ghdprentice is correct. It's not that complicated. You can get a digital mulitmeter at any hardware store, then just follow the directions Luxman provided. Don't get thrown off by the chatter anf noise. Sorry, folks, but he has new tubes and just wants to bias them correctly. The instructions are simple and quite clear.
Question on Tube Swapping and Biasing
First time tube swapper. I’ve had my Luxman MQ-88use and CL-38use preamp for about 5 years. They sound fine, but it’s good to have a backup set of tubes. So I bought a matched set of 4 Gold Lion KT88 tubes and replaced the stock JJ tubes.
So far so good, everything sounds good, and hopefully even better after breaking in.
Should I be concerned about not setting the bias for these new tubes? And how would I go about doing that? The Luxman manual says nothing about this.
Some online sources recommend having an audio professional bias the tubes, but to my limited understanding the bias is affected by the actual current going into the amp, so having a servicer bias it at a shop might not be the optimal way to go.
Could I hurt the amp or the tubes my not properly biasing them? Or am I overthinking all of this?
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@jaylat If you click on the link that @westcoastaudiophile provided for you and hover your pointer over the image you can read on the side of the box that it is a JJ tube that's been screened, tested and cryo'd. |
“Multimeters are really cheap” - yeah, kind of! LOL Cheap DMMs are really cheap, and results are not accurate or predictable, due to many factors, such as RFI impact, sampling rate etc.! I have couple of Agilent/Keithley bench DMMs in my Lab, $5000+ each, and I use them for sensitive circuit tuning! Before adjusting bias current by measuring amp’s internal resistor’s IR voltage drop, would be appropriate to test resistor(s) value itself first, which could be easily 20%+ off schematic. |
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