Haha I don't doubt it works well for you, but honestly I have never been so pi**sed off and just plain disappointed with an operating system before. I spent £90 on the upgrade Home Premium version (with SP1) and I just had nothing but endless trouble with it. Clean installs didn't help. I guess it's a platform dependant OS or is finiky with certain processors. I think you were one of the lucky ones Mooly - the net is full of tales of woe with Vista, many considering it worse than ME (which I was also unlucky enough to have hahaha!).
Tried absolutely every trick in the book to get it to speed up (did an IT degree back in the distant mists of time so fairly clued up) and wasted many evenings on it, including last nights. Never again - 4th time unlucky for it, and it's now in the bin!
My laptops on its last legs anyway so I'm saving up for a new one which should come with the super-stable Win 7 (he says.... touching wood!). Thank goodness for my Mac mini - it helps calm the nerves after a session with Microsoft...
Anyways - sorry for the off-topic-ism folks
Tried absolutely every trick in the book to get it to speed up (did an IT degree back in the distant mists of time so fairly clued up) and wasted many evenings on it, including last nights. Never again - 4th time unlucky for it, and it's now in the bin!
My laptops on its last legs anyway so I'm saving up for a new one which should come with the super-stable Win 7 (he says.... touching wood!). Thank goodness for my Mac mini - it helps calm the nerves after a session with Microsoft...
Anyways - sorry for the off-topic-ism folks
Vista - I basically paid £90 for a coaster! To add insult to injury a mere 5 months later Windows 7 comes out - reading between the lines MS basically admitting Vista was problematic for many. I was furious there wasn't a money off voucher at least - or even an exchange program - for those that had bought, in effect, a half finished piece of software in Vista. I shall be very careful about buying any MS upgrade again, and wait and see what the market/users say first in the future
Right back to the amp
There's one part I'm not quite sure what to do with... It's labelled as the 'Insulation Sheet' (page 7) in the service manual and fits between the bottom if the SMPS (i.e. the flat side of the SMPS cast chassis), and its black aluminium shielded enclosure.
Unlike all other thermal/insulation pads in this amp, this one is quite a bit thicker at about a millimeter. Now, I'm not sure if this pad serves as an electrical insulator only, or electrical and thermal to transfer heat from the SMPS into the aluminium enclosure?
There is no mention in the service manual about any thermal paste between the insulation sheet and enclosure, whereas elsewhere it does mention paste when required in other parts of the amp. So basically I am not sure if this insulation sheet needs some thermal paste on both sides before going between the SMPS/Enclosure, or whether it just goes in 'dry'?
A few pics on the internet show thermal paste on some dismantled units, but of course that could have been added by the user...
- J
Right back to the amp
There's one part I'm not quite sure what to do with... It's labelled as the 'Insulation Sheet' (page 7) in the service manual and fits between the bottom if the SMPS (i.e. the flat side of the SMPS cast chassis), and its black aluminium shielded enclosure.
Unlike all other thermal/insulation pads in this amp, this one is quite a bit thicker at about a millimeter. Now, I'm not sure if this pad serves as an electrical insulator only, or electrical and thermal to transfer heat from the SMPS into the aluminium enclosure?
There is no mention in the service manual about any thermal paste between the insulation sheet and enclosure, whereas elsewhere it does mention paste when required in other parts of the amp. So basically I am not sure if this insulation sheet needs some thermal paste on both sides before going between the SMPS/Enclosure, or whether it just goes in 'dry'?
A few pics on the internet show thermal paste on some dismantled units, but of course that could have been added by the user...
- J
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How did the sheet come out ? Was it "dry" ? It serves as both insulator and heat transfer but as the area is so large and thermal inertia high ultimate heat transfer "speed" isn't such an issue. I would leave dry I think.
If you are going for a big switch on then doesn't the PSU have to be out of the case anyway to adjust the voltage ?
If you do switch on like this I would suggest not using a bulb but just fit the correct fuses and apply power with the PSU connected to the amp. If you do this be sure to connect that jumper cable as shown in the manual.
(9 Vista updates this AM)
If you are going for a big switch on then doesn't the PSU have to be out of the case anyway to adjust the voltage ?
If you do switch on like this I would suggest not using a bulb but just fit the correct fuses and apply power with the PSU connected to the amp. If you do this be sure to connect that jumper cable as shown in the manual.
(9 Vista updates this AM
)
Mine was absolutely smoothered in thermal paste, but this was done by the last repair guy.
However just saw this picture:
http://picasaweb.google.com/895720/SONYTAF6BPLPS?feat=directlink#5325950500053174898
This is from an un-serviced amp, and it looks to me like there's some dried thermal paste on the rear of the SMPS here?
