Spirit
Been here a while! 
That's where I'm gonna go when I die
Posts: 1,107
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Post by Spirit on Mar 22, 2009 3:32:50 GMT
Doesn't say anything about caps there  Having said that, I don't know how they'd get close to the asking price for the upgrades unless they used ridiculously expensive blackgates throughout... ;D |
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XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
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Post by XTRProf on Mar 22, 2009 6:21:32 GMT
Oh, yes, what are the present USB codec chips used? Thanks.  some of the latest ones are capable of 24/192k I'm sure that will interest Alex for sure. Hmm....................., 24/192 USB codec chip. ;D  Ha, ha ..............., that's what I'm interested as well.  |
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pagan
<100
How do I activate my account?
Posts: 81
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Post by pagan on Mar 22, 2009 8:29:14 GMT
From Musical Fidelity web site www.musicalfidelity.com/tune/sonic.html"* _Re-clocking_ Re-clocking is a very sensitive area. There?s no doubt that fitting any of our DACs or CD players with our precision clock configuration results in a cleaner, smoother sound. It is /really/ important to note that doing /anything/ to the clock is extremely likely to affect the jitter performance. Our super clock upgrade has no effect on the jitter figure, this took a lot of work on our Miller and Rhode and Schwartz jitter measurement gear. Buyer beware! Many people offer clock ?upgrades? to our CD players and DACs. They have no means of measuring them to find out their effect on the jitter. On the few examples we?ve seen of so-called ?upgrades? the jitter performance has been dramatically worsened. Beware of technicians offering upgrades. Actually they?re offering downgrades. www.musicalfidelity.com/tune/dac.html"* Fit new precision clock pcb" Looks like you shouldn't mod anything especially "the clock". They can't measure it, but they will fit there own. at a cost. |
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Mar 22, 2009 8:44:08 GMT
From Musical Fidelity web site www.musicalfidelity.com/tune/sonic.html"* _Re-clocking_ Re-clocking is a very sensitive area. There?s no doubt that fitting any of our DACs or CD players with our precision clock configuration results in a cleaner, smoother sound. It is /really/ important to note that doing /anything/ to the clock is extremely likely to affect the jitter performance. Our super clock upgrade has no effect on the jitter figure, this took a lot of work on our Miller and Rhode and Schwartz jitter measurement gear. Buyer beware! Many people offer clock ?upgrades? to our CD players and DACs. They have no means of measuring them to find out their effect on the jitter. On the few examples we?ve seen of so-called ?upgrades? the jitter performance has been dramatically worsened. Beware of technicians offering upgrades. Actually they?re offering downgrades. www.musicalfidelity.com/tune/dac.html"* Fit new precision clock pcb" Looks like you shouldn't mod anything especially "the clock". They can't measure it, but they will fit there own. at a cost. Allan There may be an element of truth in their statement. Many of the MF products such as the X-DAC V3 already have excellent clocks fitted. I still believe that if you have already fitted, a good quality oscillator MODULE, as distinct from a simple 2 lead crystal, that excellent results may be obtained by ensuring that it has a clean, well regulated DC supply. Perhaps that is what they are doing ? There have been many online reports about clock modules doing the opposite to what many people expect of them.- "Caveat emptor" (buyer beware.) Alex P.S. Replies 34 and 43 show a photo which reveals that an excellent quality 24.576MHZ oscillator module is already fitted. These have excellent stability. |
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leo
Been here a while!
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Post by leo on Mar 22, 2009 16:25:27 GMT
Nobody tried the Beresford TC-7520 yet? its pretty cheap and supposed to be good
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leo
Been here a while!
Team wtf is it?
