular PS, I was mostly using 400VA, double 22V AC transformers. I also tried Variac with that and changing the voltage didn't really bring that much of a difference. I noticed a bit more bass with lower supply (18V).

I never tried 3886, as people claimed it didn't sound as good as 3875. I don't care for better drive, as I never felt lack of it.

I was reading somwhere that the most coloration SS amp gets from heatsinks (fins vibrate). The advantage of chip amp is that it doesn't require much of heatsinking and common fin style extrusions are not neccessary here. Just a block of metal is good enough as I never noticed the temp rising more than 40deg. even with a small 2 x 8 piece of aluminum (for two channels). It helps to use something that resonates very little.

I decided to use in my recent amp a piece of bronze, as it supposedly have good properties soundwise. This piece rests directly on a spike, which releases any vibrations directly to the supporting platform. Two pieces of copper act not only as front and rear panels, but as part of heat dissipation system as well. Top and bottom perforated covers provide additional heatsinking. It is not a coincidence that I used wooden sides. They can't get hot as they hold the caps in place.
 
jean-paul said:
The components you can calibrate with have been discussed several times and Peter has replied questions about them faithfully everytime.

So why another topic with the same answers ? ( No offense intended ). Private mail can be a solution too.
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What same answers and why is this your problem? You have used even more space than I have asking a fellow member a question.

I am not interested in making deductions from 500 semi relevant posts.
 
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