Worst of wait is the amp's repair stand is what normally holds outdoor pizza oven, now out of commission. Have other amps, but no other pizza oven.
Meanwhile back at ranch, two question arise on parts.
Last thing to replace is V1, V2 and OK1 and OK2. V1 and V2, on schematic are
show as LM 385-1.
Looking up that part doesnt show 3 leg device in kits, shows odd 4 leg flat square device. More like OK1 and OK2. What is V1-V2 version part number?
Also, part was 3 legs, schematic only shows 2 connections. Obviously I am on wrong part path.
https://www.mouser.com/ProductDetail/Texas-Instruments/LM385-1.2-MWC?qs=zEmsApcVOkUzCuXfvLf/Sw== (out of stock anyway)
Not same number, but will this work?
https://www.mouser.com/c/?q=LM385BLPE3-2-5
OK1 and OK2 show "PC 817" on schematic, search at both Mouser and Digikey show anything but that part! Must be searching that one wrong too.
Will this slightly different number work?
https://www.mouser.com/ProductDetail/Sharp-Microelectronics/PC81713NIP1B?qs=rrS6PyfT74eNHbzqPCYSng==
Any help figuring out these parts so can be ordered much appreciated.
Russellc
Last thing to replace is V1, V2 and OK1 and OK2. V1 and V2, on schematic are
show as LM 385-1.
Looking up that part doesnt show 3 leg device in kits, shows odd 4 leg flat square device. More like OK1 and OK2. What is V1-V2 version part number?
Also, part was 3 legs, schematic only shows 2 connections. Obviously I am on wrong part path.
https://www.mouser.com/ProductDetail/Texas-Instruments/LM385-1.2-MWC?qs=zEmsApcVOkUzCuXfvLf/Sw== (out of stock anyway)
Not same number, but will this work?
https://www.mouser.com/c/?q=LM385BLPE3-2-5
OK1 and OK2 show "PC 817" on schematic, search at both Mouser and Digikey show anything but that part! Must be searching that one wrong too.
Will this slightly different number work?
https://www.mouser.com/ProductDetail/Sharp-Microelectronics/PC81713NIP1B?qs=rrS6PyfT74eNHbzqPCYSng==
Any help figuring out these parts so can be ordered much appreciated.
Russellc
Last edited:
yup
LM385-1V2 is 3 legged part, but only two legs used
PC817 is having many names, but 817 is common denominator, and C range preferable
even if in this case not at all critical - it can be withot suffix, or B suffix
and yeah - I'm using through hole, but even smd option can be soldered "on pads"
LM385-1V2 is 3 legged part, but only two legs used
PC817 is having many names, but 817 is common denominator, and C range preferable
even if in this case not at all critical - it can be withot suffix, or B suffix
and yeah - I'm using through hole, but even smd option can be soldered "on pads"
PC817 X3 = PC817C
https://www.mouser.com/ProductDetail/Sharp-Microelectronics/PC817X3NIP1B?qs=rrS6PyfT74f4G0G4E3ul/Q==
https://www.mouser.com/ProductDetail/Sharp-Microelectronics/PC817X3NSZW?qs=t7xnP681wgUy3xhl6rlbWQ==
https://www.mouser.com/datasheet/2/365/Sharpelectronics_08292023_73758-3310502.pdf
https://www.mouser.com/ProductDetail/Sharp-Microelectronics/PC817X3NIP1B?qs=rrS6PyfT74f4G0G4E3ul/Q==
https://www.mouser.com/ProductDetail/Sharp-Microelectronics/PC817X3NSZW?qs=t7xnP681wgUy3xhl6rlbWQ==
https://www.mouser.com/datasheet/2/365/Sharpelectronics_08292023_73758-3310502.pdf
Ok, both ordered along with some more TH1, picked one that looks same and had qualifying 200 uA igt. That is all actives on board, looks like T4 was culprit.
Allow me to gush a little.
