XVSSA playing
XVSSA plays wonderful in 2 balanced channels being fed by JC80. Dead silent, much less sensitive to how the GND is configured, a very classy piece of art. Details are exceptionally well revealed, even some unknown to me until now. And one channel is quite fresh, only 1 day since powered on. Additionally, the auditioning tests are made using only digital sources (CD and ODAC fed from PC) and quite mediocre Denon loudspeakers I am using usually for tests.
The heatsinks are just a bit warm when touched by the hand, even after playing some loud notes. Power supply is as I've said, one bridge - one 18,000uF ELNA capacitor and one 50Vac winding for each channel. Works like a charm
Sadly, I have to stop it to just arrange the wiring inside and close the case. And of course, I need to make some measurements, but I should finish the SE-XLR converters first. Will do and report later.
Can't wait to do the test with the final setup as well (Bose901 at the end and Paradise phono at the beginning) , but for now I will calm down and finalize the setup and lab tests. Believe me please, that is the most difficult part, much worse than wanting to smoke a cigarette in a 8 hours flight!
Cheers and BIG THANKS LC!!!
XVSSA plays wonderful in 2 balanced channels being fed by JC80. Dead silent, much less sensitive to how the GND is configured, a very classy piece of art. Details are exceptionally well revealed, even some unknown to me until now. And one channel is quite fresh, only 1 day since powered on. Additionally, the auditioning tests are made using only digital sources (CD and ODAC fed from PC) and quite mediocre Denon loudspeakers I am using usually for tests.
The heatsinks are just a bit warm when touched by the hand, even after playing some loud notes. Power supply is as I've said, one bridge - one 18,000uF ELNA capacitor and one 50Vac winding for each channel. Works like a charm
Sadly, I have to stop it to just arrange the wiring inside and close the case. And of course, I need to make some measurements, but I should finish the SE-XLR converters first. Will do and report later.
Can't wait to do the test with the final setup as well (Bose901 at the end and Paradise phono at the beginning) , but for now I will calm down and finalize the setup and lab tests. Believe me please, that is the most difficult part, much worse than wanting to smoke a cigarette in a 8 hours flight!
Cheers and BIG THANKS LC!!!
Hy, BYRTT,
https secure only the datas between you and the server.
In France, when you make a payment, you are redirected to the https of the server of the bank account of the seller. So the seller has no visibility on your credit card
At Mouser, you are redirected... on their server.
I have no confidence to give my credit card number to any Mouser's employee or network admin i don't know, and no reason to trust the security of their databases.
Even Adobe had all their databases hacked recently, with all their customers accounts and passwords....
Hi, AP2,
The problem remain the same, i don't want to take the risk somebody hijack my credit card... even a Paypal one. See what i mean.
The only solution should be to have my bank providing E-cards (one shot number), but my bank don't do that, and, as far as i know, Paypal neither.
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Thank you all.
Having had 4 card changes this year + refunds from MasterCard & Visa totaling over £5,000, I naturally do not want to risk another bad experience.
I suspect that the site has a secure card system in place.....if not it would be well mentioned here and elsewhere. I'll research this and come back.
Having had 4 card changes this year + refunds from MasterCard & Visa totaling over £5,000, I naturally do not want to risk another bad experience.
I suspect that the site has a secure card system in place.....if not it would be well mentioned here and elsewhere. I'll research this and come back.
I used Nichicon KA 2200uF/50V rated at 105 C and Nichicon KT 6800uF/6,3V bought from the eBay shop of Home Page Vintage Hi-Fi . The nice thing is they fit very well on GB VSSA boards.
Congratulate again, agree about when neer the end of a setup it's hard to be calm as demanded for not burning circuits. I personally smoke and in end of setup the pipe runs all time nearly. Thanks for report.....Can't wait to do the test with the final setup as well (Bose901 at the end and Paradise phono at the beginning) , but for now I will calm down and finalize the setup and lab tests. Believe me please, that is the most difficult part, much worse than wanting to smoke a cigarette in a 8 hours flight!
Cheers and BIG THANKS LC!!!
and good listening.I understand your concern, my bank says good and support for the payment method at Mouser thats why i dare to do it. One is just responsible to keep and eye on misuse and report to bank, then they take over and cancel the misuse.
Don't think such big company can survive if not having a serius paying method that threats costumer fair.
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Big company ? They don't even have a bank account in my country. Just a little office with two people to answer the calls.
They pretend to make international business on line and don't accept Paypal ?
The only way to make a secure payment with them is international bank transfer. Not really friendly, isn't it ?
In the USA there are some regulations like PCI compliance and many others to protect credit card information. I buy all the time over the internet and have been doing so for the last 12 years. Never did I ever get my card hijacked. Mouser and Digikey are very safe.
Maybe I was just lucky, who knows? However, I do understand your concern.
Ciao!
Do
Maybe I was just lucky, who knows? However, I do understand your concern.
Ciao!
Do
Thats not pretty costumer friendly
.But again try the links to the Swedish site, or wait what brianco report he say he will research and come back.
Last i can send you 8 times 1mF/50V Panasonics FR same size as FG's, and 4 times Panasonic FR 6,8mF/6,3V 12,5x35 5mm spacing. I know those not recommended but not bad i think. You can have them for free as you have given me golden knowledge for free, just PM if interested.
Hi Christophe if you most comfortable with the Nichison's, i just checked March's "Idefixes" web-site if it was as i thought i could remember. Yes he has link to Mouser in France, so think they are good enough when he do this linking stuff (link Marchs web: index - audiyofield).
