|
Post by dc on Jul 12, 2007 23:44:16 GMT
dc, I hear you have fitted a new transformer? Any improvements in overall sound quality? Nigel yes I did, I've been so flat out lately that I haven't had a chance to properly tweak the thing, it's still sitting around with its guts hanging out as I get an ever so quiet but noticable hum on my more sensitive headphones I know for a certainty that it is the way it's wired, because depending on how the wires cross each other and their proximity to other components in the amp, the hum increases and decreases. haven't had a chance to creatively mount the thing or take decent shots as it's a mess at the moment but will get on to it soon i hope, i also believe that since it's now much closer to the rear RCA jacks that that is a contributing factor =\ to be honest i can't really hear a huge difference but then again it could be that the hum is throwing me off, it's there but less noticable on my DT531/DT880 but on the K701 it's a real deal breaker. I bought a metal DY2000................. this is the best I've heard yet. It's easy to fit, comes already soldered to the socket. It's a beauty. very interesting, I wonder what the difference between the ceramic and metal variants of the opamps is. and being metal would that make it more prone to RF/EM noise?
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jul 16, 2007 19:14:54 GMT
dc wrote < very interesting, I wonder what the difference between the ceramic and metal variants of the opamps is. and being metal would that make it more prone to RF/EM noise?>
Do you know you may have a point. I'm picking up some kind of noise, maybe from the mains, that wasn't there before. It's not problematic, every two hours or so one second of interference, difficult to explain what it sounds like but it's not a click or a pop.
|
|
|
Post by PinkFloyd on Jul 16, 2007 22:27:23 GMT
Have you tried that AD8620 yet man?
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jul 16, 2007 23:01:39 GMT
No, I haven't yet. I'll have a play tomorrow.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 17, 2007 0:39:15 GMT
Nigel Have you fitted the capacitor across the IEC socket as Mike recommended ? If it lasts for around a second, could it be from nearby fluoro tube or clothes iron or similar ? SandyK
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jul 17, 2007 8:44:36 GMT
No Sandy I haven't fitted the cap. I've plugged in a small plug top charger, as used to charge mobile phones, I seem to remember Mike saying these were good for soaking up any nasties. The transformer/charger isn't connected to anything.
|
|
|
Post by dc on Jul 29, 2007 15:46:12 GMT
well i finally got around to re-wiring my canamp
with better routing for the wires from the transformer to the board
finally that hum is gone
unfortunately it's been quite a while since i've had a proper sit down with the canamp (due to the hum) and since i heard it with the old transformer, my time has also been divided between the recently acquired stax sr-404 and beyerdynamic DT531s =\
anyway, i am again just blown away by how great the AKG K701 + canamp combo sounds, seriously good synergy, what can i say. male vocals with texture and realism that i can't remember electrostatics coming even close to. coherancy at the sacrifice of detail, but an altogether much more musical experience. i'm torn between electrostats and dynamics because of this =\
while under the hood i also decided to pop in the metal DY2000 and compared it to my favourite the 2 x AD843s on browndog. well, for some reason that I'm not sure of, between about 0 volume (about 7 o clock) and probably 10 o clock it has this high frequency whine, past 10 it goes quiet again
not quite sure that might be causing this, but it's probably not good =\ anyway it's getting much closer now, but the AD843s still have the edge, they have a slightly meatier bass that is completely under control and polished highs. the metal DY2000 has sparkly highs but I feel they could do with a bit of "polishing" ie they're everything i want but a bit rough, not grainy but just untempered if you know what i mean. basically the AD843 has all the detail but without the grit, great HF extension imho on the AD843s + canamp
about the transformer, well it certainly hasn't taken anything away from the canamp, like i said i was blown away from this experience and really am hooked and i dare say this is the best i've heard the canamp. i did take photos while under there, not much to see but i'll post some photos anyway later.
|
|
|
Post by PinkFloyd on Jul 29, 2007 17:11:34 GMT
<shouting>We want pics! we want pics! we want pics!</shouting>
<singing> show us the pRon! show us the pRon! show us the pRon! </singing>
|
|
|
Post by dc on Jul 30, 2007 15:50:07 GMT
ask (loud enough) and you shall receive! new tranny cable tied down AD843s browndogged couple more here at: www.a-chau.net/gallery2/v/mambo-articles/canamp/didn't get many under-board shots but there's not much new to see there except that none of the cables pass eachothers paths and are all twisted together, which i think together eliminate that hum also the fuse holder had to go as it simply couldn't fit anywhere also, don't know if you can see properly, but while i was at it i massacred a 3 prong grounded power chord and installed that, was sick of using an adaptor and this cable is much thicker
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jul 31, 2007 0:38:42 GMT
I need to find some browndogged AD843's as soon as.