Perhaps just a very, very thin layer on both sides then? I guess ultimately it can't do any harm.
Yes I'm going to test the SMPS out of the enclosure first per the manual, but I was just curious about that thermal sheet.
- John
P.S. XP - the same amount of updates!
However just saw this picture:
http://picasaweb.google.com/895720/SONYTAF6BPLPS?feat=directlink#5325950500053174898
This is from an un-serviced amp, and it looks to me like there's some dried thermal paste on the rear of the SMPS here?
Perhaps just a very, very thin layer on both sides then? I guess ultimately it can't do any harm.
Yes I'm going to test the SMPS out of the enclosure first per the manual, but I was just curious about that thermal sheet.
- John
P.S. XP - the same amount of updates!
The picture makes it clearer... so it does have paste.
In the manual where it shows adjusting the PSU, it's not made clear (that I could just see) whether that is done with the amp connected to the PSU.
I am really concerned that the PSU might do something strange with no load. As I have never worked on one of these for real I wouldn't like to say.
I know if it were myself I would probably use a 100 watt bulb for F801 and a small 40 watt or less bulb across the rails (from - 49 to + 49v) and make sure the PSU was OK.
Other option of course is just to risk it with the correct fuse and all coupled up. We know the amp is OK so no problems there.
In the manual where it shows adjusting the PSU, it's not made clear (that I could just see) whether that is done with the amp connected to the PSU.
I am really concerned that the PSU might do something strange with no load. As I have never worked on one of these for real I wouldn't like to say.
I know if it were myself I would probably use a 100 watt bulb for F801 and a small 40 watt or less bulb across the rails (from - 49 to + 49v) and make sure the PSU was OK.
Other option of course is just to risk it with the correct fuse and all coupled up. We know the amp is OK so no problems there.
It's definitely set connected to the amp. TheFragger (who's posted in this thread a few times) has his own TA-F6B thread over at Audio-Karma, and he details there setting the voltage as per the manual (with the jumper for the earth, and everything else connected).
I'm just going to try it out as it is now - everything has checked out so far, and the only change between now and then would be those four switching transistors. I'll take a chance this time and hope the audio gods are smiling down on me
Just waiting for those two 2R2s now and I should be up and running after those are installed.
At a later date I'll begin replacing all the other electrolytics in the amp (68 of them!!!) but I'll be happy for now knowing the PSU is working as it should be & all caps there have been replaced.
I'm just going to try it out as it is now - everything has checked out so far, and the only change between now and then would be those four switching transistors. I'll take a chance this time and hope the audio gods are smiling down on me
Just waiting for those two 2R2s now and I should be up and running after those are installed.
At a later date I'll begin replacing all the other electrolytics in the amp (68 of them!!!) but I'll be happy for now knowing the PSU is working as it should be & all caps there have been replaced.
Forgot I had ordered a different variety of 2R2 resistors the other day - in addition to the RS ones which didn't fit - which arrived this afternoon. Managed to shoe-horn those in. They look a bit squished in there but it's electrically safe which is the main thing and they at least fit after a fashion. I'll still replace them once the new ones arrive.
I couldn't get the voltage selector to fit back in unfortunately. A closer inpection revealed the plastic is broken in one place so I couldn't use it. Thankfully after looking at the service manual, and the board itself, realised that the norm. without the switch in place is 240V. Whew! No soldering or jumpers were needed.
Anyways, I've connected up the SMPS fully to the amp, though it's outside of the amp at present. Have also connected an earth wire from the SMPS cast chassis to the amp. as detailed in the service manual when testing the SMPS.
Switched on. No pops or bangs. Was a bit dismayed to see the VU meters not light up however. More worrying the SMPS was making a fairly high-pitched noise too. Measured quickly across the + and - on the output of the SMPS, and was reading only 27VDC.
A quick twiddle of adjustment pot and turned on again - this time there was no high pitched noise, and the VU meters lit up - whew! However was reading approx. 127V on the output so switched off again fast.
Lowered the pot a little and tried again - this time 106V and working fine.
Tried to lower the pot JUST a little, and got 89V and the noise back again, and no VU meters lighting up.
Try as I might I just cannot seem to get between 89/90ish and 106V. Which I guess means I need a new adjustment pot with greater adjustment range perhaps? The one in there is a modern Bourns blue job, though I'm not sure of the spec. I know it's a 1K though, and this is what's also listed in the manual.
Should I replace this, or will running at 106V DC be OK even though it's not the 98-99v as recommended in the manual? If I should replace it does anybody have any suggestions as to an ideal replacement, preferably from Maplin so I can nip in there tomorrow and get one:
http://www.maplin.co.uk/search?criteria=1k+preset
As ever, mucho thanks!
