marcm09
100+
Audio Monster
Posts: 119
|
Post by marcm09 on May 30, 2007 10:42:26 GMT
 Further Update- The amps up and running and sounding lovely ! It sounds nicer than my NAD amp even though the NADS is fully modded with panasonic FC'S with mylar bypass caps. However the NAD does sound ... I dont know its a little hard to explain but maybe a little more defined or clearer, but no where as much dynamic or as much rythym and a lot thinner. When you switch to the MF it comes alive and you want to sing with the track or tap your feet ! Just Wait till I pull her apart and change those nasty caps for something a little nicer, I think that the reason that the NAD sounds a little clearer is due to the Caps upgrade. Pinky - Please advise about the bigger NP caps that you mentioned and what size /type of bypass caps, thanks 
|
|
marcm09
100+
Audio Monster
Posts: 119
|
Post by marcm09 on Jun 4, 2007 1:54:22 GMT
Its a Shame that nobody has had time to answer ? I'm waiting to order the components and I know that if I replace the standard caps with the panasonic's and the NP's with the Capxon's and bypass the caps with 100nf poly's and use all of the same values that it will impove the sound.
I was hoping that from the photos that somebody could advise if I could in fact increase the vaule any of the caps for even better sound.
Pinky suggested to put bigger NP output caps but Im not 100% sure which ones ? etc
thanks
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 4, 2007 2:09:41 GMT
Marcm09
I did find the time to answer in a couple of private emails.
I gather that you are not impressed by my comments about BlackGates and Nichicons etc not always being a magic bullet ?
Fit the 100nF poys across the PSU electros and any other large value electros.
Does your amplifier actually have output capacitors to replace with bigger ones? Most modern power amplifiers with 75W per channel output are usually direct coupled from the junction of the NPN and PNP output device emitters. However, MF quite often does things differently. Hence my suggestion about the schematic, and then asking Mike or myself to advise you further.
Regards
SandyK
|
|
marcm09
100+
Audio Monster
Posts: 119
|
Post by marcm09 on Jun 4, 2007 4:06:32 GMT
Sandy - Thanks for the emails. I agree about your comments regarding the blackgates etc. I am intending on placing an order within the next few days and replacing all the caps with the panasonic FM's where available and the rest FC's and also the Teapo(cheapo) NP's with the capxon. Do you think that I should bypass all of the caps including the non-polorised ones ? I love the sound of it now, hope it'll sound even better after ! Sorry please dont think that I'm unhappy this is a GREAT site and it has helped me make my XCAN into something very special !  I surpose that I strickly speaking I should be using the same value caps especially if Im unsure, I dont want to ruin the sound of a great amp. I never realised that these were that good !!! Hopefully it'll just give it that extra little sparkle when I'm finished ! ;D |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 4, 2007 6:14:12 GMT
marcm09
You could try as high as 470nF 63V capacitors underneath the main PSU electros. 100nF in parallel with other bypass capacitors should be adequate. Regarding parallel capacitors across the non polar capacitors, in theory it sounds like a good idea, but probably due to the higher impedances involved where they are normally used, I have never noticed any obvious
improvement. I always fit parallel capacitors across them in Video applications though.
If you decide to replace the main PSU electros with better capacitors, don't go overboard with the increase in the capacitance value.
SandyK
|
|
|
|
Post by PinkFloyd on Jun 4, 2007 9:55:21 GMT
Sorry Marc, I totally forgot about this thread\  Lovely job on the PSU mate Replace all the electrolytics with panasonic FM types, I wouldn't bother bypassing them with film caps but each to their own.... the orange film caps will probably be standard MF 470nF 250V stock so you can replace these with polyprops (evox PHE series are good) possibly use the existing 470nF to bypass the polyprop you choose? I dunno, won't do any harm  Hard to tell from those pictures Marc can we please have a few more from different angles and also a few snaps of the bottom of the board.... what type of diodes are they? If you decide to fit ultrafast types then essential you fit snubbers onto them as they can / may be noisy / pick up noise in this type of amp. A few more pics if you will and the clearer the better.... I know you're in a hurry to get on Marc but rushing in is sometimes not a good idea..... let's see what's happening and let's sit on it for a few days. Mike. |
|
marcm09
100+
Audio Monster
Posts: 119
|
Post by marcm09 on Jun 4, 2007 10:54:53 GMT
Thanks mike - I will takes some more pics at some stage, think that I've got some clear thoughts on what I'm gonna do now though. Changing the orange film caps is a good idea that I never thought of, I take it you mean the ones that you can see near the 2 fuses and close by ? It gonna be one hell of a lovely amp when we are finished. Tell me a liitle more about the snubbers on the ultra fast diodes- I see that you have used them in the xcans. What value and type of snubbers do I use please ? |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 4, 2007 11:26:45 GMT
I wouldn't bother bypassing Panasonic FM types either. Just any common as a'holes electros..