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jul 31, 2007 11:21:58 GMT
dc,
How does the Heed combo stack up against the Stax?
|
|
|
Post by PinkFloyd on Jul 31, 2007 11:45:45 GMT
I need to find some browndogged AD843's as soon as. Look no further
|
|
|
Post by dc on Jul 31, 2007 12:56:33 GMT
dc, How does the Heed combo stack up against the Stax? Well Nigel they're completely different beasts. Like I noted a bit earlier, the SR-404 + SRM-1/MK-2 combo like most electrostatic rigs is very detailed, possibly artificially so. The words airy fairy come to mind, both in the sense that the sound is very delicate and articulate, but at the same time a little "in the clouds" so to speak, in that the detail is effortless and pristine but I would say at the expense of enjoyment depending on the genre of music. It's like a hyper-detailed microscopic view of each instrument its strings and each artist and their every last move. To me this is just what the doctor ordered for large orchestral pieces and smaller chamber works are bearable. When I'm in that kind of mood, you know "head in the sky" I love hearing the various parts of the orchestra and being able to focus in on any whichever portion I like. However, the Stax are not without fault, the bass by comparison to dynamics lacks impact and tangible force, the sound is so delicate and emerges from thin air that you can barely feel the air as it pushes into your ears even at high volumes, which makes it very easy to listen at too loud volumes without discomfort and you only realise when your ears start ringing afterwards. In this particular setup, although the SR-404 are much improved over the original SR-Lambda Professionals vocals are still thin and unromantic for women and nasal for men. How can I put this? They're like very sharp, in-focus and perfectly composed photographs, however they lack a realism or 3D effect, such as an oil painting or even a sketch might better convey (dynamic headphones), despite not being as detailed or accurate down to the last minute feature. So to me, the only thing I can listen to on the Stax is classical but when I do, and when I'm ready for it does it take you away... The dynamic duo - K701 + canamp - on the other hand, although being one of the more detailed dynamic headphones currently available, pales in comparison, but is much more enjoyable when you don't want all of that detail shoved down your throat. With this the sound is much more coherent, a bit like taking a step back from the photo and seeing it as a whole piece, rather than zoning in on one particular section. The bass, WoW the bass is just kicking, quick and exciting and every bit that makes me not miss the Stax. To me perfect in quantity the K701 deliver bass that is punchy and textured. It goes down, deep down and each bass hit has a musical note rather than being just another monotonous thud that "bassy" headphones tend to exhibit. Just delightful. If it isn't already obvious then I'll state it again but the analog devices house sound is exactly what I need for jamming and rocking out without going for Grado. Snappy and exciting sound that makes the songs zing and sizzle, especially for rock. In the canamp the AD843s delivery all the detail without sacrificing the snap and verve and awaken the treble in the K701 like nothing else, for some it may reach unbearable and hence deemed "sibilant" but I never felt that way. I haven't tried a Grado with this, so I can't say, but that would well be my limits in terms of the exciting sound signature, we will see... I'm on the prowl for MS-2s or MS-Pros, which are said to be everything Grados are but on the right side of neutral. Back to the lady romance this is where I melt a little sometimes, and the likes of Mariah Carey, Andrea Corr and Diana Krall really "sing" to me, almost as if in front of, in my lap, or in my head whatever but short of going tubes (save that for another day) this is the best way for me to listen to vocal musicians, jazz, pop and a little bit of r'n'b never went astray. Again the sound, particularly the bass has texture and a realism to it that I first discovered in the ceramic DY2000 then AD843. So there's my long winded ramble, I've read (not heard) in places that there are examples from both the electrostatic and dynamic camps that have the best of everything, but until I'm a rich man I'll have to make do with different rigs for different music... As always, all in my humble opinion and your mileage may vary =D dc
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jul 31, 2007 19:09:49 GMT
dc,
May I thank you for posting a most comprehensive reply.
