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Post by PinkFloyd on Mar 23, 2007 17:04:10 GMT
dc, Hi, I only ordered the ceramic op amp. Even though it will fit in place of the AD823, I had reservations about whether it would fit inside the socket. Cheers, Nigel If not, no worries, you can solder one onto a dip8 socket
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Post by daggerlee on Mar 24, 2007 3:06:03 GMT
All you guys preferring the AD823 to the LM4562 are freaking me out! You have all got to be using Senns..
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Nigel
Been here a while!
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Post by Nigel on Mar 24, 2007 11:36:02 GMT
Yes, I'm using the HD650's!
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darynalexander
100+
will probably give you some sort of disease.
Posts: 179
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Post by darynalexander on Mar 24, 2007 21:37:01 GMT
Hm. I'm using the K701's. And keeping em. Is this LM4562 a dual opamp? what are your impressions, daggerlee?
edit: ah yes, it is dual.
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Post by daggerlee on Mar 25, 2007 1:27:01 GMT
Hi daryn, yes I am using the K701. I found the LM4562 to be similar to the OPA627s, but with less of a laidback edge. I found the AD823 to be too shrill with the K701s. On the other hand I recently bought/sold a pair of HD580s and found them pretty mushy, and preferred the K701s by a large margin. But I guess I wasn't using the right opamp, according to the consensus here
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darynalexander
100+
will probably give you some sort of disease.
Posts: 179
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Post by darynalexander on Mar 26, 2007 2:54:07 GMT
And I'll bet you it was because of the low impedance, which has happened to me before with the K701s. Definitely interested in the LM4562 if you can compare it to the 627's.
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Post by dc on Mar 27, 2007 23:29:36 GMT
nigel: the ceramic DY2000 assuming it's the same one as i have is in the same size shape and form as a regular DIP-8 which is the same packaging as the AD823 so will have no worries fitting in there
d'oh! i've been saying 4652 all this time hehe
daggerlee: i used the K701s wiith the AD823 in place!
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Post by daggerlee on Mar 30, 2007 15:10:51 GMT
Ah, well I guess we all have different ears!
Nigel, have you received your metal can DY2000 yet? Any impressions?
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darynalexander
100+
will probably give you some sort of disease.
Posts: 179
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Post by darynalexander on Mar 31, 2007 22:40:10 GMT
It arrived, Pink! Strangely enough, the same day as the Rolling Stone with the Pink Floyd cover...you arranged this, somehow.
I've been listening to everything on it. Drives the wife nuts, but drives the headphones extremely well.
First, I'll touch on the AD823 and it's place in this amp. The only thing I can say that is shrill about it is the vocals at times, where it will reveal sibilance found in the recording if paired with certain headphones (in this case, the K701). However, I really can't complain given that the amp drives the headphones so beautifully that it isn't so overwhelming when compared to the rest of the music. I was simply amazed at how detailed every cymbal crash was, and how I could identify bass lines that weren't there before. The bass was below everything else, but present and not being a bass head this is what I ask for. Perhaps I'll dry a DY2000 if this becomes a problem in the future.
When I first heard this amp, I wasn't terribly thrilled. It was music on steroids and while it drove the K701's incredibly well, it felt like it was just turning up the volume without any of the added benefits. Now, the amp takes full advantage of the K701 soundstage and I'm loving the separation of instruments. It makes my Jam collection sound like it was recorded yesterday. One of the great thigns about this amp is that if you turn the volume up it just gets juicier instead of just louder, so watch the dial. I generally keep mine between 9-12 depending on the recording.
Ultimately, I think Pink has hit the spot. With the three prior amps I've tried, there was always this immediate urge to upgrade. The only urge I have right now is to swap op-amps and see all the options that are out there.
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Post by PinkFloyd on Mar 31, 2007 23:45:11 GMT
It arrived, Pink! Strangely enough, the same day as the Rolling Stone with the Pink Floyd cover...you arranged this, somehow. I've been listening to everything on it. Drives the wife nuts, but drives the headphones extremely well. First, I'll touch on the AD823 and it's place in this amp. The only thing I can say that is shrill about it is the vocals at times, where it will reveal sibilance found in the recording if paired with certain headphones (in this case, the K701). However, I really can't complain given that the amp drives the headphones so beautifully that it isn't so overwhelming when compared to the rest of the music. I was simply amazed at how detailed every cymbal crash was, and how I could identify bass lines that weren't there before. The bass was below everything else, but present and not being a bass head this is what I ask for. Perhaps I'll dry a DY2000 if this becomes a problem in the future. When I first heard this amp, I wasn't terribly thrilled. It was music on steroids and while it drove the K701's incredibly well, it felt like it was just turning up the volume without any of the added benefits. Now, the amp takes full advantage of the K701 soundstage and I'm loving the separation of instruments. It makes my Jam collection sound like it was recorded yesterday. One of the great thigns about this amp is that if you turn the volume up it just gets juicier instead of just louder, so watch the dial. I generally keep mine between 9-12 depending on the recording. Ultimately, I think Pink has hit the spot. With the three prior amps I've tried, there was always this immediate urge to upgrade. The only urge I have right now is to swap op-amps and see all the options that are out there. Hi daryn, Basically I just got her up and running for you, you did the rest of the work yourself, I'm glad she arrived safely and "working" The world's your oyster when it comes to opamps, the AD-823 is one of many and a very good starting place IMO ..... please do try the LM4562, OPA2134, OPA2132, OPA2107 etc. and on browndogs please don't hesitate to try OPA627, AD744, AD811, AD8620 etc. I'll send you a couple of choice chips over to try.... please do report back. Glad she's "working" again Daryn now just a case of finding the right chip to suit your ears All the best. Mike.
