bullpup
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Post by bullpup on Feb 9, 2017 14:59:50 GMT
In another thread I asked about a starter system for my son using a pair of Mistral Speakers plus a suitable amp in particular a Fatman itube.
Unfortunately the Mistrals didn't happen but I found a Fatman Carbon Edition locally without speakers so I bought a set of Ruark Epilogues to go with it. A few days later the original owner of the amp rang to say they had found the matching speakers and did I want them - so System 1 for my son sorted.
In the interim I had been listening to the Fatman Carbon Edition with my B&W Minipods in my office and decided not only was it a nice sound but also a lot more practical than a Headphone/amp combination - I could actually hear the phone or door bell ring!
The obvious solution was a second Fatman. Ebay duly obliged albeit Fatman 2 was sold without valves. In the interim my better half decided she liked the sound and wanted the same so Fatman 3 is on it's way.
Now it is plain I obviously know practically nothing about valves so the type of valves needed was determined from internet research. i.e. Fatman Amps especially the early ones like mine run on 6N1 although some of the later run on 6N2 with no apparent internal alteration. Further internet research suggests tha 6N1 and 6N2 are fully interchangeable especially in circumstances like this where they are being used as a pre-amp.
Since I needed at least 2 sets of valves the obvious solution was to ask Mike to source me 3 sets of some nice examples. Four sets of these have now arrived faster than a fast thing and it is fair to say his packing could survive being used as a puck in an ice hockey match- thank you Mike.
In addition I needed some 6E2 display valves. I sourced some equivalent Mullard EM87s which were sold as nos.
The replacement 6E2 valves turned up today. Despite good intentions of cleaning this,lubing that, I simply fitted them together with Mikes valves and connected up the B&W Minipods and the Marantz CD85.
First impressions - wow this set up rocks! May be a bit in your face perhaps a touch lacking in detail but the CD85 does take an hour or so to warm up and get into it's stride!
There is however some background hum with no signal and this is currently under investigation.
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bullpup
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How much is that doggy in the window?
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Post by bullpup on Feb 9, 2017 19:00:10 GMT
On the basis that the valve pins may need a clean, I found an interesting suggestion for cleaning them rather than using emery tape or similar - Take a block of hardwood, say 50mm cube, and drill a hole in it say 25mm diam to a depth of about 25mm. However I reckon a 35mm film canister would be just as good.
Then take a piece of Plasticine, and nead into it iron filings so that the Plasticine is thoroughly impregnated with the filings. Then fill the hole in the bock with the mixture.
All you have to do to clean the pins is to plunge them in and out of the plasticine a few times, and the pins come up shiny, and as good as new.
To create the filings - just use a piece of scrap cast iron (rather than mild steel), grind it away on an electirc grindstone till you have enough filings, then collect them up with a magnet. If there is some carborundum mixed in from the grindstone, so much the better. I think I may go and raid the childrens chemistry set instead.
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Post by PinkFloyd on Feb 9, 2017 20:48:02 GMT
Hi David, A wire brush on the end of a dremel brings the outer surface of the pins up like new and a bit of 800 grade wet / dry paper (folded over in two) does an equally good job to the inner sides of the pins, It's time consuming but worth the effort. The plasticine / iron filings thing "sounds" like a good idea but in practice it's not...... It may be "OK" for one solitary valve and it will probably remove the oxidisation from 70% of the pins length but won't touch the 30% nearest the glass envelope. I understand the principle, and it's a good idea, but if you are cleaning more than "one" set of valve pins per day you would find yourself spending more time reforming the plasticine / filings "mix" than cleaning pins;) One insertion into the plasticine and one withdrawal has already weakened the abrasive "force" on the pins. For that initial "insertion abrasion" to be effective again you would have to repack the plasticine / filings canister to ensure displacement was negligible. Damned good idea David, thanks for sharing, but not really practical (nor 100% effective)..... sometimes the only (and most effective way) is elbow grease If you're good with a Dremel this is pretty much what I do (but a lot better obviously!): If you're a caveman this also does the job: I'm happy with both..... they do the same job / achieve the desired result. All the best, Mike.
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bullpup
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Post by bullpup on Feb 9, 2017 21:10:31 GMT
Nice links thank you but I am not sure about grinding away with a dremel knowing my luck. As you say there is no real substitution for elbow grease so I will give that a go.
I think I have to put my hand up and say I have probably made a mistake and perhaps the 6N1 & 6N2 aren't interchangeable as internet research had suggested? In that case do you have some nice 6N2 please? Or is it the case that there is likely to be other issues?
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Post by PinkFloyd on Feb 9, 2017 21:51:21 GMT
Nice links thank you but I am not sure about grinding away with a dremel knowing my luck. As you say there is no real substitution for elbow grease so I will give that a go. I think I have to put my hand up and say I have probably made a mistake and perhaps the 6N1 & 6N2 aren't interchangeable as internet research had suggested? In that case do you have some nice 6N2 please? Or is it the case that there is likely to be other issues? I have just (in the last 20 minutes) placed an order for 1,000 of my usuals and there will be 4 x UBER premium 6""" samples supplied with the order....... I'll post them to you, as soon as they arrive, Dave. You have my word on that.
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bullpup
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Post by bullpup on Feb 10, 2017 1:10:00 GMT
That sounds amazing - thank you very much indeed!