What I was getting at was to try the existing electros with bypasses before ordering the more expensive types. Bypassing a polypropylene with an inferior type of smaller value capacitor doesn't sound like a very good idea .
SandyK
|
|
|
|
Post by PinkFloyd on Jun 4, 2007 17:47:18 GMT
I wouldn't bother bypassing Panasonic FM types either. Just any common as a'holes electros.. What I was getting at was to try the existing electros with bypasses before ordering the more expensive types. Bypassing a polypropylene with an inferior type of smaller value capacitor doesn't sound like a very good idea . SandyK Jesus I'm not making sense these days! what I mean is you can bypass the existing polyester film caps with a small value polypropylene (to give it some polyprop characteristics) or you can remove them and fit equivalent value polyprops in their place EVOX PHE 426 is a very good replacement cap and package size is not that big... I have plenty of 470nF 250V PHE 426 if those ones in your amp "are" 470nF polyesters (the size suggests they are) as to the snubber caps probably .01uF / 2kV rated ceramics.... let us know what type of diodes they are first. You can also strap a class X2 cap across live and neutral of your PSU (at the inlet) and a class Y2 cap across ground and live..... more on this later. |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 4, 2007 21:17:18 GMT
Now you are firing on all cylinders !
|
|
marcm09
100+
Audio Monster
Posts: 119
|
Post by marcm09 on Jun 4, 2007 22:55:11 GMT
On reflection this is probably the first Muisical Fidelity XA100R amplifier to me modified on the internet. When finished we should probably look at posting an article regarding the mods.  |
|
|
|
Post by PinkFloyd on Jun 4, 2007 23:22:33 GMT
On reflection this is probably the first Muisical Fidelity XA100R amplifier to me modified on the internet. When finished we should probably look at posting an article regarding the mods. It is. Which Is why I recommend you chill out and refrain from "Its a Shame that nobody has had time to answer" type posts Let's do it properly, one step at a time to ensure the mods actually "work" and the advice given is good, sound advice. This is the first XA-100R I have set eyes on Marc but already we have got you up and running with a PSU..... one step at a time sweet Jesus! Close up shots of the amp (photos) from all angles will help Marc..... |
|
marcm09
100+
Audio Monster
Posts: 119
|
Post by marcm09 on Jun 5, 2007 0:16:04 GMT
OK more Pictures are comming... It's not quite as easy to pull apart as the xcans with heatsink paste to the chasis and knobs with allens keys etc I would prefer to perform all the mods at once rather than pulling it apart several times though !
Keep posted... Pics comming soon !
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 5, 2007 0:39:23 GMT
marcm
Where the new photos don't clearly show the type and value of components (such as those little orange capacitors that look very much like ceramic capacitors,with the black dot on top) it would be helpful to write down what value and voltage rating is printed on them.
Also things like the labelling of the bridge rectifier near the AC inlet socket leads.and the capacitance, manufacturer, and voltage rating of the main supply electrolytic capacitors near the bridge rectifier (?) They should be several thousand microfarads. This extra information will assist Mike in making recommendations. Some of the existing photos seem to raise more questions than answers.