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Post by leo on Mar 22, 2009 16:42:30 GMT
From Musical Fidelity web site www.musicalfidelity.com/tune/sonic.html"* _Re-clocking_ Re-clocking is a very sensitive area. There?s no doubt that fitting any of our DACs or CD players with our precision clock configuration results in a cleaner, smoother sound. It is /really/ important to note that doing /anything/ to the clock is extremely likely to affect the jitter performance. Our super clock upgrade has no effect on the jitter figure, this took a lot of work on our Miller and Rhode and Schwartz jitter measurement gear. Buyer beware! Many people offer clock ?upgrades? to our CD players and DACs. They have no means of measuring them to find out their effect on the jitter. On the few examples we?ve seen of so-called ?upgrades? the jitter performance has been dramatically worsened. Beware of technicians offering upgrades. Actually they?re offering downgrades. www.musicalfidelity.com/tune/dac.html"* Fit new precision clock pcb" Looks like you shouldn't mod anything especially "the clock". They can't measure it, but they will fit there own. at a cost. Allan There may be an element of truth in their statement. Many of the MF products such as the X-DAC V3 already have excellent clocks fitted. I still believe that if you have already fitted, a good quality oscillator MODULE, as distinct from a simple 2 lead crystal, that excellent results may be obtained by ensuring that it has a clean, well regulated DC supply. Perhaps that is what they are doing ? There have been many online reports about clock modules doing the opposite to what many people expect of them.- "Caveat emptor" (buyer beware.) Alex P.S. Replies 34 and 43 show a photo which reveals that an excellent quality 24.576MHZ oscillator module is already fitted. These have excellent stability. £499 !! I can think of far better things to spend that amount on ;D |
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Deleted
Deleted Member
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Post by Deleted on Mar 22, 2009 20:14:16 GMT
Leo
I agree. All I am suggesting is that if there is already a good clock module aboard as in the photo, don't replace it. Just feed it a cleaner regulated supply.
Alex
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leo
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Post by leo on Mar 22, 2009 20:18:13 GMT
Leo I agree. All I am suggesting is that if there is already a good clock module aboard as in the photo, don't replace it. Just feed it a cleaner regulated supply. Alex Alex, I wonder if they sort out the X-dac V3 regulation, well actually lack of it  You should send them a link to your V3 modding thread showing them how its done |
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leo
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Post by leo on Mar 22, 2009 20:25:46 GMT
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Deleted
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Post by Deleted on Mar 22, 2009 20:32:04 GMT
Leo I agree. All I am suggesting is that if there is already a good clock module aboard as in the photo, don't replace it. Just feed it a cleaner regulated supply. Alex Alex, I wonder if they sort out the X-dac V3 regulation, well actually lack of it You should send them a link to your V3 modding thread showing them how its done Leo They already have 2 x 5V regulators and a 3.3V regulator. I only added regulators to the analogue supply. Using an outboard dual regulated +-16V via a JLH,instead of the existing AC plugpack supply, ensures clean supplies to the whole of the unit, including clock circuitry. Alex |
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Post by traf on Apr 4, 2009 20:57:25 GMT
Having bought a CA Dacmagic a few weeks ago, I couldn't quite get used to it, so..... ....having been very happy (after a bit of modding...  ) with various incarnations of the stock MF DAC stage (X-DACV3, A5 DAB and my current KW250S) I thought I'd give the V-DAC a try. The circuit topology looks very similar to the stock MF implementation, except that power suppies are a bit different and it uses all the stages of 1xQuad + 1xDual opamp, rather than only half of 6xDual opamps. Initial impressions on first firing it up were mixed - it certainly sounded better balanced than the CA, but was a bit sterile with the treble being a tad rough and the bass a bit loose. A couple of hours later though it sounded like quite a different beast with tighter bass and better focussed treble. Compared to the CA, there is a lot more ambience around individual instruments, with much better focus - the initial 'note' comes from a smaller space, much better placed, but with a lot more air around it. Overall a 3-D rather than 2-D presentation. In particular the venue acoustics are much more realistic, making some previously 'iffy' recordings (Neil Young - Decade stuff) very realistic, if not the best produced! Both treble and bass were better extended. The most noticeable thing though was much better shaped rise and decay - the CA sounded somewhat blurred with a noticeable lack of attack. Not sure if I'm using the right lingo here but hopefully you're getting the impression. Now being an impulsive engineer who can't leave anything alone I took it to bits and warmed up the soldering iron. So far I've only replaced the opamps. Having rolled a number through my KW250S the aim was to end up with 3xLME49720HA (metal can). Two of these have been hacked to replicate a quad opamp format, with a third in the dual opamp buffer position. I've previously used the stock LM4562 in the I/V and filter positions but they made the overall sound a bit lightweight - the metal canned version is quite a different beast however, with better bass extension and weight. This in turn tames the treble a tad without any loss of detail. At the mo its feeding my SCHA into ATH-W1000 and I have to say I'm pretty impressed with the result - a lot more detail than the CA, but with better extension at both frequency extremes and very realistic timbre to simple acoustic instruments, which I find to be the easiest test of any system. I've noticed that both the V-DAC and V-CANS use a quad opamp - as described above its fairly straightforward to replace this with 2x metal can dual opamps - I'll post a pic of my 'spaghetti version' opamp tomorrow if it helps. Just need to try a better power supply (inc JLH) next.... cheers simon |
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robertkd
Been here a while!
