Shielding the cores
Hi, in the photo you can see a simple but effective and save way to shield the air cores of charlize and other amps using air core inductors.
I used 0.15 mm copperfoil. Cut a stip of 2 cm wide and appr. 3 cm long. Bend it around a bar appr. 2 cm in diameter. In every tools box you can find one. Solder a piece of wire on the copper foil. Make it so that the copperfoil circle neetly fits a 19mm insulating and shrinking tube so that there is a little overlap in the copperfoil so that if shrink the tube with a little hot air the copperfoil also shrinks. The tube should be a little bit longer than the copper as not short circuit some connection on the pcb.
Every air core receives its shielding and the wires can be grounded on the board, voila.
Hi, in the photo you can see a simple but effective and save way to shield the air cores of charlize and other amps using air core inductors.
I used 0.15 mm copperfoil. Cut a stip of 2 cm wide and appr. 3 cm long. Bend it around a bar appr. 2 cm in diameter. In every tools box you can find one. Solder a piece of wire on the copper foil. Make it so that the copperfoil circle neetly fits a 19mm insulating and shrinking tube so that there is a little overlap in the copperfoil so that if shrink the tube with a little hot air the copperfoil also shrinks. The tube should be a little bit longer than the copper as not short circuit some connection on the pcb.
Every air core receives its shielding and the wires can be grounded on the board, voila.
Attachments
The new Little Dot T-150 looks interesting 150w of power! even if it is only half that it is impressive.
http://www.musical.ca/catalog/item/4377302/4639260.htm
http://www.musical.ca/catalog/item/4377302/4639260.htm
TA-10 Vs Krell KAV 400i and Arcam Part II
Hi All,
Well, I've learned a load about listening and my system this weekend. First off, to those who say that all amps for the same SPL are the same - I don't believe them. At least for the same "perceptible" SPL. I suppose that if you measured a musical delivery with more bottom end grip, then the SPL would be higher, even though the perceived sound level was the same. Listening was done with my Brother in Law, Dave, who built my superb IPL speaker cabinets linked below.
The system as tested was:
1. As I currently listen - Pedja 1.1b DAC, shunt pot, Oyaide PA-05 interconnects, TA-10, IPL S3TLM Ribbon http://www.diyaudio.com/forums/showthread.php?s=&threadid=82947&highlight=
We packed the women off to Bath for the morning and while I was out walking the Dog etc, Dave had a listen to the system to get his ear in. Music was a selected track from each of Jack Johnson, Eagles Hell Freezes Over, Annie Lennox Medusa, Dido Life For Rent, Dire Straits Brothers in Arms.
We found:
JJ - Intimate presentation. Polite, enjoyable and good rhythm. Not a wide soundstage, but you could almost be sat there right next to Jack himself.
Eagles - Track 4. Nice, but bass light. Bass was present, but did not drive the music. Also missing (compared with usual "Dave" system) was the width of soundstage and space between instruments.
Mid Point Comments - System strengths are realistic presentation of performers, weakeness is no 3d separation of the performers.
Annie Lennox - The system was becoming less satisfying with the more complex productions. With rock tracks, the politeness, gentleness and intimacy prevented the drive that moves the track along. There was more confusion and a lack of separation.
Dido - This very commercial mix fared the worst of all. It's a difficult mix to get inside of and unravel, and it was almost as if the system didn't bother trying to. A note would be played, but nothing more was done with it - no attack, timbre or drive. Sound effects that would in Dave's system "swirl" with a giddiness were not there and merely flattened out into a nice presentation.
Dire Straits - Money for Nothing opening minute. As the song opens up to the crescendo, many systems will smear the instruments into a blur at this point. It happened here, too.
Overall, we wanted to see what the bass would do. There was insufficient bass in the delivery to actually be gripped by the kit. It was not the foundation of the music that Dave was used to in his system and I agree. In terms of the top end, Dave was not sure if all the info was coming off the disc and he questioned whether the source was up to the job - particularly with Lennox and Dido. We coud hear parts of the songs that were present in the mix, but would never be pulled out separately from it.