I couldn't get the voltage selector to fit back in unfortunately. A closer inpection revealed the plastic is broken in one place so I couldn't use it. Thankfully after looking at the service manual, and the board itself, realised that the norm. without the switch in place is 240V. Whew! No soldering or jumpers were needed.
Anyways, I've connected up the SMPS fully to the amp, though it's outside of the amp at present. Have also connected an earth wire from the SMPS cast chassis to the amp. as detailed in the service manual when testing the SMPS.
Switched on. No pops or bangs
. Was a bit dismayed to see the VU meters not light up however. More worrying the SMPS was making a fairly high-pitched noise too. Measured quickly across the + and - on the output of the SMPS, and was reading only 27VDC.A quick twiddle of adjustment pot and turned on again - this time there was no high pitched noise, and the VU meters lit up - whew! However was reading approx. 127V on the output so switched off again fast.
Lowered the pot a little and tried again - this time 106V and working fine.
Tried to lower the pot JUST a little, and got 89V and the noise back again, and no VU meters lighting up.
Try as I might I just cannot seem to get between 89/90ish and 106V. Which I guess means I need a new adjustment pot with greater adjustment range perhaps? The one in there is a modern Bourns blue job, though I'm not sure of the spec. I know it's a 1K though, and this is what's also listed in the manual.
Should I replace this, or will running at 106V DC be OK even though it's not the 98-99v as recommended in the manual? If I should replace it does anybody have any suggestions as to an ideal replacement, preferably from Maplin so I can nip in there tomorrow and get one:
http://www.maplin.co.uk/search?criteria=1k+preset
As ever, mucho thanks!
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I'm thinking... it's not necessarily the pot. The PSU could be "flipping" between two modes of operation as the voltage is adjusted.
John... I'm wondering whether in some strange way the design is "dependant" on the characteristics of the Switching transistor... it was the one thing I hoped it would not be.
The BUT11 and 2SC2335 are very similar with regard to switching times (1us)
All the electros were replaced weren't they on the primary side particularly C613.
Let me think
John... I'm wondering whether in some strange way the design is "dependant" on the characteristics of the Switching transistor... it was the one thing I hoped it would not be.
The BUT11 and 2SC2335 are very similar with regard to switching times (1us)
All the electros were replaced weren't they on the primary side particularly C613.
Let me think
Mmmmm that doesn't sound good
Yes absolutely all caps on the SMPS (and PSU board for that matter) replaced.
Just tried again and it's takes literally an infinitesimal move on the pot to get either the 90 or 106V output. It would probably change if the amp happened to be banged or something it's so sensitive.
Yes absolutely all caps on the SMPS (and PSU board for that matter) replaced.
Just tried again and it's takes literally an infinitesimal move on the pot to get either the 90 or 106V output. It would probably change if the amp happened to be banged or something it's so sensitive.
"The BUT11 and 2SC2335 are very similar with regard to switching times (1us)"
The original design used 2SC2023s, not 2335s (the 2335s were added by the repair man who originally looked at this amp). If you look at my pictures on page 1 there's a pair of 2023s and 2335s.
They should all be 2023s when all original.
The original design used 2SC2023s, not 2335s (the 2335s were added by the repair man who originally looked at this amp). If you look at my pictures on page 1 there's a pair of 2023s and 2335s.
They should all be 2023s when all original.
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Re the pot,
If there is any doubt then of course we change it. Any small 1K pot is fine as long as it fits. I wouldn't go for a multi turn tbh, just the £0.49 one.
I wonder why it was changed originally... was the same thing happening I wonder.
The 2SC2335 was used by Sony in many early switching PSU's. I think those resistors might be worth a try to see what happens.
If there is any doubt then of course we change it. Any small 1K pot is fine as long as it fits. I wouldn't go for a multi turn tbh, just the £0.49 one.
I wonder why it was changed originally... was the same thing happening I wonder.
The 2SC2335 was used by Sony in many early switching PSU's. I think those resistors might be worth a try to see what happens.
I'd rather not start adding in additional parts Mooly and experimenting I'd rather get the correct transistors in there. There's hardly any space under the clamp to fit any resistors, and the solder pads are nearly lifting in all instances too...
I've noticed Little Diode on Ebay do 2SC2023s, albiet at £5 a pop! I may get four of those when I have the cash and pray they're all similar hFEs (as specified they need to be in the servie manual).
To be honest I've had enough of this project - at least for today. Seems everytime I'm nearing completion I need another part, and then another, and then something isn't right etc. etc.
