| Author | Message | ||
     Ian McLaren (evilcat) Username: evilcat Registered: 10-2006 |
I am new to all of this stuff and I seem to have a reverb problem. It is very weak even when the level is turned to 10. My chassis date is 82/4 and it has the 6l6gc's. I pulled the tank and it is marked 8FB2A1B. I think it is original but i thought it should be 8BB2A1B. I believe the tank is connected correctly (red is output and chassis has bees marked). Will the wrong tank impiedance cause more hum? Any input would be very helpfull. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Can't find my freaking tank chart but that sounds like a fender tank number. Those loads will be way off for a MM. Wait-here it is. That's a SLM tank according to this and the input impedance is 190ohms instead of the MM 1475. Wrong tank. According to my chart, you should have a 4FB3D1B tank. I imagine if you can't find one, the general high impedance tank would be a 9FB2A1C which would be 1925 ohm input. If you want the tank chart for yourself: http://www.stf-electronics.com/Page0014. Html | ||
| Ian McLaren (evilcat) Username: evilcat Registered: 10-2006 |
I believe this is wrong. It is not a 4 type tank they are the long type. these amps use Type 8 (short)tanks. My question is does the tube type affect the input imedance of the tank. I know the F code(1475ohm) input impedance is correct for EL34 based amps. It seem that the 6L6 amps had used both F or B code(150ohm) units. Was this done on purpose or was it a product of the change from EL34 to 6L6. The 8FB2A1B in my 6L6 amp is weak. Could the high input impeedance of 1475 ohms cause this. If that is the case would the 8BB2A1B and its 150 ohm impedance strenthen the reverb. | ||
| Ian McLaren (evilcat) Username: evilcat Registered: 10-2006 |
Well I took a chance and orderd a 8BB2A1B. For my 6L6 based RD112-65 the other threads have said 8FB2A1B or maybe 8BB2A1B, and I can assure that 8BB2A1B is correct. What a diiference. I guess when they made the switch from EL34 to 6L6 they must not have changed the tanks right away. |