To cut a long story short, we swapped the Krell into the system. Big difference. But we also took the chance to compare the ICs (the PA-02 were rolled off - as commented on by t. in a PM - we both agreed that it would be better to swap the creamy midrange presentation for the more extened top and and therefore soundstage of my StraightThru ICs). We also compare the 1.1b, the 1543 Nixon DacKit, Stock CD960 and CD80. The 1543 was good, but didn't have the fuller presentation of the 960 as a standalone. The 1.1b was the best, for sure. The CD80 sounded horrid. I'm really disappointed with the CD80 sound and wonder if it was the FMs, the BG Nx, the Clock or what that has upset it. More work needed here I reckon!!
The 1.1b was the only source that REALLY managed to get into the Dire Straits crescendo. At the very end, before the song starts for real, the audio frenzy finishes with an upward roll of tom toms that you can really make out.
We tried the Arcam D290P (not biamped though) and although they had a load of power and a refined pesesntation, they seemed a little too rolled off in this system by comparison.
The Krell - ahhhhh. What I found was very interesting. A sound similar to Dave's system at home. Power, soundstage, grip, clarity etc etc. I loved it. But, for the JJ, the intimacy was GONE - no doubt. That little magic, the sparkle was missing. Replaced by an altogether more direct presentation. Velvet glove and iron fist stuff here. I could listen to it for hours. The next day, I tried some Nu Soul discs and they sounded just as alive with that genre. Some Faure classical was beautifully presented.
I like the Krell very much - but what we both found really amazing was that with the right music, the TA-10 was a gem; an absolute little belter! Intimate, excellent - within certain limits. I would certainly like to cross the two amps to get a powerhouse that has the same delicacy and imtimate presentation the TA-10 has. For me, that'd be the one!! What's the biggest T-Amp out there - 100WPC? Or maye the UcD 400s are the way to go - bang for
buck?
What I learned about my system, that is even more telling, is that the source and speakers were not once embarrased by the day's listening. My CD960 transport pulled sufficient data off the discs for the 1.1b to get working on, and the IPLs, I believe, have even more to give quality-wise, even when paired with what is, to me , a high end amp. Dave's advice was that I get the soldering iron onto those AX boards and get some Class A love going myself. Can't say I disagree, but I'm still looking towards a higher powered T-Amp or the UcDs as a solution.
We had a great time!! The next instalment will be his source in my system - that'll show just what sort of level the 1.1b is comparable to, and how the TA-10 (by then with some Platinum Sonicap bypasses and a mass of others trialled) works with a decent source. I'm currently delighted as I know that just by sorting out the right amplification, I can be most of the way to excellent sound quality.
Dontcha just love it??? §:0)
Jon
Hi All,
Well, I've learned a load about listening and my system this weekend. First off, to those who say that all amps for the same SPL are the same - I don't believe them. At least for the same "perceptible" SPL. I suppose that if you measured a musical delivery with more bottom end grip, then the SPL would be higher, even though the perceived sound level was the same. Listening was done with my Brother in Law, Dave, who built my superb IPL speaker cabinets linked below.
The system as tested was:
1. As I currently listen - Pedja 1.1b DAC, shunt pot, Oyaide PA-05 interconnects, TA-10, IPL S3TLM Ribbon http://www.diyaudio.com/forums/showthread.php?s=&threadid=82947&highlight=
We packed the women off to Bath for the morning and while I was out walking the Dog etc, Dave had a listen to the system to get his ear in. Music was a selected track from each of Jack Johnson, Eagles Hell Freezes Over, Annie Lennox Medusa, Dido Life For Rent, Dire Straits Brothers in Arms.
We found:
JJ - Intimate presentation. Polite, enjoyable and good rhythm. Not a wide soundstage, but you could almost be sat there right next to Jack himself.
Eagles - Track 4. Nice, but bass light. Bass was present, but did not drive the music. Also missing (compared with usual "Dave" system) was the width of soundstage and space between instruments.
Mid Point Comments - System strengths are realistic presentation of performers, weakeness is no 3d separation of the performers.
Annie Lennox - The system was becoming less satisfying with the more complex productions. With rock tracks, the politeness, gentleness and intimacy prevented the drive that moves the track along. There was more confusion and a lack of separation.
