Hi Rick,
No, they are plate loads for the voltage amplifiers. The 3rd choke is in the place of Rg for the output tube.
So far I have noticed a slight gain increase and clearer highs over the 36k resistors I used to have there.
Makes sense since, for any frequency greater than 38Hz, I would have increased impedence over the stock RC stage.
No, they are plate loads for the voltage amplifiers. The 3rd choke is in the place of Rg for the output tube.
So far I have noticed a slight gain increase and clearer highs over the 36k resistors I used to have there.
Makes sense since, for any frequency greater than 38Hz, I would have increased impedence over the stock RC stage.
Rick, the problem is always going to be the bass response. So, you want to have enough inductance to maintain adequate gain at low frequencies.
Using 2*Pi*F*L=impedence, you get 18k ohms for my circuit at 20Hz... which is just fine. The plate resistance of the 01A is 10k ohms, so a load of 10k would be the -3dB point.
You can see why, when using inductors, lower plate resistance tubes have better peformance. Although with a big enough choke, it doesn't matter.
Using 2*Pi*F*L=impedence, you get 18k ohms for my circuit at 20Hz... which is just fine. The plate resistance of the 01A is 10k ohms, so a load of 10k would be the -3dB point.
You can see why, when using inductors, lower plate resistance tubes have better peformance. Although with a big enough choke, it doesn't matter.
WALKING THE TIGHT ROPE.
Hi,
Just as with OPTs,using chokes as anode load is a matter of balancing Henry in a quest of having sufficient bandwidth at the frequency extremes.
A lot of inductance will hopefully give good frequency response at the bottom and depending on the quality of the choke may compromise high frequency response to some extend.
It ain't simple,
Hi,
Just as with OPTs,using chokes as anode load is a matter of balancing Henry in a quest of having sufficient bandwidth at the frequency extremes.
A lot of inductance will hopefully give good frequency response at the bottom and depending on the quality of the choke may compromise high frequency response to some extend.
It ain't simple,
Most transformer winders consider plate chokes to be more difficult than transformers. Parasitic capacitance becomes a real issue in a 150H choke. So you're kinda getting an even better deal this way: for your 10 bucks - 150H and quite a few nanos for free.
10 bucks gets you a very reasonable resistor and a disastrous plate choke.
But don't worry - you'll come around - the fact that you like the chokes is already a good sign.
cheers
peter
Frank,
Since Peter has not heard my amp, has not seen it on a scope, and has not ever seen or used the mentioned chokes - how else can I take a comment such as "makes a disasterous plate choke"?
Again and again he criticises any design or component that does not cost a lot of money. This is worthless "advice" to me.
Also, your endless commentary is becoming really boring.
Does anybody with a brain have some discussion on this subject? Please?
Since Peter has not heard my amp, has not seen it on a scope, and has not ever seen or used the mentioned chokes - how else can I take a comment such as "makes a disasterous plate choke"?
Again and again he criticises any design or component that does not cost a lot of money. This is worthless "advice" to me.
Also, your endless commentary is becoming really boring.
Does anybody with a brain have some discussion on this subject? Please?
...Eagle eyes...
Nice spot Joel!!!
They're 10 euros over here in Italy. Advertised as a filter choke but good specs for a cheap plate choke. I've used power supply trans as pp trans before and they can work well. This is the same sort of thing...
I'll order some up before the price goes up!
thanks
James
Nice spot Joel!!!
They're 10 euros over here in Italy. Advertised as a filter choke but good specs for a cheap plate choke. I've used power supply trans as pp trans before and they can work well. This is the same sort of thing...
I'll order some up before the price goes up!
thanks
James
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