Amp biasing - do you do your own? - The Gear Page
WEBOct 23, 2023. #6. The Eurotube bias probe is the way to go. It measures both plate current and voltage, allowing you to calculate the dissipation and do whatever adjustment. However, unless there is an external access point to the bias pot (if there is one), you need to access the chassis, where high voltage risk exists.
KT88's...max watt rating and where to bias? - The Gear Page
WEBDec 31, 2017 — Looking at the data sheet for the Penta/Shuguang/Ruby KT88V-STR, the max anode dissipation is 50 watts! Compared to the regular 42 watts or even 35 watts on some more common KT88 data sheets that seems pretty high and really makes a big difference (about 10 mA) for the bias calculations.
low ouput DRRI: bias probe reads zero on one 6v6 only
WEBDec 31, 2015 — I have a DRRI from 199? that has been problematic for some time (years). Currently the output is low and the breakup is way early and sounds bad. I bought a bias probe from Eurotubes and one tube reads zero no matter where the bias pot is set. The other has a reading ranging from a few ma to...
Amp biasing - do you do your own? | Page 3 | The Gear Page
WEBOct 23, 2023 — Most of the bias probes on the market only give you a reading on the tube bias, but no reading on the plate-to-cathode voltage. From what I understand, you need to know the value of the plate-to-cathode voltage in order to set the bias correctly. So what gives? Are all these probes incomplete? In contrast, the EuroTubes "ProOne probe" …
Biasing A '65 Fender Deluxe Reverb Reissue With A ... - The Gear …
WEBAug 6, 2023 — More importantly and to the question I wanted to ask here, are all 65 DRRIs designed to have a 70% 'crossover distortion' point of 25mA (+/- 2.5ishmA) when the bias pot is dimed, hence my finding GT-6V6-S #7s in all of the ones I've owned? Every tube I have measured with my Pro One reads between 402-419V & 23.2-27.3mA when I max …
Do you bias your tube amps? - The Gear Page
WEBNov 21, 2020 — Two of my amps (Gries 35 and Gries 18) have bias test jacks and an adjustment pot on the chassis so yes, I bias those. The third amp is a 5E3 and cathode biased so no adjustment is necessary. My VOX has the same access with a pot and test points. Very convenient and very easy to perform.
Help! Bias probe reading really high mA on Deluxe Reverb
WEBOct 18, 2014 — So I am trying to bias my DRRI using a Eurotubes bias probe and I am having some issues. Per the instructions, I am on the DC mA setting on my multimeter. I had the probe plugged in between one of the power tubes. When I fired it up, I was getting a reading of 269.5 mA Adjusting the bias pot...
Which bias Meter ?? bias Probe, biasrite, biasking | Page 2 - The …
WEBDec 10, 2007 — I bought a probe from Amp-head for $40. I use a craftsman meter with it. It has a switch for plate voltage as well. It came with pretty good instructions as well. Schaf
Using "1ohm shunt type" bias probe with metro builds. Need help
WEBDec 11, 2010 — I'm confused and need some clarification. I want to use an amp-head dual bias tester to rebias my metro 100watt plexi and just got to thinking and that's where I went astray! To put it simply, on metro builds does the 1 ohm resistor on pin 1 and 8 to ground cause accuracy problems when using a...
Do you bias your tube amps? | Page 2 | The Gear Page
WEBNov 21, 2020 — So at 70%, I should bias to about 15mA, right? (13/620*700 = 14.7). But the lowest my bias pot will go is 19mA. Is my math wrong? I’m using a bias probe that sits between the tubes and the sockets for these measurements. Maybe its malfunctioning... the plate voltage seems really high. This is a Vintage Sound 20 amp.