Electronics Engineer from sunny Queensland
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Post by robertkd on Apr 4, 2009 21:36:47 GMT
Having bought a CA Dacmagic a few weeks ago, I couldn't quite get used to it, so..... ....having been very happy (after a bit of modding... ) with various incarnations of the stock MF DAC stage (X-DACV3, A5 DAB and my current KW250S) I thought I'd give the V-DAC a try. The circuit topology looks very similar to the stock MF implementation, except that power suppies are a bit different and it uses all the stages of 1xQuad + 1xDual opamp, rather than only half of 6xDual opamps. Initial impressions on first firing it up were mixed - it certainly sounded better balanced than the CA, but was a bit sterile with the treble being a tad rough and the bass a bit loose. A couple of hours later though it sounded like quite a different beast with tighter bass and better focussed treble. Compared to the CA, there is a lot more ambience around individual instruments, with much better focus - the initial 'note' comes from a smaller space, much better placed, but with a lot more air around it. Overall a 3-D rather than 2-D presentation. In particular the venue acoustics are much more realistic, making some previously 'iffy' recordings (Neil Young - Decade stuff) very realistic, if not the best produced! Both treble and bass were better extended. The most noticeable thing though was much better shaped rise and decay - the CA sounded somewhat blurred with a noticeable lack of attack. Not sure if I'm using the right lingo here but hopefully you're getting the impression. Now being an impulsive engineer who can't leave anything alone I took it to bits and warmed up the soldering iron. So far I've only replaced the opamps. Having rolled a number through my KW250S the aim was to end up with 3xLME49720HA (metal can). Two of these have been hacked to replicate a quad opamp format, with a third in the dual opamp buffer position. I've previously used the stock LM4562 in the I/V and filter positions but they made the overall sound a bit lightweight - the metal canned version is quite a different beast however, with better bass extension and weight. This in turn tames the treble a tad without any loss of detail. At the mo its feeding my SCHA into ATH-W1000 and I have to say I'm pretty impressed with the result - a lot more detail than the CA, but with better extension at both frequency extremes and very realistic timbre to simple acoustic instruments, which I find to be the easiest test of any system. I've noticed that both the V-DAC and V-CANS use a quad opamp - as described above its fairly straightforward to replace this with 2x metal can dual opamps - I'll post a pic of my 'spaghetti version' opamp tomorrow if it helps. Just need to try a better power supply (inc JLH) next.... cheers simon yep still trying to disperse these, funny thing is I loose money doing this for fellow group members Simon you on the other hand are trying to derive a commerical profit, you steel my ideas you front here with the intent to make a commercial profit Robert |
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Post by traf on Apr 4, 2009 21:48:44 GMT
Having bought a CA Dacmagic a few weeks ago, I couldn't quite get used to it, so..... ....having been very happy (after a bit of modding... ) with various incarnations of the stock MF DAC stage (X-DACV3, A5 DAB and my current KW250S) I thought I'd give the V-DAC a try. The circuit topology looks very similar to the stock MF implementation, except that power suppies are a bit different and it uses all the stages of 1xQuad + 1xDual opamp, rather than only half of 6xDual opamps. Initial impressions on first firing it up were mixed - it certainly sounded better balanced than the CA, but was a bit sterile with the treble being a tad rough and the bass a bit loose. A couple of hours later though it sounded like quite a different beast with tighter bass and better focussed treble. Compared to the CA, there is a lot more ambience around individual instruments, with much better focus - the initial 'note' comes from a smaller space, much better placed, but with a lot more air around it. Overall a 3-D rather than 2-D presentation. In particular the venue acoustics are much more realistic, making