Dido - This very commercial mix fared the worst of all. It's a difficult mix to get inside of and unravel, and it was almost as if the system didn't bother trying to. A note would be played, but nothing more was done with it - no attack, timbre or drive. Sound effects that would in Dave's system "swirl" with a giddiness were not there and merely flattened out into a nice presentation.
Dire Straits - Money for Nothing opening minute. As the song opens up to the crescendo, many systems will smear the instruments into a blur at this point. It happened here, too.
Overall, we wanted to see what the bass would do. There was insufficient bass in the delivery to actually be gripped by the kit. It was not the foundation of the music that Dave was used to in his system and I agree. In terms of the top end, Dave was not sure if all the info was coming off the disc and he questioned whether the source was up to the job - particularly with Lennox and Dido. We coud hear parts of the songs that were present in the mix, but would never be pulled out separately from it.
To cut a long story short, we swapped the Krell into the system. Big difference. But we also took the chance to compare the ICs (the PA-02 were rolled off - as commented on by t. in a PM - we both agreed that it would be better to swap the creamy midrange presentation for the more extened top and and therefore soundstage of my StraightThru ICs). We also compare the 1.1b, the 1543 Nixon DacKit, Stock CD960 and CD80. The 1543 was good, but didn't have the fuller presentation of the 960 as a standalone. The 1.1b was the best, for sure. The CD80 sounded horrid. I'm really disappointed with the CD80 sound and wonder if it was the FMs, the BG Nx, the Clock or what that has upset it. More work needed here I reckon!!
The 1.1b was the only source that REALLY managed to get into the Dire Straits crescendo. At the very end, before the song starts for real, the audio frenzy finishes with an upward roll of tom toms that you can really make out.
We tried the Arcam D290P (not biamped though) and although they had a load of power and a refined pesesntation, they seemed a little too rolled off in this system by comparison.
The Krell - ahhhhh. What I found was very interesting. A sound similar to Dave's system at home. Power, soundstage, grip, clarity etc etc. I loved it. But, for the JJ, the intimacy was GONE - no doubt. That little magic, the sparkle was missing. Replaced by an altogether more direct presentation. Velvet glove and iron fist stuff here. I could listen to it for hours. The next day, I tried some Nu Soul discs and they sounded just as alive with that genre. Some Faure classical was beautifully presented.
I like the Krell very much - but what we both found really amazing was that with the right music, the TA-10 was a gem; an absolute little belter! Intimate, excellent - within certain limits. I would certainly like to cross the two amps to get a powerhouse that has the same delicacy and imtimate presentation the TA-10 has. For me, that'd be the one!! What's the biggest T-Amp out there - 100WPC? Or maye the UcD 400s are the way to go - bang for
buck?
What I learned about my system, that is even more telling, is that the source and speakers were not once embarrased by the day's listening. My CD960 transport pulled sufficient data off the discs for the 1.1b to get working on, and the IPLs, I believe, have even more to give quality-wise, even when paired with what is, to me , a high end amp. Dave's advice was that I get the soldering iron onto those AX boards and get some Class A love going myself. Can't say I disagree, but I'm still looking towards a higher powered T-Amp or the UcDs as a solution.
We had a great time!! The next instalment will be his source in my system - that'll show just what sort of level the 1.1b is comparable to, and how the TA-10 (by then with some Platinum Sonicap bypasses and a mass of others trialled) works with a decent source. I'm currently delighted as I know that just by sorting out the right amplification, I can be most of the way to excellent sound quality.
Dontcha just love it??? §:0)
Jon
Hi Jon, have you considered the tripath kits from 41hz? The new 2x300W truepath model should be of interest to you. I actually purchased one of the Audiosource 200W T-Amps posted in an earlier thread, and the power it provides makes a large difference to some speakers. Also, have you read through the ucd vs t-amp thread? http://www.diyaudio.com/forums/showthread.php?s=&threadid=81719
Finally I have found a new smps supply. I bought a Delta Elektronika SX-150-15-15 wich is an industrial power supply. The build quality is very impressive, much better an solid than any high-end audio equipment I have seen in my life. The estimated time before failure of this unit is 500.000 to 1 million hours !!!!, that's 30 to 60 years, 24/7 duty.
