Eico HF81 amp build with NOS Eico iron. This is an amazing PP EL84 amp the Jimmy built. around 12-14wpc and it sound amazing. He used NOS Eico iron from his vast stash in this build. Its all the great Eico sound without the integrated controls and such. 4, 8, and 16ohm taps.
From Jim on the build:
“It is a clone of the HF81 minus the preamp sections. The output transformers were new old stock in sealed boxes when I got them. The power transformers on the HF81s were know to overheat and burnout(likely due to shorted power supply from age). Heyboer makes replacements, but the one on this amp I ordered from Heyboer was built with a higher current rating of the B+ winding. The original Eico used EZ81/6CA4 rectifier tubes, the clone was built for damper tubes and 6AX4, 6DM4, 6DA4 can be used and all available NOS in various USA made brands. Also, I added a choke to the power supply and set up the circuit for a bit lower B+ compared to the original possibly longer life of modern EL84s. I kept the hum balance pots as per the original, though those were likely needed only because of the signal voltages of the phono section of the preamp stage. This this amp is basically a power amp so the pots have little or no effect.”
1,500.00 shipped
From Jim on the build:
“It is a clone of the HF81 minus the preamp sections. The output transformers were new old stock in sealed boxes when I got them. The power transformers on the HF81s were know to overheat and burnout(likely due to shorted power supply from age). Heyboer makes replacements, but the one on this amp I ordered from Heyboer was built with a higher current rating of the B+ winding. The original Eico used EZ81/6CA4 rectifier tubes, the clone was built for damper tubes and 6AX4, 6DM4, 6DA4 can be used and all available NOS in various USA made brands. Also, I added a choke to the power supply and set up the circuit for a bit lower B+ compared to the original possibly longer life of modern EL84s. I kept the hum balance pots as per the original, though those were likely needed only because of the signal voltages of the phono section of the preamp stage. This this amp is basically a power amp so the pots have little or no effect.”
1,500.00 shipped
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