some previously 'iffy' recordings (Neil Young - Decade stuff) very realistic, if not the best produced! Both treble and bass were better extended. The most noticeable thing though was much better shaped rise and decay - the CA sounded somewhat blurred with a noticeable lack of attack. Not sure if I'm using the right lingo here but hopefully you're getting the impression. Now being an impulsive engineer who can't leave anything alone I took it to bits and warmed up the soldering iron. So far I've only replaced the opamps. Having rolled a number through my KW250S the aim was to end up with 3xLME49720HA (metal can). Two of these have been hacked to replicate a quad opamp format, with a third in the dual opamp buffer position. I've previously used the stock LM4562 in the I/V and filter positions but they made the overall sound a bit lightweight - the metal canned version is quite a different beast however, with better bass extension and weight. This in turn tames the treble a tad without any loss of detail. At the mo its feeding my SCHA into ATH-W1000 and I have to say I'm pretty impressed with the result - a lot more detail than the CA, but with better extension at both frequency extremes and very realistic timbre to simple acoustic instruments, which I find to be the easiest test of any system. I've noticed that both the V-DAC and V-CANS use a quad opamp - as described above its fairly straightforward to replace this with 2x metal can dual opamps - I'll post a pic of my 'spaghetti version' opamp tomorrow if it helps. Just need to try a better power supply (inc JLH) next.... cheers simon yep still trying to disperse these, funny thing is I loose money doing this for fellow group members Simon you on the other hand are trying to derive a commerical profit, you steel my ideas you front here with the intent to make a commercial profit Robert Robert My post was simply a record of my experience of modding a V-Dac, that's all. Simon |
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robertkd
Been here a while!
Electronics Engineer from sunny Queensland
Posts: 111
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Post by robertkd on Apr 4, 2009 22:14:39 GMT
yep still trying to disperse these, funny thing is I loose money doing this for fellow group members Simon you on the other hand are trying to derive a commerical profit, you steel my ideas you front here with the intent to make a commercial profit Robert Robert My post was simply a record of my experience of modding a V-Dac, that's all. Simon Simon, the only thing missing is this cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=110361929525&_trksid=p3907.m32&_trkparms=tab%3DWatchingI would have thought that would complete your your modding 101 for the V-Dac Robert |
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robertkd
Been here a while!
Electronics Engineer from sunny Queensland
Posts: 111
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Post by robertkd on Apr 6, 2009 13:07:06 GMT
Having bought a CA Dacmagic a few weeks ago, I couldn't quite get used to it, so..... ....having been very happy (after a bit of modding... ) with various incarnations of the stock MF DAC stage (X-DACV3, A5 DAB and my current KW250S) I thought I'd give the V-DAC a try. The circuit topology looks very similar to the stock MF implementation, except that power suppies are a bit different and it uses all the stages of 1xQuad + 1xDual opamp, rather than only half of 6xDual opamps. Initial impressions on first firing it up were mixed - it certainly sounded better balanced than the CA, but was a bit sterile with the treble being a tad rough and the bass a bit loose. A couple of hours later though it sounded like quite a different beast with tighter bass and better focussed treble. Compared to the CA, there is a lot more ambience around individual instruments, with much better focus - the initial 'note' comes from a smaller space, much better placed, but with a lot more air around it. Overall a 3-D rather than 2-D presentation. In particular the venue acoustics are much more realistic, making some previously 'iffy' recordings (Neil Young - Decade stuff) very realistic, if not the best produced! Both treble and bass were better extended. The most noticeable thing though was much better