But how does it sound. To be honest, only slightly better than the stock supply. I have also tried to add some extra buffer caps between the supply and the amp but that doesn't make any audible difference, I mean completely inaudible. I have tried 2200uF up 100.000uF of caps but in either case I can't hear any difference. Maybe because the power supply is allready stabilized. I measure an output voltage of 12.07 V at zero load and a voltage of 12.05V at 5A load, with only 5mV of rubbish, that's quite impressive
I was hoping for a bit more low/mid "drive" from the amp but this is still the area where it completely fails against my other amps. Higher mids and highs have become quite nice after intensive modding though. Yesterday I have compared it against my other still unmodded TA10 and that one...... well guess you all know allready what I think of them.
Maybe the difference is so small in my case because I'm driving 97dB efficient loudspeakers with them so it doesn't have to deliver any power anyway.
But how does it sound. To be honest, only slightly better than the stock supply. I have also tried to add some extra buffer caps between the supply and the amp but that doesn't make any audible difference, I mean completely inaudible. I have tried 2200uF up 100.000uF of caps but in either case I can't hear any difference. Maybe because the power supply is allready stabilized. I measure an output voltage of 12.07 V at zero load and a voltage of 12.05V at 5A load, with only 5mV of rubbish, that's quite impressive
I was hoping for a bit more low/mid "drive" from the amp but this is still the area where it completely fails against my other amps. Higher mids and highs have become quite nice after intensive modding though. Yesterday I have compared it against my other still unmodded TA10 and that one...... well guess you all know allready what I think of them.
Maybe the difference is so small in my case because I'm driving 97dB efficient loudspeakers with them so it doesn't have to deliver any power anyway.
Well it seems to be that the power supply was brand new so it needed some time to burn in as well. After more than a week of continues playing it now sounds really better than the stock Trends supply, more air, better detail,less sibilance and a lot less listening fatigue (due to the lessenign of the sibilance) something wich you can not hear by A/B comparising but becomes very clear after all day listening.
Also tried some ERS sheets in the supply but it doesn't do any good here, mids become a bit compressed it seems so I removed it. difference is very subtle but noticable.
At this point the amps start to become interesting to me. Funny that with a little tweaks an amp that I have found very hard to listen to for longer than 10 minutes really smoothens out. If I didn't know any better I could live with them for a very long time.
a list of tweaks I have done
1: dampen the housing with SIREX damping sheets
2: Shielding the top and bottom of the case, the output coils and the output filter caps with ERS sheet
3: replaced the input cap with Obbligato pio's in an outside box
and replaced the 0,1uF bias cap with an Auricap
4: removed all of the input circuitry and soldered a shielded wire directly to the gain setting resistor of the chip, so power amp only
5: replaced the input/gain setting resistors with RN55 military grade 27k resistors
6: Made a direct connection from the power input plug to the buffers caps on board. This way the power ground comes in directly at the caps and the signal ground is coming in directly at the input of the chip instead of connected together at the groundplane at the input o the case. Also soldered some small silvermica's directly to the pwer pins of the chip
7: changed the stock power supply to a better regulated smps
tweaks that worked out negative
1: putting ERS sheets everywhere, way too much, takes the lif out of the amp
2: Adding buffer caps between the power supply and the amp, makes hardly any difference to me, have to listen very very hard to hear the slightest difference. i only tried this with the new regulated smps though, not with the stock smps because that wasn't as easy to do.
3: Putting ers and sirex directly on the chip, ouch, really bad idea, even a heatsink made it a little worse. Will experiment wih other heatsinks or even with a solid piece of copper, bronce, aluminium or whatsoever
4: put a 10nF silvermica bypass on the Obbligato's, not a good idea either
As far as I'm concerned I can't come up with other tweaks no more so I declare them finished, this is what it is. It a lively amp wich in my ears sound better in higher mids and high then my UCD700's but they sound way better in the bottom and that's where I use them anyway. That said doesn't mean that the Trends in in absolute sence better then the UCD, it is in MY SYSTEM with MY SPEAKERS, nothing is more important than amp/speaker matching
But still my 300B SET amps sound better after all IN MY SYSTEM, unfortunatly because I was really hoping that some more maintance free and less power consuming design could replace them
Also tried some ERS sheets in the supply but it doesn't do any good here, mids become a bit compressed it seems so I removed it. difference is very subtle but noticable.
