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Post by alit on May 12, 2021 14:00:19 GMT
Some more work on the Krell, swapped out the Roederstein Lytics-   All back together now. Just letting it warm up before setting bias and DC offset. I measured the bias the other day, one channel is running a bit hot at 673mV, I'll drop both channels to 575mV or so, that'll give the output stage a bit of an easier life. This gives a good idea of the size of the main PS caps, they are not small-  These look to be fine so I'll probably just leave them in for now  |
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Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,430
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Post by Bigman80 on May 12, 2021 15:23:36 GMT
Spot on. They are very good caps IMO.
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Post by macca on May 12, 2021 16:08:23 GMT
'Capacitors the size of Coke cans'
No, actually they're quite a bit bigger than that...
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Post by alit on May 12, 2021 16:09:01 GMT
Hope so, given the cost lol.
Backed off the bias now, and got the offset down to 0.1-0.3mV or so. Have a set of cheapie sacrificial speakers which I've been playing it on for an hour of so, I can hear the potential. Looking forward to slotting it into my system when I get back to my place.
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Post by alit on May 12, 2021 16:15:30 GMT
Picked these up a few weeks ago locally for next to nowt-   Pair of Falcon Acoustic Nightingale NM-1. Don't look like much but they actually sound very decent. TL bass so the Krell should grab them by the scruff of the neck nicely and chuck out some nice deep notes. |
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Post by alit on May 12, 2021 16:19:51 GMT
'Capacitors the size of Coke cans' No, actually they're quite a bit bigger than that... LOL aye, just a bit. |
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Post by firebottle on May 12, 2021 16:21:00 GMT
Nice one Ali.
Have you got any way of testing the big 'lytics?
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Post by alit on May 12, 2021 18:42:26 GMT
No just have a Fluke. Could take it to Nicks', probably will at some point, get it on his scope.
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Post by antonio on May 13, 2021 0:22:44 GMT
Nice work Ali, enjoy your Krell.
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Post by alit on May 13, 2021 5:16:34 GMT
Thanks mate. Don't enjoy lugging it around lol.
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Post by macca on May 13, 2021 5:32:21 GMT
Those speakers look like they could bring the world to an end. Never even heard of them before, what sort of vintage are they? Early 1980s?
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Post by alit on May 13, 2021 8:39:22 GMT
A Seventies design. Isophon tweeter, Peerless mid ( known for surround rotting but these have been redone) and of course the KEF B139 racetrack woofer. There were several designs made by I forget who, which were subsequently sold to Falcon. The woofers sound fine but have some dings, I might look out for a pair in better nick. You can get new versions from Falcon but they are 200 quid each.
They are actually pretty bloody good, enough that I will swap out the lytics for film caps, see what that sounds like. There are a few threads about on these if you look around.
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Post by sq225917 on May 14, 2021 8:53:35 GMT
How are those cardboard pcbs holding up to rework?
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Post by alit on May 14, 2021 11:19:40 GMT
The cap swap you mean? Yeah had to be careful with them. Did raise one of the solder pads taking out the old caps, managed to get it back into place though. Did think about new boards with all new components, have you come across any direct replacements?
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Post by sq225917 on May 14, 2021 12:06:22 GMT
I've never seen a like for like
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Post by alit on May 14, 2021 18:45:51 GMT
OK Cheers.
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