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darynalexander
100+
will probably give you some sort of disease.
Posts: 179
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Post by darynalexander on Apr 1, 2007 21:20:46 GMT
Thank you kindly, Mike. I will report back my findings. I have the strange feeling that opamp will become addictive.
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Post by leftnose on Apr 9, 2007 17:48:55 GMT
This is where the heat comes from folks! Not so much the transistors but from the 5W 100ohm resistors, put your finger on one and you'll see what I mean! HOT eh? I added a bit of supplementary heatsinking round this are and actually bonded a sink onto the sides of both the 100ohm resistors with stuff similar to JB weld, so powerful is this gear you'll never get it off, the resistors now run warm to the touch so job well done.... the grey epoxy steel looks a bit mickey mouse but believe me it does the job very well. How big are those resistors? My Heed is on order but I was thinking I'd stick a few of these on as soon as I got it: www.thermaltakeusa.com/2005/coolers/memory/ramsink.htmNeed to know what size to buy, though. Thanks.
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Post by dc on Apr 11, 2007 1:33:07 GMT
www.bursonaudio.com/Burson_HDAM_Module.htmanyone here have experience or opinion on one of these babies? another aussie heed owner is going to try to pop one in though he hasn't received it yet, i also wonderin whether it will fit inside the canamp case if this is used it will transform the canamp into a completely discrete design as well!
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darynalexander
100+
will probably give you some sort of disease.
Posts: 179
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Post by darynalexander on Apr 11, 2007 4:19:16 GMT
I'm also interested in what that would do to the sound. What's discrete design, anyhoo? Or am I better off not fussing over these little things.
All I know is that this amp is great. The op amp is a bit shrill though, at times. I'll try others some time soon (when I have some of that. time, that is).
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Post by dc on Apr 11, 2007 4:26:59 GMT
I'm also interested in what that would do to the sound. What's discrete design, anyhoo? Or am I better off not fussing over these little things. All I know is that this amp is great. The op amp is a bit shrill though, at times. I'll try others some time soon (when I have some of that. time, that is). discrete means it doesn't use opamps or other ICs where there is a whole bunch of components under a single piece of black silicon so all the pieces are visible on the board and can be individually replaced
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leo
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Post by leo on Apr 11, 2007 11:16:43 GMT
I've actually got a few of the Burson bits and pieces, the Discrete op-amps, one of the external buffers, some of the discrete regulators and one of their clocks. I don't have a Heed or know its circuit so don't know if the discrete op-amps would be suitable, I do know they sound really good used in a decent cdp's output stage (not I/V)
Let us know how the Burson sounds in the Heed if your friend decides to try one. I may try and squeeze one in my Chiarra, only problem is the Burson needs a very good supply!
Just had a quick look at the a picture of the Heed, I doubt the Burson would physically fit unless those pair of electrolytics and the mylar film cap are moved to the bottom of the pcb. If those caps are for decoupling the op-amps supply rails be better to fit them to the pins anyway if using something like the Bursons, trust me these need a good supply and local decoupling, if this isn't good enough you'll risk oscillation giving DC offset, they'll also sound bad so just be careful;)
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Post by dc on Apr 12, 2007 1:38:56 GMT
yep, turns out burson replied and said that the HDAM would not be suitable for the i/v stage of the heed so no luck there
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leo
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Post by leo on Apr 12, 2007 19:13:05 GMT
I/V is current to voltage conversion used on the output of multibit cdp's, this is normally done by op-amps but the Burson isn't suitable here. I'd have thought the op-amp in the Heed is just used as a buffer? I still can't guarantee the Burson is suitable in this unit though I'll try it in the Chiarra and do measurements when I get time
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Post by dc on Apr 22, 2007 13:00:18 GMT
hey can anyone check the bottom of their canamp for me and see if there are traces that look like they were cut, by hand? following the traces it looks like it's the rca left right and ground lines that look like they were hacked with a stanley knife or something. it appears whatever it is that the cable running beneath the board is carrying the signal in its place wondering what happened here... circuit error discovered after a whole bunch of PCBs were printed maybe? haven't had a chance to take photos yet, but one of my earlier photos pictures it, cant believe i never noticed it before www.a-chau.net/gallery2/v/mambo-articles/canamp/DSCF8152.JPG.htmlin this photo, you can quite clearly see that the board has been hacked, above left of the left polyprop cap in this picture also, was getting buzzing noises into the amp when i tapped/knocked on the amp enclosure. fixed it by reconnecting ground which was cut by the abovementioned hacking in the same photo, to the right of the right most polyprop there's 2 square pads just above the nut. by connecting these you restore ground and the amp no longer makes the buzzing when it's tapped or feels vibrations does anyone else's amp do this? i know it's not safe practice to go hitting audio gear, but i don't think it will do any irreversable damage and it's fixed by switching the amp on and off one other user had this problem, i thought it was just me and my incompetant modding ... edit: actually i found a picture! www.a-chau.net/gallery2/v/mambo-articles/canamp/whatthe.jpg.html?g2_imageViewsIndex=1can anyone confirm whether or not their canamps have or haven't got this? cheers Dave
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Post by daggerlee on Apr 22, 2007 16:46:06 GMT
So I was thinking of this possibility:
Could I tap the volume pot outs and then run that to the "OUT" RCA jacks in the back, in effect turning the RCA outs into preamp outs? (after cutting them from the board first of course)
Can anybody who's familiar with the Canamp circuit? After all I've heard most headphone amps actually would make splendid preamps...