shaped rise and decay - the CA sounded somewhat blurred with a noticeable lack of attack. Not sure if I'm using the right lingo here but hopefully you're getting the impression. Now being an impulsive engineer who can't leave anything alone I took it to bits and warmed up the soldering iron. So far I've only replaced the opamps. Having rolled a number through my KW250S the aim was to end up with 3xLME49720HA (metal can). Two of these have been hacked to replicate a quad opamp format, with a third in the dual opamp buffer position. I've previously used the stock LM4562 in the I/V and filter positions but they made the overall sound a bit lightweight - the metal canned version is quite a different beast however, with better bass extension and weight. This in turn tames the treble a tad without any loss of detail. At the mo its feeding my SCHA into ATH-W1000 and I have to say I'm pretty impressed with the result - a lot more detail than the CA, but with better extension at both frequency extremes and very realistic timbre to simple acoustic instruments, which I find to be the easiest test of any system. I've noticed that both the V-DAC and V-CANS use a quad opamp - as described above its fairly straightforward to replace this with 2x metal can dual opamps - I'll post a pic of my 'spaghetti version' opamp tomorrow if it helps. Just need to try a better power supply (inc JLH) next.... cheers simon Simon I do wonder if perhaps some vero board might be advantageous here if only to provide some mechanical stability. The can isn't actually tied directly to -Ve and would be better not allowing the 2 op-amps to touch. you could carefully feed the leads through the perf board tracks to the top and solder to locate, don't forget to cut the tracks in between, leaving enough lead length to fit into the socket, some careful plumbing for the supply leads, better yet a fabricated adapter PCB. Robert |
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Post by traf on Apr 6, 2009 13:41:25 GMT
Thanks Robert I'll post a pic of the arrangement when I get home - pictures speak 1000 words and all that. The metal cans don't touch (well they weren't touching when I put the cover back on....) The 2 negative leads are soldered together with one trimmed leaving the other to create the Pin 4. The 2 positive leads (which are on the 'outside' of the arrangement) are carefully routed underneath each can and joined to create Pin 11, making sure that there is not contact with any other lead. I did consider mounting them on perf board but didn't to keep the legs as short as possible. This did mean that Pin 11 required a little assistance to push it home into the socket I'll probably solder them into the IC socket when I'm happy that I'm not going to change it. cheers simon |
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robertkd
Been here a while!
Electronics Engineer from sunny Queensland
Posts: 111
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Post by robertkd on Apr 6, 2009 13:49:13 GMT
Thanks Robert I'll post a pic of the arrangement when I get home - pictures speak 1000 words and all that. The metal cans don't touch (well they weren't touching when I put the cover back on....) The 2 negative leads are soldered together with one trimmed leaving the other to create the Pin 4. The 2 positive leads (which are on the 'outside' of the arrangement) are carefully routed underneath each can and joined to create Pin 11, making sure that there is not contact with any other lead. I did consider mounting them on perf board but didn't to keep the legs as short as possible. This did mean that Pin 11 required a little assistance to push it home into the socket I'll probably solder them into the IC socket when I'm happy that I'm not going to change it. cheers simon agreed probably best to to try and keep the leads as short a possible but practical, sure sounds like your pretty happy with what these little beggars bring to the table, I know I am Robert |
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Post by traf on Apr 6, 2009 18:58:24 GMT
As promised, a pic of my version of fitting 2x dual TO99 package opamps into a 14pin quad opamp DIL socket:  cheers simon |
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leo
Been here a while!
Team wtf is it?