SandyK
|
|
marcm09
100+
Audio Monster
Posts: 119
|
Post by marcm09 on Jun 6, 2007 11:46:57 GMT
Ok I've been busy taking photos and there are quite a few ... Firstly a breif description of the components - Orange Film caps are 104J 250V x 5 and 224J x 2 - That I can change to polyprops Diodes Have the number 148 on them x 12 Main caps size is 10,000uf 50v x 2 Other caps are mentioned in above posts including the NP ones. The ceramic capacitors- I'm not sure about trying to change but please advise - are 471J x2, 331J x 2, 221J x2 and the slightly smaller ones with the black tops have the numbers '5' x2 and '47' x 6 caps Here goes with the photos - Lots of them and nice and big !      ![]() i203.photobucket.com/albums/aa68/marcm09/IMG_1126_1.jpg[/IMG]    Look forward to your comments ! |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 6, 2007 12:07:49 GMT
That's more like it ! Nice photos too. You are going to be quite busy, with lots of capacitors to replace. I will let Mike have the floor on this one, but I expect that we will be in fairly close agreement on what he recommends. Mike may also be able to supply many of the recommended replacements from his parts bins and save you some stuffing around with different suppliers, as well as save you some money.
SandyK
|
|
|
|
Post by PinkFloyd on Jun 6, 2007 20:26:32 GMT
|
|
marcm09
100+
Audio Monster
Posts: 119
|
Post by marcm09 on Jun 6, 2007 20:47:25 GMT
Do RS componets have an ultra fast Diode in this value ? Also please confirm the snub value and if its going to make a reasonible difference changing these ?
|
|
|
|
Post by PinkFloyd on Jun 6, 2007 21:59:12 GMT
Do RS componets have an ultra fast Diode in this value ? Also please confirm the snub value and if its going to make a reasonible difference changing these ? 1N4148 is an ultra fast diode. Remember Marc that I never heard the XA-100R nor seen it so your guess is as good as mine as to what will make it sound better. I would try .01uF / 2kV rated ceramics across the diodes (10nF) and see what it sounds like, they are cheap and well worth a try..... you certainly won't do any damage paralleling them across the 1N4148 and you may find they do a lot of good sonically. I can see a few 1N4007 there too? Certainly replace these with UF4007 and snub with 10nF / 2KV ceramic. As to the caps I would replace the 10,000uF / 50V ones with Panasonic TS-HA series in the same value or a lot more if you can fit them in (15,000uF / 50V types would be better I think) datasheet here: www.panasonic.com/industrial/components/pdf/pic_ts-ha_dne.pdf The 15,000uF are 35mm diameter so you should be ok.... measure up the bays before ordering them but deffo more capacitance in this section will improve things, no doubt about that! The rest of the caps replace like for like but instead of "teapo" go panasonic FM or FC... with the non polars I'd be inclined to veer toward capXon (105C rated) or (if you can get them) go with Nichicon non polars. I wouldn't do anymore than that at the present time.... change the caps and see where you're at SQ wise (should be a pretty marked improvement) no point going full throttle and throwing everything into it.... start with the caps. |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 6, 2007 22:15:16 GMT
marcm09
Did you get a remote control with the amplifier ?
SandyK
|
|
|
|
Post by PinkFloyd on Jun 6, 2007 22:22:44 GMT
marcm09 Did you get a remote control with the amplifier ? SandyK I noticed the motorised pot too |
|
marcm09
100+
Audio Monster
Posts: 119
|
Post by marcm09 on Jun 7, 2007 0:34:02 GMT
Remote was missing together with the power supply. At some stage I will borrow a remote and program it into my learning remote control from a new MF amp, I'm not too worried... Mike I'll start with the caps and the poly's . A few final Questions also - 1. Are you suggesting putting snubs on the existing diodes ? Presume they are RS Stock No. 305-5255 please advise. 2. Also what number components on the board do you think are 1N4007 diodes? I thought all 12 were the same just some where mounted upside down so I couldnt read the numbers ? I'm unsure... 3. RS dont have the 15,000uf caps. I could use 10,000uf TS-HA's on the top and then 4700uf's TS-ha's connected to the bottom of the board. I know that the amp will benefit from more cap value here but will it make a difference as to the cap quality here or can I simply leave the 2 existing standard 10k caps here and a pair of 4700 TS-HA's to the bottom ? I would attach them to the bottom of the board connected by a couple of short runs of wire if I have room. Or if not enough room I could drill two holes carefully thru the board and wire them to the extra 2 caps mounted on there side and next to the orginal one. Even if I did find 15,000uf one I'm a little worried that it might be a tight fit. 4. If the above is an option - what would be the maximun length that I could run the 'jumper' wires. ie if I had to pass thru the board via holes or even around the transistor heatsink area gaps could / would the caps still be effective at a 50-80mm wire length ? Thanks- With these questions answered I'm ready to order the caps, np's, polys etc |