At this point the amps start to become interesting to me. Funny that with a little tweaks an amp that I have found very hard to listen to for longer than 10 minutes really smoothens out. If I didn't know any better I could live with them for a very long time.
a list of tweaks I have done
1: dampen the housing with SIREX damping sheets
2: Shielding the top and bottom of the case, the output coils and the output filter caps with ERS sheet
3: replaced the input cap with Obbligato pio's in an outside box
and replaced the 0,1uF bias cap with an Auricap
4: removed all of the input circuitry and soldered a shielded wire directly to the gain setting resistor of the chip, so power amp only
5: replaced the input/gain setting resistors with RN55 military grade 27k resistors
6: Made a direct connection from the power input plug to the buffers caps on board. This way the power ground comes in directly at the caps and the signal ground is coming in directly at the input of the chip instead of connected together at the groundplane at the input o the case. Also soldered some small silvermica's directly to the pwer pins of the chip
7: changed the stock power supply to a better regulated smps
tweaks that worked out negative
1: putting ERS sheets everywhere, way too much, takes the lif out of the amp
2: Adding buffer caps between the power supply and the amp, makes hardly any difference to me, have to listen very very hard to hear the slightest difference. i only tried this with the new regulated smps though, not with the stock smps because that wasn't as easy to do.
3: Putting ers and sirex directly on the chip, ouch, really bad idea, even a heatsink made it a little worse. Will experiment wih other heatsinks or even with a solid piece of copper, bronce, aluminium or whatsoever
4: put a 10nF silvermica bypass on the Obbligato's, not a good idea either
As far as I'm concerned I can't come up with other tweaks no more so I declare them finished, this is what it is. It a lively amp wich in my ears sound better in higher mids and high then my UCD700's but they sound way better in the bottom and that's where I use them anyway. That said doesn't mean that the Trends in in absolute sence better then the UCD, it is in MY SYSTEM with MY SPEAKERS, nothing is more important than amp/speaker matching
But still my 300B SET amps sound better after all IN MY SYSTEM, unfortunatly because I was really hoping that some more maintance free and less power consuming design could replace them
Nice write up..........
Thanks!!
I too am currently running PIO Obbs, but found them very, very smooth. I have added a BG NX-HiQ 0.1uF bypass that I had sitting around on my cap rack and that has helped brighten things up a bit. I do have a selection of other bypass caps to try over the next few weeks, and then I want to try the copper Obbs I have here. Couldn't resist a few minutes with the buffing wheel - brings them up a treat!!
Much more work to do on my amp, but we're getting these slowly.
Cheers
Jon
Thanks!!
I too am currently running PIO Obbs, but found them very, very smooth. I have added a BG NX-HiQ 0.1uF bypass that I had sitting around on my cap rack and that has helped brighten things up a bit. I do have a selection of other bypass caps to try over the next few weeks, and then I want to try the copper Obbs I have here. Couldn't resist a few minutes with the buffing wheel - brings them up a treat!! Much more work to do on my amp, but we're getting these slowly.
Cheers
Jon
Attachments
Yes, please let us know about your bypass cap experience. I was also thinking of trying it but I wouldn't try much more than 10 to 47nF to maintain the overall character of the Obbligato's and to avoid nasty effects wich can make bypassing caps sound worse then without. A 10nF cap have a lot of effect from about 5kHz upwards wich is more then enough to take effect on the highs and spice it up a little. from 5 to 8kHz upwards the human ear is less sensitive to phase anomalies anyway
This reminded me that I still have the skynet 8080 SMPS ... I just ordered the resistor
I'll try it when I'm back from Scotland.
I recently changed the volume pot to a PEC carbon 50K
( Diyhifisupply) , and the amp is SMOOOOOTH. More warmth too now. I grounded the pot and obbligatoos casing ( thanks Sjef) and this reduced the hum to almost inaudible on my 96db speakers.
I'll try it when I'm back from Scotland.
I recently changed the volume pot to a PEC carbon 50K
( Diyhifisupply) , and the amp is SMOOOOOTH. More warmth too now. I grounded the pot and obbligatoos casing ( thanks Sjef) and this reduced the hum to almost inaudible on my 96db speakers.
