Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,407
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Post by Bigman80 on Apr 27, 2021 16:34:53 GMT
We'll try them in your system at some point, see what happens then. I've got loads of power amps here, don't have problems with any of them except these two KSA50S. That does imply that it's nothing I'm doing. If it sat unused for 10 years then all the capacitors would need to reform, so maybe once reformed one goes bad. It was fine here for over an hour the first time I used it. No problems at all. I'll go back to using the NAD for the time being. You had a listen to that and it's good, it's just not the very best possible. I'm absolutely gutted for you. Honestly, I cant understand what's occuring. Bring them down and we'll plug them in. See what happens. |
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Post by macca on Apr 27, 2021 16:40:20 GMT
That PR Audio is not too far away in Leigh. Might give him a shout see if he will look at them.
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Post by macca on Apr 27, 2021 16:43:39 GMT
We'll try them in your system at some point, see what happens then. I've got loads of power amps here, don't have problems with any of them except these two KSA50S. That does imply that it's nothing I'm doing. If it sat unused for 10 years then all the capacitors would need to reform, so maybe once reformed one goes bad. It was fine here for over an hour the first time I used it. No problems at all. I'll go back to using the NAD for the time being. You had a listen to that and it's good, it's just not the very best possible. I'm absolutely gutted for you. Honestly, I cant understand what's occuring. Bring them down and we'll plug them in. See what happens. It's no big deal, I've been buying second hand amplifiers for 30 years, not the first time I've had a faulty one by a long shot. Goes with the territory. |
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Post by firebottle on Apr 27, 2021 17:36:43 GMT
I reckon the driver transistor array (There are about 12 of them) gets far too hot.
I would like another bash at one, perhaps replacing the array with a smaller number of transistors and better heatsinking on them (there is none).
Up for it?
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Post by antonio on Apr 28, 2021 3:06:48 GMT
Nice offer Alan, and you being a toobs man  |
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Deleted
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Post by Deleted on Apr 28, 2021 5:23:30 GMT
I reckon the driver transistor array (There are about 12 of them) gets far too hot. I would like another bash at one, perhaps replacing the array with a smaller number of transistors and better heatsinking on them (there is none). Up for it? Could this be caused by an unusually high mains voltage? I am just trying to understand why Macca has so many issues. |
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Post by macca on Apr 28, 2021 6:37:50 GMT
I reckon the driver transistor array (There are about 12 of them) gets far too hot. I would like another bash at one, perhaps replacing the array with a smaller number of transistors and better heatsinking on them (there is none). Up for it? I'm up for any possible solution! |
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Post by macca on Apr 28, 2021 6:46:22 GMT
I reckon the driver transistor array (There are about 12 of them) gets far too hot. I would like another bash at one, perhaps replacing the array with a smaller number of transistors and better heatsinking on them (there is none). Up for it? Could this be caused by an unusually high mains voltage? I am just trying to understand why Macca has so many issues. I don't think so as I've got loads of amps that don't give me any bother. The XTZ that I've had amost ten years, served about 5 in the main system, now does TV duties, on every day 4 or 5 hours, no bother. My Linn LK100 almost 20 years, bought used, 10 years in the main system, no problems, was using it for a few weeks a couple of months back, works fine. The NAD, used off eBay, no issues with that. And the Krell KSA100, never a moments bother. It's just these frigging 50S jobbies that don't bloody work! The thing is you only have to listen to one for 5 minutes before you realise they are better than almost anything else. The sound is just so pin-sharp compared to the rest. I think even compared to the 686 they have a slight edge in that respect. |
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Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,407
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Post by Bigman80 on Apr 28, 2021 7:16:59 GMT
Could this be caused by an unusually high mains voltage? I am just trying to understand why Macca has so many issues. I don't think so as I've got loads of amps that don't give me any bother. The XTZ that I've had amost ten years, served about 5 in the main system, now does TV duties, on every day 4 or 5 hours, no bother. My Linn LK100 almost 20 years, bought used, 10 years in the main system, no problems, was using it for a few weeks a couple of months back, works fine. The NAD, used off eBay, no issues with that. And the Krell KSA100, never a moments bother. It's just these frigging 50S jobbies that don't bloody work! The thing is you only have to listen to one for 5 minutes before you realise they are better than almost anything else. The sound is just so pin-sharp compared to the rest. I think even compared to the 686 they have a slight edge in that respect. I think the Krell sounded a little "harder" than the 686 from memory, so i would accept your observation. |
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Post by macca on Apr 28, 2021 7:31:48 GMT
I'd be just as happy with a 686 the difference is tiny and not anywhere near enough to care about.
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Bigman80
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The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,407
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Post by Bigman80 on Apr 28, 2021 7:36:01 GMT
I'd be just as happy with a 686 the difference is tiny and not anywhere near enough to care about. I was very impressed by what we heard at your place. I don't impress easily these days either. |
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Post by macca on Apr 28, 2021 7:50:16 GMT
That was the result I was getting with the DCB1/KSA50S combo too. Almost every note is a 'wow' moment - that's why I was so keen to get another 50S!
