Good day. And why did you use the rectification of the power supply of the incandescent lamps, and not just apply a voltage divider and did not apply a positive potential to the incandescence of the lamps? I collected a similar circuit and the 50 hertz background was cured precisely by supplying a positive potential to the incandescence of the lamps.
Can you please explain exactly what you mean? I kinda understand but I'm not exactly sure how one would implement this.
Everyone is just a colleague. From the rectified anode voltage of + 440 volts, we put a voltage divider on the case, consisting of two resistors, the voltage of which should be + 90 volts, from the same connection point of the resistors on the case we put a capacitor of 1 MkF. Disconnect the heating circuit from the case and apply voltage from the divider. In my amplifier, the filament winding is one, so all the lamps, including the weekend ones. powered from it - there is no background and it is close even on the spectrum analyzer and by ear. Until I did so, the background was quite noticeable.
Really common to see 6J32P referred to as EF86, some are even labelled as EF86. It should work just fine.
I have also tried E80F as a pin compatible replacement with a slightly higher filament current. (0.3mA vs 0.2mA) It's rather expensive but it is a special quality valve with 10,000 hour heater. It seems to work just fine Some people say it sounds better, some say it sounds worse. I couldn't hear any appreciable difference in my 5-20.
The best replacement I found is Brimar 6BR7/CV4006/CV2135 as it's very, very cheap by comparison and the quality of construction is very high. It was worth rewiring the sockets for them as I could buy 2x 6BR7 for less than the price of one cheap EF86 and nearly 4x for the price of the more expensive EF86's. (at least in the UK anyway)
I have also tried E80F as a pin compatible replacement with a slightly higher filament current. (0.3mA vs 0.2mA) It's rather expensive but it is a special quality valve with 10,000 hour heater. It seems to work just fine Some people say it sounds better, some say it sounds worse. I couldn't hear any appreciable difference in my 5-20.
The best replacement I found is Brimar 6BR7/CV4006/CV2135 as it's very, very cheap by comparison and the quality of construction is very high. It was worth rewiring the sockets for them as I could buy 2x 6BR7 for less than the price of one cheap EF86 and nearly 4x for the price of the more expensive EF86's. (at least in the UK anyway)
Used a pair of EF86 in one Quad II, and a pair of 6J32P in the other, and no discernible difference. I want to try 6BR7, and even 6BS7 with the grid taken to a top cap, but I would have to rewire the socket or make an adaptor, so I think that will be when I finally get round to building a copy of the Brimar 25P1 25W amplifier.
Hi,
I've a power transformer with 365 Vac @ 400mA secondary (510/520 Vdc after rectification NO LOAD).
Can I use this for a first quick test of one channel of this amp? Just to evaluate any problems (and sound
) before purchasing and putting the final transformer.
You think that B+ it's too high and risk of serious damage?
Naturally B+ under load it will be lower but not much.
Thanks
I've a power transformer with 365 Vac @ 400mA secondary (510/520 Vdc after rectification NO LOAD).
Can I use this for a first quick test of one channel of this amp? Just to evaluate any problems (and sound
) before purchasing and putting the final transformer.You think that B+ it's too high and risk of serious damage?
Naturally B+ under load it will be lower but not much.
Thanks
baudouin0 Hi, welcome back I am very happy with your support.
The 510-520 Vdc is my estimate voltage output (365*1.41=515Vdc).
I simulated and built this PSU and measured around 480Vdc (NO LOAD) so i think it might work. The PI section filter goes down a bit the voltage closer to specification.
Under load it should go about simulated. Of course, as already mentioned, only for the purpose of the first test.
What do you think?
I use the bulb in series as rightly suggested.
The 510-520 Vdc is my estimate voltage output (365*1.41=515Vdc).
I simulated and built this PSU and measured around 480Vdc (NO LOAD) so i think it might work. The PI section filter goes down a bit the voltage closer to specification.
Under load it should go about simulated. Of course, as already mentioned, only for the purpose of the first test.
What do you think?
I use the bulb in series as rightly suggested.
