MF X-Can V2 Good For Which HPs And Modes

[XTRProf]

Oh, no. That's not me here. I just wanted to know from what HP impedance to what. I saw some threads mention from 30 to 300 ohms no problem with good loudness for the usual suspects. But 600 ohms HP is a no, no.

Please confirm. Btw, this using what as output, tubes? Input, yeah, OPA. Thanks.

[Deleted]

The hd600 is good. I find it not as good with low impedance headphones, Chong. It also drives Beyers nicely.

So I guess around 200 ohms is about right.

I use the K601 with it and it's not bad. Maybe it could do with a higher impedance output but loud volume could be difficult with a higher output impedance. If I drive the headphone loud, the vol pot is between 1 and 2 o clock. So it's starting to run out of juice with AKG's. Mind you, it's not just the X Can but the Neco MOSFET is the very same.

[XTRProf]

Hi Ian,

I know somehow this amp will not be powerful enough to sing well. But I just wanted to try one to see what you guys are talking about the V2 being so good in sound in other threads. It seems that only higher impedance HPs can apply and that makes matter worse for loudness at the same time.

[Deleted]

It's a balancing act, Chong. It's an amp with character which is why I like it. With K701 - very loud at 1 - 2 o'clock but not the best match imo. It starts to get 'shouty'.

HD600 - really nice.

It's remained one of my favourites ever since I got it from, Mike.

[pcourtney1]

I have always used my AKG K-340 phones (400 ohms) with my X-Can v2, and whilst people say the K-340 is a notoriously difficult can to drive, the v2 has no problem :-)

I also have a pair of AKG K-240 Monitors (600 ohm) , they sound great with the v2 as well, but the K-340 is the one I turn to for easy listening most evenings, no fatigue just lots of foot tapping, immersed in the music and just relax for a few hours before I turn in.

[Deleted]

Perhaps it's more to do with sensitivity? The K701 and K601 do take a bit of pushing. I'm surprised that it pushes a 600 ohm headphone. That's really good.

It doesn't mind the Senns and works at what I'd call 'normal' volume control levels. About 11 to 12 o clock. The AKG's just take a bit more and once you get near 2 o' clock, there's not a lot left after that.

[XTRProf]

Based on this, anyway to mode it for better or worse? Frans or Alex?


www.rock-grotto.co.uk/x-canv2.pdf

[Deleted]

Everything can be modified.
The schematics aren't correct b.t.w.

The question is what do you want it to do ?
As it is now it should easily put out 13V (and thus drive 120 to 600 Ohm loads with ease to high levels)
1.2W into 32 Ohm
800mW into 120 Ohm
500 mW into 300 Ohm
280mW into 600 Ohm

There are not many amps around that reach that output voltage.

If you want it to be modified for the better you would have to ditch the tubes ;D

[pcourtney1]

yes, the v2 is a very versatile amp, nearly half a watt driving my K-340's, the AKG brochure for them states that the peak input power is 9 V (200 mW) and the maximum power (for less than 1% distortion) is 2 V (10 mW).

[XTRProf]

Mar 31, 2012 16:16:37 GMT @solderdude said:

Everything can be modified.
The schematics aren't correct b.t.w.

Eh, not me. I'm not guilty. It's Pinkie site. Hey, Pinkie, take that out ........... !@#^(*&^%^#@*(^

Ok, ok, I'm hot so cool down to a ................

Mar 31, 2012 16:16:37 GMT @solderdude said:

The question is what do you want it to do ?

For even better sound quality. You jolly know I'm Hifi greedy ..........

Mar 31, 2012 16:16:37 GMT @solderdude said:

As it is now it should easily put out 13V (and thus drive 120 to 600 Ohm loads with ease to high levels)
1.2W into 32 Ohm
800mW into 120 Ohm
500 mW into 300 Ohm
280mW into 600 Ohm

There is not many amps around that reach that output voltage.

Wow, I didn't know that although the specs did say 1W but at what HP ohms? That pipe up my interest somewhat on seeing and it's quite a high power full discrete hyrbid, man. Thanks Frans. That seems enough and I'm not so greedy now. No wonder Miguel and Ian are olalaing over it and one of their top favourite toys. So Ian, there should not be any clipping distortion coming wrt to low power if you are seeing this. It seemd initially that you were having some kind of insufficent volume thru our discussion.

