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Post by Deleted on Apr 25, 2008 14:37:50 GMT
It was first published in Silicon Chip magazine (Aust. ) in November 2005. Alex Good to see someone actually mention the people who deserve the real credit. The guys at Siliconchip design and test the circuit, create a nice PCB and then write the article and instruction sheet that's easy to follow. www.siliconchip.com.au/cms/A_105435/article.htmlJaycar just stick the bits in the bag and post it to you. regards Greg |
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Post by PinkFloyd on Apr 25, 2008 16:25:57 GMT
Couldn't agree more Leo! Bloomin' horrid things that suck the soul out of the sonics.... much better strapping a good old class X2 cap across the IEC L/N tags. You don't happen to have any LM4562 kicking about do you Leo? I went hunting for mine today and couldn't locate them for the life of me  I'll be happy to do a swap with you if you do have any at Leo HQ. Sorry I'm late getting back mate, been busy, not had time to fart  I only had one of the LM4562 DILs BUT I do have one SMD LM4562 in my stash, would that be ok for you? it obviously needs to be mounted on a browndog if you have one That would be great Leo.... I do have a spare B-Dog  |
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Post by PinkFloyd on Apr 25, 2008 16:28:57 GMT
BTW guys the circuit for this amp looks SOOOO similar to a commercial unit out there which is FAR from cheap ;D Any hints? NAIM or Sugden? |
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leo
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Post by leo on Apr 25, 2008 19:08:09 GMT
Sorry I'm late getting back mate, been busy, not had time to fart I only had one of the LM4562 DILs BUT I do have one SMD LM4562 in my stash, would that be ok for you? it obviously needs to be mounted on a browndog if you have one That would be great Leo.... I do have a spare B-Dog No probs, I'll stick it in a envelope and post box in the morning, its only a tiny thing |
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leo
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Post by leo on Apr 25, 2008 19:12:26 GMT
BTW guys the circuit for this amp looks SOOOO similar to a commercial unit out there which is FAR from cheap ;D Any hints? NAIM or Sugden? L*****n ;D Just had a look at the schematic, its not exactly the same but is easily converted, well be no problem for the experienced bodger  The feedback is different and a bit of the output section, all it takes is a bit of altering I'd actually put a small bet on it this cheapo will beat it once its been modified |
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leo
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Post by leo on Apr 25, 2008 19:21:54 GMT
This amp could be converted to quite a few different designs too, dead simple  |
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Post by PinkFloyd on Apr 25, 2008 19:41:19 GMT
That would be great Leo.... I do have a spare B-Dog No probs, I'll stick it in a envelope and post box in the morning, its only a tiny thing Cheers man..... anything you need? |
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Post by PinkFloyd on Apr 25, 2008 19:43:28 GMT
Who me? ;D Looks like I'll have a bit of time before the rest of the kit turns up so I might as well. It would be most appreciated CJ.... you want me to put one of these transformers to one side for you? or you prefer notes in a brown bag? |
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leo
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Post by leo on Apr 25, 2008 19:53:22 GMT
No probs, I'll stick it in a envelope and post box in the morning, its only a tiny thing Cheers man..... anything you need? I'm ok thanks mate, you've given me more than enough bits and pieces to keep me amused |
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Post by PinkFloyd on Apr 25, 2008 20:50:09 GMT
Cheers man..... anything you need? I'm ok thanks mate, you've given me more than enough bits and pieces to keep me amused Not the way it works man... I WANT to send you something |
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leo
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Post by leo on Apr 25, 2008 21:05:42 GMT
I'm ok thanks mate, you've given me more than enough bits and pieces to keep me amused Not the way it works man... I WANT to send you something wait until you receive it first |
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Post by canjunkie on Apr 25, 2008 21:52:02 GMT
While we're sharing..... I've ordered up a PCB etching kit & it looks like I should be able to make up 3 or 4 JLH boards (the mini type) as easily as making up 1, so if anyone wants to try it when they get their kits let me know.  I won't be waiting for the amp kit so with a bit (lot?) of luck I should have a few done pretty soon. |
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Post by rossman on Apr 27, 2008 23:56:16 GMT
I picked up the headphone amp and PSU kit from Jaycar over the weekend. It cost about 21GBP ( I won't know exactly until the bill arrives ) as I managed to get at trade rates so it wasn't much more than ordering from the UK and at least I now have one.
There was another amp and PSU on the shelf so if anyone in the UK wants me to get it for them I will try but I can't say if I will be able to get trade rate again, it will then need postage on top once I get back home. PM me if interested.
Alex, would I be better off getting a toroidal from Jaycar or asking Mike for a traffo? Also the kit says that a pot is needed any ideas? Do jaycar to a good one?
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Post by Deleted on Apr 28, 2008 0:10:23 GMT
Rossman
If you can get a 15-0-15 20 VA toroidal from Jaycar, and are not worried about the little extra weight in your luggage, why not ? Just one thing less to worry about later on, and they aren't too expensive here.(30VA would be a little better, but only Altronics stocks them over the counter) You could use ordinary 50K dual logarithmic pots initially, then upgrade to something like Alps Blue Velvet later on.
Mike may be able to supply one of those ?
Did you get the kits at Hornsby ? If so, you better grab the other HA kit before I do !( just kidding, I have another to modify in the full SC Studio Preamp! )
Alex
P.S. I have sent you a PM and email.
