Yesterday me and a friend listened to a small system: NAIM SuperUniti as a source, THIEL CS2.4SE loudspeakers and VSSA amp. System was so musical that friend of mine almost didn't allow me to left the building. Speakers are 4 Ohm nominal impedance, deeps down to 3 Ohm and have low efficiency of 87 dB/W/m. VSSA was warm, almost hot, but manage to deal with the speakers, it probably gave 150 Watts or something, with ease and comfort in musical presentation. 
Andrej if i use a +/- 35v power supply what power should i expect on 8 ohms ?
I agree with Idefixed in the Nichicon FG issue. Only Mouser is selling them and is crazy to pay tens of euros on shipping for few caps.
The FG nichicons 16V is easier to get but is 16mm diameter.
What other caps did you tried and liked apart those hard to get FG's ?
I agree with Idefixed in the Nichicon FG issue. Only Mouser is selling them and is crazy to pay tens of euros on shipping for few caps.
The FG nichicons 16V is easier to get but is 16mm diameter.
What other caps did you tried and liked apart those hard to get FG's ?
+/-35 V DC rails from stable PSU will give 62 Vpp on 8 Ohm and that's exactly 60 Wrms/8 Ohm.
Yes, Mouser has the policy to send free of charge if ordered more than 50 EUR, they sell much more that way.
I tried Panasonic FM and FC in the feedback and it was not so good as with Nichicon FG. It would certainly be nice if some GB member could confirm that or some other comparison combination. Every possible info will consequently lead us all to better parts choice and eventually better sound.
I like to measure and listen.
A paralleled cap combination should IMO be measured for resonances, specifically on the final destination (PCB). Measure paralleled caps is revealing and will tell a lot about what the amplifier will 'see'.
About VSSA building. I will probably finalize my build and listen within 2-3 weeks. So I will hardly be the first one with a working VSSA.
A paralleled cap combination should IMO be measured for resonances, specifically on the final destination (PCB). Measure paralleled caps is revealing and will tell a lot about what the amplifier will 'see'.
About VSSA building. I will probably finalize my build and listen within 2-3 weeks. So I will hardly be the first one with a working VSSA.
I am waiting till after 8th july, mouser then will send the FG's and I like to start with those.
About SMPS. All Hypex SMPS seem same, unregulated. (aux output regulated sometimes) On another dutch forum some speculated that they sounded better than regulated SMPS, and I don't think Hypex is unable to make regulated onces...
Back in march on this forum it was assumed regulated SMPS would be even better than the Hypex SMPS400-180 and would be tried soon. I missed those post about other SMPS that were tried, maybe in Peeceebee tread? Or just too many posts here that I could not find them? Two modified Hypex SMPS 400 will cost me around 250 euro, the coldamps are close in price I believe?
About SMPS. All Hypex SMPS seem same, unregulated. (aux output regulated sometimes) On another dutch forum some speculated that they sounded better than regulated SMPS, and I don't think Hypex is unable to make regulated onces...
Back in march on this forum it was assumed regulated SMPS would be even better than the Hypex SMPS400-180 and would be tried soon. I missed those post about other SMPS that were tried, maybe in Peeceebee tread? Or just too many posts here that I could not find them? Two modified Hypex SMPS 400 will cost me around 250 euro, the coldamps are close in price I believe?
As for capacitor, I'd like to follow LC recommendation for sound quality wise and go with the FG for both 1000uf/50V and 2200uf/6.3V, however the type 1000uf/50V could only be ordered from digikey and 2200uf/6.3V could only be ordered from Mouser or RS Component, that's make its shipping cost financially trouble for me, especially for buying just a few capacitors.
If some of you intend to order those capacitor from digikey/ mouser, we can do a mini group buy for those capacitor and sharing the cost.
If some of you intend to order those capacitor from digikey/ mouser, we can do a mini group buy for those capacitor and sharing the cost.