Btw, it's transistor output, right? Just to confirm since the above schema is wrong. Anyway to change to better specs transistors to up the ante in specs and not necessary the sound. I'm greedy again.

Mar 31, 2012 16:16:37 GMT @solderdude said:

If you want it to be modified for the better you would have to ditch the tubes

Oh, that will reduce the SOUND quality for sure. So for worse to the more Zen audiofool like me but up TECHNICAL quality. Why can't this two just be happily married ever after most of the time instead of a divorce? Damn it!

[XTRProf]

Finally .............. Found one in very good condition eventhough after so many years.










Nothing is left unturned like a police photo taking session. Time to sleep and clean her up after jogging at the reservoir.

Thanks all for getting me the 2 months itch again especially Frans' datas jump started me. Arrgghhh ............., I shouldn't be here! I'm a speakerfi audiofool, damn it!

This is no April Fool but real Audiofool day. So anyone also joined me on Audiofool Day? Anything bought?

[PinkFloyd]

There is not many amps around that reach that output voltage

Yep... you could almost drive a pair of speakers with the V2

1.3 WATTS into 32 ohms! Look at the Solo (for example) 27mW into 32 ohms... the V2 with 1,300mW.... it's not a punative amp by any means.

Get the amp / headphone balance correct, fit a pair of healthy valves and up the capacitance in the PSU section and it is STILL up there when it comes to making good sound

A lot of people are running tired V2's.... one guy recently bought a pair of 6N23P-EB from me and was AMAZED at the sound quality.... erm, no wonder, he'd been running the same pair of 6922's for over ten years... sure, they were still "working" but not working to their optimum specification.... much like getting used to a noisy exhaust pipe, it's only when you fit a new one you realise the old one was totally knackered

[PinkFloyd]

Apr 1, 2012 7:28:34 GMT XTRProf said:

Finally .............. Found one in very good condition eventhough after so many years.










Nothing is left unturned like a police photo taking session. Time to sleep and clean her up after jogging at the reservoir.

Thanks all for getting me the 2 months itch again especially Frans' datas jump started me. Arrgghhh ............., I shouldn't be here! I'm a speakerfi audiofool, damn it!

This is no April Fool but real Audiofool day. So anyone also joined me on Audiofool Day? Anything bought?

Nice one Chong! Be sure to treat that puppy to a pair of brand new valves / tubes... open her up and check the capacitors for bulging... also check the bottom board around the transistors... if the amp has been left on 24/7 for years there will be signs of browning on the PCB under the transistors... this is more indicative of cheap PCB than it is anything else.... if there is scorching then check the pads on the underside of the board as these become very brittle and can lift.

Hopefully you've got one with a nice "white" PCB Other things to look for... check the RCA quad socket, sometimes the ground pins snap off... also check the valve sockets, grab one with your hand, turn the board over, start rocking it and make sure the solder joints are not moving... it is ALWAYS a good idea to reflow the joints on the valve bases... people who have rolled a lot of valves over the years find that these joins actually seperate (well, I tell them to look there!) and they have intermittent "crackling" problems... it's simply the joints which have become compromised.

Another thing you can do is get a pin and gently lever the connectors inwards on the valve sockets... this will tighten the grip on the valve pins If you are going to use the stock valves for a while then remove them and get some 600 grade wet / dry paper.... remove the surface oxidisation from the pins, this helps.... I can tell you this for a fact, I have measured plenty of valves on my tube imp analyser, a simple cleaning of the pins can change the readings.

Best to go with the 6N23P-EB for starters, it's the best allrounder IMO (best VFM, very robust, long life, superb SQ) and it has chromed pins so no worries about oxidisation.... built like tanks and stay in spec much longer than the 6922.

You can lose the 10uF input caps, just jumper across the pads... if you want to keep them then replace them for non polar types. The 220uF non polar ouput coupling caps can be replaced with 470uF or 1000uF non polar types (nichicon MUSE are good) this is a good idea if you are using low Z 'phones.... enter your headphone impedance in the "resistance" field and your value of output cap in the capacitance field www.sengpielaudio.com/calculator-RCpad.htm

All the best,

Mike.

