MF X10-D Refurb...

[DSJR]

I'd typed paragraphs about impedance (mis)matching in domestic audio and inserted pics, but in trying to find some info online I forgot to open a new tab and lost the lot, so here we go again...

I know there are companies out there who create a "problem" noone thought they had and then market a "solution" to it, but in the case of the X10-D line buffer, I think there was a genuine need.

My Croft preamp has a volume control fed line buffer built-in to drive a normal stereo power amp, but the tape outputs are only "buffered" by a 100 Ohm resistor. Using this output to feed the Crown D-60 "headphone-amp" caused the phono stage to lose considerable amounts of bass, as the Crown's input impedance is "only" 25K Ohms. Glenn's aware of this and will update my preamp completely when I can afford to lose it for a week or three. In the meantime, Clive here kindly sold me his old X10-D for a very reasonable sum to try..

The first things I did were to re-instate the red LED on the front, turn the outer case back-to-front to hide the scratched top as best as possible and to find a higher current transformer, which I did in the form of a 12V AC one, rated at 4A. I terminated this with the required 5mm plug with 2.1mm inner hole.

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1346.jpg

A "Soundstable" phono to phono lead was cut in half and re terminated to suit and off I went.

Initial results were great, the Croft phono stage keeping its bass and headphone listening improved, albeit with the X10's added warmth and "dirt."

Although the original caps looked intact and not bulging (as some are now in other units), some Googling led me to the Rock Grotto site and these pages..

http://www.rock-grotto.co.uk/x-10dupgrade.html

and this

http://www.rock-grotto.co.uk/ufast.htm

Especially as the caps and diodes now come as a pack. I also asked for the purple LED to differentiate this unit from a standard one. Fitting these wasn't difficult and here's a before-

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1349.jpg

followed by the after-

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1350.jpg http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1351.jpg

I found the change in sound quite noticable and initially didn't like it, as the sound became "stripped" and a little "bare" in a clinical fashion, but with total removal of the "dirt" I'd had before. I threw caution to the winds and bought the recommended valves and all the "emotion" came back. I reckon the performance is now up to the standard of the Croft, and that's a high recommendation in my book.. However, I also have a Quad 33 to which I added a Dada Cap-Kit, larger value Wima film output caps and lately, two high-speed diodes (plus 47nF snubbers as in the Rock Grotto kit, hoping for the best). I think I now have the Quad up to the X10-D standard with an indefinable "something" which I love about old Quads. The 33 has a volume control too and the tone controls help with the peaky HD25SP headphones and all this despite the basic screened wires i'm using as interconnects at present.

The X10-D is, like the Lentek Head Amp, one of those things that many of us might have played with at some point or other and, if we can afford to keep one, one that will live in a cupboard or drawer somewhere for years until curiosity takes over or a particular need arises. It would be interesting to see if an updated and better componented version would be good with some of the add-on DAC's out there - or not, as the case may be. Worth a punt though if one can be obtained for well under £100...

[darkstar078]

Dave,
Nice project! Informative, Instructive and utterly Useful. And good pictures

[Spectral Morn]

Nicely done Dave.

I have an X10D and external MF PSU but I must be honest and say I don't rate it at all and found it to be very patchy in the extreme. If you read my write up on the Ecofan buffer Zone (either on AOS or on AIHFA)you can read about what I heard from that MF unit. However like all things audio there is the question of component matching etc to be taken into account.

In saying the above though, I reckon what you have done would improve things a lot, as all MF kit is made with cheap parts as Anthony M does not believe in the difference better quality parts make; at least that is what he says in public.

I might dig mine out and let Rodney have a look at it.

However the trick will be to get one for the price you quote, as they usually sell for more....

Nice post :)


Regards D S D L

[The Vinyl Adventure]

Yeah I got one hanging about that I think sounds a bit average ... I wonder if, with my cack handedness I could do this... What at the "recomended valves"

[Rare Bird]

Dave: the best sounding for the money polyprop caps providing you dont want to go stupid like a lot do & keep it all neat & organised are the WIMA box Polyprops..I've tried a lot of Electrolytics aswell & i still prefer the Panasonic 'FC'

[Ali Tait]

Best I've heard at a cheap price are Clarity Caps.SCR's are the best I've heard,but they are very silly money.

[Rare Bird]

Best I've heard at a cheap price are Clarity Caps.SCR's are the best I've heard,but they are very silly money.

