jc
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Post by jc on Jul 28, 2015 13:32:39 GMT
With an insect inside the sound might have more bite You'll need to play a fitting track as you remove said bug, maybe something from The Beatles, oh it just gets worse doesn't it. Hat, coat, brolly, keys, shades all taken on my way out....
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Post by PinkFloyd on Jul 28, 2015 20:01:31 GMT
I got the amp finished this morning, flicked the switch and she fired up first go Inky black silence across the full range of the volume control with a CD on pause, it's as quiet as a mouse. I let her warm up for 20 minutes before having a listen and, woweee!, what a piece of quality this is! It's snappy, it's punchy and has great PRAT...... a mellifluous flow where the music calls for it and a real punchy attack when required..... it responds to the music so well and can't be described as "neutral" or "warm" or "coloured"..... I would be more inclined to describe it as natural or maybe even "organic", it's a lovely involving listen with spade loads of minutiae becoming a lot more apparent in the mix. The bass digs deep but doesn't make your teeth rattle, it integrates perfectly with the rest of the frequencies and doesn't "stand out" like a Vauxhall Corsa with a giant woofer in the boot It's seriously well balanced and is seriously proper "Hi Fidelity". I don't quite know what has made it sound THIS good but I suspect it to be a combination of the carbon composite resistors and the metal bodied Burr Brown OPA111BM. The other JLH amps I built sounded damned good but this one sounds something very special indeed. I had a quick listen to the metal bodied OPA627 and it just didn't cut the mustard, to my ears, it was ever so slightly sugar coated and schmaltzy.... chocolaty and "easy listening" type listen...... as if it were coating the music with a "one size fits all" layer of golden syrup. It may be good on paper but it doesn't do a lot for my ears..... don't get me wrong, it sounds great but it doesn't allow the music through "as is", it most definitely adds its own sonic signature to the proceedings and I'm not too keen on that. The OPA111BM lets it all through without the coat of syrup and I really do stand by my liking for this opamp...... It was great in the portables I tried it in (back in 2011) and is even better in the JLH Chiara amp! My original thread on the OPA111BM can be found here: rockgrotto.proboards.com/thread/6842/give-whirl-opa111That's just my initial impressions after a pretty short 2 hour listening session and I have yet to try a LOT of other opamps from my stash but all I have to say is this for the time being: WOW!! We all like pictures so here are a few of the final build...... I'll only bolt the lid down when I'm sure I've fitted the best opamp for the job..... the OPA111BM was proven to be a revelation when I tried it in a portable amp and I think it may "possibly" prove to be a shining star in the JLH Chiara (unless my ears deceive me). I'm really looking forward to getting my box of opamps out once again, there is some pretty zany shit in that box including the Sun, Moon and Earth discrete opamps (remember those?!) damned great idea but the buggers were too big to fit into any amp I own (and I own quite a few ). They are also too big to fit into the JLH Chiara thanks to the nitwit who placed the dip 8 socket right next to the heatsinks but there is a workaround. Anyhoo........ state of play as it is........ I feel quite happy and proud with this build and am happy to share it with you guys..... It's simple and I hope it's also neat and tidy and I know it will last forever because I know the geezer who put it together
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Deleted
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Post by Deleted on Jul 28, 2015 20:49:12 GMT
great ... well done you
told you it was a classic design that can be modded and pulled about, very pleased for you
My pics and build to follow soon .............. doesn't that transformer look lovely
Now try my 2oZ solid coper track power supply for even better results (with your extra psu captitors)
glad I contacted you now and contributed to your wonderful site
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Post by PinkFloyd on Jul 28, 2015 20:50:15 GMT
Kool Red Electronic Eargasm Lust
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Deleted
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Post by Deleted on Jul 28, 2015 21:01:59 GMT
errm ..
got me thinking now about op-amp car parks for my build
watch this space
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Deleted
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Post by Deleted on Jul 28, 2015 21:11:55 GMT
sorry Mike .. what a twit no argument from me mate ... hats off to you! great build (copper / capacitor) as I said .. mine to follow Meeeeoooowwwwwwwwww
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Deleted
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Post by Deleted on Jul 28, 2015 21:57:39 GMT
I haven't been in this zone for years..... this is where I belong...... Everything is just so "right"..... it's gonna be an all nighter with this JLH........ awesome! Nice work Mike, and I am pleased that it all came together so well. I took the liberty of tidying up the thread a little .