[PinkFloyd]

Get a toothbrush..... warm soapy water.... give the enclosure a good scrubbing with the toothbrush... rinse with cold water... it will come up like new. You can clean the faceplate with some isopropyl alcohol and a piece of kitchen roll... this will remove any ingrained dirt and will bring it up like new.... when putting it all back together be sure to scrape the paint where the ground tag connects to the enclosure... may sound daft but it helps

[XTRProf]

Thanks Mike,

Will look into those pointers you had brought up. In the meantime just clean the V2 with a wet cloth and these are the pictures of it naked.




Found snap thru probably too big a RCA inner rod insert.


So first fixy fixy with superglue ...........

and back to like original. Anyway, these female RCAs are of poor quality and so they will be changed with real RCA COPPER sockets. Not BRASS type, ok?
Tubes are Philips. Are these the originals from MF? If are, time to change as quite sure already very near to expiry date.


Also, the bloody transitors are moving in the pads. Probably from too hot during operations. Surprisingly, the power transistors area is more brown than the tubes area showing that they are in fact giving out more heat. Can't fix this now as need to work Monday. Here:



That's all folks. Need to sleep as tomorrow is Blue Monday after April Fool Day. No, no, after Audiofool Day and it's already past 11pm local time.

[PinkFloyd]

All of the points I mentioned earlier appear to have materialized in your amp Chong... the browning on the board, the loose transistor pads, the RCA sockets.... good news is that it is NOT a problem, just indicative of the amp being used a lot (if not left switched on 24/7)... all easy to rectify and I will tell you how later on.

Yes, the JAN Philips (6922) are the stock valves, they will probably be VERY tired by now.

More later, gotta pop into town.

[PinkFloyd]

Chong, no need to glue the RCA quad socket, I'll send you one I've got 200 of them

The tracks that lead to the pads where the transistors are located are green... the green is a thin coating... all you have to do is get a sharp craft knife and gently scrape about 5mm (length) of the green coating off until you reveal the copper beneath... when you reveal the shiny copper all you do then is solder onto it... if you have enough "leg" left on the transistors then bend them over the pads....

Desolder the legs from the pads... scrape back the tracks as above... replace transistors and bend the legs over the pads so they are flush, also ensure the legs are touching the exposed copper track.... flood with solder... this will not only supplement the joint, it will also get the pads stuck back down and the "bending over" will prevent any future lifting of the pads but DO make sure you've pushed the transistor legs right in until their end stop touches the board (basically you won't be able to push them in any further). MF don't do this which is WHY the pads have room to lift, the heat, the weight of the transistor and an eventual break of connection... I think they do it this way so you go back to them to get it repaired... if the transistor legs were fully seated in the first place AND bent over the pad this would not be a weak spot. The transistors will be fine, don't worry about replacing them.

The caps are the usual 85C crapicon and will undoubtedly need to be replaced... by the looks of the amp is has seen heavy usage, possibly has been left "always on" (as MF recommend / I wonder why? ) so I would replace all of the electrolytics with 105C types... the stock power caps are 1000uF / 35V, I replace these with 1500uF / 35V and the extra 5000uF brings welcome improvements to the performance.

The 4 x 100uF have VERY fragile pads (and I mean VERY fragile)... get them out FAST and don't fart about with the soldering iron. The best way is to grab one of them and pull up at an angle whilst "quickly" applying heat to the pad... if you spend too long on there the pads just curl up and disappear into thin air... if you do lift them then just scrape back the tracks as explained above:



Don't worry about the browning on the PCB, you can't "un brown" it.... it's just a crap PCB material, the browning will not affect the SQ in any way Just pay attention to the pads / joint integrity and she'll be as good as new.

I pointed out the weak spots before you posted those pictures and, right enough, they are there for all to see I have seen V2's with totally white PCB's where the owner listens maybe once or twice a week and then there are the "brown" jobs where the owner has had the damned thing switched on for 10 years non stop... there is NO advantage to leaving them switched on 24/7/365 ... it's a sure fire way of drying out the 85C caps, scorching the board, lifting pads and generally wasting electricity (in my opinion, of course).... fire them up, leave them for 20 minutes and then have a listen.. switch off when not listening.

