I like this "green" idea. I always want a 3W ~ 5W class A amp to use with highly effecient speakers. That will consume less power and emit less heat. The same way I like "flea" tube amps.
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Its respectable amplification if you have super efficient speakers. Hope chchyong89 keeps us informed of his progress. Looks like a neat project and would be nice to have that first watt plus just a few more while not using such massive sinks. Still it will suck a lot of power, but at 12V you could use batteries!
Yes, it is a "flea" amplication. I've been listening to a 1 watt "flea" single-ended triode tube amp for years.
My friend Walter(I met him here in Turkey🙂 ) has a 115db of Goto drivers
http://www.diyaudio.com/forums/swap-meet/20269-goto-horndriver-sale.html
I think it is difficult to listen at 3 watts 😀
This is interesting.Maybe can be used output transistors which is more complementary and have less input capacitance?Which transistors can be used?
Some DCB1 builders told me that they mate extraordinarily well for SQ but I keep on warning them that they create a fully DC coupled chain from source to speaker that will send their woofers to kingdom come in any mishap. Its wise to compromise with a coupling cap between them. Or use a highly reliable DC sense and protection system on the amp's output.
If DC offset is under control to a very low range or using a DC servo circuit with it, I prefer not to compromise with a coupling cap. Any way to avoid adding back a coupling cap ? A cap make a DCB1 not DC anymore.
Yes it would. Tie two batteries in series and point of connection is your new ground, like this:
Attachments
Or it makes an F5 AC input. Offset is no problem with DCB1. Very low near zero, no wandering.
Safety first is to be advised in such situations. Although, we haven't heard of any DC failure on any Mez or Hypno yet. The disaster scenario is when some build will lose one reg, the opposite voltage is going to appear full on output. Also there are sources that can leak DC and it will pass, whatever.
The best way is a power output DC protection and delay relay scheme. That will guard speakers from any possible failure in the F5 too. Having a full DC path from source to speakers is another order of transparency I must admit.
I see. I would rather make the protection in the F5, like a speaker DC protection relay with high current contacts, than add a coupling cap either in the DCB1 or in the F5 for possible failure situation. I know some ones would say "no" to relay anyway. For transparency, I think a cap is worse than a DC protection relay.
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Electro,
Class A amps without a budget, eh! I love it - my "wish list" gets bigger, .....
Adding a coupling cap (in series with signal) also requires a dc bias of a few volts across it and hence, back to a basic/standard B1.
The output relays are okay if you get the high current, twin contacts, low Z, etc and not the usual small dual things, plus good ccts for the dc protect, delay, mute, etc.
Class A amps without a budget, eh! I love it - my "wish list" gets bigger, .....
Adding a coupling cap (in series with signal) also requires a dc bias of a few volts across it and hence, back to a basic/standard B1.
The output relays are okay if you get the high current, twin contacts, low Z, etc and not the usual small dual things, plus good ccts for the dc protect, delay, mute, etc.
plastic film and similar non electrolytic capacitors do not need any DC bias voltage.
You can choose from Air, Ceramic, Mica, Glass, Paper, Polycarbonate, Polypropylene, Polyester, Polystyrene, Polysulphide, Teflon, Vacuum, etc.
If the Power Amplifier is DC coupled, then I believe, it must have supplementary systems to protect the speakers.
DC servo to reduce output offset,
DC detect and activate speaker isolation,
Supply Rail isolation or fusing,
Input mute on excess DC, to reduce signal through the amp to help activation of output isolation.
Taken to extreme, you could use DC activated crowbar protection across the output and/or across the supply rails.
DC servo to reduce output offset,
DC detect and activate speaker isolation,
Supply Rail isolation or fusing,
Input mute on excess DC, to reduce signal through the amp to help activation of output isolation.
Taken to extreme, you could use DC activated crowbar protection across the output and/or across the supply rails.
Good power for headphones i guess ...............
Also very good power for 115dB high quality high sensitivity speakers 🙂
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