Fisher statesman help

jjprager

New Member
Hi all,
I recently unearthed a Fisher Staesman IV from my grandparents house. I turned it on and it sounded pretty good. All the tubes were glowing so I figured I would take it and stop listening to music through a home theater. After listening for a bit at home I noticed the audio fading in and out, not completely but noticeable. Then I started to pan left to right. The right channel is missing clear treble. And the right channel's bass is cutting in and out. I had a bunch of ecc83 tubes laying around so I popped them in, and replaced the output transistors as these were the two easiest things to change. If I crank the volume an bass the full output will come through until I turn it back down to a listenable level. I'm new to tube hi fi systems. Do I need new output tubes? Also I noticed the white calendar between the ell80 tubes was REALLY hot. Any help is greatly appreciated.
 
Hi all,
I recently unearthed a Fisher Staesman IV from my grandparents house. I turned it on and it sounded pretty good. All the tubes were glowing so I figured I would take it and stop listening to music through a home theater. After listening for a bit at home I noticed the audio fading in and out, not completely but noticeable. Then I started to pan left to right. The right channel is missing clear treble. And the right channel's bass is cutting in and out. I had a bunch of ecc83 tubes laying around so I popped them in, and replaced the output transistors as these were the two easiest things to change. If I crank the volume an bass the full output will come through until I turn it back down to a listenable level. I'm new to tube hi fi systems. Do I need new output tubes? Also I noticed the white calendar between the ell80 tubes was REALLY hot. Any help is greatly appreciated.

You need to recap (coupling caps and power supply caps) at the very least. A bad cap can ruin your day (along with a lot of components in that console).

-D
 
Good thing would be to DE oxit then fader lube the controls and switches (clean and lube ) If you haven't done that already Your symptoms could be related to that problem .
Member Arkay wrote a very good guide to do that . Not sure what you mean by "calender" selenium rectifier perhaps ?
http://www.audiokarma.org/forums/showthread.php?t=207005

OH and what derekva said also real important !
 
Stop shotgunning things that probably don't need to be replaced and fix the things that really should be addressed. Derekva and frankxbe put you on the right track.
 
yep, its almost certainly the capacitors, but crusty controls won't do you favors either.
 
The Statesman IV, Ambassador VI, and Futura V all used the 690T/690A Hybrid combo. REPLACE ALL THE ELECTROLYTIC CAPS in the amp, and the preamp. FISHERCONSOLE.COM doesn't have the 690 combo. The closest I can come is the 65 49T and 59A as cousins to the 690's.

The Output transistors are germanium. Try not to fry them. not only are they hard to find, but they are outrageously expensive. Don't mess with the Output's BIAS. PERIOD! Messing with it will guarantee Magic Smoke, and a LARGE DOORSTOP!

Larry
 
Larry, I have already emailed jjprager a copy of the schematics for the Ambassador VI which should work for his Statesman. I thought that I had previously sent a PDF to Jon to put up on the website but this model fell through the cracks somehow. Jon definitely has a copy now - as well as quite a few other new console schematics he acquired recently. He is putting them up as he finds the time to do so.

Here is the 690-A schematic:

64Ambassador690-A.jpg


I can post the 690-T schematic, too, if that would be helpful.
 
I can wait on the 690-T when Jon gets it up.

I'm gonna compare this with the 59-A and see how different they are,(if at all).

thanks
Larry
 
Thank you all for the help, I have already promised thered1 scans of all of the original manuals. They are coming soon. I plan on replacing the caps as soon as I have time to pull the beast apart. I am completely converted to tube sound now. Also very good advice Sam, but my nature is to replace what I see before tearing apart.
 
At least don't throw everything away. The original 12AX7s are probably Fisher-branded Telefunkens or Mullards.
 
So I've been tinkering. I've replaced the majority of caps inside the power amp, rebuilt the crossover on the right side (the large capacitor was partly blown up). Here is what's happening, as the console starts up there is a little bit of crackling, that fades very quickly. Then the audio comes on. There is no bass in the right channel, the bass in the left channel is fine, but cuts out after a few minutes. If I crank the bass knob or volume knob the left channel bass kicks back on.

I am not sure what to swap out next. Any help would be appreciated.

One other question I have is what are the big black cylinders that stick out of the amp? And also the white cylinder between the two ell80 tubes is getting quite hot.
 
Have you tried running the speaker outputs through different speakers? It's possible the problem is the caps in your crossover networks. You can isolate the problem by using a different set of speakers to see if it persists.
 
The white cylinder is a 2 part resistor for the speaker circuit. R37A&B and R39A&B according to what i can see on the schematic above.

The two black cylinders, if they are in the corner are the MAIN FILTER CAPS.
 
Thered1 yes I tried other speakers skipping the crossover.
Larryderouin should I worry about that resistor being hot to the touch? And I guess it's time to search for those filter caps
 
check the resistor temp while running with 8ohm outboard speakers. They get hot. You could get separate resistors of the same value and bump up the wattage some. That would cool them down some. BUT they won't be that type(not made any more.)
The cans are 3000uf 35v iirc. You can get 3300uf 50v nichicon's and stuff them. They make up a voltage doubler, so draw the hookups on paper and take a bunch of pictures of the connections. Be real careful of the isolation adapters. Available at AES. The can's are not available, is why i said to stuff them.
 
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