LM317HV and TL783 regulators--no stock

[Matt Syson]

783 and 317 can be very reliable but you must be careful to ensure that all the 'limitations' that are mentioned in the data sheets are attended to. Sticking a couple of milliamps the wrong way into the adjustment pin must not happen for example so a carefully 'protected' circuit overall, can be zapped by random probing. The suggested 'reverse polarity' diodes might need to be low forward volatage types but then schottky diodes can be a bit 'leaky'.

 

[pwgtang]

Hi Fred Forssell, I am looking for the TL783 to repair a Moscode preamp, can you sale me few ? Thanks.

 

[gyraf]

..reichelt.de currently have plenty of them..

/jakob E.

 

[Mr. Moscode]

Hi Fred Forssell, I am looking for the TL783 to repair a Moscode preamp, can you sale me few ? Thanks.

You have one of my preamps. Congrats.

 

[pwgtang]

Hi Mr Moscode, you preamp were well designed , the power supply high voltage output very stable, the mosfet constant current supply also make this preamp very quiet with high gain. I had fixed the issued and upgrade the volume control to the Alps Blue RK27 pot.

​

 

[Mr. Moscode]

How did you fit the volume pot? Is it a big blue one? Post a pix if you don't mind.

There is no constant current supply in it. 2 stage regulation TL783 with TIP50 to extend voltage range, followed by 4 op amp follower buffers, 2 /channel.

Yes, rock solid B+ 335 VDC.

 

[pwgtang]

Hi Mr Moscode, the original pot channel balance not good, the Alps Blue pot is much better.

 

[Mr. Moscode]

Thanks for the pix, yes, it tracks better. It looks like it fits ok, too.
Excellent

 

[MidnightArrakis]

Hi Fred Forssell, I am looking for the TL783 to repair a Moscode preamp, can you sale me few ? Thanks.

How about these???.....

https://www.onestopelectro.com/?mfgPartNo=TL783CKTT&utm_source=octopart#contacts
Available: 188 Price Each: $1.41

ORDER SKU NUMBER: 55433007

https://www.onestopelectro.com/?mfgPartNo=LM317HVKSTEEL&utm_source=octopart
LM317HVKSTEEL -- Available: 7,105 Price Each: $1.67

ORDER SKU NUMBER: 55433253

/

 

[MidnightArrakis]

Recent posts here:

https://groupdiy.com/threads/the-official-g9-help-thread.17980/page-119
....raised my eyebrows. Sure enough, Mouser , Digikey, Allied, etc. won't have stock for the TL783 in TO-220 package until NEXT SUMMER! On a whim, I also checked stock for the LM317HV. Same story!

I did find some NOS of the 317HV (TO-220 package) at Jameco and placed an order. I didn't buy their entire stock (and they claim to have more available Sept. 2) so I left some stock on their shelves for other folks to purchase.

I seldom need the higher voltage regulators but don't want to be left empty handed in the future.

Strange Times.....

Bri

How about these???.....

https://www.onestopelectro.com/?mfgPartNo=TL783CKTT&utm_source=octopart#contacts
Available: 188 Price Each: $1.41

ORDER SKU NUMBER: 55433007

https://www.onestopelectro.com/?mfgPartNo=LM317HVKSTEEL&utm_source=octopart
LM317HVKSTEEL -- Available: 7,105 Price Each: $1.67

ORDER SKU NUMBER: 55433253

/

 

[pwgtang]

Hi all,
I had fixed the preamp, thank you for all the information.