alexberger
Responses from alexberger
300b lovers Hi Lynn, In my SET amplifier is IT coupling between driver and 300b and RC between an input and a driver stages. I think I understand why the tone issue appeared. I played with driver tube B+ voltage and current. The cathode resistors 680 ... | |
300b lovers Following Lynn and Don recommendations, I added a separate filament transformer for 300B. It made the sound clearer. Then I added a separate transformer and rectifier for driver and input tubes. I use a Hexfred bridge (Ralph's recommendation) and ... | |
Loudspeaker sensitivity and dynamics: are the two inexorably linked? Another factor is - the crossover parts like resistors, inductors are heating when you push dozens of watts on a speaker. As a result, parameters of drivers and crossover parts are changing with the power. As a result most low sensitivity speakers... | |
Loudspeaker sensitivity and dynamics: are the two inexorably linked? Just imagine speaker voice coil even with most effective dissipate heat is possible. When you need dozens of watts to drive the speaker the heat on this voice coil is huge. You can’t cool it in closed small box without fan. Another story if it is ... | |
300b lovers The question is about of calculating C-Miller for a pentode tube in triode mode. If we have no data of C input at triode mode, or also no data of Cg1-g2, then how do we calculate C-Miller? How is big the total input capacity in 6V6 in triode mode ... | |
300b lovers Here is Eleckt schematics: http://4tubes.com/2-SCHEMATICS/BY-BRAND/ELEKIT/TU-8600/TU-8600R-Amplifier-300B-Schematic.jpg Global negative feedback, parallel 12au7 driver, 12ax7 input, semiconductor bias control and power supply stabilizers. chrom... | |
300b lovers Hi @atmasphere , I will use this rectifier for the driver and the input stages. So i don't need a very high current and power capability. | |
300b lovers Hi @donsachs , I have a question. I bought and received a power transformer for the driver tube's power supply. This transformer has a central tap for the rectifier. I also bought 4 schottky diodes. What type of rectifier will sound better: a cen... | |
300b lovers @charles1dad 45 and 6v6 tubes that Lynn and Don use to drive 300b also designed and mostly used as output tubes and also give around 2 watts output power. | |
300b lovers Hi @charles1dad , I am not a tube amplifier design guru like Lynn, Ralph and Don. But here is some information about your amplifier. https://www.audioasylum.com/cgi/vt.mpl?f=set&m=75278 The 6EM7 is a very strong tube for the driver wit... | |
300b lovers 300B - the total input capacity is 82pF, voltage swing peak to peak 150 volt. 45 - the total input capacity is 35.5pF, voltage swing peak to peak 100 volt. There is a difference in number but it is not a huge. Why is so much harder to drive 300B? | |
Speaker that are 'KEEPERS" for the long haul!!! I have been listening my Altecs 604E since 2005. | |
300b lovers Hi @atmasphere , McIntosh MC30 has the similar cathode follower driver 12ax7 to drive 6L6 directly. The output tube works in fixed bias in this schematics. Isn't it? Can you explain how the output tube bias is self adjusted? | |
300b lovers What is the minimal inductance is acceptable for 6sn7 interstage transformer ? 80H, 70H, 60H? The problem is transformers with high inductance have narrow high frequency bandwidth. But if interstage transformer doesn't have high enough inductance... | |
300b lovers Hi Lynn and Don, It is very interesting to hear more details about IT versus LC coupling between 6sn7 and 6v6. What is a difference in sound? |