I have some point to point wired "gainclone" using LM3886 which I built years ago and have worked great ever since (I brought it to a NEBO some time ago). They are a very good solution to cheap high quality power.....
I have some point to point wired "gainclone" using LM3886 which I built years ago and have worked great ever since (I brought it to a NEBO some time ago). They are a very good solution to cheap high quality power.....
Location: stoke-on-trent
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I'm andrew.
They were the ones being demo'ed by Colin from Chevron Audio and belong to Gary Hargreaves.
They defiantly were not playing loud, there was a passive pair in another room which sounded nowhere near as good as the active ones.
The Lab Gruppen amps have now been replaced by Hypex ones.
Colin will be at Scalford again this year with some active NS10M's.
Andy.
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I'm Deleted.
Yes, I assumed there was a strong link with Chevron Audio.
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Modulus - These boards are single channel without power supplies (90x70mm), so you need lots of them and suitable power supply/s for all of these plus my pair of crossover boards, which use a different voltage, it sounds as though it would end up a bit bulky.
I'm not sure you can parallel two of these boards.
It's getting too far away from my one box active filter/Amplifier objective for this project.
The board I have on test is 100x100mm 2 channel with built in SMPS.
Last edited by Qwin; 25-02-2016 at 19:01.
Jez - I remember that mass of bits you assembled at one of the early NEBO meets, it sounded a lot better than it looked.
Another reason Gainclones were in my sights, though I wasn't sure which chip you had used.
EDIT: I realise implementation is everything, but this little LM3886 with on board SMPS is sounding pretty damn good, listening to Malia/Boris Blank at present.
Last edited by Qwin; 25-02-2016 at 20:30.
Well, the Gainclone has continued to improve and now has 35 hours on it, I had to increase the bass and tweeter levels as the Gainclone seemed to get louder as it ran in, if that is possible. I have no complaints with the sound quality when used for the mid range amplification, in the active set up it is as good, if not better, than the Nakamichi. There are only very subtle differences in presentation between the two, that comes down to personal taste, but I could live with either. I like the vocal reproduction with the Gainclone a lot and brass instruments on some Mexican music I sampled was very clean, bright without being harsh or spity. Just listened to Hugh Masekela blowing his horn and it was sweet.
Overall very pleased with how it is performing and I'm confident enough to use these modules in my build, as amplification for mids and tweeters.
Received a pack of resistors and Caps this morning for the next crossover build, this is going to have balanced XLR input and all opamps will be discrete devices, I have the PCB's and I'm trying to source Header/Housing/terminals to suit the pin centres for the input/outputs. Although the crossover is currently free standing, the wiring on this build is going to be socketed so the boards can easily be transferred into the final combined filter/amp project. It's a nightmare trying to marry up the connectors from the basic spec that Farnell or RS gives, so many inaccurate details, so you have to check the manufacturers data sheets. Just for the female crimp terminals there is a choice of Brass/Copper/Bronze substrate and plated in either Tin/Nickel/Gold or a combination of several of these. I'm a bit bog eyed with it all but managed to get a full list of part numbers required.
Why the XLR balanced input, you might ask?
My intended Pre Amp for the final set up is the Pro-Ject Pre box RS, which has ECC88 (6922) tube output and has balanced output connections only. It has an RCA unbalanced output, but this is for taping and has no volume control on it, so no good for controlling my active set up. The most effective and straight forward solution, is to build the crossover board variant designed for balanced input and use stock balanced connection leads (Klotz mc5000).
There are a lot of stages to go through before this one is put to bed, but I'm getting there slowly, even when accommodating a few changed ideas, due to my pre conceptions, along the way.
Last edited by Qwin; 27-02-2016 at 15:49.
Shockingly good for a "car radio chip" are those LM3886 They are a prime example of how sometimes in this game one can get lets say 85% of the performance that it's even possible to get for little money.... but then to get another 10% you need to add at least a nought to the cost
LM3886 - Yes I believe it has been used quite often for car radios, flat screen TV's, etc.
It certainly does extremely well with price v performance and in a very compact package.
Wassup Ken, any progress?
Thorens td124 mk2 / Bokrand AB309/ 103r
SLAT L75 / Jelco 850S / AT VM740ML
Marantz CD63 / Bluesound / Musical Paradise 701 II/ ESP 500Hz eXO / PL Prologue 4 and Nord 1UP amps / JK Wynn semiactive NS1000 upgrade
/ESP 700 Hz eXO / JBL 4333 components
Hi Shahrin
Progress is slow, I'm either strapped for cash or parts. I just bought a Pro-Ject Pre Box RS, this Pre Amp has the balanced outputs I was after to feed the 3rd generation x-over boards. I'm now waiting on the Burson discrete opamps which have not been available since I tried to order them first week in January. They have told me they are working on the board layout, so either there is a problem with the design or they are simply repositioning things to make production easier. Either way I am prepared to wait for them to be happy with everything. I could buy some more of the first issue V5 modules from their distributor in France who still has stock, but I'll wait.
Meanwhile..............
I've populated the PCB's for my 3rd generation build. These are designed to accept balanced input and the input/outputs are socketed to allow easy transfer between projects. It took a bit of head scratching, but I managed to find some stock sockets that could be modified to fit the hole pattern on the PCB's. I had to use Takman 1% metal film resistors as the PRP I liked are not being restocked at HiFi Collective. The terminal blocks are to allow a quick change of resistors when I come to balance the output levels for the amplifiers/drivers requirements. I will start with pots then measure the values and use fixed resistors, this way I can do some final tweaking of the resistor values, if required, without having to unsolder anything.
I will initially use these boards in the existing separate x-over enclosure which feeds the multi channel Nakamichi Amp. Once I'm happy with them using the balanced inputs and a full complement of discrete opamps, I'll transfer them into my combined one box Amplifier/x-over build, hence the sockets, for easy change over. I'm taking my time with the changes and only progressing after each step has been optimised and proven to work.