Anyways Chong, you'll soon have her firing on all four (100%) cylinders.

Mike.

[XTRProf]

Just have enough time to write this before rushing off to work. The bloody Right channel is giving some kind of "tube like noise rush or crackle" on warm up. Quite loud. The left channel is A-ok. So is this the bloody right channel valve going? Luckily still have sound.

Anyway, just a thinker even with basking in all those right channel "tube rush" for a few minutes. The sound is really wonderful even without modes yet as can be heard from the left channel. It's correct to say that it much better the laptop computer sound card. So I can't really imagine how great it will be with all those modes in place. Will compare to the Alex's Class A AHA after all the modes to be fair as that was with the full monty in terms of boutique parts.

I'll be back, the famous words, at the work place. Arrrggghh, that morrning rush again .....................

[PinkFloyd]

Definitely a knackered valve, swap them over and the crackling will migrate to the other channel. A few caps and a new pair of valves and she will sound sweet.

[XTRProf]

Apr 2, 2012 5:07:55 GMT PinkFloyd said:

Definitely a knackered valve, swap them over and the crackling will migrate to the other channel. A few caps and a new pair of valves and she will sound sweet.

Ok, tonight if I ever go home early.

[XTRProf]

Btw, Mike how much you selling those 6n23p-eb/ev shipped? Also, 6n1b-eb/ev shipped? Matched? In the meantime, I have some quite matched NOS audiophile 6DJ8 lying around somehwere to make the V2 sing again if that's the problem on switching the 2 tubes in the V2.

Thanks.

[Deleted]

1.2W into 32 Ohm800mW into 120 Ohm500 mW into 300 Ohm280mW into 600 OhmThere is not many amps around that reach that output voltage.

That's a lot of whack. With my vol pot then, it must be the way it's set up so I can use the whole travel perhaps?

I don't go beyond 1 o clock with the K601 and never really tried it but I guess the volume will keep going then, rather than what a lot of amps do....

Their real maximum is often round about 2 o clock and then turning up adds nothing. I guess the V2 will keep going - mind you, I don't want to deafen myself.

Of all the amps I've tried Chong, this one has always remained as my favourite. It's a real workhorse and is full of character.

It makes many SS amps seem like you're in a white walled hospital!! Like that thin soup you can get with nothing in it - water and a few bits.

[PinkFloyd]

Apr 2, 2012 8:31:15 GMT @iancraig10 said:

1.2W into 32 Ohm800mW into 120 Ohm500 mW into 300 Ohm280mW into 600 OhmThere is not many amps around that reach that output voltage.

That's a lot of whack. With my vol pot then, it must be the way it's set up so I can use the whole travel perhaps?

I don't go beyond 1 o clock with the K601 and never really tried it but I guess the volume will keep going then, rather than what a lot of amps do....

Their real maximum is often round about 2 o clock and then turning up adds nothing. I guess the V2 will keep going - mind you, I don't want to deafen myself.

Of all the amps I've tried Chong, this one has always remained as my favourite. It's a real workhorse and is full of character.

It makes many SS amps seem like you're in a white walled hospital!! Like that thin soup you can get with nothing in it - water and a few bits.

If you reverse the gain mod to stock it will blow your ears off at 1pm Maybe time for a valve change Ian, have you used it a lot since fitting them?

[XTRProf]

Apr 1, 2012 19:23:05 GMT PinkFloyd said:

Chong, no need to glue the RCA quad socket, I'll send you one I've got 200 of them

Actually don't need to as I will be fixing COPPER RCAs there. This is only temporary to enjoy first before the "hard" work. Unless you do have some spares matched 6N23P-EB/VB or 6N1B-EB/VB shipped to sell me at a good price.

The rest all noted too!

[XTRProf]

Apr 2, 2012 8:31:15 GMT @iancraig10 said:

Of all the amps I've tried Chong, this one has always remained as my favourite. It's a real workhorse and is full of character.

It makes many SS amps seem like you're in a white walled hospital!! Like that thin soup you can get with nothing in it - water and a few bits.

Really, I'm very confident of your hearing as you are a pro musician for so many years and know what is just right. Miguel too as he has been hearing and hearing at many meets until probably he hears babes calling out sweetly in those he heard as well.