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leo
Been here a while!
Team wtf is it?
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Post by leo on Apr 22, 2007 20:39:00 GMT
hey can anyone check the bottom of their canamp for me and see if there are traces that look like they were cut, by hand? following the traces it looks like it's the rca left right and ground lines that look like they were hacked with a stanley knife or something. it appears whatever it is that the cable running beneath the board is carrying the signal in its place wondering what happened here... circuit error discovered after a whole bunch of PCBs were printed maybe? haven't had a chance to take photos yet, but one of my earlier photos pictures it, cant believe i never noticed it before www.a-chau.net/gallery2/v/mambo-articles/canamp/DSCF8152.JPG.htmlin this photo, you can quite clearly see that the board has been hacked, above left of the left polyprop cap in this picture also, was getting buzzing noises into the amp when i tapped/knocked on the amp enclosure. fixed it by reconnecting ground which was cut by the abovementioned hacking in the same photo, to the right of the right most polyprop there's 2 square pads just above the nut. by connecting these you restore ground and the amp no longer makes the buzzing when it's tapped or feels vibrations does anyone else's amp do this? i know it's not safe practice to go hitting audio gear, but i don't think it will do any irreversable damage and it's fixed by switching the amp on and off one other user had this problem, i thought it was just me and my incompetant modding ... edit: actually i found a picture! www.a-chau.net/gallery2/v/mambo-articles/canamp/whatthe.jpg.html?g2_imageViewsIndex=1can anyone confirm whether or not their canamps have or haven't got this? cheers Dave Its hard to make out as those blue caps are covering a lot of the track, it seems the ground track has been cut to isolate it from the chassis (where theres that hole with the round pad around it. Is there a better picture of the bottom?
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Post by PinkFloyd on Apr 24, 2007 10:22:35 GMT
Common practice, they obviously had a ground loop and cutting these sections of track cured it........ it's the same on all canamps.
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Post by dc on Apr 26, 2007 14:55:36 GMT
i just dropped a couple of AD843s on a browndog adaptor and installed her in the canamp. had to put a DIP-8 socket in between the browndog and the DIP-8 already soldered on to the board so as to boost the height of the browndog as it was touching the caps at the front of the amp. I don't imagine the effect on sound quality is that detrimental, though I felt it was better than using short runs of wire between the legs and socket
first of all, it works! yay \o/ it could be that the extra capacitance in the modded canamp has the sufficient voltage/current to power these hungry opamps (earlier reports indicated that a stock wouldn't adequately feed them)
secondly, they sound heavenly. going from the AD823 > DY2000 > AD843 has been a very natural and successive progression. as you can probably see, i lean towards the analog devices house sound, with each step being a good improvement over the previous
I feel the jump between the AD823 > DY2000 is probably greater than between the DY2000 > AD843 however there are some things that the AD843s do so well such as crystalline, untarnished highs that don't display a hint of sibilance, and fast, deep and tight bass that going back to the AD823 or any burr brown opamp leaves me in great want
so far my favourite opamp
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Post by dc on Apr 26, 2007 14:56:40 GMT
Common practice, they obviously had a ground loop and cutting these sections of track cured it........ it's the same on all canamps. is there any reason i shouldn't reconnect the ground if it doesn't cause a loop in my system? (it actually fixed what i thought was a ground related problem only producable between my canamp and my DAC-AH)
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Post by yrh0413 on Apr 28, 2007 19:09:09 GMT
I have this list with me, but i'm not sure whether it is suitable or not. (2) Panasonic TSHA Al electrolytic cap,10000uF 35V (2) Elna Silmic II 10uF 25V (2) Elna Silmic II 100uF 25V (4) Rectifier diode,MUR820 8A 200V (4) Rectifier diode,UF4002 1A 100V
I'll solder a dip8 socket that's for sure. However i do not have any knowledge on electronics (i'm an IT undergrad); can anyone answer some of my questions? 1. Does the voltage matters for the 10uF and 100uF caps? I only can get 25V Silmic II though. So may i use these caps? 2. I read through the data sheet and notice the MUR820 has faster response time compare to the UF4002. I wonder why isn't anyone using the MUR820 instead?
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