Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Login
Question Can't adjust output voltage - using alternative transistor
Options
View
Go to last post Go to first unread
Previous Topic Next Topic
bill  
#1 Posted : Wednesday, December 6, 2017 1:14:22 AM(UTC)
bill

Rank: Member

Groups: Member
Joined: 9/15/2011(UTC)
Posts: 25
Location: NZ

Thanks: 1 times
I couldn't find original QN1 /2 parts and used MJE15032G instead. Is this part ok?

Input voltage is approx. 18 VAC
I set VR1 to about 440 and VR2 to 997.
Output voltage is 13.2 vdc

I cant change the output voltage by adjusting VR2 (10K).

I'm only using the positive side of a V1 Placid bipolar board.

Any help is appreciated.
Back to top

Wanna join the discussion?! Login to your Twisted Pear Audio Support forum accountor Register a new forum account.
Back to top  
bill  
#2 Posted : Wednesday, December 6, 2017 7:50:23 PM(UTC)
bill

Rank: Member

Groups: Member
Joined: 9/15/2011(UTC)
Posts: 25
Location: NZ

Thanks: 1 times
I had previously found a wrong transistor QN4 and swapped it for a new correct one. Maybe others were affected?
Back to top
SCompRacer  
#3 Posted : Thursday, December 7, 2017 8:12:16 PM(UTC)
SCompRacer

Rank: Member

Groups: Member
Joined: 1/6/2012(UTC)
Posts: 305
Location: Plainfield, IL

Thanks: 11 times
Was thanked: 26 time(s) in 21 post(s)
I connected transformer incorrectly and ended up with fixed voltage (21v) on positive side of HD BP 2.1.

I ended up replacing QN 3, 4, 5 and Ref1B, 2B.

Check under Twisted Pear parts page. IIRC they sell the MJF122G and LT1034IZ. Check the parts list for supplier part numbers, like Mouser, digikey.

Good luck.
Rich

http://www.twistedpearau...-Denon-DVD-3910-Mod.aspx
Back to top
bill  
#4 Posted : Friday, December 8, 2017 2:56:09 AM(UTC)
bill

Rank: Member

Groups: Member
Joined: 9/15/2011(UTC)
Posts: 25
Location: NZ

Thanks: 1 times
Thanks. But are MJF122G and LT1034IZ suitable for the v1 boards?
Back to top
bill  
#5 Posted : Friday, December 22, 2017 3:43:23 AM(UTC)
bill

Rank: Member

Groups: Member
Joined: 9/15/2011(UTC)
Posts: 25
Location: NZ

Thanks: 1 times
Anyone?
Back to top
Brian Donegan  
#6 Posted : Saturday, December 23, 2017 2:13:20 PM(UTC)
Brian Donegan

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 2,868
Location: Massachusetts, USA

Thanks: 2 times
Was thanked: 141 time(s) in 134 post(s)
The LT1034IZ is fine. The MJF122 will not work well with the older Placid boards, as it is a darlington. I have abunch of the older transistors (FJPF5200/1943) available. I will add them to the parts bin.
Back to top
WWW
bill  
#7 Posted : Saturday, December 23, 2017 10:31:28 PM(UTC)
bill

Rank: Member

Groups: Member
Joined: 9/15/2011(UTC)
Posts: 25
Location: NZ

Thanks: 1 times
Thanks Brian. I placed the order :-)
Back to top
Rss Feed  Atom Feed
Users browsing this topic
GuestUser (3)
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

Youtube
Copyright © Twisted Pear Audio