Dual CV120 amplifier. Transistor ID? - UK Vintage Radio Repair and Restoration Discussion Forum

jim221 · 18th Jan 2017, 5:03 pm

Hello there, I recently purchased this amplifier off and to my dismay it didn't work. I liked the look of the amplifier so I thought I would spend some time trying to fix it. I immediately found that the output transistors on one (might be both yet) side did not work. Anyway I carried on and looked up the output transistors in Towers and could not find them. They were marked on the transistor as TJ 2499 and I could not find these anywhere. There are two of these in each channel and I just wondered if someone had just stuck four transistors in to fill up the holes.

The amp looks too good to scrap so has anyone got any ideas?

paulsherwin · 18th Jan 2017, 5:08 pm

Hifi Engine has the service manual (in German) - you need to register but it's free and quick: https://www.hifiengine.com/manual_li...l/cv-120.shtml

The TJ2499 is an early Motorola Si NPN power transistor. Info is certainly a bit thin on the ground but it's probably similar to a 2N3055. The amp design is quite advanced for 1972.

jim221 · 20th Jan 2017, 1:49 pm

hi Paul. Thank you for your your reply. yes i do have the service manual which I downloaded from hifi egine. I just don't know enough German to be able to make head or tale of it.
jim

18th Jan 2017, 5:03 pm	#1
jim221 Pentode Join Date: Dec 2005 Location: Dereham, Norfolk, UK. Posts: 140	Dual CV120 amplifier. Transistor ID? Hello there, I recently purchased this amplifier off and to my dismay it didn't work. I liked the look of the amplifier so I thought I would spend some time trying to fix it. I immediately found that the output transistors on one (might be both yet) side did not work. Anyway I carried on and looked up the output transistors in Towers and could not find them. They were marked on the transistor as TJ 2499 and I could not find these anywhere. There are two of these in each channel and I just wondered if someone had just stuck four transistors in to fill up the holes. The amp looks too good to scrap so has anyone got any ideas? Last edited by jim221; 18th Jan 2017 at 5:06 pm. Reason: missing words

18th Jan 2017, 5:08 pm	#2
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,947	Re: Dual CV120 amplifier. Transistor ID? Hifi Engine has the service manual (in German) - you need to register but it's free and quick: https://www.hifiengine.com/manual_li...l/cv-120.shtml The TJ2499 is an early Motorola Si NPN power transistor. Info is certainly a bit thin on the ground but it's probably similar to a 2N3055. The amp design is quite advanced for 1972.

20th Jan 2017, 1:49 pm	#3
jim221 Pentode Join Date: Dec 2005 Location: Dereham, Norfolk, UK. Posts: 140	Re: Dual CV120 amplifier. Transistor ID? hi Paul. Thank you for your your reply. yes i do have the service manual which I downloaded from hifi egine. I just don't know enough German to be able to make head or tale of it. jim