Dipping My Toe Into Class A

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Bmsluite

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Joined 2023
#1
Greetings from the Multi Way group.


I have spent all my DIY audio time so far making loudspeakers. Mostly I make 3 ways but will probably make a 4 way next with some high end drivers.

I thought I'd pop in here and ask some questions about amplifiers. My experience with them is limited. I am considering dipping my toe into a cheaper class A or tube amplifier to see if this is worth pursueing for me. I can hear a difference between amplifier but so far it has been subtle. The difference between amplifiers seems to pale in comparison to the difference between loudspeakers. This is, quite likely, because I am always using cheaper amplifiers and there may not be a big difference between them.

I have been looking at building and Aleph first watt for some time but I want to know how great a difference a good amplifier makes before I drop a good chunk of money and time doing it right.

All my cheap amplifiers:
I use AIYIMA T9 pros in my office and my pool room
I use a Fosi MT20 for my kitchen
I use a Nobsound Mono for my bedroom 3 way.
The best amplifier I currently have is my Wiim. I use that for my 3 way towers in my living room. Nice to only need one remote for the TV since the Wiim has HDMI.

I want to make a huge jump rather than a small one. I have had my eyes on one of these cheaper EL34 tube amplifiers or a cheaper class A rated. The class A would have 20w. The EL34 maybe 6w.

I listen at much lower levels than most people I think. I measured it and 95% of my listening is done at 55-75 db. My speakers are not the most sensitive. Its usually the woofers that hold me back but I vary between 83-89db on the woofers. Everything else is padded down to meet the woofer. I believe small wattage still might be ok for me.

I will likely start with the class in my office with my 3 way desktop monitors. I will use my audio interface as the DAC and preamp.

I am very open to any other suggestion you have. The EL34 and the class A keep me around $200 just to try this which I consider to be very reasonable for what is, to me, currently and experiment. I don't think I want to spend $1000 right now for something I am not confident I want or need.

I have watched many review videos and read a lot of threads. These two cheap amps seems to be the biggest bang for my buck. Far and away from the quality that I am sure most of you are used to. Open to other amplifiers to try out.

EL34
https://www.aliexpress.us/item/3256...yv4l43Px&utparam-url=scene:search|query_from:

Class A
https://www.aliexpress.us/item/3256...LjE3NDEyNzQyNDIuNDIuMC4w&gatewayAdapt=glo2usa
 
#2
There are many excellent amplifiers in the Pass Labs section on this platform. Easy to build, even 'on budget' yields good results.
I'm a fan of the Hiraga amplifiers, a subtle 6W and a more robust 30W design are posted here abundantly.
In the Tubes/Valves chapter you can find single ended, balanced and OTL designs of affordable quality.
I'm not sure about the oriental products (save JP & SK), as the promotion is often very exaggerated...
 
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#4
The Music Fidelity A1 copy looks nice, but the heatsinks are quite small for class A. They look like they're barely adequate. It likely runs very, very hot. Apparently the real A1s did, too. The real A1s used the top plate of the case as a heatsink, and it would have made a good surface for grilling a nice cheese sandwich.
 
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#5
rayma said:
They only list 110VAC for line voltage (could be a real problem), and shipping will be quite high.
Click to expand...
I already have a 12.6 little transformer in my shop. I can use that to buck 15v off of the line voltage.

Some of the shopping is crazy high. Some is reasonable. For these I'm looking at $200 for both shipping and the product. There are multiple listing's of the same thing all with varying prices and shipping costs. Interestingly, there also seems to be a knockoff of the knockoff. I'm going to avoid the double knockoff unit
 
#6
Citizen124032 said:
There are many excellent amplifiers in the Pass Labs section on this platform. Easy to build, even 'on budget' yields good results.
I'm a fan of the Hiraga amplifiers, a subtle 6W and a more robust 30W design are posted here abundantly.
In the Tubes/Valves chapter you can find single ended, balanced and OTL designs of affordable quality.
I'm not sure about the oriental products (save JP & SK), as the promotion is often very exaggerated...
Click to expand...
Will definitely take a look at the hiraga. I haven't heard of that one before. 30 watts should be plenty
 
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#7
pinholer said:
The Music Fidelity A1 copy looks nice, but the heatsinks are quite small for class A. They look like they're barely adequate. It likely runs very, very hot. Apparently the real A1s did, too. The real A1s used the top plate of the case as a heatsink, and it would have made a good surface for grilling a nice cheese sandwich.
Click to expand...
I have no reference to how hot this will run but I'm guessing maybe 140F. It it becomes a problem I can hook up some noctua fans (silent fans) or figure out some sort of passive airflow for it. The duty cycle will remain low. I generally don't have the luxury of listening for hours in a row.
 
#13
I would probably avoid Ali and the other China options as the new rules could start soon and it will be a mess.
  • On February 1, 2025, President Trump issued an executive order imposing additional tariffs on China and eliminating the de minimis exemption for low-value products made in China or shipped from China.
  • This means that even shipments valued under $800 from China will no longer be eligible for duty-free entry.
That's not to say it won't be possible but it's going to require paperwork and at least an additional $100, the implementation will likely be sloppy and get held up for months.

It's wait and see.

Build a Pass amp, great support is what you need on your first build!
 
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#16
adason said:
If you want the best, build AN39. Boards with support available. Have not heard anything better.
Good luck!
Click to expand...
If this little test with the little Chinese one goes well I'll be building the aleph or the AN39. I like to try things for verification, and then go full bore. Just build the end game amplifier straight off. I could keep the little Chinese one in my office at work.
 
#17
jamesswarren said:
I would probably avoid Ali and the other China options as the new rules could start soon and it will be a mess.
  • On February 1, 2025, President Trump issued an executive order imposing additional tariffs on China and eliminating the de minimis exemption for low-value products made in China or shipped from China.
  • This means that even shipments valued under $800 from China will no longer be eligible for duty-free entry.
That's not to say it won't be possible but it's going to require paperwork and at least an additional $100, the implementation will likely be sloppy and get held up for months.

It's wait and see.

Build a Pass amp, great support is what you need on your first build!
Click to expand...
I've been buying stuff off Aliexpress for work and haven't had any issues. I don't think that all has been implemented yet. That's why I'm trying to buy this now.

The Canada tariff is insane and is messing up a huge work order I have with Microsoft right now
 
#20
jamesswarren said:
I would probably avoid Ali and the other China options as the new rules could start soon and it will be a mess.
  • On February 1, 2025, President Trump issued an executive order imposing additional tariffs on China and eliminating the de minimis exemption for low-value products made in China or shipped from China...
Click to expand...

....and then he suspended the elimination of the de minimis exemption of February 7th...
 
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