Gainclone builders

[DSJR]

Apologies if this has been mentioned before, but in the Mini-T amp enthusiasm, I fear that kit amps based on the Gainclone may have gone out of fashion...

Has anyone made one of these up. What did the end result look like and obviously, how did you think it sounded?

I ask because - it appears the Mini-T doesn't perform at its very best into BBC Legacy speakers, the bass disappearing and the soundstage seemingly rather flat ina very non HiFi kind of way. Enough people have had the opposite results with different speakers for me to assume it's just incompatibility here.. The gainclone only has around a dozen components, all the work being done in the chip itself, the power is around 40W conservative class AB I believe and Audiosector do some nice looking kits. All one nees is a transformer or two (for full dual-mono operation) and a heatsink plate cum case to put it all in....

Thoughts chaps?

[John]

They are suppossed to be quite good. I am playing around with this at present http://www.ebay.co.uk/itm/MKll-Version-Tripath-TA2020-PCB-25w-CLass-T-amplifier-/251054941745?pt=UK_AudioTVElectronics_HomeAudioHiF i_Amplifiers&hash=item3a740a6631
A lot more bass than the standard version which for me did not have a enough grunt, still might be enough for your speakers but then their this
http://www.ebay.co.uk/itm/PAIR-MKII-STA508-Tripath-100W-monoblock-amplifier-/251040537858?pt=UK_AudioTVElectronics_HomeAudioHiF i_Amplifiers&hash=item3a732e9d02

[Patrick Dixon]

I build amps based on the LM3886 IC and they sound really excellent. I use mine to drive Briks - one's good, but two into a split crossover is better. One day I might even get around to going active with them. They're bullet-proof and the LM3886 is good for around 70W depending on the PSU.

As ever with these things, the devil's in the detail and small circuit and component changes can make quite big differences to the end result.

[john blackburn]

The Peter Daniels Audiosector LM3875 kits are lovely quality but be aware there is also someone on ebay using that name so ensure you get the right one. The Chipamp.com 3886 kits are very good too.

I like the LM1875s best but they would be hard pressed to meet your power needs.

John

[DSJR]

Thanks. I think I'd go straight to Audiosector in the first instance :)

[howlindawg]

Here's mine.
Basically a clone of the AudioZone amp-2 based on a Peter Daniels Premium kit.
This is an old pic, those yellow wired to the centre of the toroids are no longer there. :doh:
It's a dual mono design with a 300VA toroid per channel. Internal mains wiring is Mark Grant.
http://img20.imageshack.us/img20/4744/layoutkm.jpg

Since this pic was taken all the signal wire is now solid single core silver and the RCAs are silver CMCs.
http://img713.imageshack.us/img713/5403/circuitr.jpg

The case is from HiFi2000 in Italy (Modushop).
The switches are Onpow.
The feet are recycled from a dead Arcam tuner.
http://img21.imageshack.us/img21/1734/frontvjm.jpg

I'm running 25v secondaries giving around 37v on the rails which is near the max for this chip. Theoretically that should mean 55-60W per channel.

All in all it was a fun little project and even a build using top quality components won't break the bank. Sound bloody good too!

[Puffin]

I have made several GCs. A few point to point LM3886s (one bridged - nice rats nest of wires!), a couple of LM3875 monoblocks. Very rewarding to build them from a schematic. I also had some Chipamp.com 3886 boards, but that amp never sounded as good as my "home brewed":lol:

Didn't realise I still had phuckbucket pic of the bridged amp

http://i73.photobucket.com/albums/i239/saxonsex/DSCF1801.jpg

[DSJR]

That amp looks absolutely beautiful. My first effort may wel be on a blockboard chopping board I have, but of course everything will be exposed, which I'm not happy with. I'm sure a neat assembly, layout and vital attention to earthing makes all the difference :)

[Puffin]

Have you seen the "basic GC" drawing on Decibel Dungeon? IMO the LM3875 makes a nicer sounding amp to the 3886.

http://i73.photobucket.com/albums/i239/saxonsex/Gainclone.gif

http://www.decdun.me.uk/gainclone.html

[sondale]

Dave,

Like Puffin I have built several gainclones - the LM3875s sounding the best. I did build a 10-channel amp using Peter Daniels Premium kits (for a pair of Linkwitz Orion speakers) - they sounded pretty good!

However I do not use this anymore so if you want to try out the sound I can loan you a pair of amp boards and psu's - the transformers are a bit heavy to send!

Let me know if this is of interest.

