The Amp Garage

The RC high pass filter component values before the bias rectifier largely determine the rectified V DC at the bias reservoir cap. Such that if more voltage is required, the R or the C or both values could be increased. Increasing the value of C will increase the Vdc at the bias reservoir capacitor...

Here is a bias supply with both level and balance.

Here is a basic bias supply. If you install a standby switch, then change the 220k balancing resistors to 47k/2W and put the standby switch after the reservoir caps.

Here are four ways to do it:

What power tubes are you using?

audiosalvage wrote: ↑Thu Sep 28, 2023 2:00 am Built a high voltage effects loop using lnd150s and got a whole lotta loud blaring noise with the volume me knobs down.

Was that the Mojotone design?

Hello. I have a newly built 1987 plexi circuit which is cathode biased. I'm very pleased with the sound, but I'd really love to add my reverb and delay pedals. Using them in front sounds terrible. I'm currently using an attenuator and experimented with running the LINE out into the reverb and then ...

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The zener diode does not conduct for most of the AC cycle. When the rectifier diode first becomes forward biased, the zener diode still doesn't break over because the reservoir capacitor has discharged to a voltage that is below the zener voltage. Once the reservoir capacitor has charged-up enough, ...

For the Carvin at hand, the two 4136's will typically draw 12mA just sitting there with no signal and no load. The 5532 will typically draw 8mA under the same conditions. The two 2N3391 circuits will draw 2.8mA when the switches are closed. This leaves the 2N5550/2N5400 push-pull amplifier that driv...

The AC voltage source on at least some of the simulators puts out a sine wave of the same magnitude regardless of the load that it is driving. This causes the simulator to come up with voltages that are higher than those obtained by driving the same load with a real world transformer. Sometimes the ...

The only time that the rectified and filtered voltage is 1.414 times the peak AC voltage is when there is no load on the DC voltage and you have a perfect rectifier. Once a DC load is introduced, the sine wave that the transformer puts out becomes flattened. Taken to the extreme, the transformer wou...

First, the sentence as I wrote it is correct. Did I say that your sentence was incorrect? No, I did not. Now, I may well have implied that your sentence was irrelevant in the context of the power supply at hand. But worse than that, it could give some the impression that we will have to deal with b...

50Vac rectifies to about 71Vdc... Not in this power supply. This is half-wave with a 200R resistor in series with the diode. I would expect 16V to 17V at the first filter capacitor with a 50mA load and no zener diode. It doesn't take very much more current for the voltage to be under 15V at the fir...

A follow up question: since the CF is just a buffer and not a gain stage, is it correct to say that the DC coupled gain stage before it will be the first to distort, if the CF is placed last in the preamp? And if so, will it distort/behave like a normal gain stage would? The cathode follower causes...