Picked up a Sansui 350A - any info?

WOW that's troubleshooting !

:thmbsp:Stene !

How did you find problem was this precise transistor ?
 
Isn't it using the same power supply configuration ( 2200uf ) with the same O/P caps ( 1500 uf ) with the same drivers ( 2Sc1030 )?

What is the difference ?
To me there are differencies. See pics
 

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Many thanks Stene - I have looked at board F1248 and there is a transistor - TR704 - thank reacts to freeze spray and the background noise drops of dramatically. I am presuming this is the board associated with the tone control - its attached to the volume/ balance/bass/treble controls. The transistor is marked C458 4H. Also, what polarity should I be looking for - NPN or PNP?
cheers once again Stene - finally feel as if its possible to raise this phoenix from the ashes!:thmbsp:
There are two transistors
on the board. C458 = 2SC458 it's a NPN. Replace both. A transistor like 2SAxxx = PNP
 
WOW that's troubleshooting !

:thmbsp:Stene !

How did you find problem was this precise transistor ?
Experience :D

2SC458 is a noise generator, especially the orange type. The black colored version is a little bit better but still noisy. 2SC2240 is quiet.
 
There are two transistors
on the board. C458 = 2SC458 it's a NPN. Replace both. A transistor like 2SAxxx = PNP

Stene
Can you recommend a method of comparing old transistors with modern replacements - is there some holy grail like guide that shows suitable contemporary transistors, possibly online??
J
 
Stene
Can you recommend a method of comparing old transistors with modern replacements - is there some holy grail like guide that shows suitable contemporary transistors, possibly online??
J
Comparing old with modern ? The best method is by their specs
 
I use NTE cross reference #s. They usually works. But you need to verify as I was misleaded sometimes like NTE # 123A and 123AP has same specs but different pin out... Very bad to use wrong pin out. And you don't suspect this transistor as you just replaced it... When you have corespondent, you can also check the HFE using a multimeter. You can match pairs this way too.

Do you agree Stene ?
 
I use NTE cross reference #s. They usually works. But you need to verify as I was misleaded sometimes like NTE # 123A and 123AP has same specs but different pin out... Very bad to use wrong pin out. And you don't suspect this transistor as you just replaced it... When you have corespondent, you can also check the HFE using a multimeter. You can match pairs this way too.

Do you agree Stene ?
I'm not fond of NTE as you never know what you get. It can be good but also bad because NTE isn't a manufacturer of transistors. They are buying large quantities from different companies and rename them to NTExxxx. Some DMM has a hFE mode other µF mode.
 
I usually get the NTE cross ref. number and buy a transistor with the same number at the electronic surplus store around which buys good and not so good transistors. I can then decide which one I want. I never bought NTE brand transistors.
 
I usually get the NTE cross ref. number and buy a transistor with the same number at the electronic surplus store around which buys good and not so good transistors. I can then decide which one I want. I never bought NTE brand transistors.
Hm :scratch2: So in this case the transistor is 2SC458 and you get the NTE cross ref number which is NTE85.
What's next step if you never buy NTE ?
 
I get to my "surplus" electronics store with my transistor #. He first look if he has the exact replacement. If not, he uses the NTE #. He looks in his list and see what he has ( usually he can propose me 4 or 5 different "replacement" #s ). He then go and pick what I asked him to or what he propose me. If 2SC2240 is NTE85 in the charts, 2SC2240 will be in his list under NTE85 correspondant transistors if he has some in stock. Can be many others too. Never these parts has the "NTE" logo on them. Can be toshiba, Sanken, Sanyo, etc.

Quick one for you Stene, as you seems to have a lot of Sansui schems, is the AU-505 built using the same configuration as the AU-555 ?
 
Hey that's a good haul!
What I am after is the schematics for the the 350A - want to try and give it the once over plus find a replacement for the 'needle ' bulb on the tuning display.
Any info you have would be cool
Cheers
J
I always replace those nasty little filament lamps in the pointer with a miniature LED. If fed by AC you MUST bypass the LED with a reverse connected Si junction diode to take the reverse 1/2 cycle voltage (this goes for all LED's - they have a very low tolerance to reverse voltage.)
Aim for no more than 15 mA through the LED so calculate the needed series resistance by Ohms law, viz: R series = (supply voltage - LED forward voltage (about 2 vdc))/0.015 ohms. I've forgotten the 350A's lamp voltage, also if it is AC (likely), so you'll have to measure it! Use the lowest LED current that gives you decent brightness on the pointer.
Cheers,
Roger
 
There are two transistors
on the board. C458 = 2SC458 it's a NPN. Replace both. A transistor like 2SAxxx = PNP

Hi I have the same problem with my 350A, so am replacing the transistors as suggested. But I see 4, not 2, transistors on that board. 3 are labeled "C4582A", and 1 is labeled "C4581M". Should I replace all 4 with the 2CS2240?

Thank You
 
2SC2240 works great. (BTW, the 2A and 1M at the end of the c458 are probably production codes - they are 2sc458 and notorious for becoming noisy and intermittent.) Good luck.
 
A buddy of mine had a 350A in mint condition, still in the original box and I had a very nice Sansui 4000 he was interested in so we worked out a trade. We're both happy. The 350A's a punchy little receiver for the 20-22wpc it's rated at. I'm listening to smooth jazz on sky.fm through the 350A as I type this... :music:

The 350A
P1030120.jpg
 
Wow, that's really quite a coincidence since I just picked up beautiful Sansui 4000 from a co-worker of mine, all he wanted was my 350a. I can't tell you how happy I am with the 4000, but I do miss that little 350a. :thmbsp:
 
Wow, that's really quite a coincidence since I just picked up beautiful Sansui 4000 from a co-worker of mine, all he wanted was my 350a. I can't tell you how happy I am with the 4000, but I do miss that little 350a. :thmbsp:
Well you're not getting the 350A back Mr. Onkyo! But I'm glad you're enjoying the 4000. I'll have to come down to hear the 4000 with your setup.

Happy listening, my friend. :music:
 
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