Just the originals?
You do know how to stoke up an over long response with that!!
As I'm pondering cap choices so this will certainly come up! I haven't looked myself yet but the potential victims are:
2SC634
2SA678
2SA639
2SC1124
2SA835
It would be nice if the complementary ones were actually complementary - it would also be pleasing if I could actually get hold of any suggested replacement
Of more urgency are replacements for the 1T22A, SH-IS, 10E-2 (sorry if not clear in 1 vs I and O vs 0) I know some are germanium types and best kept as such, but swapping some for UF400x types might be an option for the SH-1S?
Andy
First problem solved? germanium (?) 1T22A on the 'wet' side are corroded into the glass so can't be re-fitted really. However, these are used on the TA-5650 so source found! don't worry this is on the amp that's already fallen on the grenade....
In other news; motivation levels took a boost with delivery of a TAE-5450 pre-amp. Just need a source of the wooden side panels now to finish it off (still less difficult to find than a set of Vfets)
Those SH-1S are next
Andy
In other news; motivation levels took a boost with delivery of a TAE-5450 pre-amp. Just need a source of the wooden side panels now to finish it off (still less difficult to find than a set of Vfets)
Those SH-1S are next
Andy
SO most of the flat components are in (and of course I'm a 22k resistor missing)
Reused the 1T-22A's - or at least the less corroded ones, I managed to find 4 that were good visually and tested OK
All 4, SH-1S test good too but frustrated by the lack of a datasheet I'll probably re-use these in the transistor protection circuit. Whilst the modern UF4004 seems like a good alternative it's hard to be sure, and taking a chance seems unnecessary
Andy
Reused the 1T-22A's - or at least the less corroded ones, I managed to find 4 that were good visually and tested OK
All 4, SH-1S test good too but frustrated by the lack of a datasheet I'll probably re-use these in the transistor protection circuit. Whilst the modern UF4004 seems like a good alternative it's hard to be sure, and taking a chance seems unnecessary
Andy
Sooo update
SH1S's re-used
1S1555 replaced with 1N4148
10E-2 replaced with UF4004
All caps are now Wima or Polymer types as appropriate
And frankly amazingly all transistors test good - that is a nice surprise
Found / discovered that the green on the bigger transistors was copper oxide emerging from under the tinning, while cleaning them with IPA and a scalpel (very, very carefully)
Anyway photo attached, 10uF Caps are (mostly) omitted as I need to check polarity - original silkscreen vs correct, there's an article somewhere suggesting they might be off
Very red isn't it
Andy
SH1S's re-used
1S1555 replaced with 1N4148
10E-2 replaced with UF4004
All caps are now Wima or Polymer types as appropriate
And frankly amazingly all transistors test good - that is a nice surprise
Found / discovered that the green on the bigger transistors was copper oxide emerging from under the tinning, while cleaning them with IPA and a scalpel (very, very carefully)
Anyway photo attached, 10uF Caps are (mostly) omitted as I need to check polarity - original silkscreen vs correct, there's an article somewhere suggesting they might be off
Very red isn't it
Andy
Attachments
To Quote Agent Smith; 'more'
Couple of PRP resistors and some volts will ruin all the fun no doubt. But these are halcyon days, reality may still bite
Nevertheless all transistors have been checked (again) before fitting and checked against photos of prior orientation to mitigate the silk screen... Slowly slowly the ice is thin
the 0.22 ohm resistors are 12w Mills wire wound, they fit pretty well, even without their insulating 'legwarmers' to prevent random shorts
Andy
Couple of PRP resistors and some volts will ruin all the fun no doubt. But these are halcyon days, reality may still bite
Nevertheless all transistors have been checked (again) before fitting and checked against photos of prior orientation to mitigate the silk screen... Slowly slowly the ice is thin
the 0.22 ohm resistors are 12w Mills wire wound, they fit pretty well, even without their insulating 'legwarmers' to prevent random shorts
Andy
Attachments
Unexpected complication!
I do realise I'm likely talking to myself at this point, but looking for info on the thermistors Sony label as PTH401, PTH501 and PTH701
I know they are positive types in that the resistance goes up at temp but that's it.
I'd assumed that all these amps would have the same Thermistor as hot is hot, but apparently not. TA-4650 , TA-5650 and the TAN-5550 all have different types as it turns out, so I have a mixed bag of unmarked 'spares' that aren't the same...
Andy
I do realise I'm likely talking to myself at this point, but looking for info on the thermistors Sony label as PTH401, PTH501 and PTH701
I know they are positive types in that the resistance goes up at temp but that's it.
I'd assumed that all these amps would have the same Thermistor as hot is hot, but apparently not. TA-4650 , TA-5650 and the TAN-5550 all have different types as it turns out, so I have a mixed bag of unmarked 'spares' that aren't the same...