I think I need a day or two away from it
Perhaps I'll take up stamp collecting instead
I've noticed Little Diode on Ebay do 2SC2023s, albiet at £5 a pop! I may get four of those when I have the cash and pray they're all similar hFEs (as specified they need to be in the servie manual).
To be honest I've had enough of this project - at least for today. Seems everytime I'm nearing completion I need another part, and then another, and then something isn't right etc. etc.
I think I need a day or two away from it
Perhaps I'll take up stamp collecting instead
"I wonder why it was changed originally... was the same thing happening I wonder. "
Perhaps it was after the repairer was using 2 x 2023s, 2 x 2335s, plus two unknown brand 2023s for the other two transistors. Surprised it wasn't oscillating. Factor in that plus the lack of a clamp.....
I'm going to forget about Hi-Fi for the rest of the evening now Mooly. Need a change of scene.
Mucho thanks for all your help again
- J
Perhaps it was after the repairer was using 2 x 2023s, 2 x 2335s, plus two unknown brand 2023s for the other two transistors. Surprised it wasn't oscillating. Factor in that plus the lack of a clamp.....
I'm going to forget about Hi-Fi for the rest of the evening now Mooly. Need a change of scene.
Mucho thanks for all your help again
- J
Thanks for the kind offer Mooly, but I really want to get something (if I have to) that is a near-enough exact match for the Sony specified 2SC2023s:
http://www.datasheetcatalog.org/datasheet/Sanken/mXsqzq.pdf
I'll get that cermet pot tomorrow (the 89p one from maplin) and see if that makes any difference. If it does, problem solved. If not - we know it's those BUT11As (and to think I've bought two lots in the past 2 weeks - my wallet is hurting lol!)
- J
EDIT: Just had the multimeter on the legs of the voltage adjustment pot - seems to be OK no sudden jumps when it's slowly turned, so I guess that does point the finger at the BUT11As (unless you have any other ideas here?). So I need to search for something with near-enough the same specs as the 2SC2023, or get those 2023s from Little Diode and hope they're from the same hFE batch...
What would happen if I just ran it at 106V output instead of the 99V? Would it make that much difference, heat increase etc?
http://www.datasheetcatalog.org/datasheet/Sanken/mXsqzq.pdf
I'll get that cermet pot tomorrow (the 89p one from maplin) and see if that makes any difference. If it does, problem solved. If not - we know it's those BUT11As (and to think I've bought two lots in the past 2 weeks - my wallet is hurting lol!)
- J
EDIT: Just had the multimeter on the legs of the voltage adjustment pot - seems to be OK no sudden jumps when it's slowly turned, so I guess that does point the finger at the BUT11As (unless you have any other ideas here?). So I need to search for something with near-enough the same specs as the 2SC2023, or get those 2023s from Little Diode and hope they're from the same hFE batch...
What would happen if I just ran it at 106V output instead of the 99V? Would it make that much difference, heat increase etc?
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Managed to find a company that still stocks the original Sanken 2SC2023s:
Semiconductor: 2SC2023 (2SC 2023) - TRANSISTOR SILICON NPN / 300V / 2A / 40W / 20MHz... - UK (GBP)
Have ordered 3 packs (5 in each) to be on the safe side with the hFE.
Fingers crossed this'll make this damned amp work properly
Semiconductor: 2SC2023 (2SC 2023) - TRANSISTOR SILICON NPN / 300V / 2A / 40W / 20MHz... - UK (GBP)
Have ordered 3 packs (5 in each) to be on the safe side with the hFE.
Fingers crossed this'll make this damned amp work properly
Managed to find a company that still stocks the original Sanken 2SC2023s:
Semiconductor: 2SC2023 (2SC 2023) - TRANSISTOR SILICON NPN / 300V / 2A / 40W / 20MHz... - UK (GBP)
Have ordered 3 packs (5 in each) to be on the safe side with the hFE.
Fingers crossed this'll make this damned amp work properly
Absolutely fingers crossed... nothing else left.
I wouldn't keep trying the PSU in it's present state, and running the amp on a higher supply isn't advised. I see some of the caps are 50 volt rated (on a 49v supply).
I know you have been meticulous rebuilding all this and checking all the parts etc.
I don't know whether you have done this or not, but have you checked the continuity of the print between parts where it has been worked on a lot. Partiularly the resistors around Q601/2/3... I know the parts are OK... does the print have continuity. Sometimes it can break right at the pads of the components. If for example any of the parts R601/2/3 etc wasn't actually in circuit it might give this kind of symptom. Just for completeness check the same for the four transistors too.
If you don't find anything definite then of course replace the transistors with the new. Also replace Q601/613 as they are shown as the same type.