[Jason T]

Guys
If your going to do your own cap upgrade here are a few tips for those of you that aren't sure about chancing it.

Be sure the solder is melted through both sides of the board before pulling the old caps out or you'll pull the traces off the circuit board.

Clear the holes of the old solder (use a solder removal tool)

Insert the cap leads straight through the holes and not at an angle.

Solder from the bottom side of the board if at all possible and if not make sure you put enough solder on the top and get it hot enough so that it travels through the board to the traces on the bottom.

We love the fa t that our amps are diy ready but we don't want an upgrade going wrong any more than you do.


The Mr caps leads are big and barely fit through the holes of the circuit board so being careful is a must!

Enjoy

[dboulet]

Thanks for the tips Jason. I might give this a try, but I’m still not 100% confident in my abilities  .

May I ask what kind of soldering iron you recommend for this type of job? What wattage would be appropriate?

Also, would you have a recommendation as to a good place from which to order the MR caps?

[wsturner]

Also, would you have a recommendation as to a good place from which to order the MR caps?

Caps can be ordered here:

http://www.madisoundspeakerstore.com/mr-cap-630vdc

[Jason T]

Thanks for the tips Jason. I might give this a try, but I’m still not 100% confident in my abilities  .

May I ask what kind of soldering iron you recommend for this type of job? What wattage would be appropriate?

Also, would you have a recommendation as to a good place from which to order the MR caps?

I use this simple cheap station for most things.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=374-100
for the money its a very reliable soldering station. I've had mine for about 2 years and have only had to put a few tips in it.

Otherwise I use a Weller 45watt station.
Typically you don't need 45watts to solder to these boards, I use my cheaper station at about 75% for most of the upgrades I do.

I buy the Mr caps from madisound but last time I called they were all out. You guys need to quit buying my supplier out of these

Another point I should have made is that the leads on these caps are not insulated and will need heatshrink or Teflon around them to keep things free of shorts (I use heatshrink)

[bardamu]

Hello,
I am about to buy a secondhand m901 and i want to use it only above 80hertz . I wanna replace the 100nf with a russian paper in oil and maybe i will try a teflon from russia too. Both can be found in a 200 volt version and i think the smaller the voltage the smaller the cap and the less degradation it will have on the signal passing through it. I think i did read it is possible to use the switch to compare between 2 100 nf caps when you are sure you only want to use it above 80 hertz. The best way to solder is from the bottom side of the circuit. BUT how easily can it be reached? Do i have to desolder a lot of things besides the caps to do so?
Many thanks in advance, Edward

[tenantman]

Hello,
I am about to buy a secondhand m901 and i want to use it only above 80hertz . I wanna replace the 100nf with a russian paper in oil and maybe i will try a teflon from russia too. Both can be found in a 200 volt version and i think the smaller the voltage the smaller the cap and the less degradation it will have on the signal passing through it. I think i did read it is possible to use the switch to compare between 2 100 nf caps when you are sure you only want to use it above 80 hertz. The best way to solder is from the bottom side of the circuit. BUT how easily can it be reached? Do i have to desolder a lot of things besides the caps to do so?
Many thanks in advance, Edward

If you have the time and patience removing the board is the best way to solder those MR caps in securely and safely. As to the degree of difficulty, its challenging if you have no experience taking a board out. There is very little room so work slowly through removing all the connections.  You must use the soldering tool carefully. Jason is right about the Clarity leads, you may have to "trim" them a little to fit through the board hole. Nice shiny solder completes the job.



Lots of connections involved but the reward is over the top.

[bardamu]

Hello Tenantman and all the others,
I have some time after all that why it is called a hobby. There are some candidates for the cap replacement. Like i said i will probably get paper in oil and teflon both 200 volts from Russia, i have silver mica as big as a small matchbox, i can buy the dueland alexander or the Mr clarity caps. Because it is just for a 2.1 audio video set up i like the sound to be spatial and natural.
If i am planning to change caps in the future i might try to make a big hole in the bottom or just make a new bottom with a hole that can be opened and closed to reach for the soldering '' positions '' of the caps. Maybe fit 2 pairs of 100nf and compare the caps by the switch. Maybe the sonic character of the amp can also be adjusted by making some changes in my outboard choke input power supply. I didn't hear about anyone trying to use this approach for the virtue amps/
Sicere greetings and many thanks for any additional information, Edward

[tenantman]

Any diy task can be hit or miss. In this case, the Sensation responds very well to cap and internal hook up wire upgrades. I have not considered trying an outboard choke input power supply or a power supply from someone like Paul Hynes.  Bardamu let us know how it turns out, may be worth the effort.