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Post by leo on Apr 6, 2009 19:05:01 GMT
Looks like some mutated dead bug  Seriously though, nice work! |
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oldson
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Older than a well used glove
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Post by oldson on Apr 6, 2009 19:13:14 GMT
Having bought a CA Dacmagic a few weeks ago, I couldn't quite get used to it, so..... ....having been very happy (after a bit of modding... ) with various incarnations of the stock MF DAC stage (X-DACV3, A5 DAB and my current KW250S) I thought I'd give the V-DAC a try. The circuit topology looks very similar to the stock MF implementation, except that power suppies are a bit different and it uses all the stages of 1xQuad + 1xDual opamp, rather than only half of 6xDual opamps. Initial impressions on first firing it up were mixed - it certainly sounded better balanced than the CA, but was a bit sterile with the treble being a tad rough and the bass a bit loose. A couple of hours later though it sounded like quite a different beast with tighter bass and better focussed treble. Compared to the CA, there is a lot more ambience around individual instruments, with much better focus - the initial 'note' comes from a smaller space, much better placed, but with a lot more air around it. Overall a 3-D rather than 2-D presentation. In particular the venue acoustics are much more realistic, making some previously 'iffy' recordings (Neil Young - Decade stuff) very realistic, if not the best produced! Both treble and bass were better extended. The most noticeable thing though was much better shaped rise and decay - the CA sounded somewhat blurred with a noticeable lack of attack. Not sure if I'm using the right lingo here but hopefully you're getting the impression. Now being an impulsive engineer who can't leave anything alone I took it to bits and warmed up the soldering iron. So far I've only replaced the opamps. Having rolled a number through my KW250S the aim was to end up with 3xLME49720HA (metal can). Two of these have been hacked to replicate a quad opamp format, with a third in the dual opamp buffer position. I've previously used the stock LM4562 in the I/V and filter positions but they made the overall sound a bit lightweight - the metal canned version is quite a different beast however, with better bass extension and weight. This in turn tames the treble a tad without any loss of detail. At the mo its feeding my SCHA into ATH-W1000 and I have to say I'm pretty impressed with the result - a lot more detail than the CA, but with better extension at both frequency extremes and very realistic timbre to simple acoustic instruments, which I find to be the easiest test of any system. I've noticed that both the V-DAC and V-CANS use a quad opamp - as described above its fairly straightforward to replace this with 2x metal can dual opamps - I'll post a pic of my 'spaghetti version' opamp tomorrow if it helps. Just need to try a better power supply (inc JLH) next.... cheers simon you sound like a man who would have an opinion on something i read on another forum!? a guy stated that the quality of components used in the v-dac was significantly sub-standard, when compared to those used in the CA dacmagic! your point of view would be appreciated. thanks |
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Post by traf on Apr 6, 2009 19:28:47 GMT
Having bought a CA Dacmagic a few weeks ago, I couldn't quite get used to it, so..... ....having been very happy (after a bit of modding... ) with various incarnations of the stock MF DAC stage (X-DACV3, A5 DAB and my current KW250S) I thought I'd give the V-DAC a try. The circuit topology looks very similar to the stock MF implementation, except that power suppies are a bit different and it uses all the stages of 1xQuad + 1xDual opamp, rather than only half of 6xDual opamps. Initial impressions on first firing it up were mixed - it certainly sounded better balanced than the CA, but was a bit sterile with the treble being a tad rough and the bass a bit loose. A couple of hours later though it sounded like quite a different beast with tighter bass and better focussed treble. Compared to the CA, there is a lot more ambience around individual instruments, with much better focus - the initial 'note' comes from a smaller space, much better placed, but with a lot more air around it. Overall a 3-D rather than 2-D presentation. In particular the venue acoustics are much more realistic, making some previously 'iffy' recordings (Neil Young - Decade stuff) very realistic, if not the best produced! Both treble and bass were better extended. The most noticeable thing though was much better shaped rise and decay - the CA sounded somewhat blurred with a noticeable lack of attack. Not sure if I'm using the right lingo here but hopefully you're getting the impression. Now being an impulsive engineer who can't leave anything alone I took it to bits and warmed up the soldering iron. So far I've only replaced the opamps. Having rolled a number through my KW250S the aim was to end up with 3xLME49720HA (metal can). Two of these have been hacked to replicate a quad opamp format, with a third in the dual opamp buffer position. I've previously used the stock LM4562 in the I/V and filter positions but they made the overall sound a bit lightweight - the metal canned version is quite a different beast however, with better bass extension and weight. This in turn tames the treble a tad without any loss of detail. At the mo its feeding my SCHA into ATH-W1000 and I have to say I'm pretty impressed with the result - a lot more detail than the CA, but with better extension at both frequency extremes and very realistic timbre to simple acoustic instruments, which I find to be the easiest test of any system. I've noticed that both the V-DAC and V-CANS use a quad opamp - as described above its fairly straightforward to replace this with 2x metal can dual opamps - I'll post a pic of my 'spaghetti version' opamp tomorrow if it helps. Just need to try a better power supply (inc JLH) next.... cheers simon you sound like a man who would have an opinion on something i read on another forum!? a guy stated that the quality of components used in the v-dac was significantly sub-standard, when compared to those used in the CA dacmagic! your point of view would be appreciated. thanks I might agree with most that the quality of SOME of the components in MF gear might be considered 'sub-optimal', but there's no denying that for the most part the basic design is very good. For the more pricey kit, it would not have cost a lot extra to use some decent components. That said, fiddling with opamps and using Schottky/UF diodes in the rectifier stages is straightforward and gets you most of the way there in terms of sound improvement. I like the sound of the MF DAC stage and am pretty sure that the V-DAC can be modded to get pretty close to my KW250S(mod) reference. That's all I want. There is also no denying that the CA has a nicer box, but it doesn't fit out of sight under my sofa s |
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robertkd
Been here a while!