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Post by antonio on Apr 28, 2021 9:22:46 GMT
It's a strange one, sorry to hear you are having trouble again Macca.
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Post by macca on Apr 28, 2021 10:04:41 GMT
Cheers Dave. It's just one of those things. Worse happens at sea.
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Post by antonio on Apr 29, 2021 2:40:22 GMT
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Post by macca on Apr 29, 2021 7:16:04 GMT
Gives me page not found. Probably a '50' not a '50S' though, they are completely different amplifiers. |
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Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,407
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Post by Bigman80 on Apr 29, 2021 7:32:35 GMT
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Post by jandl100 on Apr 29, 2021 8:33:02 GMT
Not a 50S,but it probably won't go phut if Martin plugs it in at his place - no guarantees on that, of course. But it's soft edged not hard edged, so not suitable anyway. Sincere sympathies on your 50S problems, macca.  |
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Post by antonio on Apr 30, 2021 0:04:26 GMT
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Post by macca on May 2, 2021 11:49:44 GMT
had a fight with the NAD amp and managed to get all the crappy binding post things off, needed to get pliers to one of them as it wouldn't shift.
But now I can just go straight in without using the adaptors. Probably won't help but can't hurt.
Have hooked it up with the Soncoz DAC into the DCB1 pre into the NAD. Looks like the pro-shop fixed the DCB1 as no hum on either channel now, so at least that's a positive.
Doesn't sound the same as when using the Philips pre-amp. Not sure which I prefer at the moment but only had it running 10 minutes.
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Post by macca on May 17, 2021 10:05:38 GMT
Thanks to Alan now got the Philips pre-amp back in the system.
Sounds better than DAC into the pre-amp section of the NAD, which is okay but a bit bland.
Also sounds better than DAC straight into the power amp section of the NAD, which sounds a bit fat and thick.
Impedance matching I suppose. I can't think of any other reason why sticking an extra component into the signal path would improve sound quality.
I did try the DCB1 pre-amp into the NAD but that also sounded a bit thick and bland. Why would that be worse than the Philips? It should resolve any matching issues.
I wish I understood this but you ask anyone technical and they say it shouldn't matter. But it does.
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Bigman80
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The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,407
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Post by Bigman80 on May 17, 2021 10:18:36 GMT
Thanks to Alan now got the Philips pre-amp back in the system. Sounds better than DAC into the pre-amp section of the NAD, which is okay but a bit bland. Also sounds better than DAC straight into the power amp section of the NAD, which sounds a bit fat and thick. Impedance matching I suppose. I can't think of any other reason why sticking an extra component into the signal path would improve sound quality. I did try the DCB1 pre-amp into the NAD but that also sounded a bit thick and bland. Why would that be worse than the Philips? It should resolve any matching issues. I wish I understood this but you ask anyone technical and they say it shouldn't matter. But it does. Yup. Exactly that. It does matter. |
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Post by macca on May 17, 2021 10:27:54 GMT
The thing is, the DCB1 should serve the same purpose. But with that in place of the Philips there was something about the sound that put me on edge. Switched it all off after one album. Thought it might just be my mood but coming back to it a day later same thing happened, one album, didn't want to listen anymore.
But with the Philips in I can listen all day. I want to listen all day. It makes zero sense to me.
I might ask about it on ASR but I'll probably get savaged lol.
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Post by firebottle on May 17, 2021 10:56:16 GMT
The DCB1 doesn't have a low output impedance, it is in effect just a passive pre with all the associated drawbacks in some installations.
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Post by macca on May 17, 2021 11:01:24 GMT
That's what I don't understand. What's the point of the active circuitry in it then? I thought that was to negate the usual issues with passives?
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Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,407
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Post by Bigman80 on May 17, 2021 11:21:07 GMT
That's what I don't understand. What's the point of the active circuitry in it then? I thought that was to negate the usual issues with passives? The DCB1 is only proving drive (the buffer bit) to the signal without amplification. It doesn't match impedances. That little Chinese DAC and Pre all in one thing that was doing the rounds on AoS battered my Hot Rodded DCB1. |
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Post by firebottle on May 17, 2021 11:34:52 GMT
The active circuitry is the power supply to the 'buffer'. As I'm sure you know the better the power supply the better the circuit works, as with almost any circuit.
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Post by macca on May 17, 2021 11:36:08 GMT
Okay that makes sense.
Chinese pre/dac? You mean that Xiang Sheng thing? I had a go on that, had some good qualities but I didn't rate it overall.
DCB1 - Krell KSA50S still remains the best amplification I ever heard although BT2/Neurochrome ran it very close.
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Post by firebottle on May 17, 2021 11:41:00 GMT
You should have the 50S back very soon. See PM.
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Post by macca on May 17, 2021 11:45:48 GMT
seen and replied.  |
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