[bardamu]

Hello Tenantman,
I will receive the m901 without power supply . The previous owner did use it with batteries.
In the past i did have an hiraga 30 watt class a transistor amp that i did use with a choke instead of a .22 ohm resistor in the power supply. Because i have some potted 0.1 henry 1.3 ohm and 1.3 amp chokes in stock. I did decide to try the m901 with a choke input power supply. So just did have to buy an EI 300va transformer. It will be rectifier , choke ,cap 10.000mf or less, another 0.1henry choke followed by another cap. This outboard supply weighs about 10 kilogrammes one more reason you don't many transistor amps with chokes.
The caps changing can be hit or miss too. I have quiet a lot of candidates so i wanna make a change to the m901 housing that will allow me to change caps easily.
First i will have to wait for the m901 to arrive. Maybe the standard cap will sound already good.
Choke input usually gives an amp an easy sound, effortless. BUT i never heard a virtue amp before.
Sincere greetings, Edward

[Jason T]

Hello Tenantman,
I will receive the m901 without power supply . The previous owner did use it with batteries.
In the past i did have an hiraga 30 watt class a transistor amp that i did use with a choke instead of a .22 ohm resistor in the power supply. Because i have some potted 0.1 henry 1.3 ohm and 1.3 amp chokes in stock. I did decide to try the m901 with a choke input power supply. So just did have to buy an EI 300va transformer. It will be rectifier , choke ,cap 10.000mf or less, another 0.1henry choke followed by another cap. This outboard supply weighs about 10 kilogrammes one more reason you don't many transistor amps with chokes.
The caps changing can be hit or miss too. I have quiet a lot of candidates so i wanna make a change to the m901 housing that will allow me to change caps easily.
First i will have to wait for the m901 to arrive. Maybe the standard cap will sound already good.
Choke input usually gives an amp an easy sound, effortless. BUT i never heard a virtue amp before.
Sincere greetings, Edward

if you solder and un solder to many times you risk damaging the circuit board, the traces for the low voltage are quite fragile so be careful.
if your going to switch caps multiple times you best bet is to solder in some short test leads into the board and then solder the test caps to those leads.

[bardamu]

Hello Jason, tenantman and all the others,
I know printed circuits can be damaged especially by heat and non supported heavy caps floating above the circuit board. The 100nf aren't as big as the clarity mr 3.3mf caps.
In the french laudiophile magazine i remember reading about caps in a tube circuit sounding better because of the higher tensions involved. Could this be a reason why these BIG caps need such a long time before they start sounding good. Theoreticaly what dc tension would be enough for the 100nf?
The French were talking about the plastic in the cap getting kind of charged and giving the charge back influencing the musical signal. Teflon is difficult to charge and that might be a reason it sounds good. I think the man writing about is was called Pierre Johannet. Do some googling and don't ask me to explain. I can translate but explain no way.
Just did find some siemens 100 nf in a copper housing in my stock. They look like paper in oil to me. Maybe i can crash one to find out. I know there will be pcb inside but i am a non smoker so i am willing to take some risk.
Sincere greetings, Edward

[bardamu]

Hello,
Because i did talk about my future power supply in this topic i did paste and copy a few lines from another site where people are also talking about chokes in a power supply.
Should i not use the two 100 millihenry chokes in my power supply for the m901?  I am about to order 2 27.000uf panasonic t-ha to use in my outboard power supply.
Directly on the topic of this thread: small inductors in the PS can be used to get rid of switching pulses or RF, but beware of using large inductors in a power supply that has to deliver fluctuating current. The more efficient an amplifier, the more current demands fluctuate.

Therefore, in a power supply for a class A, inductors may be used, for class AB it is not recommendable, for class D it could be suicide. The reason is that coils store energy in the form of a magnetic field, the strength of which is determined by the current running through it. This not only means that a ps with a heavy coil will sag if current is demanded (energy is required to build up the magnetic field), but if the current demand suddenly diminishes, there will be a voltage spike. The energy stored in the magnetic field is suddenly released, causing this. Since class D usually is operated close to its maximum supply voltage, this spike could easily fry your device.
I would love to have an answer from the " virtue design board '' to be sure what to do.
Thanks in advance and kind greetings, Edward

[bardamu]

Hello,
Did connect my choke input power supply to my sensation m901 after changing the 2.2 auricap with a 100nf polystyrene covered with superblack. So now i can switch between the original 100 nf and my polysterene. Still waiting for my Russian paper in oils. I think the Russian teflon will be to big. We will see once they arrive.
The m901 have been '' out of service'' for some time so i think they need some time to settle down. I can hear some serious potential but sometimes there are sounds that remind me of four way speakers with a bad cross over when i need it to sound like a electrostatic loudspeakers. Some sounds are really good but for some other sounds i have to wait a little longer.
I did use the xlo burn in cd for some hours. Maybe tomorrow i make a switch to the polysterene or wait untill the unit is no longer improving and then make the change.
Sincere greetings, Edward

[virtue]

Edward,

Thanks for your incredible play-by-play.