Now how will you solder ALF-s if all ELCO-s are in place already? I think in assembly instructions transistors preceed capacitors.
Otherwise nice built.
Hi Andrej,
I will solder the ALF-s once the chassis is ready, I don't want to solder it now I'm afraid it might get damaged by ESD
. soldering is not a problem I can manage.Btw I'm using a "NEW" nichicon (KA series)caps in the feedback, I ordered it from FARNELL.
http://www.nichicon.co.jp/english/product_news/new116.html
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Look to my SSA thread's final schematic (signature link bellow) and see what you need to do to use bipolar outputs. You cannot just replace laterals with bipolars, it would simply not "drink the water".
What speakers will be connected to? Did you have some troubles calibrating the VSSA according to instructions? Was it a quick procedure? VAS bias current and DC offset OK? Why not Nichicon FG for feedback too?
Regards Lazy Cat
I have used a singleton Magnat All-ribbon 6, this 3-way speaker is quite revealing. My main speaker is a pair of Quadral Shogun Mk.3 (the one with the ribbon tweeter).
I had to do a bit of fiddling with Vas current calibration, but setting the MOSFET bias was easy and it was at the minimum bias when I started. I may take a few notes when I calibrate the second channel.
One point that I want to add is:
After step 3 on page 2, Clean the solder flux off the top pcb layer BEFORE soldering the capacitors.
I have tried a few different feedback capacitors, My preference is in the following order:
Nichicon HE
Rubicon ZL
Panasonic FM
I also have ordered the Nichicon FG 2200uf/16V(16mm dia) which I can make it to fit on the official VSSA board. I found them take a long time to burn in on my home-made board so I cannot make a fair comparison.
Interestingly, all the most respected Japanese electrochemical capacitor companies openly refer to subjective audio qualities even in the very datasheets of ranges designated "for audio". They haven't introduced some metric or FOM (figure of merit) to give a comparison clue though. Its either sound is really a "spirit" or they are secretive about formulas and their criteria. They must have some sort of measurable priorities or techniques (I hope) besides some lab director calling a few audiophile friends in the weekend and deciding on some capacitor substitutions.
To test an audio amplifier for accuracy is not that hard.
You can use Diffmaker from Bill Waslo.
There is also the Haffler and the more sophisticated Baxandall nulling test.
Many years ago i measured the Hiraga Le Class A with the Haffier test and got a totally disappointing null with lots of distortion in the residuum.
It sounded very good though. It seems to be that a lot of subjectively nice sounding amps use distortion to " enhance " the sound.
If that is true, everything is possible and all is good.
You can simply say : my amp sounds better then your amp.
That is exactly what i see happen.
You can use Diffmaker from Bill Waslo.
There is also the Haffler and the more sophisticated Baxandall nulling test.
Many years ago i measured the Hiraga Le Class A with the Haffier test and got a totally disappointing null with lots of distortion in the residuum.
It sounded very good though. It seems to be that a lot of subjectively nice sounding amps use distortion to " enhance " the sound.
If that is true, everything is possible and all is good.
You can simply say : my amp sounds better then your amp.
That is exactly what i see happen.
Alright an amp is a sum of things and belongs to a system and an operator that has his likings. But a component such as an electrolytic capacitor type officially marketed for audio from giant industries even, deserves some agreed metric standard like THD on some test scheme so a datasheet has something to explain for merit and compare between models and brands.
Here they say that 3rd harmonic distortion is lower then -120dB at 10kHz with 100mA :
http://www.elna.co.jp/en/capacitor/alumi/catalog/pdf/rfs_e.pdf
http://www.elna.co.jp/en/capacitor/alumi/catalog/pdf/rfs_e.pdf
Yes but there is no agreed standard, the others don't quote exactly that for instance. It may even be some preferred harmonic or a certain distribution. Or even some organized subjective ABX panel. Anyway if all they got is some construction techniques they trust or some non standard metric reference among subjective lines, diyers can put their own ears in use in their own amps for caps all the same.