Kind Regards Alex
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Post by PinkFloyd on Jul 28, 2015 22:08:29 GMT
I haven't been in this zone for years..... this is where I belong...... Everything is just so "right"..... it's gonna be an all nighter with this JLH........ awesome! Nice work Mike, and I am pleased that it all came together so well. I took the liberty of tidying up the thread a little .
Kind Regards Alex
Thanks Alex, I took Nick's comments the wrong way and went in with force........ I was wrong to do that. Mike.
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jc
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Post by jc on Jul 28, 2015 23:29:29 GMT
Very tidy indeed, mine always look a bit rat-nesty but that's impeccable.
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jc
Fully Modded
Posts: 5,417
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Post by jc on Jul 29, 2015 18:40:15 GMT
Krazy Raging Ear Energising ...... Lump
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Post by PinkFloyd on Jul 29, 2015 20:27:31 GMT
I tried a few more opamps today and, so far, my ratings are: OPA 627 = 8 / 10 OPA111 = 8.5 / 10 AD 843 = 8 / 10 AD 744 = 9.2 / 10 SUN = 10 / 10 I've got tons more to get through and am taking notes which I will upload here once I have finished evaluating all of the chips. If two chips get the same rating it doesn't mean they sound the same, the overall rating is based on a lot of factors and is a "general" indication of what to expect..... I'll go into more detail when I explain the strengths and weaknesses of each individual chip. This type of thing is never easy as there are snappy, organic, raw chips, there are chocolaty syrup coated chips, there are coloured chips, there are warm chips, there are neutral chips..... each one has it's own sonic signature and it's up to the individual to decide what one suits his ears best. I won't knock points off if a chip has a warm sonic character as some people love that type of melliflous, flowing, music on valium type presentation. Neither will I add points if the chip sounds natural, organic and snappy....... the final rating will be based on the "overall" strengths and weaknesses and not on a "tonality" although I will indicate what type of sonic signature each chip possesses. First chip I rolled in today was the Analogue Devices AD744. You won't see it from the photo but this has been biased into Class A using the pin 5 to substitute pin 6 method..... I've done it under the DIP 8 socket which is why you don't see it By the way, all of these chips are well and truly tried and tested and are certainly not "virgin rolls" And there was me thinking the OPA111 sounded good!.......... A good old favourite, the AD843 was up next: Yep, classic 843 signature..... there was no mistaking that. Stupid me has been criticising the close proximity of the DIP8 socket to the heatsink, with regard to the inability of fitting discrete modules due to the space constraints, and it dawned on me that the simple solution is to reduce the size of the heatsink! There is no need (whatsoever) for heatsinks that size, the obvious thing to do is to replace the heatsink, which is parked up right next to the DIP8 socket with a smaller one and that would facilitate ample room to fit a discrete module. In the meantime, until I strip the board out and fit a smaller heatsink, I wired in an Audio GD "SUN" discrete module and this is, so far, the meat and two veg! I won't elaborate at this juncture, apart from saying "Oh My (expletive here) God!" Meat and two veg? More like the full English in your belly, a Savile row suit on your body, a fine cuban in your right hand, a tart on your left arm and a chauffeur ready and waiting in your Roller to drive you back to your penthouse...... I'm not giving anything away but will say that the "SUN" really does shine in the Chiara and it's not just a subtle couple of celcius, it's a noticeable heatwave!
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Post by PinkFloyd on Jul 29, 2015 21:51:15 GMT
Over to you Nick.................
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Post by PinkFloyd on Jul 29, 2015 22:20:46 GMT
Here Kitty Kitty......................................
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Post by Deleted on Jul 29, 2015 23:15:18 GMT
And the AD744 when biased into Class A ?
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pingu
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Post by pingu on Jul 30, 2015 9:25:12 GMT
Hi Nick and Mike, Following this with some interest I have an old Chiara which I have been using from a new build. Some mods including the Moon opa and yes it is tight but I got the dremel out and slimmed down one of the heat sinks to fit , unfortunately without a case as I have not bothered to get a bigger one and the Moon will not fit in the old case. Will be good to know how you feel the Sun compares to the Moon Mike Martin
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Post by PinkFloyd on Jul 30, 2015 19:26:21 GMT
Hi Nick and Mike, Following this with some interest I have an old Chiara which I have been using from a new build. Some mods including the Moon opa and yes it is tight but I got the dremel out and slimmed down one of the heat sinks to fit , unfortunately without a case as I have not bothered to get a bigger one and the Moon will not fit in the old case. Will be good to know how you feel the Sun compares to the Moon Mike Martin Hi Martin, I searched high and low for the moon today but it seems to have disappeared! I found the earth so now have the sun and earth but god knows where I put the moon, I'm sure it will turn up but it's really annoying when things just disappear like that It's well worth getting a case mate! Mike.