I value your opinions & have never had the opportunity to meet with Mr Stax but I plan to find the time.
|
|
|
Post by dc on Aug 1, 2007 1:37:12 GMT
most welcome.
the first time i tried stax it was just like nothing else i'd heard before
now it's part of my mainstay.
if i had to summarise all of the above:
stax is listening to instruments
dynamics is listening to music
|
|
|
Post by aang on Mar 26, 2008 18:53:02 GMT
This is a question from a newbie to modding, who is somewhat anxious about trying to solder parts into his new toy. How big is the improvement I'll gain by replacing the two big caps with Dubilier 10000uF's, the two caps in between those with Rubycon's and perhaps replacing the diodes? Is this a night and day difference, or is it fairly subtle? Which aspects of the sound do these mods improve upon? I just ask to see if the improvements justify the risk of me poking around my beloved headphone amp with a soldering iron :-) Thanks for any thoughts Chris
|
|
|
Post by aang on Mar 26, 2008 18:56:46 GMT
One other quick question; if all I can find in the US are 25 watt 100ohm Koolohm resistors, would these work just as well as the 10 watt? Are these much better than Mills resistors? Thanks Chris
|
|
|
Post by dc on Mar 27, 2008 13:30:31 GMT
Wouldn't consider it a night and day difference, it's obviously still the same amp.
25 watt resistors might not fit where the previous ones sat. But there is nothing wrong with using 25 watt in place of 10 watt, if anything it's probably better. But here space is a premium
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Mar 27, 2008 14:03:03 GMT
As the standard psu arrangement is quite poor any improvements to help lower noise would be worthwhile
Use a suitable op-amp with the best PSRR you can, replace the feedback capacitors to low leakage electrolytics
Don't use too high capacitance for the main smoothing caps as the small pcb traffo will struggle, may also cause it to hum mechanically
|
|
|
Post by aang on Mar 27, 2008 15:10:09 GMT
Hi DC and Leo Thanks for the helpful responses. Even if it's not night and day, would you say the trouble of switching the caps is worth the effort/expense/worries? What would I notice as far as sound improvements? Also, to Leo, are the feedback caps the two caps between the large ones that Pink Floyd says to swap for Dubiliers? If not, which ones are these? Would Rubycons be good low leakage caps to use here? Also, how high is too high on the main smoothing caps (these are the ones to be swapped for Dubiliers; right?) Is there a chance of struggling/humming as a result of going to 10,000uF, or does this only occur if one goes much higher? Thanks so much Chris
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Mar 27, 2008 15:37:04 GMT
10'000uf should be ok but I wouldn't go any higher, for the cost to replace the caps I'd do it tbh, you should hear a cleaner more tidy sound, if the bass sounds slow and muddy they are too high. Those two smaller caps between the large ones are in series with a resistor to ground, bit of extra filtering for the output transistors
The feedback caps are located between the pot and jack socket at the front of the op-amp. If cheapo leaky caps are used here you get garbage fed into the op-amp
|
|
|
Post by aang on Mar 27, 2008 16:01:55 GMT
Thanks Leo Just to be sure I understand, they would be the caps that fit in the spots marked "C1" and "C2" in the photo posted above by DC? If so, where are the caps; on the bottom of the board? Thanks Chris
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Mar 27, 2008 16:11:32 GMT
No, theres a pair of 10uf electrolytic caps right at the front of the amp, the led is situated between them, I'll see if I can find a pic
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Mar 27, 2008 18:02:46 GMT
|
|
|
Post by aang on Mar 28, 2008 3:18:48 GMT
Hi Leo Thanks so much. Are the caps that come stock with the amp in this spot of poor enough quality to justify upgrading? If so, which brand and value should I swap in? Also, did you put 10,000uF Dubilier's in at the recommended spot, or did you use something different? From your picture, it's clear you put in something bigger than the stock caps, but I can't tell what. Thanks for all your help. Chris
|
|