My xa252 was out of commission for a couple of days and the Aleph J was back in action. Returning the xa252 to the rack reminded me how incredibly transparent this amp is. You can practically 'see into the music' discerning details that are masked with the Aleph. Then there is the low end. It is so nicely resolved and present, even at low volumes. I particularly notice this with the 'hall reverberation' on classical recordings where the Aleph may indicate that information exists on the recording while the xa252 resolves and plays it. All of this while being extremely musical.
The thread may suggest this amp is somewhat 'high maintenance' ... to me, it is well worth it.
Thanks ZM!
My xa252 was out of commission for a couple of days and the Aleph J was back in action. Returning the xa252 to the rack reminded me how incredibly transparent this amp is. You can practically 'see into the music' discerning details that are masked with the Aleph. Then there is the low end. It is so nicely resolved and present, even at low volumes. I particularly notice this with the 'hall reverberation' on classical recordings where the Aleph may indicate that information exists on the recording while the xa252 resolves and plays it. All of this while being extremely musical.
The thread may suggest this amp is somewhat 'high maintenance' ... to me, it is well worth it.
Thanks ZM!
I don't know about high maintenance, while operating, mine was stable as can be. It blew up through my own fault, accidentally passing a transient, R24 and a few associated parts cooked.
You might want to keep some spares around, and while I don't know if any amp would have done this (I am not going to try) it was a terrific transient, not just a mild pop.
In one of the answers from zenmod he said something about a plan to make the "R24 area" a bit more poof proof from builders pulling stunts like mine did. BTW, mine is straight mosfet, no sit or set.
Russellc
You might want to keep some spares around, and while I don't know if any amp would have done this (I am not going to try) it was a terrific transient, not just a mild pop.
In one of the answers from zenmod he said something about a plan to make the "R24 area" a bit more poof proof from builders pulling stunts like mine did. BTW, mine is straight mosfet, no sit or set.
Russellc
Yes, it is. Enough so I am trying to talk self into the real McCoy. Passed on one "open box" for about a grand less..
Stupid me
Stupid me
Parts all came but not sure about my TH1 choice. All the right numbers appear to me to be correct, but when I opened box, part is significantly smaller than the original supplied TH1 part. Here's a pic with packaging. Quite a bit smaller in size, so I think I may need to reorder?
Or is this part fine, despite much smaller size? (Pic shows original removed part )
Comments again appreciated 😁
Russellc
Or is this part fine, despite much smaller size? (Pic shows original removed part )
Comments again appreciated 😁
Russellc
Attachments
Right. I saw numbers good, but size so far off I had to ask. If error can happen high chance of me falling for it.
Thanks,
Russellc
Thanks,
Russellc
Oh, also regarding reading on chinese gizmo of TH1, recall original part measured as Thyristor one way, reversed as diode...I guess it is just artifact of gizmo as new parts measure the same way.
Russellc
Russellc
Yes, I'm sure I will. At this point, when ready to re fire it up, every part on board except the tiny bits that were pre attached and the outputs are replaced. Seems like it should fire up as it did originally.Good point. To some degree, my inexperience and mistakes are to blame for the downtime. I should have stated my amp has been somewhat higher maintenance. Still love it, though. Hope you get yours back online soon.
The through hole parts on the board are pretty inexpensive, to keep it going no risk I'm keeping spares of everything! I have bought them and extras. This way it can be fixed without a bunch of different separate orders wasting more time!
The other channel was corrected with minimal parts dead. This channel didn't respond same way.
Sorting through the parts I do believe the only dead part extra compared to other channel was T4. Went ahead and replaced all as I had the parts
Of course!

Though, Plethora of Pinjatas is actually amp optimized/more optimal for these conditions
sorta dead race - pucks are having wilder and bigger capacitances (to deal with) while having greater xcondcutance
IRFP pixies are having tamer capacitances while having smaller xconductance

Though, Plethora of Pinjatas is actually amp optimized/more optimal for these conditions
sorta dead race - pucks are having wilder and bigger capacitances (to deal with) while having greater xcondcutance
IRFP pixies are having tamer capacitances while having smaller xconductance
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