Ah..... Grounding the Obbs case! I didn't think. I also had a clicking noise occasionally that disappeared when I touched the tank caps. Could be a grounding thing too?
Yes, I'll report on the bypass caps. Might make a list here and then do them with a method - second thoughts, might just gash it as usual!
I like the 8080, but haven't played around with mine for a few weeks as I'm currently builing a boutique Pass D1 IV stage.
How about shunt modding that PEC carbon pot? I think that'll be worth a try - does it fit the original casing nicely??
Cheers
Jon
Yes, I'll report on the bypass caps. Might make a list here and then do them with a method - second thoughts, might just gash it as usual!
I like the 8080, but haven't played around with mine for a few weeks as I'm currently builing a boutique Pass D1 IV stage.
How about shunt modding that PEC carbon pot? I think that'll be worth a try - does it fit the original casing nicely??
Cheers
Jon
No it's bigger than an ALPS blue 
Never done a shunt mod- but it seems very simple. What kind of resistor do I need? 91R?
For I/V stages , you might want to check out DIYPARADISE :
http://diyparadise.com/ssiv.html
E-shop:
http://diyparadise.com/shop/index.php?main_page=index&cPath=3&sort=20a&page=2
and the forum for more info:
http://diyparadise.com/yabb/YaBB.pl?board=DIYParadise
Yeo(diyparadise) even made his monica dac into an USB version (without /jittery/ SPdif conversion) + the SS/IV stage on one board!
Never done a shunt mod- but it seems very simple. What kind of resistor do I need? 91R?
For I/V stages , you might want to check out DIYPARADISE :
http://diyparadise.com/ssiv.html
E-shop:
http://diyparadise.com/shop/index.php?main_page=index&cPath=3&sort=20a&page=2
and the forum for more info:
http://diyparadise.com/yabb/YaBB.pl?board=DIYParadise
Yeo(diyparadise) even made his monica dac into an USB version (without /jittery/ SPdif conversion) + the SS/IV stage on one board!
Bypass Caps
OK Folks,
Here is the list of caps I'll be trying out in slow time over the next few weeks. They will be bypassing the 2uF PIO Obbs that are currently installed. I will also be comparing with the copper Obbs (of the same value) as well at a later stage.
Big thanks to t. who has loaned me the majority of the caps for testing here. Appreciate that, mate!
PIO Obbs (spare set - they are installed already - honest!!)
2 x 100nf Multicap RTX
2 x 100nf Mica caps
2 x 100nf Sonicap Platinums
2 x 470nf Jensen PIO's
2 x 100nf Vishay MKP1837
2 x 100nf Black Gate NX-HiQ
2 x 680nf Auricaps
Caps with leads needing lengthening will be extended with 5N silver wire. Caps will be tacked between the PIO leads where they enter the board, for ease of swapping out.
Test music will be Jack Johnson, Annie Lennox, Dire Straits and Dido (as we used these for the Krell shootout).
This will be a longer term test, as caps will need to be reasonably run in the amp. All other caps will be working out on the rack while they wait in line. Caps will not follow any particular running order either.
More news as it comes...............
Cheers
Jon
OK Folks,
Here is the list of caps I'll be trying out in slow time over the next few weeks. They will be bypassing the 2uF PIO Obbs that are currently installed. I will also be comparing with the copper Obbs (of the same value) as well at a later stage.
Big thanks to t. who has loaned me the majority of the caps for testing here. Appreciate that, mate!
PIO Obbs (spare set - they are installed already - honest!!)
2 x 100nf Multicap RTX
2 x 100nf Mica caps
2 x 100nf Sonicap Platinums
2 x 470nf Jensen PIO's
2 x 100nf Vishay MKP1837
2 x 100nf Black Gate NX-HiQ
2 x 680nf Auricaps
Caps with leads needing lengthening will be extended with 5N silver wire. Caps will be tacked between the PIO leads where they enter the board, for ease of swapping out.
Test music will be Jack Johnson, Annie Lennox, Dire Straits and Dido (as we used these for the Krell shootout).
This will be a longer term test, as caps will need to be reasonably run in the amp. All other caps will be working out on the rack while they wait in line. Caps will not follow any particular running order either.
More news as it comes...............
Cheers
Jon
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