I have been busy upgrading my Xcans v2 since finding this forum the caps are panasonic fc's 1800 uf I've changed the volume pot for a 10k Alps and changed the Led for a blue one the valves have been changed to Mullard ECC88.
Out of interest have you fitted a 5K resistor (or thereabouts) in series with the blue LED? Stock pot is a dual log 50K but 10K should be perfectly fine.
Sounds good, 50VA maybe a bit OTT for the application as you have to take the voltage drop under load into consideration. Nuvotem toroids are specced assuming full load will be applied so at no load a 12V 50VA toroid will measure about 14V to 15V under full load Vsec will measure 12V. Should be perfectly fine though.
Quite common. If you run the amp with your old wallwart (the 500mA stock one) you'll notice the wallwart "itself" runs very warm... you'll find your new PSU runs as cool as a cucumber and the "amp" runs slightly warmer? The amp is getting the juice it should be getting, IMO the stock 500mA wallwart runs out of steam too easily, so it will run a "bit" warmer. Considering the core temp of the transistors is around the 50C region this is perfectly acceptable considering the temperature range of the TIP 110 is -65C to 150C I wouldn't want to run them at anything greater than 80C for audio purposes though.
It's not normal after just upgrading the caps using 1000uF - 1200uF types but it can be very likely once you start upping the capacitance. What to do is to perform a few tests to establish what is getting warm and what's causing it. As I say, if it's just "slightly warmer" than it was before then no worries at all but if it's "hot" then you should investigate.
First off run the unit "naked" (ie: out of the enclosure) Try it with the stock wallwart for starters and pay particular attention to the diodes on the PSU board and the TIP110/TIP115 transistors. If you've got a temperature probe (most multimeters come with them these days) probe the centre of the transistors, should read anywhere between 50C to 60C. The diodes are always bastard hot to the touch (have never measured the temp but they're "hot") run your finger over them to get an idea.
Now substitute your wallwart with the 50VA nuvotem and measure everything again, does the temperature of the transistors change? You could also touch the 10ohm resistors around the TIP110/115's these can be replaced with higher wattage types if they feel "too" hot to the touch.
To be honest, though, some stock V2's run "hot", some run "warm" and some run as cool as a cucumber. You could also try it with the stock valves and see what effect they have on temperature.... you could also drive yourself MAD and never be done probing, and prodding, the thing..... you'd be amazed at just how much heat these puppies can give out and just go on for ever. Heat is NOT a bad thing (usually a sign it's working on all 4 cylinders) but, obviously, if it burns you when you touch it something isn't right
A couple of steel washers in between the back plate will help dissipate the heat. I'm now of the opinion that the enclosure should be left well alone as holes spoil the look of the unit (however well they're cut out) You've fitted 105C caps, no way will the internal temperature EVER get anywhere
near that, so they're good to go. The only internals I'd watch are the pads / tracks the transistors are secured to they have a tendency to slightly lift on some older units, it may be an idea to scrape those tracks (carefully) to the copper and then flood them with solder. You "could" sink the transistors but finding one small enough will be a nightmare, you'll have to cut one down to size yourself (easy) Remember that the enclosure itself is already dissipating quite a lot of heat, if it wasn't it wouldn't feel warm to the touch, but a degree of "venting" through the innards wouldn't go amiss. Your idea of washers between front plate and back plate is actually a VERY GOOD idea and, maybe, a tastefully cut 20MM hole bang in the centre of the base of the unit.
PSU board venting is also very effective. The heat from the transistors wants to escape upwards and the PSU board sits directly above them causing a bit of an obstruction. A few holes drilled through the PSU board helps see picture:
As many as you can drill, obviously ensuring you don't drill through any tracks, helps the cooling process a few percent.
More on cooling here
www.rock-grotto.co.uk/v2cooling.htm and your washer between panel idea will be tried and, if successful, uploaded to that page with credit given to you. Hell, so simple but I never thought of it..... nice one.
All the best.
Mike.
Edit: Just put my thinking cap on. The "washer" mod would be fine assuming you've replaced the pot and have a bit of excess shaft to work with. The headphone socket would be fine, it would just be recessed a bit further into the front plate. The back panel would not be a problem at all as the quad phono sockets are attached to the back plate so any washers inbetween the back plate and enclosure would simply "pull" the board backwards a bit with the result that the headphone socket will recess deeper into the fascia. I think you'd "have" to fit a new pot with longer shaft (otherwise the stock pot shaft would disappear into the enclosure) such as this:
Without trimming the pot you'd have enough shaft left to fit one of these:
Yes, easily "doable" plenty of length on the allen screws to get a good 5mm vent either end of the unit.
