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This is DIY, we’re not advocating over painting the Mona Lisa
FYI
https://www.diyaudio.com/forums/tubes-valves/212673-wimpy-drivers-2a3.html#post3024777
FYI
https://www.diyaudio.com/forums/tubes-valves/212673-wimpy-drivers-2a3.html#post3024777
So far, the music sounds great with the bypass capacitors removed, Overall nothing has really changed, aside from the gain. I think I'm hearing more of the 2a3 goodness?
Schmitz77.
Part of the genius of the designer of the Sun 2A3 amp, is that there is no negative feedback (at least the schematic in Post # 1 did not show any negative feedback).
As I said, taking out the second bypass cap would destroy the maximum power from the amp, and that would mean mean early distortion.
The purpose of taking that bypass cap out, and only the 2nd bypass cap out, was merely to see if the gain was at the amount that the owner desired.
That amount of gain change was more drastic than removing the first bypass cap.
(27k / 27k; versus 62k / 470 Ohms.
The answer to that, was to determine the possibility whether the gain will be right with only a single 6SN7 triode driving the 2A3.
Modifying an amplifier is up to the owner, at his own risk.
I have seen multiple threads on this forum that asked about volume controls, or attenuators to reduce the gain in a system; and those threads were going 50 Posts or more (without a clear single decision of how best to do it, and without a consensus of the best way).
A poor "Newbee" will give up by then.
We are now at Post # 20.
The sound of a 2 stage amplifier and a 3 stage amplifier are often different.
Any 2 single ended stages in series will have some degree of cancellation of the 2nd harmonic. And the resultant 2nd harmonic from the first 2 stages, will have some degree of cancellation of the 2nd harmonic of the output stage.
Predicting how that will change the sound is quite a task.
If the change is large, it can be detected by many persons by 'listening'.
The OP is looking for a different sound.
How would you suggest he get the sound he wants?
A new amplifier?
An attenuator?
A different speaker?
Part of the genius of the designer of the Sun 2A3 amp, is that there is no negative feedback (at least the schematic in Post # 1 did not show any negative feedback).
As I said, taking out the second bypass cap would destroy the maximum power from the amp, and that would mean mean early distortion.
The purpose of taking that bypass cap out, and only the 2nd bypass cap out, was merely to see if the gain was at the amount that the owner desired.
That amount of gain change was more drastic than removing the first bypass cap.
(27k / 27k; versus 62k / 470 Ohms.
The answer to that, was to determine the possibility whether the gain will be right with only a single 6SN7 triode driving the 2A3.
Modifying an amplifier is up to the owner, at his own risk.
I have seen multiple threads on this forum that asked about volume controls, or attenuators to reduce the gain in a system; and those threads were going 50 Posts or more (without a clear single decision of how best to do it, and without a consensus of the best way).
A poor "Newbee" will give up by then.
We are now at Post # 20.
The sound of a 2 stage amplifier and a 3 stage amplifier are often different.
Any 2 single ended stages in series will have some degree of cancellation of the 2nd harmonic. And the resultant 2nd harmonic from the first 2 stages, will have some degree of cancellation of the 2nd harmonic of the output stage.
Predicting how that will change the sound is quite a task.
If the change is large, it can be detected by many persons by 'listening'.
The OP is looking for a different sound.
How would you suggest he get the sound he wants?
A new amplifier?
An attenuator?
A different speaker?
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It is the good natured intentions of many to pile in as soon somebody offers that they want advice, so I agree we’re doing well to see the OP happy after so few posts.
In my not humble opinion, OP is living the dream, having built a nice amp with own hands, now playing around to keep the fun going. Next step is to listen to amp and do some reading about how amplifier works, why different people make their design choices, but keep safely playing and doing it yourself without badgering & constraints of past masters etc. from us lot.
Of course modifying an amp you built yourself is at own risk, it’s DIY, you sound like that’s a problem!
In my not humble opinion, OP is living the dream, having built a nice amp with own hands, now playing around to keep the fun going. Next step is to listen to amp and do some reading about how amplifier works, why different people make their design choices, but keep safely playing and doing it yourself without badgering & constraints of past masters etc. from us lot.
Of course modifying an amp you built yourself is at own risk, it’s DIY, you sound like that’s a problem!
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nice speakers!
your new 2A3 may well sound cleaner than that old Scott. A good single ended DHT isn’t of itself a lush sound.
That was Bigun's quote.
But describing only 2 items of an amplifier, like single ended DHT does not describe a lot of the other factors that can make an amplifier sound a particular way, or another way, or a 3rd way, etc.
So, with that much variability of parts, topology, and circuits that are in a single ended DHT, there can be different sound characteristics.
But describing only 2 items of an amplifier, like single ended DHT does not describe a lot of the other factors that can make an amplifier sound a particular way, or another way, or a 3rd way, etc.
So, with that much variability of parts, topology, and circuits that are in a single ended DHT, there can be different sound characteristics.
I'm really enjoying this amplifier with the bypass caps removed now ^_^, Its not bright sounding anymore, and I feel like I'm hearing more of what a 2a3 amplifier is suppose to sound like, maybe getting 80% there... Vocals are beautiful sounding!
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I think I am going to try to wire the 6sn7's in parallel like in this blog
2A3 Maniac strikes back!: Sun Audio Uchida Model SV-2A3H - Special Edition by 2A3 Maniac and Analog Tube Audio
Does anyone know what values for the plate and cathodes I have to change in order for this setup?
2A3 Maniac strikes back!: Sun Audio Uchida Model SV-2A3H - Special Edition by 2A3 Maniac and Analog Tube Audio
Does anyone know what values for the plate and cathodes I have to change in order for this setup?
I hope that I always say the right thing, when anybody quotes my statements,
and then ascribes it to someone else's name.
I do not want to get anybody into hot water.
and then ascribes it to someone else's name.
I do not want to get anybody into hot water.
My fault - careless deletion of parts of a post when quoting, leaving the wrong attribution. Sorry! But of course you guys are always very well informed, so no damage could possibly be done!
It would be better to attenuate the signal pre power amp than to modify a great amp design to a mediocre one. Putting tube systems in parallel makes them sound blurry because you parallel two not identical systems and they never have the exact same loadlines.
Those people make money with modding great gear for no reason but to make a living out of it instead of designing and building their own gear.
Thats their business model but it doesn't meant to be a reasonable one.
Schmitz77, 6a3summer made hundreds of measurements and multiple controlled listening sessions he shared in Parallel operation of triodes.. It seems to me you have been listening to opinions of incompetent designers.
https://1.bp.blogspot.com/-dTnsTy78...E44XYr0-YRkQ2niOvAgCLcBGAsYHQ/s1600/S+05.jpeg
Forget Resistor R2 - it should not be used.
Forget Resistor R2 - it should not be used.
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I just studied the books. And if you study the book of the best hundred classical tube amps, you won't find so many which did it that way (OK, EMI did it).
All the others are choosing tubes for their parameters, and there is a fair share of tubes for every application.
Another designer I respect Thomas Mayer said "There is a misbelief that paralleling triode halves creates some smear or other loss of resolution." in VinylSavor: Tube of the Month: The 6A6. Do you have measurement or other supporting evidence to your "Putting tube systems in parallel makes them sound blurry"? Probably happened to badly mismatched or defective tubes or incompetent design.
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hello, excuse me if I engage in this tread ... can you tell me how many volts the 330uf tantalum capacitor should have? i can't read from the schematic... thanks
This has been an interesting thread. Where are you now with the 2a3 amp if you still have it?