Yeh but there too big for that PCB, i was recommending as to fit all neat & compact. I think PCB look stupid with massive specialised caps all over the place..

[Ali Tait]

Aye but you can't see it when it's in the box!

[Rare Bird]

Aye but you can't see it when it's in the box!

That alone is an illness of mine, the inside has to perfect in every respect compare to the out ;)

[Ali Tait]

Ah I see.It doesn't bother me what it looks like,it's what it sounds like that matters!

[DSJR]

This X10 wasn't intended originally to be a serious project and I'm not enough of a DIYer (yet!) to want to go any further. I think the Rock Grotto chap has his X series nailed well, recommending particular components for the product kits he sells. he uses different makes of cap for different units too and I must admit the UF4007 diodes make a beneficial difference on the Quad as well IMO and don't cost hugely more (well, 25p against 10p ;)). With the recommended valves, the thing comes together well and sounds extremely good - MUCH clearer than standard IMO.

Neil, I just don't have the readies to splash out on stuff and people like Martin on here (with his mega-thousand bills this month) wouldn't know how to live on my current income;) but for pin-money I'm happy..

[Rare Bird]

What about some gold plated/ceramic valve bases, there not that expensive..cheap bases can be unreliable at times.

[Clive]

Dave,

Great job! Looks like you fitted a blue LED too?

I'm very pleased the X10D has found a home where it can flourish!

I wonder how it's current incarnation compares to the SS Burson buffer.

Clive

[DSJR]

Bloody IE8 - lost me reply again :steam:

Yep, now with purple LED.. I also made the DIY power supply shown on the site. Cutting the holes was a nightmare for me and I discovered not to use a heat gun (for neat heatshrinking) anywhere near a nylon "chocolate block" connector, 'cos the nylon melts - uggghh! But I had spares and it's been in use all afternoon.

I bought the "two on one" issues of the four Mandingo albums from the 70's. This percussive stuff was superbly (analogue) recorded and the first album suffered in a recent re-mastering by having too much no-noise applied. These double-album discs were done in 1999 and IMO the results are superb, genuinely 3D, a very gentle silky hiss from the tapes at high level except where it's faded out between tracks and real power in the percussion (we had side 1 of Mandingo III on a 15IPS master copy at the time and I do remember how good it was).

Clive, sincere thanks again for letting me have this X10 at such a reasonable price. The DIY bug has bitten and once my turntable situation is sorted, I'll tackle a Sowter SUT (I have the box and sockets, but the funds have run out for now.

[Alex_UK]

Top work Dave, nice one!

[colinB]

Great posts Dave. Ive been thinking about getting a cheap MF headphone amp 2nd hand and was wondering how good the Rock Grotto mods were. With the new caps , valves and little pinkie PSU i think i could get a nice unit for a little out lay.

[The Vinyl Adventure]

.... Why are the recomended valves ... And what's a little pinky

[colinB]

I think he tells you the valves on his upgrade page ( hi fi tweaks on Rock Grotto)
The little pinkie is meant to be a good PSU he sells for £100 that replaces the crappy wall wart psu you get with most small electronic components.
I read a lot of people were buying them to replace cambridge magic DAC psu because they were so shit they were bursting into flames. He originallly made it for the MF x can amp though

[Ali Tait]

You could make your own for far less than that.

[colinB]

Does seem a lot. I could buy a Aikido headphone amp kit from the states that has a low impedance output built with my Grados in mind plus the psu unit for $140.

[DSJR]

I think he lists the components, so that if you have access to Rapid, RS and/or Farnell, you could obtain the bits yourself. For me, it was easier to buy all the parts from Mike direct. More experienced DIYers may have their own take on the mods anyway.

I had a long session last night using the X10 and there's no doubt that it's been transformed.. I'd love to see what a similar fettling would do to the XP-100 preamp, which sounded pretty darned good in standard form. I have no need of one, but on fleabay they usually fetch around £225 approx. With a few tens of pounds in better caps and diodes etc, it could become very serious indeed... The X-DAC's were also pretty good as were the XA200 and XAS-100 power amps. All these are ten years old plus now and would be in line for a re-cap on the power supplies at least..

[Rare Bird]

I had a long session last night using the X10 and there's no doubt that it's been transformed..