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Post by mistergreen on Apr 28, 2008 20:07:10 GMT
Just as a quick question, what sort of wiring should I be using for the amp internals, say, like between the case-mounted phono plugs and the amp board, or, between the various i/o and the pot?
(bear with me, this is pretty much all new to me)
Thanks.
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Post by Deleted on Apr 28, 2008 21:02:37 GMT
mistergreen and Miguel
Due to the short lengths involved,any kind of shielded audio cable is fine. I often buy a 1 metre length of S-VHS cable, and strip the sheathing to obtain the thin shielded red and
white cables inside it. For power supply wiring I usually use the 3 conductors from inside a short length of 7.5A or 10A mains cable. Use the yellow-green (or green) for earth wiring.
I normally use the blue for -VE DC , and brown for +ve DC.
SandyK
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Post by mistergreen on Apr 28, 2008 21:07:55 GMT
Wonderful, thanks.
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Post by kittenyberk on Apr 29, 2008 0:49:15 GMT
Bugger.
Finally got an email from jaycar (after 4 days)
Ordered on the 11th, Shipped on 23rd.
Credit card shows I've been refunded £8.75 (The cost of the amp kit).
Looks like we're SOL until june.
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Post by Deleted on Apr 29, 2008 1:08:29 GMT
kittenyberk
A chance is if you are able to contact Rossman by PM,( or other means). He did say that for anyone wanting one, that he could bring one back, plus postage at your end.
I understand that Jaycar at Hornsby still had one left on the shelf after his visit.
He hasn't been on line since earlier yesterday.
SandyK
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Post by kittenyberk on Apr 29, 2008 1:24:44 GMT
Cheers, I've just PM'd him.
*crosses fingers*
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Post by Deleted on Apr 29, 2008 1:35:28 GMT
Good Luck !
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Post by PinkFloyd on Apr 29, 2008 20:54:08 GMT
I had a quick prod about under the bonnet today, was pretty zonked so didn't do a lot, basically whipped the inductors out of circuit, replaced the 47R with a 33R (33R sounded better to my ears), removed the 10uf input caps (slight improvement again) and then fitted the LM4562 (cheers Leo). LM4562 was quite nice in circuit but not the bassiest of chips is it? Not offensive, quite nice presentation but ever so slightly wishy washy sounding in places.... "airy" yes but satisfying overall? No. Not so far anyways, I'll try it again once performing all of the AK mods and fitting the JLH. Fired my original AD-843's (on B-Dogs) back in and "aha", the bass had returned.... a lot warmer sounding than the LM4562 however. Then rolled in an AD8066 which I currently prefer to both the 4562 and 843 being not only generous in the bass department but also extremely detailed, spacious and musically involving.... I'll let this puppy burn in for 24 hours and see how she sounds then but so far, excellent. I haven't bothered with any component changes (apart from 4 x 100uF fine gold) and will be doing one thing at a time and evaluating the changes..... deffo better with the input caps removed, the inductors removed etc. and I expect it to get better and better the more it's tweaked. Great little amp to work on too, those pads will withstand a fair bit of abuse I'd imagine       |
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Post by Deleted on Apr 29, 2008 21:20:35 GMT
Mike
AD8066 is one of my favourite chips too. BUT keep it running at
+ and - 15V, and BURN might be the result. Leo and myself recently had a discussion with the Singapore Stallion about this.
Even if it survives, it will deteriorate. 24V in this case, is + and -12V. Analog Devices data sheets are worded differently to the others. (5V =+ -2.5V)
Re the LM4562 being bass shy : Trust me, this won't be a criticism when the JLH is fitted !
Alex
AD8065/AD8066
FEATURES
FET input amplifier
1 pA input bias current
Low cost
High speed: 145 MHz, −3 dB bandwidth (G = +1)
180 V/ƒÊs slew rate (G = +2)
Low noise
7 nV/ãHz (f = 10 kHz)
0.6 fA/ãHz (f = 10 kHz)
Wide supply voltage range: 5 V to 24 V
Single-supply and rail-to-rail output
Low offset voltage 1.5 mV max
High common-mode rejection ratio: −100 dB
Excellent distortion specifications
SFDR −88 dB @ 1 MHz
Low power: 6.4 mA/amplifier typical supply current
No phase reversal
Small packaging: SOIC-8, SOT-23-5, and MSOP
APPLICATIONS
Instrumentation
Photodiode preamps
Filters
A/D drivers
Level shifting
Buffering
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Post by Deleted on Apr 30, 2008 1:16:41 GMT
Miguel
No thoughts on those . The general consensus at the moment is that the LM4562 (or the LME named one) is the chip to beat if properly implemented. Naturally, I have fitted a quality DIL socket ready for the next greatest since sliced bread. Don't take too much notice of the rersults with different chips before a JLH is fitted. Leo and Allan will vouch for the fact that things are very different when using a JLH.
Alex
P.S. EMAIL sent.
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Post by Deleted on Apr 30, 2008 5:28:47 GMT
Jaycar Headphone Amp Kit availability problems. In Silicon Chip magazine's May issue, Altronics has the Headphone Amplifier kit at the reduced price of AU$25. I understand that they do export as far afield as the USA. Their catalogue no. is K5503. Enter the kit no. into "Search" Their catalogue no. is K5501 for the Power Supply (AU$15.95) www.altronics.com.au |
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I'll be happy to do a swap with you if you do have any at Leo HQ. 
