Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TerryD on March 18, 2017, 07:51:12 pm
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I sold this to a friend. He cracked up the PCB board with the electrical cord. I had to replace the O.T. I did point to point around the power tubes and scraped the PCB board connections. Seems to be working. I sold him the unit with 2 RCA EL84s. One bit the dust in this scenario. I have one Fender GT EL84. I've been running the 1 RCA and the 1 GT EL84s. I don't see a problem with this thing cranked for 10 minutes. Both tubes seem to be running the same, glow wise. Sounds goodt.
Any problem giving it back to him with this power tube configuration??
Thanks a lot for the help fixing this up and for the reply to this,
Terry
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Take readings from the power tubes pins and post it, the gurus might shine in, and then they will be able to tell you how's it going to be in the long run. You might need to balance the bias between the 2 different tubes.
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Using two different tubes will work just fine, but if they're not balanced it can add unwanted noise since either side of the push/pull would be imbalanced, but everyone out there has different ear sensitivity, you may not notice a difference. it definitely can't hurt anything, it may just be a bit unbalanced.
~Phil
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Different brand didn't signify that tubes can't be used together
if they bias correctly and the bias of each tube isn't so different eachother
Franco