I have to ask though, what do you do with a 1000 valves? Lay them down like wine? Lie down on them like a DIY purple hued heated Fakir's bed or just build your greenhouses out of them?
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bullpup
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How much is that doggy in the window?
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Post by bullpup on Feb 23, 2017 9:48:35 GMT
In fairness, Fatman 3 was sold as spares or repairs albeit the vendor had identified that it had faulty valves. It duly arrived and was fired up only to discover 1 channel not working. Swapping valves didn't improve the situation but further research suggested the volume control was unduly stiff. A tin of servisol Super 10 was bought and duly applied. Success! 2 channels purring nicely.
One of the attractions of the Fatmans is the Ipod docks. The carbon Edition has this integrated into the Amp while on the others it is a stand alone with seperate PSU.
First thoughts are this is OK but nothing special. A cable swap from the supplied generic offerings was a noticeable upgrade but not great. In the interim, one of the docks needed a PSU as one wasn't supplied. RequirEment is 12V 500mA. I didn't have a suitable spare but do have a 12V 3A so on it went. Bingo a significant improvement but still not great.
I have a ridiculously expensive ALO ipod cable - the sort of thing coated with cryogenicly frozen hymens etc and so removed the Fatman dock and tried it instead - not really expecting much. Wow the improvement isn't subtle. Significant clarity gains. Massive bass. Overall a much more detailed, richer sound!
I haven't taken any under the bonnet shots yet but a search of the internet show plenty - not sure if I should link them or just take my own? Any way it does seem that there are a number of large capacitors of a fairly generic nature so the obvious question is should these be replaced with larger capacity better quality items such as the Panasonics Mike fits in the X-Cans etc?
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bullpup
Been here a while!
How much is that doggy in the window?
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Post by bullpup on Mar 1, 2017 12:24:34 GMT
Nice links thank you but I am not sure about grinding away with a dremel knowing my luck. As you say there is no real substitution for elbow grease so I will give that a go. I think I have to put my hand up and say I have probably made a mistake and perhaps the 6N1 & 6N2 aren't interchangeable as internet research had suggested? In that case do you have some nice 6N2 please? Or is it the case that there is likely to be other issues? I have just (in the last 20 minutes) placed an order for 1,000 of my usuals and there will be 4 x UBER premium 6""" samples supplied with the order....... I'll post them to you, as soon as they arrive, Dave. You have my word on that. Good morning Mike By any happy chance did these arrive? I only ask on the basis that they might be packaged with the Aune? Best regards David
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bullpup
Been here a while!
How much is that doggy in the window?
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Post by bullpup on Mar 1, 2017 12:26:05 GMT
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bullpup
Been here a while!
How much is that doggy in the window?
Posts: 517
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Post by bullpup on Mar 24, 2017 14:07:43 GMT
I decided to diagnose why Fatman 4 isn't working - I tried some working tubes but all lights are off and no one was home. A spray of servisol in the appropriate places made no difference so time to dig deaper.
It appears that there are various soldered fuses within the amp board so that seems a sensible place to start: 2 are fine but 2 are blown. My guess is that someone followed bad internet advice and fitted the wrong valves. The fuses in solder fit T3A 250V Fuses. I guess they will be easy enough to do. However to remove the board I will need to disturb some thermal potting compound - can that be re-used or will I need some fresh? If so can anyone please recommend a supplier for both that and indeed the fuses?
Photos to follow when the battery re-charges.
Many thanks
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bullpup
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How much is that doggy in the window?
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Post by bullpup on Mar 24, 2017 14:32:15 GMT
I think the correct way to describe the fuses may be T 3A 250V axial or pig tail fuses?
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bullpup
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Post by bullpup on Mar 27, 2017 12:23:43 GMT
The obligatory under the bonnet overview: Amplifier Board: And a reverse view of the same: The blown fuses: And what I think are the output Caps:
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bullpup
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Post by bullpup on Apr 4, 2017 17:34:17 GMT
So I don't loose my notes: The 2 large Caps are Nippon Chemicon 35v 105c 8200mf The 2 small blues are pretty indistinct but seem to be marked F 1.Ok MD 200V The 2 small brown are also pretty indistinct but seem to be marked 105 K and 105 J and 100 DI And the 3 others in the first picture from front left to rear right are: A SK 250v 85c 100mf A Samsung SSL 250v 85c 47mf A Rubicon YK 35v 2200mf
Any advice on changing these and indeed a source for the fuses would be gratefully received.
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Post by PinkFloyd on Apr 4, 2017 19:59:07 GMT
So I don't loose my notes: The 2 large Caps are Nippon Chemicon 35v 105c 8200mf The 2 small blues are pretty indistinct but seem to be marked F 1.Ok MD 200V The 2 small brown are also pretty indistinct but seem to be marked 105 K and 105 J and 100 DI And the 3 others in the first picture from front left to rear right are: A SK 250v 85c 100mf A Samsung SSL 250v 85c 47mf A Rubicon YK 35v 2200mf Any advice on changing these and indeed a source for the fuses would be gratefully received. The fuse is not the fix Dave.... the question is "what is causing the fuse to blow"
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bullpup
Been here a while!
How much is that doggy in the window?
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Post by bullpup on Apr 6, 2017 12:06:56 GMT
Thank you for the comment Mike.
So my guess that the previous owner was using the wrong Valves is unlikely?
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