Electronics Engineer from sunny Queensland
Posts: 111
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Post by robertkd on Apr 7, 2009 12:39:41 GMT
As promised, a pic of my version of fitting 2x dual TO99 package opamps into a 14pin quad opamp DIL socket: cheers simon indeed well executed, I wonder though for the sake of repeatability if the units were fitted to some vero board in such a way to provide an easy way for V-DAC owners to fit into sockets. My thinking would be to have the copper track to the top and have the leads formed as you have and fit to a socket and solder in place to form the leads. Should make it easy for even an inexperienced person to fit into a turned 14 DIP socket or solder directly to PCB? Could see where a retro fit kit could be put together So what mods have you done to the SC HA? Robert |
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Post by traf on Apr 7, 2009 13:13:40 GMT
Hi Robert I think this is probably a one-off for me.... Well, maybe 2-off as I bought 2 V-DACs, one as a reference, one to mod, so I might end up modding both.. TBH anyone with the skills to remove the existing 14pin opamp and solder in a socket should be able to do this, or even better, solder it directly to the pcb, which avoids stressing the 'new' legs. One other thing - I've just checked the output dc offsets, which are now nice and low at 0.3mV and 1.1mV (compared to 11mV and 10mV in unmodded form), so the output caps have now been shorted, making a further small but noticeable improvement (a bit more 'air') As far as the SCHA is concerned - I've implemented most of the recommended tweaks, including a JLH board, improved transistors and 49720 opamp - see post #960 of 'THE' thread cheers simon |
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robertkd
Been here a while!
Electronics Engineer from sunny Queensland
Posts: 111
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Post by robertkd on Apr 7, 2009 13:46:53 GMT
Hi Robert I think this is probably a one-off for me.... Well, maybe 2-off as I bought 2 V-DACs, one as a reference, one to mod, so I might end up modding both.. TBH anyone with the skills to remove the existing 14pin opamp and solder in a socket should be able to do this, or even better, solder it directly to the pcb, which avoids stressing the 'new' legs. well maybe but not so sure just because someone can remove an DIP IC just a thought. are yes that was 6 months ago, mm I see all the usual mods however again a very nice build Simon. Yes I and others have noticed this effect I guess better trimming of the devices in production no doubt. Robert |
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Post by skunkworks on Apr 8, 2009 19:17:29 GMT
Hi all,
I've pulled my V-dac apart again to make a list of the caps.
This was what I found:
jamicon
2x -47uF 16v NP
13x -10uF 63v
3x -1uF 63v
10x -100uF 25v
1x -1000uF 16v
Now a question for the cap masters at Rock Grotto: What cap's should I replace the jamicons with to get the biggest bang for the buck?
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www.musicalfidelity.com/tune/index.html
) with various incarnations of the stock MF DAC stage (X-DACV3, A5 DAB and my current KW250S) I thought I'd give the V-DAC a try.
