Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: snowman on September 07, 2024, 12:37:52 pm
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This might be a silly question, but I was wondering,
if you are able to properly distribute your rectified voltage from your PT(HT) with a suitable RCL matrix configuration/load, would 'too' many mA's available from your Secondary 1 (HT) be a concern to the design of your amp?
Thank you in advance.
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not clear on what you're asking?
you can never have too much "available current"
You can have to much LOAD for available current.
You can "math out" a ballpark load that will simulate the current draw of an amplifier.
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you can never have too much "available current"
That answers my question. Thank you.
Is it fair to say that TOO much load will draw too much current and likley run your PT beyond the amps it is spec'd for?
And too little current available from your PT causes either sag or cutoff usually?
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Ohms law is your friend
TOO much load will draw too much current and likley run your PT beyond the amps it is spec'd for?
The "amp" IS the LOAD, the PS is designed for that specific load
too much current draw by the load causes HEAT, heat causes parts to fail.
Yes you can get sag when the PS cannot provide the "Instantaneous" current required by the load. but that should be a "short term" effect, not a design feature.
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If using a valve rectifier, the minimum value of protecting resistance in series with the anode circuits (as specified for the valve type) must be considered.
It's usually provided by the HT etc winding resistance.
If that's not the case, separate resistors can be added to meet the requirements.
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Just a considerations
Assuming you are planning a clone of an old famous amp, too much current may be OK for the project or not because, the more in the past, some brand used components the cheaper they can, so SAG is an effect they didn't planned but is present on some amp, if you want to recreate that sound, however, you can achieve it simply adding a SAG resistor on the PS
Franco
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And while it's true that you can't have too much available current, you do have to plan for it. :icon_biggrin:
Using a transformer spec'd at a higher than required current will normally result in voltages that are higher than expected. Easily dealt with by using dropping resistors -- but, it's always better to spec the correct transformer in the first place. It will be lighter, maybe cheaper, and there will be less extraneous heat generated.
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This is all helpful. Thanks for the responses.