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Calbest 8211 stereo twin amplifier

gadget73 said:
EL84 push-pull with reasonable size output transformers you can expect 15 watts or so, maybe a smidge more depending on the voltages. This thing looks reasonably built. Shame about the circuit boards, the old ones are a PITA but hopefully they aren't so bad that it can't be re-worked.
Click to expand...
the top circuit board looks like alot of traces are shot but the bottom one doesnt look too bad unless its the lighting.
 
If a trace is broken, lay a piece of bare wire across it and solder. If it's broken at a component lead, loop the end around the lead and solder. Lifted traces can be held down with epoxy, but it doesn't take heat that well, will smell...

5V4 ought to be adequate for rectifier, draws 2A vs. 3A for 5U4. And will have output voltage a little lower than 5AR4.
 
Tom Bavis said:
If a trace is broken, lay a piece of bare wire across it and solder. If it's broken at a component lead, loop the end around the lead and solder. Lifted traces can be held down with epoxy, but it doesn't take heat that well, will smell...
Click to expand...
None of the traces seem to be lifted, the solder on the traces seems a bit dry looking though.
 
Another question, how do I figure out which pins correspond to which values on the multi section capacitors. I can check them with my multimeter but if there values are way off due to age that won't help me too much.
 
Usually the higher values are used closest to the rectifier. Two reasons: Larger caps can take more ripple current, and the lower current used in following stages can be filtered well with a larger resistor and smaller cap. That said, they'd have used larger values if they had been available at the same cost...

For what it's worth, the Calbest 7615 was a mono amp with the same tubes, schematic attached. Odd that the Stereo version also has the "Rolloff" EQ switch as RIAA was standard for stereo LPs.
 

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Tom Bavis said:
Usually the higher values are used closest to the rectifier. Two reasons: Larger caps can take more ripple current, and the lower current used in following stages can be filtered well with a larger resistor and smaller cap. That said, they'd have used larger values if they had been available at the same cost...

For what it's worth, the Calbest 7615 was a mono amp with the same tubes, schematic attached. Odd that the Stereo version also has the "Rolloff" EQ switch as RIAA was standard for stereo LPs.
Click to expand...
Oh! I just figured out, the little symbol after the values corresponds with the shape of a little tab coming off each pin.
 
yeah there should be a shape next to the tab, and the cap itself will have a legend indicating which is what. Square, half circle, triangle, and no symbol are typical.
 
Hey all, I'm sorry for resurrecting this thread but am in need of some input here. My buddy recently was gifted one of these, 8211, and everything seems to work, however being super newbies we are unsure of exactly how to hook this up and cannot find any manual's for it.

How does he connect his pair of speakers, (Forte's) to this via each channel and a single input? we don't want to experiment and break something so we come asking for some direction.

Appreciate any help in advance


*****Update...feeling pretty stupid, but it sounds awesome so makes my dumbness a little better!
(ignorance is bliss!)

Faster
 
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