PDA

View Full Version : My latest vintage tuner/amp purchase



selfaddict
24-09-2011, 19:23
I just needed :) to write my first impressions of this lovely piece of vintage hifi, which I received by post yesterday. It is Sansui 250 and has more valves than I have fingers in both hands :eyebrows:.

http://www.thevintageknob.org/sansui-Model_250.html

For some reason since I was introduced to valves, I always have wanted to see what ECL82 can do in push-pull design and when this amp came to the market I had to have it. For my surprise it came with its original box, packing and user manual. Previous owner had had the amplifier since new, that is more than 40 years. He had received it from Singapore when his relative had been working there in the 1960's.

I opened the box and was pleased to find out that Royal Mail hasn't damaged anything during its way to this tiny island in the Irish sea. Then opened the box and saw a few decades worth of dust and some rusting on the amp's chassis plate. This must have been due damp or condensation at the sellers residence, but managed to clean the dust and get rid of worst of the rust without taking anything apart. I was too exited to test the valves and just plugged the amp to the mains and waited to see what happened. All valves started gradually glowing and slight hum from the speakers, so everything seems to be OK. Then I turned the volume up and was rewarded with just lovely soft, cuddly warm tone that I was hoping to have. The left speaker was slightly quieter that the right but within few minutes sound was equal between the speakers. It was perfect match with my 16ohm Bastanis Atlas speakers, when used amps 16ohm speaker tabs, this is great I was thinking. Listened most of the evening and was really pleased for my purchase.

Then this morning started to listen again and same quieter left speaker was there to start with, but this time it seem to last longer and there was more hum from left speaker so decided to swap ECL82 output valves around. No change, so decided to test all four of them with my vintage valve tester. All tested OK but weak, so tried a pair of Telefunken ECL82, still the same problem. Then tested rest of the valves and two of them tested bad/needs replacing. So then to the trusty ebay and I was pleased to see that the replacement valves I need are not expensive and easily available. It looks that I can indulge with NOS Telefunken valves and see what the fuss is all about. At least the pair of Telefunken ECL82 I tried, sounded very very promising, so when I get another pair of them and the other valves which needs replacing, I should be very happy bunny :lol:

selfaddict
24-09-2011, 19:45
Few pictures. Sorry I am not smart enough to attach them directly here, so link instead.


http://imageshack.us/g/90/20110924img0024.jpg/

DSJR
25-09-2011, 19:27
There are possibly some important caps to replace as well, for reliability issues as much as anything else...

Rare Bird
25-09-2011, 19:54
Too much writing to read but looks nice.

selfaddict
25-09-2011, 20:02
There are possibly some important caps to replace as well, for reliability issues as much as anything else...

Hi Dave.

I was wondering about the capacitors as well. How does one know when capacitors needs to be changed? Sorry about silly question, but I am just taking my first steps on the DIY route :).

Rare Bird
25-09-2011, 20:14
Something that old, i just do it anyway because the Electrolytics all past it

selfaddict
25-09-2011, 20:24
Too much writing to read but looks nice.

I was trying my very best to waffle a bit for a change ;)

selfaddict
29-09-2011, 19:03
This has been very interesting experiment all in all. Sansui sounded great to start with but very soon started to get worse. First left channel started to fade away, then there was really bad distortion especially on the bass. Distortion increased greatly when loudness was turned on. Tested output valves and noticed that all 6BM8/ECL82's were weak and replaced all of them with matched quad Mullard ECL82's. The bass distortion disappeared, but the left channel still was weaker compared to the right. Next tested three 6BA6's and one was dead, changed all of them to Telefunken EF95's. Now had both channels the same volume, but tuner was not right, CD and TT played great. Tested 6BE6 and found it needed replacing.

What I learned from this: Take your time and test ALL the valves before rushing to listen to gear which hasn't been used for a long time :)