You are amazing!

Seth

[bardamu]

Hello,
That rectangular hole isn't exactly rectangular because it is home-made with not the proper tools. Much easier to make with no other things attached to it. If i will make a new bottom/back side it with a real big hole in it to be able to reach all the solder joints on the circuits it will be done with a cnc punching machine at work so tolerances will be less than 0.1 mm.
Some cap replacement will require some kind of surgery on the circuit board. The holes are difficult to make a bit bigger because the tracks are not very wide.
I didn't take a good look at the hardware that was used for connecting the speaker and interconnect cable to the circuit. I think both cannot '' accept '' the multiple strand cables virtue is making. For the ls cable it is possible to find some kind of solution.
For the input connections it will be hard to find a solution if one wants to use virtue cable all the way. Even it will not be the best solution there will always be less connections ( be it solder or crimping ) than the original. The cinch connections on the chassis look very decent but finding a way to get rid of them might be an improvement ( is this called blasphemy?)
The amp is fully connected and in a rack and i will not be able to make the bottom change before the annual closing of the company so i better start comparing caps first. Some of the candidates are lower voltage and because of that smaller so i think this will reduce break in time.
Sincere greetings, Edward

[bardamu]

Hello,
Today i did make the change from the original 100nf virtue cap to my surplus bought 100nf  63 volts polysterene cap.
If i remember correctly plosterene caps cannot never be metalized but always be film and foil. This one has 2 output leads on each side.Is very tightly wound. The French did do test with caps that could work as ''loudspeakers'' because they did have a lousy construction!
This cap was made in France 30 years ago. It is a professional one not the typical audiophile types. I have them too.
I did match the pair and did apply superblack to them. Let us see if anyone can find out what that is.
How does it sound after just 10 hours burn in with xlo burn in tones. It sounds easy, melodic, like a record instead of a mp3, lots of detail without the high-endish sound. If you cannot type a message with the music playing there is something wrong for me. If it sounds impressive at first usually it will be wrong in the end. Like all these tv's in the shop with these cartoon like colours.
Still waiting for my russian paper in oils. Long live ebay i guess i have to order again at someone's shop.
Sincere greetings, Edward
P.s Moral a 20 dollarcents surplus 63 volts cap can be very good. It could have come from a production run of 50000 pieces. If these audiophile caps are they made at these numbers the seller needs load of money or we customers are paying way to much.

[bardamu]

Hello,
Did decide to make a new back/bottomplate. A few reasons in the near future i wanna hardwire the loudspeaker cable directly to the circuit by means of a bit bigger '' printterminal '' The post used now is okay but no post is surely better!
I wanted to hardwire the inputs as well  but there are not many cables that will fit into the existing terminal and there is not much space for another terminal. I did break one of the tiny cables at the point where it enters the little white plug. I need a smaller soldertip to try to remove that little white terminal.
As you can see all the connections are mounted on a little circle that is connected at the inside of the chassis. I already have circles with a bigger hole that will allow me to fit a strain relief. If the cable is way thicker i can use the hole in the backside itself.
I did remove the cover of the big cap because i did feel a little dent underneath. I did buy it secondhand so i don't know if it has been there all the time. Same for the black disc.( ceramic cap? mov? ) Maybe i will decide to exchange the cap for a bigger one?
Everything is 2.5 mm aluminium. I could have made it stainless steel in the same time but if i will need to make a few extra holes once the board is mounted it will be hard.
Still waiting for my russian paper in oils
Next sensation will be 100$ more expensive and have more sturdy terminals.
What about replacing the cables to the pot. In my set up 50% of the interconnect cable will be inside the amp.
Sincere greetings, Edward

[bardamu]

Hello,
Just curious what other people are using as a cap in an 80 hertz above set up. I remember reading about Dueland alexander but that amp was offered me a few weeks ago just after i did find mine.
Still using my French polystyrene superblack covered.
Wanna try the russian caps from ebay too. My first ebay order did not arrive here if it ever will.
Maybe order a few at another supplier.
Sincere greetings, Edward

[bardamu]

Hello,
Just wondering how to delete messages.
Happy Bose days, Edward

[virtue]

Edward,
If you can't delete a message and want to... send me a PM so I can take care of it for you.
Perhaps I should contract with you to prototype my next generation of enclosures!  Amazing!
Seth