Quick advice on PSU for TA2024 T-amp

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IslandPink
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#46

Post by IslandPink »

Ummm..
Well it's more a case of where the energy goes in the room Mike - it's there, but only in the front corners ! Not sure how the mains AC would be connected to this - just seems like an odd room-mode.
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Mike H
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#47

Post by Mike H »

Fairy nuff, just thought it was quite a coincidence. Just wondering if you might have a residual 50 Hz hum in the room (?)
 
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IslandPink
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#48 Build

Post by IslandPink »

Mike - having residual 50Hz hum ( or 100Hz hum ) in the room is always a possibility :) but not much at the moment .

Ali - Just got the TDA7297 properly sorted and running .
Should have taken a picture of the insides before I closed it up, but I basically did the 'Salis' mods from that thread I linked.
Picture below of it in-situ - a 'half-shoddy' job ( not telling you which half ! ) in an RS box I already had .
I used a gold Nichinon 4700uF/16 as the final big PS cap on the board ; the pair of Nichinon Muse 1uf/50's on each input, paired with opposite orientations ( almost missed that detail on the first read-through the AudioCircle thread ) and took out the 'D2' diode and the small mustard-coloured cap.
Power supply as descrbed above, with 5A regulator .
Has had about 2hrs running in .
Sound is very musical in the bass and mids. The 2uF input cap really gives it some low-bass welly - very solid and satisfying. Midrange tone is also good, and quite spacious .
From the upper mids upwards it gets rather bright and edgy to my taste - makes the Ariels sound bright ! Couldn't put up with it long-term vs. the proper treble of a valve amp , but would work OK with speakers that are rolling-off at the top . This may be no worse than the TA2024 for all I know, but I never got the gain problem sorted out with the TA2024, so never heard it on music.
Maybe I shouldn't have removed the mustard-coloured cap ? - would be good to try with/without probably .
Should run-in more, but the trend is for the treble to get brighter, so may not improve as such . In any case, will be excellent for the purpose I intended - bass amp .
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Ali Tait
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#49

Post by Ali Tait »

Cheers Mark, sounds like you got a good result.
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IslandPink
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#50

Post by IslandPink »

As I mentioned to Ali on e-mail, this unit started to come back in a more useful direction after a lot more run-in over the weekend . Not often this sort of U-turn happens, in my experience of run-in with caps and the like.
I had it on the main system with vinyl on Sunday, and was really enjoying it - it has very solid bass and timing, good midrange tone, plenty of space and low-level stuff .
Maybe the top-end will improve a bit more, or there are more tweaks on the board to influence that ?
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Ali Tait
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#51

Post by Ali Tait »

Have to give my set a go soon, still busy refurbishing a set of wad PSE monoblocks...
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