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Post by freddypipsqueek on Jul 30, 2015 22:18:24 GMT
I ended up with the moon - rockgrotto.proboards.com/thread/8507/chiarra-op-amps?page=2I initially cut the heatsink but ended up as per the photo. My intention has always been to build another Chiarra (and I will - I realise I am slow off the mark despite having the board - James i think I will need some bits from you) but this one has been really very good. Mike - You gave up with the extra capacitance on the power supply ?.
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pingu
Been here a while!
Reallising what has been taken on with the GB
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Post by pingu on Jul 30, 2015 23:17:13 GMT
Hi Nick and Mike, Following this with some interest I have an old Chiara which I have been using from a new build. Some mods including the Moon opa and yes it is tight but I got the dremel out and slimmed down one of the heat sinks to fit , unfortunately without a case as I have not bothered to get a bigger one and the Moon will not fit in the old case. Will be good to know how you feel the Sun compares to the Moon Mike Martin Hi Martin, I searched high and low for the moon today but it seems to have disappeared! I found the earth so now have the sun and earth but god knows where I put the moon, I'm sure it will turn up but it's really annoying when things just disappear like that It's well worth getting a case mate! Mike. Got that tee Mike still looking for my other set of PCBs for it and the PSU maybe my other house guest (the stray tom cat who pops in now and again) has hidden them Yes been getting around to a new case for awhile will get there eventually. If I find the boards I may build another with an attenuator and a Sun in a nice posh case off flee-bay Martin
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pingu
Been here a while!
Reallising what has been taken on with the GB
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Post by pingu on Jul 30, 2015 23:21:31 GMT
I ended up with the moon - rockgrotto.proboards.com/thread/8507/chiarra-op-amps?page=2I initially cut the heatsink but ended up as per the photo. My intention has always been to build another Chiarra (and I will - I realise I am slow off the mark despite having the board - James i think I will need some bits from you) but this one has been really very good. Mike - You gave up with the extra capacitance on the power supply ?. Now that goes back awhile Like you I take time to get around to things. Problem is life keeps getting in the way.
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Deleted
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Post by Deleted on Jul 31, 2015 20:42:23 GMT
meeeoww meeeowww
sounds of a wounded pussy cat ..... just licking my scratches
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Deleted
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Post by Deleted on Jul 31, 2015 21:13:08 GMT
Mike
Just out of interest what camera do you use take pics ?
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Post by PinkFloyd on Jul 31, 2015 21:35:58 GMT
Mike Just out of interest what camera do you use take pics ? A damned old one Nick. It's not a camera you are looking for, it's knowing how to use the one you already have. Most modern cameras will have a "Macro" setting..... that's the setting you want to use when you are taking close up shots of resistors and other sexy items Enter your camera model number into "Google" along with "Macro function" and if your camera has a macro function all will be explained The camera I use is my trusty Nikon Coolpix PX100..... you can pick them up for peanuts secondhand: www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR2.TRC1.A0.H0.TRS0&_nkw=nikon+coolpix+p100&_sacat=0They do the job and they are bulletproof....... Mike.
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Deleted
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Post by Deleted on Jul 31, 2015 21:52:22 GMT
Thanks mate
I hope one day we meet .. as we have similar interests and character
lets keep in touch ..
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Deleted
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Post by Deleted on Aug 22, 2015 14:28:34 GMT
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Post by Deleted on Aug 22, 2015 21:55:04 GMT
Hi Nick Experience has taught many of us that increasing the supply rails to at least + and -20V results in a marked improvement in SQ. This was demonstrated originally by E.E. Robert K. Dwyer from Rockhampton Qld. in the Silicon Chip (Jaycar) thread from years ago, when he trialled this, but due to opamp voltage limitations at the time, he had to regulate the opamp supply to the LM4562HA (LME49720HA) to + and -15V with the output stage at +-20V approx. Recently Bill Wilson also used a higher voltage version of the LME49720HA with higher voltage rails to good effect. We also found this with my posted discrete Class A/HA Preamp project where we also initially started out with + and -15V supply rails. Reports from constructors who tried higher voltage supply rails, eventually led to me also doing that too. We now use 2 x 18-0-18 30VA transformers in this design . Kind Regards Alex
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