You may have noticed that the address and phone number are incorrect on the flyer shown in some of the scenes. New word processing software likes to autocorrect things, even after you finalize it and press save. It's crazy! I realized the problem as I was researching replacement output transformers. Thank you for watching my video!
Noticed you wired up the 4 ohm tap on the output transformer. I have a 100watt JCM900 4100 and the normal wiring is 16 ohms for one 4/12 cabinet and 8 ohms for 2 4/12 cabinets. The amp has to be rewired to run 4 ohms. Which is in parentheses on the back panel. Seems unusual to use 4 ohms. Did they have 4 ohm cabinets? Thanks. Also there is a switch for low or 50 ohm config on mine. In the low power configuration is it basically the same configuration as the 50 watt head? Do you know? Thanks
Thank you for watching my video and for leaving a comment! I am uncertain as to what you mean by "switch for low or 50 ohm config". The low power switch is colloquially called a triode/pentode switch. In normal mode, the screen and suppressor grids in the power tubes function as normal. In triode mode, the switch connects the screen grids and plates together, eliminating the fluctuating screen grid voltage function. This effectively turns the power tubes into triodes. This feature functions in the same way on both the 50 Watt and 100 Watt models. You can read more about this here: robrobinette.com/Generic_Tube_Amp_Mods.htm#Half_Power_Switch0 I did not wire the 4 Ohm tap on the transformer differently than what is shown on the factory schematic diagram. I put everything back exactly as it was when the amplifier was given to me, just with new components. This amplifier belongs to a rehearsal studio, so I cannot answer your question about speaker cabinet impedance, sorry.
Thank you for watching this video and for leaving another comment. Isolation washers do reduce vibration, but they are mainly used to electrically isolate the bolts that mount a transformer to a chassis. This is done to reduce eddy currents. A transformer works through electromagnetic induction. If the bolts are allowed to be conductive, they can vibrate and heat up. This diverts some of the electromagnetic energy from the transformer core and makes it less efficient.
You may have noticed that the address and phone number are incorrect on the flyer shown in some of the scenes. New word processing software likes to autocorrect things, even after you finalize it and press save. It's crazy! I realized the problem as I was researching replacement output transformers. Thank you for watching my video!
Noticed you wired up the 4 ohm tap on the output transformer. I have a 100watt JCM900 4100 and the normal wiring is 16 ohms for one 4/12 cabinet and 8 ohms for 2 4/12 cabinets. The amp has to be rewired to run 4 ohms. Which is in parentheses on the back panel. Seems unusual to use 4 ohms. Did they have 4 ohm cabinets? Thanks.
Also there is a switch for low or 50 ohm config on mine. In the low power configuration is it basically the same configuration as the 50 watt head? Do you know?
Thanks
Thank you for watching my video and for leaving a comment! I am uncertain as to what you mean by "switch for low or 50 ohm config". The low power switch is colloquially called a triode/pentode switch. In normal mode, the screen and suppressor grids in the power tubes function as normal. In triode mode, the switch connects the screen grids and plates together, eliminating the fluctuating screen grid voltage function. This effectively turns the power tubes into triodes. This feature functions in the same way on both the 50 Watt and 100 Watt models. You can read more about this here: robrobinette.com/Generic_Tube_Amp_Mods.htm#Half_Power_Switch0
I did not wire the 4 Ohm tap on the transformer differently than what is shown on the factory schematic diagram. I put everything back exactly as it was when the amplifier was given to me, just with new components. This amplifier belongs to a rehearsal studio, so I cannot answer your question about speaker cabinet impedance, sorry.
Are the isolating washers on the OT just used as dampaners for vibration??
Thank you for watching this video and for leaving another comment. Isolation washers do reduce vibration, but they are mainly used to electrically isolate the bolts that mount a transformer to a chassis. This is done to reduce eddy currents. A transformer works through electromagnetic induction. If the bolts are allowed to be conductive, they can vibrate and heat up. This diverts some of the electromagnetic energy from the transformer core and makes it less efficient.
@@mendittoamplification interesting, thanks!
@@soapboxearth2 You're welcome. Thank you again for watching my videos. Have a nice day!