Swapping the resistors now would make an even bigger difference ;)

[The Vinyl Adventure]

http://i728.photobucket.com/albums/ww282/hamish_gill/36eb6277.jpg

Just done mine...
Cheers for the pointers dave
I also can confirm the rock grotto upgrades do make a significant upgrade ... Even straight after the upgrade much of what I describe as the "wackiness" of the sound of it has gone ... Usein it instead of my gg pre it sounds pretty neutral with perhaps just a touch less of the drive depth and dynamics of the pre amp ...
Next test will be to see if it takes away some o the hardness o the sound from the hlly90 when used with the caiman as a preamp ...
I'm pretty chuffed for the £50 ish quid :)
Oh yeah, and I did it by my self, and let's face it my track record for diy hifi is a bit dubious :)

[DSJR]

Did you change the valves and upgrade the power supply? The former refines what's there and the latter will give more "drive" as the MF supply upgrade did..

The purple LED has failed on mine, gradually fading out one session. I've put the red one back and it's fine. I think the inline resistor Rock-Grotto fit is a 470 Ohm one, so I'll look for some LED's on fleabay and make my own, as I have the resistors and loads of small heat-shrink. The LED's are nominal 3.6V I believe.

[Alex_UK]

Well done Hamish, good work and glad you didn't break anything! ;)

Methinks maybe you're getting back into this hifi malarky after taking a bit of a back seat for a little while?

[The Vinyl Adventure]

Valves are next... Then the psu ... I'm just happy with the non whacky sound ... My pre is going to Anthony for a service and new valves so it will be sat in it's place there for a few days

Alex

I've not stopped, I'm just sticking with little things mostly to my second system which is constantly changing ... I have a new turntable project in the pipe line, my active dynaudio project, powersupply for the x10-d ... I want to get some big snells (or other such vintage speakers) ... All sorts ... Just non of it is really about the main system (bar the turntable) ... I'm very happy with the main system!

[DSJR]

Hamish, that's the best way to do it - keep the main system more or less as-is and have a little "project system" you can play around with, transferring skills you learn on the way over to the main system occasionally as and when you feel the need.

I now have more than enough to make a second system up, but space precludes it at present and it's really unnecessary until I finally ditch the computer speakers in the upstairs "office/junk room" and use the M-Audio 24/96 soundcard (thanks Ash) as a source for a proper little hifi up there - darned good soundcard that, i could even hear a small improvement from the Audigy SE one I was using before - either that or feed the digital output into the QED Digit/Positron.

[The Vinyl Adventure]

Yep, music system and hobby system ... It's quite good, it means I'm less neurotic about the main system ... Not there is much to be neurotic about really but ...
The goal is to get the hobby system as close to the main system in sq at a 10th of the retail price... Using similar products ie pc/dac - valves - active speakers.... It's good fun!

[Alex_UK]

I kind of know what you mean - I'm so happy with my main system but have been playing around with my upstairs systems for a bit of fun, trying different components with each other, etc.

Anyway, glad you're still hanging around Hamish :)

[DSJR]

I've got to have a go on your Rega haven't I? I found my bearing spanner and also the tonearm one as well. All I need is the correct grade of EP80 for the bearing and we'll be away (my Garrards need a viscous oil for the main bearing shafts)

[Reid Malenfant]

Anyway, glad you're still hanging around Hamish :)
Did i miss something here? I'm also pleased he's hanging about, i didn't have any idea he was off anywhere? :scratch:


I'm WearingLacePanties.
The less said about this the better :eyebrows:

:lolsign:

[The Vinyl Adventure]

Cheers Alex

Mark, alex might have not seen my rantings recently and my post rate, believe it or not, is much less than it used to be since I got my main system sorted... I have also had a few periods of not posting with being busy with work... If I'm honest it's nice someone noticed! ;)

[Reid Malenfant]

Mark, alex might have not seen my rantings recently and my post rate, believe it or not, is much less than it used to be since I got my main system sorted... I have also had a few periods of not posting with being busy with work... If I'm honest it's nice someone noticed! ;)
Well i'm pleased you got your main system sorted chap :)

As for the posting bit i guess 3 or 4 months isn't enough for me to see a trend, Alex has been a member far longer than me so i guess he should have noticed (which he duly did) ;)

You keep enjoying the music :cool:

[Alex_UK]

Hamish has been a bit quieter than normal the past few months, but seen him posting a bit more just recently, I thought.

No rush on the Rega Dave, but I would be interested to see what needs to be done to them and learn something new.

Thanks for noticing Mark - felt I had to share :eyebrows: As soon as I get home I'm going to rip off the wife's knickers - they're flippin' killin' me! :lol: