I agree with you Andy, I bought the suggested tools, but did not like what I was seeing. With some more time, I think I could master it, but it seemed the supplied tip was a bit large and heating to much of an area. I went back and soldered most conventional. With "Quad hands" holding the part in a pair of, normally closed, forceps I placed them so they has pressure on the part and board. Very small tip and heated the pad first... the results where good.
When I have some time, I might go back and play with it, but I have a workable solution, so I don't know if that will ever happen.
When I have some time, I might go back and play with it, but I have a workable solution, so I don't know if that will ever happen.
X, I received my PC boards promptly, a few days ago, many thanks, and will be collecting parts and supplies over the next few weeks for my AN build. I’m a bit nervous with the soldering of tiny parts and will follow your advice to use solder paste. Do you use the kind in a syringe or jar? Could you recommend a brand you use, please.
This works well.
No Clean SnPb Leaded Solder Paste 15 Grams No Clean SnPb Leaded Solder Paste 15 Grams - - Amazon.com
You need tweezers and an old skillet and hot plate. Watch some YouTube videos on “SMT soldering with a hot plate”
With the few parts on Alpha Nirvana you could do it with regular iron and string solder if you wanted to. It looks neater with paste though.
No Clean SnPb Leaded Solder Paste 15 Grams No Clean SnPb Leaded Solder Paste 15 Grams - - Amazon.com
You need tweezers and an old skillet and hot plate. Watch some YouTube videos on “SMT soldering with a hot plate”
With the few parts on Alpha Nirvana you could do it with regular iron and string solder if you wanted to. It looks neater with paste though.
I thought if you used that tin/lead solder paste ... all you needed then was a hot air gun, X? Like this:
yihua 952d+ 2 in 1 rework solder station hot air gun soldering desoldering iron Sale - Banggood.com
Why do you need a skillet and a hot plate?
Andy
If you don’t have a SMT hot air pencil anyone can do it with an old frypan and stove. Having an IR thermometer helps though.
The best way is to use both. The hot plate from bottom at low heat to get PCB to about 130C. Then local hot air from top will quickly melt the paste and hold heat for extra 10 seconds after liquidus to allow surface tension time to self align and pull all residual molten solder onto the pads to prevent bridges. In this way, only parts locally heated by hot air pencil get hot and then only for maybe 20seconds. The remaining components can be kept at 130C indefinitely without fear of damage. If using only hot plate and pan, you have to be careful not to heat the whole thing too hot for too long.
But plain hot air pencil alone works for small parts like chip resistors and caps. Big electrolytic etc need hot plate and hot air.
The best way is to use both. The hot plate from bottom at low heat to get PCB to about 130C. Then local hot air from top will quickly melt the paste and hold heat for extra 10 seconds after liquidus to allow surface tension time to self align and pull all residual molten solder onto the pads to prevent bridges. In this way, only parts locally heated by hot air pencil get hot and then only for maybe 20seconds. The remaining components can be kept at 130C indefinitely without fear of damage. If using only hot plate and pan, you have to be careful not to heat the whole thing too hot for too long.
But plain hot air pencil alone works for small parts like chip resistors and caps. Big electrolytic etc need hot plate and hot air.
The amplifier was just released and not many people have built it yet, so there is little feedback on the sound. I have only one channel built right now, so I haven't done any critical listening. The other side is ready to go in, but I'm just waiting for the case. Other than the designers, I think there are only one or two who have built it.
One of them is forum member Vunce, perhaps he will chime in.... Depending on where you are in Illinois, you could listen here when I get it finished. I'm about 1.5 outside Chicago.
One of them is forum member Vunce, perhaps he will chime in.... Depending on where you are in Illinois, you could listen here when I get it finished. I'm about 1.5 outside Chicago.
You can rest assured that this is one of the best amplifiers you will ever hear. It’s the culmination of several SE Class A Alpha’s. Even the 1st Alpha 20 amp is an excellent and very formidable amp. It’s such an easy amp to build given the low parts count. I think what might be hard for some people is wrap their head around the flying leads on the outputs. But trust me, that is the easiest way to mount amplifiers and their outputs into a chassis as the two operations are separate.
Hopefully, we will hear from more people who build and listen in the coming months.
JT,
From the designer aspect, I'd support X's comment strongly. I do not recall precisely what drove my thinking in the design of the original ALPHA, but X and I were talking about the Aleph J in some detail and I recall being amazed at Pass' brilliant active current control system. It propelled me to throw myself into hundreds of spice analyses so that I could completely understand the theory. Then X suggested cleverly I put the AKSA/Lender front end onto the output stage of the Aleph J, and I saw a great opportunity in the output stage which simulation revealed about 15 times lower distortion at full power. The rest was history, I spent a couple of weeks at the PC drawing up circuits, then testing each of them for FFT profiles.
X then built it and was astonished how good it was, he felt it was one of the best amps he'd heard, and he's heard just about everything. I was disappointed with the early clipping on the negative half cycle which limited power to only 20W from 24V rails, and continued after X had published it and set the ball rolling. It made quite a splash on the forum, and in a couple more weeks I had a solution for almost double power. IN the meantime, X had suggested the Big Boy, a 52W version using 36V rails, and I draw this up fairly quickly, then after a lay off of a couple of months, I told X about the Nirvana version, the one you are building.
This larger, far more efficient ALPHA really is the bee's whisker. It adds much more power and heft to the exquisite original ALPHA, and I was able to move away from the Pass active current system, because I like my amps to be as much as my own ideas. KK suggested some changes to the active current system for improved stability, but by and large this new version could automatically accommodate 8R and 4R speakers - a huge improvement from the point of flexibility and load tolerance. And this second design did not require adjustments after being built.
If you look over the ALPHA build you will find a few comments on the sound quality, including JWArch who compared it to a very highly rated tube SE amplifier. This Nirvana has all those qualities, and more power and dynamics, so it should be very good.
Recommended.
Hugh
From the designer aspect, I'd support X's comment strongly. I do not recall precisely what drove my thinking in the design of the original ALPHA, but X and I were talking about the Aleph J in some detail and I recall being amazed at Pass' brilliant active current control system. It propelled me to throw myself into hundreds of spice analyses so that I could completely understand the theory. Then X suggested cleverly I put the AKSA/Lender front end onto the output stage of the Aleph J, and I saw a great opportunity in the output stage which simulation revealed about 15 times lower distortion at full power. The rest was history, I spent a couple of weeks at the PC drawing up circuits, then testing each of them for FFT profiles.
X then built it and was astonished how good it was, he felt it was one of the best amps he'd heard, and he's heard just about everything. I was disappointed with the early clipping on the negative half cycle which limited power to only 20W from 24V rails, and continued after X had published it and set the ball rolling. It made quite a splash on the forum, and in a couple more weeks I had a solution for almost double power. IN the meantime, X had suggested the Big Boy, a 52W version using 36V rails, and I draw this up fairly quickly, then after a lay off of a couple of months, I told X about the Nirvana version, the one you are building.
This larger, far more efficient ALPHA really is the bee's whisker. It adds much more power and heft to the exquisite original ALPHA, and I was able to move away from the Pass active current system, because I like my amps to be as much as my own ideas. KK suggested some changes to the active current system for improved stability, but by and large this new version could automatically accommodate 8R and 4R speakers - a huge improvement from the point of flexibility and load tolerance. And this second design did not require adjustments after being built.
If you look over the ALPHA build you will find a few comments on the sound quality, including JWArch who compared it to a very highly rated tube SE amplifier. This Nirvana has all those qualities, and more power and dynamics, so it should be very good.
Recommended.
Hugh
Daanve,
It is both. It is Single Ended Push Pull, where the upper device sets voltage on the load, and bottom device sets current demand to meet the voltage requirement. This is a very old technical name, I believe given to a very old 1950s design from Murray in Australia using tubes.
This is a difficult concept to grasp - but the harmonic profile of the amplifier, despite schematic appearances, is pure Single Ended. Not quite the same, but very, very close, and much more efficient.
There is no requirement to explain anything to X, Daanve, if you knew him as I do you would realise he is cleverer than you and I put together.
Hugh
It is both. It is Single Ended Push Pull, where the upper device sets voltage on the load, and bottom device sets current demand to meet the voltage requirement. This is a very old technical name, I believe given to a very old 1950s design from Murray in Australia using tubes.
This is a difficult concept to grasp - but the harmonic profile of the amplifier, despite schematic appearances, is pure Single Ended. Not quite the same, but very, very close, and much more efficient.
There is no requirement to explain anything to X, Daanve, if you knew him as I do you would realise he is cleverer than you and I put together.
Hugh
Dannve - Let’s just call it “George”.
But seriously, no more pedantic arguing or snarky comments about what the topology is or isn’t. For almost 30years the Aleph-style amps are traditionally described as single-ended with an active CCS that tracks in sympathy with the load. The inventor and holder of the patent talks about this at length in various articles.
If you wish to discuss/argue about this, start a new thread. I’m sure there will be a lively and stimulating debate.
But seriously, no more pedantic arguing or snarky comments about what the topology is or isn’t. For almost 30years the Aleph-style amps are traditionally described as single-ended with an active CCS that tracks in sympathy with the load. The inventor and holder of the patent talks about this at length in various articles.
If you wish to discuss/argue about this, start a new thread. I’m sure there will be a lively and stimulating debate.
Was done months ago...but it lacks the lively and stimulating debate:
Discussion of Alpha Nirvana Operation
Mmmm ... possibly because you persisted in jumping in, boots and all, to push your PoV onto the respondents at every available opportunity?
Andy
Thank you so much!
Even if I don’t quite understand I’m happy to build my amp and listen. However, I was hoping for more subjective feedback, if any was available.
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Daanve, please stop it! You have made your point and it did not stick. Does it really matter what class amp it is, if highest fidelity is the objective?
Preamp requirements to drive Alpha Nirvana 8 ohms
My apologies if I missed this important bit of information in the three different threads dealing with the Alpha Nirvana amplifier, but I could not find the drive requirements to drive AN to full 39 watts output into 8 ohm speakers.
Do I really need a preamp with the Alpha Nirvana, of could I drive it via a 25k-100k potentiometer from a standard CD output?
Your help will be appreciated. Building the AN will be my first Solid State amplifier since a Dynaco ST80 in 1978, with numerous tube amplifiers since then.
My apologies if I missed this important bit of information in the three different threads dealing with the Alpha Nirvana amplifier, but I could not find the drive requirements to drive AN to full 39 watts output into 8 ohm speakers.
Do I really need a preamp with the Alpha Nirvana, of could I drive it via a 25k-100k potentiometer from a standard CD output?
Your help will be appreciated. Building the AN will be my first Solid State amplifier since a Dynaco ST80 in 1978, with numerous tube amplifiers since then.