|
|
|
Post by PinkFloyd on Jun 7, 2007 22:38:39 GMT
Remote was missing together with the power supply. At some stage I will borrow a remote and program it into my learning remote control from a new MF amp, I'm not too worried... You do realise the pot onboard is a motorised pot and you can control it from the remote control? Not one of those mickey mouse jobs..... when you turn the volume up or down from your remote the pot itself rotates (ie: the volume knob moves around) I can only "suggest" here having never set eyes on an XA-100R but, yes, I am suggesting you parallel some .01uF / 2kV ceramics onto the existing diodes for starters (If you're really pedantic you may also want to fit a 100ohm resistor in series with the cap to dissipate any spikes) you won't do any harm and may possibly gain quite a bit sonically. They will do very nicely Marc. The three adjacent to R34 (D5) they look very much to me like 1N4007.... you'll see them at the bottom left of this picture: If I'm correct and these are 1N4007 then Fit UF4007 here and parallel a .01uF / 2kV ceramic onto them and fit a 100R resistor in series with the cap. (I'd just bypass the UF 4007 with the 10nF / 2KV ceramic for starters... the 100R resistor may not be required / suck it and see. Go with the 10,000uF TS-HA for starters, A bloody good cap with very low ESR. Of course, this is an area where more capacitance generally means "better" but go fully Panasonic (they ain't expensive) instead of strapping a 4,700uF onto your existing teapo cap get yourself that 50V / 10,000uf panasonic and a 4,700uF panasonic to strap on under the board.... measure the space under the board, you may well get more than 4,700uF in there Keep any hook up wires as short as possible.... I can tell from your postings you're not an idiot and probably know more than I do,...... you know the score, if you're paralleling another 'lytic keep the connections close. If I had to choose a length between 50 - 80mm I'd choose 25mm..... an inch in old money That's the best I can do having never seen the amp, keep us updated. All the best. Mike. |
|
marcm09
100+
Audio Monster
Posts: 119
|
Post by marcm09 on Jun 8, 2007 11:00:14 GMT
I'm just in the middle of ordering the caps thru RS components and also need to clarify these two toughts (its late and night and I've had a long day...)
1. Two of the caps that I need to replace are small polarised 1uf 50V ones (cant even remember what ones in the pics , but they were on my list !) There are no FC or FM panasonic's in these - could I use a non-polarised Capxon Rs part no 521-1839 (1uf 63v)instead or 105C NHG panasonic (1uf 50v) RS part no365-4199 ?
2. Regarding the orange polys caps by the fuses etc the 104J 250v works out to be (I think) a 0.1uf value so I could use a Evox PHE426 Rs part 414-7614
and the 224J is a 0.22uf - evox phe426 RS part 414-7715 - but looking at the spec these caps seem kind of small ? do I have the correct ones to replace the orange caps around the fuse/transformer/power supply area ? If you look at the photos the original 104J and the 204J look like they are simular sizes , I'm worried that the new evox will be too small, is this the case?
thanks guys your help is appreciated !
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 8, 2007 11:52:47 GMT
Marc
The 220nF from RS look fine just check that their lead pitch is suitable for the existing PCB holes.i.e. if they don't fit straight in, is their enough lead length when bent, to go right through the PCB. Regarding the 1uF, Mike may have other thoughts on this, but if you have a nearby Jaycar or DSE you could try a 1uF 63V poly. with 5mm lead pitch. I have done this before with no problems, they are probably better than an electro. RS would also have something similar. Just make sure you have room for them.
Alex
|
|
Further Update- The amps up and running and sounding lovely ! It sounds nicer than my NAD amp even though the NADS is fully modded with panasonic FC'S with mylar bypass caps. However the NAD does sound ... I dont know its a little hard to explain but maybe a little more defined or clearer, but no where as much dynamic or as much rythym and a lot thinner. When you switch to the MF it comes alive and you want to sing with the track or tap your feet !
Lovely job on the PSU mate 