[vencel]

Hello,

I also made a dual mono LM3875 based GC clone but with improved (regulated) power supply.
Find attached some photos about it. I used resistor brands suggested by Peter Daniel in the most important places and some AudioNote silver wires plus Shinkoh resistor for the voltage divider suggested by my friend as my Kondo M7 clone tube preamp has high amplification.

I am not an expert but I will be glad to answer any questions (if I know the answer :-))

Regards,
László

https://dl.dropbox.com/u/22181492/GC/Gaincard_001.jpg
https://dl.dropbox.com/u/22181492/GC/Gaincard_002.jpg
https://dl.dropbox.com/u/22181492/GC/Gaincard_004.jpg
https://dl.dropbox.com/u/22181492/GC/P003.JPG

[vencel]

Although I did not have the possibility to try Peter Daniel's DIY kit but I find it very impressive and read very good reviews about them on the net.

[DSJR]

Looks very smart indeed - thank you for posting :)

[r100]

Hi,

I stumbled on this thread by accident while researching the information on chip amps specifically based on LM3x and LM4x chips. I would like to revive this thread if anyone is interested as I have built a first LM3886 based on the chipamp.com boards and have a second one based on the Peter Daniel kit on order... so it would be nice to exchange some knowledge and specifically opinions on the sound of these amps within the AoS membership. Yes, there are active threads on the subject over at diyaudio.com but they are for the most part quite technical and less focused on the sound quality as I see it.

In any case, if there are any other GC builders or owners still out there then lets keep this thread alive :)

Best to all

[tubehunter]

I have built many Gainclones.
Great little amps, easy to build.
I find the LM3875 none inverted the sweetest sounding but don't use a transformer with 25 volt secondaries.
18v or 22v are enough, you don't want to venture into the SPiKe protection:(, I have successfully used transformers with 25v secondaries and unwound some copper to measure 22v.

http://i514.photobucket.com/albums/t350/halx00/IMG_3724_zps0d921345.jpg (http://s514.photobucket.com/user/halx00/media/IMG_3724_zps0d921345.jpg.html)

http://i514.photobucket.com/albums/t350/halx00/IMG_3727_zps08827f06.jpg (http://s514.photobucket.com/user/halx00/media/IMG_3727_zps08827f06.jpg.html)

http://i514.photobucket.com/albums/t350/halx00/IMG_3747_zpsbcef550d.jpg (http://s514.photobucket.com/user/halx00/media/IMG_3747_zpsbcef550d.jpg.html)

http://i514.photobucket.com/albums/t350/halx00/IMG_3750_zpsce3a541d.jpg (http://s514.photobucket.com/user/halx00/media/IMG_3750_zpsce3a541d.jpg.html)

http://i514.photobucket.com/albums/t350/halx00/IMG_3752_zps0ee63d93.jpg (http://s514.photobucket.com/user/halx00/media/IMG_3752_zps0ee63d93.jpg.html)

http://i514.photobucket.com/albums/t350/halx00/IMG_4190_zps2171c3ec.jpg (http://s514.photobucket.com/user/halx00/media/IMG_4190_zps2171c3ec.jpg.html)

http://i514.photobucket.com/albums/t350/halx00/IMG_4192_zpsca9d3bf6.jpg (http://s514.photobucket.com/user/halx00/media/IMG_4192_zpsca9d3bf6.jpg.html)

http://i514.photobucket.com/albums/t350/halx00/IMG_4193_zps480a0164.jpg (http://s514.photobucket.com/user/halx00/media/IMG_4193_zps480a0164.jpg.html)

[r100]

WOW !

I love those beehive heat sinks :cool:

I have only built one from chipamp (standard double mono build). I am also very happy with the sound and punchiness of these little amps. I plan to try some other builds based on the Peter Daniel designs and maybe some very cheap ones from fleabay. The only really expensive items in these builds are the transformers and the case if not build from spare parts. The build is quite accessible to anyone who knows how to solder which IMHO makes them the ideal intro DIY projects with great results.

All the best
rupert

[r100]

Hi,
some pics of the completed amp. It is very compact but weighs a ton ! The sound is extremely detailed which sometimes makes me jump ! The soundstage is almost unbelievable. The speakers literally disappear. The only slight negative is that I had to take my volume attenuator out of the chain in order to tame a slight harshness it was causing at very hight listening levels.

Next up will be a Peter Daniel design.

13740

13741

13742

13743

13744



sorry, can't get the pics to rotate :eyebrows:

[Puffin]

Your cat has amazing powers to be able to cling vertically to the amp:D

Nice build, what is the guts of the amp? LM3886 or LM3875 based.

[tubehunter]

Nice job, but I like to see the insides.

Funny you should say that it sometimes makes you jump, I also found this with my builds.
To be honest it's the only amp that did.

Perhaps something to do with very short signal paths maybe.

Must build a pair of monoblocks, point to point wiring to see how they drive my Kef 105s.

[r100]

It must be the amp that has a very strong attraction. The cat is actually stuck to it, hence his surprised look:lol:

The build is based on the BrianGT chipamp.com kit with a LM3886 per channel and a separate power board and transformer per channel. It's my first true dual mono amplifier and if anything the sound staging is really freaky.

Internal wiring is standard Lapp PTFE insulated, silvered copper wire. The toroids are 150VA 22v+22v. I'm currently driving them directly from a Yulong DA8 DAC which has its own preamplifier.

Here a early image of the base plate populated with the bits and pieces.

13745


measuring the temperure at full load .. approaching 50°C :stalks:

13748

[Puffin]

I built one with some Brian GT boards (sold it to Hamish who used to hang out here). However having delved into making GC's point to point, the one's I made from scratch sounded sooooooooo much better:D as a result of all the labour involved;)

[r100]

My only current reference is a modded Quad. The Chipamp pumps out a lot more detail in a much larger sound stage. Percussion and drums, basses and guitars sound very real and nicely textured (if that makes sense ?). Even piano music (which I never really listen too - probably because it didn't sound too good in my previous configuration) is now a pleasure to listen too.

I couldn't be happier. Especially when the price for this kit is considered. Ok, the transformers are quite expensive but I would definitely recommend to use one per channel.

Do you have some instructions or references for your point-to-point build ? I would like to give that a try as well :) one of these days

Cheers
Rupert

[Puffin]

Yes I do. I would suggest you follow the diagram on Decibel Dungeon for a simple LM3875 or 3886 amp.

http://www.decdun.me.uk/gainclone.html

http://i73.photobucket.com/albums/i239/saxonsex/LM3875GC_zpse8353ea2.gif

[r100]

Thanks ! I knew about that site but I now realize how informative it is. Great stuff !

[r100]

I have had the LM3886 amp running for the last couple of weeks with different configurations and setups. I finally settled for the Yulong DA8 preamp with its DAC section.

The setup is sounding very, very good to my ears. My reference amp, the venerable Quad 306, modded with some nice components from Dadaelectronics has been dethroned by a large margin. Or lets say, it is not at all the same kind of sound. Whereas the Quad is quite laid back, relatively detailed and has a quite large soundstage (after mods that is), the LM is a different beast altogether.

First off, it is stunningly detailed. It is almost scary at times. Snare drums, kick drums, percussions are so lifelike that you can almost feel the skin of them vibrating. It delivers a tight, deep, textured, fast (if that makes sense) and engaging bass which makes the people in the room want to boogie ;-).. Voices, drums, guitars, especially acoustic guitars are "in the room". The soundstage projection is so large and deep, I have never experienced anything like it, even from the best amps I have owned, (including a pair of NVA A40.2 mono blocks :D). And all that even at low listening levels.

I know this all sounds too good to be true, but it is, at least for me. I did have to move around some components and let it all settle in a bit but I can honestly say now that for the 100 or so dollars for the kit, a couple of fun hours of building and some shuffling stuff around, it has largely payed off and I am extremely happy with it.

Disclaimer :eyebrows: My only source is streamed high-res (Spotify) music from a lowly Airport Express which may put some folk off. But I think I have a great synergy going on in my current setup which really squeezes every last bit of goodness out of the bits and bytes it is fed without ever sounding analytical or synthetic or whatever.

13819

[Puffin]

Yes, IMO the LM3886 chips give a very detailed performance. The LM3875 chip (again IMO only?) gives no less detail, but perhaps a less in your face performance. The LM3875 monoblocks I made using the info on Dec Dun are run at the max of the chips voltage capability as I only had 30-0-30 trannys to hand (and as I am tight didn't want to buy any more!). In view of this I also built the voltage regulator modules on the DEC Dun site so that the voltage does not exceed 45vdc. The chips are attached to fairly modest heatsinks and they do not get very hot. I might take a pic if you are interested.

[r100]

Very interesting!. I received the LM3875 kit from Peter the other day. He describes the 3875 as his favorite chip compared to the 3886. I am still waiting for the trannies which will be the same as use in the 3886 build 2x23/150vA so I won't have to worry about frying my speakers or the chip 😀. I'm looking forward to comparing them. The case, heat sink and cabling will be identical to the first build as well.

Are you still using your builds ? Pics would be nice if no hassle.