Andy
My Head Hurts
Not from the indulgences of yesterday but because I just realised that the 5550 is very different in operation from the 5650's and so on
The Drain is at volts now it's all upside down!!
I'm still expecting to see a mix of 89v, 58v and 0v on the pins of each VFET board but HT is off the walls varing from -39 when it should be positive to absolutely OK , 58v and almost 0v (0.1v) is good as are all the voltages at the feed to the class B board... to make it worse its the 2SJ18's on one channel and the 2SK60's on the other. that are skewed
All transistors were checked on the way in this should just work but OH am I missing something here
The gift that keeps on giving this one
Andy
Not from the indulgences of yesterday but because I just realised that the 5550 is very different in operation from the 5650's and so on
The Drain is at volts now it's all upside down!!
I'm still expecting to see a mix of 89v, 58v and 0v on the pins of each VFET board but HT is off the walls varing from -39 when it should be positive to absolutely OK , 58v and almost 0v (0.1v) is good as are all the voltages at the feed to the class B board... to make it worse its the 2SJ18's on one channel and the 2SK60's on the other. that are skewed
All transistors were checked on the way in this should just work but OH am I missing something here
The gift that keeps on giving this one
Andy
This thread is not too old to react on... Got a restored TA-4650 ("Polonaise Mod") with burned out lateral MOSFETs. The heat sink had gotten so hot that the connector to the board had melted. Now posistor PTH401 should go high in value and trigger the speaker relay. It does but the relay does not release. But the value of the posistor over temperature may be of interest:
So the posistor is perfectly fine. Now to find why the relay doesn't switch off...
| T [°C] | R [ohm] |
| 33 | 168 |
| 73 | 287 |
| 89 | 698 |
| 102 | 3.33k |
| 112 | 20.4k |
So the posistor is perfectly fine. Now to find why the relay doesn't switch off...
Thanks. hard to find info that. I will admit I have got distracted by a TA 636 that refuses to un-mute (an easy fix, two weeks ago) and some TA-AX2's etc but the TAN-5550 is still lurking.
Andy
If you are hopeless, I have a lost 4650 with 4 good ones available. Your reports are very valuable. PM.
Thanks for the manual! I can't read them... this is what the guy that sold it to me said- it does not seem right:
"An Amplifier doesn't have "coupling" capacitors, It has electrolytic capacitors in power supply, protection circuitry (C506, C508, C606, C608), and one in feedback in differential amplifier C106. It is a "open input" type amplifier.
In the "normal" mode it has non-electrolytic capacitors C151 and C152. they are active when you move switch to "normal" position. They are 0.22 uf film capacitors."
"An Amplifier doesn't have "coupling" capacitors, It has electrolytic capacitors in power supply, protection circuitry (C506, C508, C606, C608), and one in feedback in differential amplifier C106. It is a "open input" type amplifier.
In the "normal" mode it has non-electrolytic capacitors C151 and C152. they are active when you move switch to "normal" position. They are 0.22 uf film capacitors."
Hi, looking at the schematic, there are no caps in the signal path, (unlike the TA-4650/5650), This is something I'd not noticed before. Hope I'm not wrong there
I have heard anecdotal feedback that these amps are all a bit bright, I would guess it also depends on the source / pre that are coupled with it. I don't know for sure as I STILL haven't got mine working.
I've never found a frequency response curve in any literature... On the integrated amps the 'loudness' toggle does help, that would be a function of the pre-amp here.
Andy
I have heard anecdotal feedback that these amps are all a bit bright, I would guess it also depends on the source / pre that are coupled with it. I don't know for sure as I STILL haven't got mine working.
I've never found a frequency response curve in any literature... On the integrated amps the 'loudness' toggle does help, that would be a function of the pre-amp here.
Andy
"I have heard anecdotal feedback that these amps are all a bit bright, I would guess it also depends on the source / pre that are coupled with it. I don't know for sure as I STILL haven't got mine working."
As the owner of working 4560 and 5650 amps I'd say that they are warm'ish in sound, not overly bright (but also not dull). I'm using these with various TDA1541a CD players and Yamaha NS1000 speakers. Like many things, they do seem to benefit from being on for a day or so to settle down, being winter, I don't turn off the one I'm using.
As the owner of working 4560 and 5650 amps I'd say that they are warm'ish in sound, not overly bright (but also not dull). I'm using these with various TDA1541a CD players and Yamaha NS1000 speakers. Like many things, they do seem to benefit from being on for a day or so to settle down, being winter, I don't turn off the one I'm using.
Yes that's fair. Me too - Teac cd-Z500 to TA 5650 to Castle Harlech being the current set up. I like it
The trouble (AKA my trouble) with the TAN-5550 is it's quite a different beast to get going - hence the massive pause.