Thanks brianco for research, you can then buy at the swedish links from earlyer post.
Thanks brianco for research, you can then buy at the swedish links from earlyer post.
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I cannot accept as my ' knowledge ' is not worth this price ;-). But i am so touched by your nice proposal.
I have a lot of parts to buy, so i think i will make a bank transfer. Again, BYRTT, thanks so much.
Christophe your decision about the caps. I understand if you want to try the recommended FG ones. I PM you tomorrow just to tell what worth you made my audio, but was up 03:00AM this day so these words are last gasoline for today.
XVSSA plays wonderful in 2 balanced channels being fed by JC80. Dead silent, much less sensitive to how the GND is configured, a very classy piece of art. Details are exceptionally well revealed, even some unknown to me until now. And one channel is quite fresh, only 1 day since powered on. Additionally, the auditioning tests are made using only digital sources (CD and ODAC fed from PC) and quite mediocre Denon loudspeakers I am using usually for tests.
The heatsinks are just a bit warm when touched by the hand, even after playing some loud notes. Power supply is as I've said, one bridge - one 18,000uF ELNA capacitor and one 50Vac winding for each channel. Works like a charm
Cheers and BIG THANKS LC!!!
Well done!
Me too; I am finishing the enclosure for the true VSSA, which took more than one week compared to hours to finish LC's boards...ready build enclosures get too expensive shipped to South America...
Dear LC and experts, I have one more question if you can help me with my BJT-VSSA: can I increase the input to ground resistor from 10k to 50K???
Thanks and congratulatons again to Metallicus69 for pioneering work.
M.
I don't recommend this for several reasons.
This will make the DC offset less stable. This will encourage-you to use higher impedance source, witch is not optimal for sound quality: More sensible to ground loop noises, little more distortion, more change of quality depending the position if the source is a potentiometer etc...
Thank you for your input, mon cher.
The case is that I was planning to feed the future XVSSA with a TVC (Transformer Volume Control) which is ideal to pair unbalanced/balanced units, but whose limit would be 10K as input impedance of the next stage. The TVC would be less sensitive to the other drawbacks you mention.
Merci bien,
M.
In this case, i think better use the exact recommended load for this TVC (often 10K). If the transformer has a secondary middle point (when balanced) or a ground connection (when unbalenced) and direct coupled, the DC resistance will be la lot lower than the 10K. So, no problem with this polarization resistance value.
Maxlorenz, thanks and good luck with yours.
About input impedance, I am with Esperado here: you may double it maybe, but 5 times is a bit too much. But you may experiment a bit, provided you have high hFE input transistors: set a 50k trimmer in series with 10k at the input and check how offset behaves.
My best bet is that LC has found a sweet spot with 10k and VSSA should be really attacked by lowish impedance sources. I hope he can comment more about input impedance, as far as I know there were also others interested.
I believe keeping the impedance low on transmission path helps keeping the system quiet. Don't want to say that is not possible to get a clean sound the other way around, just a bit more difficult...
DRV134 is a relative cheap and clean way to convert unbalance to balance, but I am not sure if you agree adding integrated circuits in signal path. Even cheaper is a transistor with equal resistors in C and E like here
Best would be a balanced preamp, and that was my main motivation in testing XVSSA; I already had the wonderful JC-80.
About input impedance, I am with Esperado here: you may double it maybe, but 5 times is a bit too much. But you may experiment a bit, provided you have high hFE input transistors: set a 50k trimmer in series with 10k at the input and check how offset behaves.
My best bet is that LC has found a sweet spot with 10k and VSSA should be really attacked by lowish impedance sources. I hope he can comment more about input impedance, as far as I know there were also others interested.
I believe keeping the impedance low on transmission path helps keeping the system quiet. Don't want to say that is not possible to get a clean sound the other way around, just a bit more difficult...
DRV134 is a relative cheap and clean way to convert unbalance to balance, but I am not sure if you agree adding integrated circuits in signal path. Even cheaper is a transistor with equal resistors in C and E like here
Best would be a balanced preamp, and that was my main motivation in testing XVSSA; I already had the wonderful JC-80.
Thank you guys.
Maybe better than DRV134 are the newer THAT chips:
THAT Corporation 1606/1646 OutSmarts Balanced Line Driver ICs
I also have input TXs from Jensen, but they reduce voltaje so I need high voltaje preamp.
Just more fun...
Cheers,
M.
Maybe better than DRV134 are the newer THAT chips:
THAT Corporation 1606/1646 OutSmarts Balanced Line Driver ICs
I also have input TXs from Jensen, but they reduce voltaje so I need high voltaje preamp.
Just more fun...
Cheers,
M.
XVSSA details
After finishing the mounting, I add here some pictures with details, to spare a lot more words.
The SMD-Through hole mixed P2P Cap multiplier, heatsink preparation details, the inside of the box and the outside after closing it.
And of course the tandem JC80-XVSSA in the testing room.
Still busy with the RCA-XLR adapter to start some independent tests of XVSSA.
Just a bit until serious music tests
After finishing the mounting, I add here some pictures with details, to spare a lot more words.
The SMD-Through hole mixed P2P Cap multiplier, heatsink preparation details, the inside of the box and the outside after closing it.
And of course the tandem JC80-XVSSA in the testing room.
Still busy with the RCA-XLR adapter to start some independent tests of XVSSA.
Just a bit until serious music tests