Cheers

[r100]

stumbled on this link.. looks like the one Puffin made ? point to point with nice photos and step by step instructions..

peace
greetings

http://dogbreath.de/Chipamps/ThreeResAmp/ThreeResAmp.html

13824
:painting:
13825

[Puffin]

No Rupert, I can't take the credit for that one - mine is much neater:D

I thought I had some pics of the LM3875 amps on Ph*%kbucket, but thenm realised that they were on my previous Dell that died. I will try to get some pics done, but as I am on holiday this week I am VERY busy:comatose:

I did the mods to some Sony PS1's a few years ago as per Dogbreath and made the suggested PSU. Very good and worth doing, but time moves on and the PS1's lasers are a bit flaky and in any event don't like reading CDR's.

[r100]

:lol:


Have a good one !!

:partytime:

[r100]

Hi All,

I have just finished the bread board version of my new Peter Daniel LM3875 chip amp. It is a very simple build which involves soldering a small number of parts to the PCB's and then joining the two boards to each other with 4 pieces of wire. The whole process to this point only took a couple of hours.

After testing DC offset and a quick listen on a pair of old speakers, I moved it to the main system exposing the typical Gainclone sound I have gotten used to since my previous build. (transparency, tight punchy bass and dead quite, large soundstage). These builds are almost addictive because they are so accessible (price wise / simple build). I will post more pics when it is in its final case.

All the best

13917

[Puffin]

Yes a bit of an addiction indeed. I built too many really - simply because I could! I must get that camera out:D

[r100]

I finally got some time to put the components onto a laser cut aluminum base. Old school terminals :stalks: No magnetic parts inside... not sure that would make a difference, it was just a design goal I had set myself.

more updates when I get a moment to finish the bonnet
all the best

[6L6]

Fantastic work! Wonderful construction. Very neat and tidy, looks great.

I have built a couple chipamps, BrianGT 3886 and Peter Daniel 3875, both are wonderful.

For your next project, I suggest something from the Nelson Pass school of DIY, they are all wonderful and you will be extremely impressed with the performance. You mention that the chipamps soundly trounced the modded Quad, the class-A amps will do the came to the chipamps. :)

[r100]

Thank's !

Yep, I had actually considered a Pass build. Everything I read about them is positive sound wise. The only thing holding me back is the enormous power consumption of these A Class designs.

The next level up from a standard GC build n the low power consumption leage, would probably be something like the Modulus86 Rev. 2.0 I think. Things evolve fast in DIY these days :eek: (build thread (http://www.diyaudio.com/forums/chip-amps/267802-modulus-86-build-thread.html)) (constructor site (http://www.neurochrome.com/audio/)).

Cheers
Ru

[6L6]

Don't worry about the power draw... You also get the benefit of heat in your room! :)

Yes, genuine Class-A is not particularly efficient. But they do sound wonderful. Amazing.

But if it's a genuine concern, it's worth looking into a SMPS, the total efficiency will be better than a linear PSU.

[r100]

As a guy over at diyaudio.com said "Class A needs to soak (in the current)".
Maybe I'll get a second hand (obviously) Pioneer A717 one of these days...

[6L6]

Yes. Very true.

...but that statement is akin to saying "Water must be wet." :) :) :) It's part and parcel that Class-A is heavy in the current - the devices never turn off.

[fatmarley]

The next level up from a standard GC build n the low power consumption leage, would probably be something like the Modulus86 Rev. 2.0 I think. Things evolve fast in DIY these days :eek: (build thread (http://www.diyaudio.com/forums/chip-amps/267802-modulus-86-build-thread.html)) (constructor site (http://www.neurochrome.com/audio/)).

Cheers
Ru

Rupert,

Did you ever get around to building the Mod86?

I'm thinking about building a chip amp but still searching for ideas.

[Qwin]

This Conexelecronic board is one of the simplest ways of doing a Gainclone, based on LM3886 it has a SMPS on the same 100mm square board.
DC detection/shut down, over/under voltage protection, soft start all built in. Just connect mains power an audio input and speakers.
I finished this lash up recently to asses its suitability for use on mids and tweeters within an active 3-way crossover. (Class D for bass)

http://www.jkwynn.co.uk//Pics/LM3886_Lashup.JPG

[danilo]

Tread lightly with the Connex Gizmos !
A few years back I had one right out of it's package immediately self destroy itself
A dual mono design DIY lm3886
Other connex unit worked.
Response from Connex was useless and accusatory.
Seriously unsatisfying
Needless to say, Both the dead and 'working' Connex were immediately into the rubbish bin.
Built a Cap multiplier ps as replacement.

[Qwin]

Noted Danilo.
I've only had experience of one unit, which works fine, but I take on board what your saying.