Hello Folks,
In the last few weeks, I have been pondering all over the place about the pros and cons and merits of various First Watt designs (mainly F5,F6,J2,M2 Aleph J,etc.) I understand they are all unique designs, it can get quite confusing and frustrating trying to find the right kit. My question was probably asked a millions times before so I apologize in advance.
Seeking for clarity and advice from the community on most appropriate Pass amp kit t to match my current line of speakers as I am not planning on upgrading them any time soon :
1. Angstrom 500S 3 way full range design 89dB 1watt/ 1 meter 45Hz-20kHz +/- 3 dB). Impedance 8 Ω (MOSTLY USED)
2. Magnepan 0.7i 2 -Way/Quasi Ribbon. Freq. Resp. 45-22kHz ±3dB. Sensitivity, 86dB/500Hz /2.83v. Impedance, 4 Ω
Right now, they are hooked up to Class AB & Class D amps. Listening mostly to low/moderate levels.
Secondly, also important are good tutorials and guide for sourcing the parts and build instructions - my building skills are just average and will need a good manual. Aleph J instructions appear to be easy to follow.
Many thanks in advance for your appreciated feedback!
In the last few weeks, I have been pondering all over the place about the pros and cons and merits of various First Watt designs (mainly F5,F6,J2,M2 Aleph J,etc.) I understand they are all unique designs, it can get quite confusing and frustrating trying to find the right kit. My question was probably asked a millions times before so I apologize in advance.
Seeking for clarity and advice from the community on most appropriate Pass amp kit t to match my current line of speakers as I am not planning on upgrading them any time soon :
1. Angstrom 500S 3 way full range design 89dB 1watt/ 1 meter 45Hz-20kHz +/- 3 dB). Impedance 8 Ω (MOSTLY USED)
2. Magnepan 0.7i 2 -Way/Quasi Ribbon. Freq. Resp. 45-22kHz ±3dB. Sensitivity, 86dB/500Hz /2.83v. Impedance, 4 Ω
Right now, they are hooked up to Class AB & Class D amps. Listening mostly to low/moderate levels.
Secondly, also important are good tutorials and guide for sourcing the parts and build instructions - my building skills are just average and will need a good manual. Aleph J instructions appear to be easy to follow.
Many thanks in advance for your appreciated feedback!
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The Aleph J is an outstanding design that has become the reference amplifier in my system. It has plenty of power to drive my old Vandersteen 2C speakers, rated at 87dB sensitivity.
I recommend a dual-mono power supply that is capable of delivering +/– 24V to the amp PCBs. A pair of 300VA transformers with 20V secondaries would be a good place to start.
I recommend a dual-mono power supply that is capable of delivering +/– 24V to the amp PCBs. A pair of 300VA transformers with 20V secondaries would be a good place to start.
+1
A gentleman just posted a very nice build guide intended for first time builders. It should have everything you need and then some.
DIY Aleph J: A Build Guide
No matter what you choose, you'll love it.
A gentleman just posted a very nice build guide intended for first time builders. It should have everything you need and then some.
DIY Aleph J: A Build Guide
No matter what you choose, you'll love it.
Thanks - makes sense to beef up the power supply
Any instructions/tutorials/parts list how to build dual mono PS that would fit inside the 4U chassis?Those transformers a pretty large
The chassis will need to be 400mm deep to allow enough room to fit dual PSU boards + rectifiers and transformers. Either 3.5U or 4U in that size will have plenty of power dissipation. I used a pair of CRCRC boards by Prasi, and have been happy with those. The store "Universal PSU" boards will also work with proper attention to the rectifiers and filter caps. There are many possible ways to go here.
No exact tutorials I'm aware of, but cross that bridge when you get to it. It'll fit.
Basic parts are 2x your normal PSU parts + mounting brackets if you want to go vertical with your toroids. You can fit them flat in the chassis if you use monolithic bridges.
Test each independently, then when you're ready to wire it up, ask if you're unsure.
My best advice is to read the blog first.
Edited to add - +1 to TA's post. Typing at the same time... that'll teach me to refresh. 😀
Basic parts are 2x your normal PSU parts + mounting brackets if you want to go vertical with your toroids. You can fit them flat in the chassis if you use monolithic bridges.
Test each independently, then when you're ready to wire it up, ask if you're unsure.
My best advice is to read the blog first.
Edited to add - +1 to TA's post. Typing at the same time... that'll teach me to refresh. 😀
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Another question: Is the soft start power & speaker protection board a must for this build? I would not want to damage my expensive speakers. My Bryston has built-in protection soft start to prevent in-rush current and speaker protection.
Soft Start & Speaker Turn-On Delay / DC Protector Combo – diyAudio Store
Soft Start & Speaker Turn-On Delay / DC Protector Combo – diyAudio Store
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^ No, I consider that to be an unnecessary complication that typically causes more problems than it is supposed to solve.
You will notice that none of the original FirstWatt amps sold by Nelson Pass use this type of circuit. Adequate soft-start is achieved through the use of thermistors in series with the primary windings of the power transformers.
You will notice that none of the original FirstWatt amps sold by Nelson Pass use this type of circuit. Adequate soft-start is achieved through the use of thermistors in series with the primary windings of the power transformers.
