I currently have a moreplay preamp from bottlehead with the ACA 1.8. I would like to experiment with another First Watt amp build but I’m not sure how important it is to pick the right combination of preamp and amp. Are there preamp / amp combinations that should be avoided in general and specifically with the moreplay?
My listening experiences are extremely limited. I’m enjoying the learning and building process and having something that sounds good is a nice bonus.
My listening experiences are extremely limited. I’m enjoying the learning and building process and having something that sounds good is a nice bonus.
if you like what you have now, but needing more power, just go for bigger FW amp
whichever you choose, no mistakes and regrets
when speaking of amps, always say what room size is, what speakers and describe your listening habits and aspirations
whichever you choose, no mistakes and regrets
when speaking of amps, always say what room size is, what speakers and describe your listening habits and aspirations
The preamp, with your sources, should be able to drive the amplifier to its full output at clipping.
Your preamp's gain is +9dB, which is about a factor of 3.
The preamp output impedance should be less than the amp input impedance by about x5 or more.
If the preamp has a tube output stage, make that even more, to minimize distortion.
Your preamp's output impedance is 3.2k.
The preamp output capacitor should set the low frequency roll off with the amp to below 20Hz.
If it is electrolytic, the preamp output capacitor should set the low frequency roll off to below 2Hz.
Your preamp's gain is +9dB, which is about a factor of 3.
The preamp output impedance should be less than the amp input impedance by about x5 or more.
If the preamp has a tube output stage, make that even more, to minimize distortion.
Your preamp's output impedance is 3.2k.
The preamp output capacitor should set the low frequency roll off with the amp to below 20Hz.
If it is electrolytic, the preamp output capacitor should set the low frequency roll off to below 2Hz.
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Just build F4. It can drive any speakers. Completely in different league above aca.
Then try as many preamps you can put your hands on. Eventually you arrive to the point you are totally happy.
Cheers.
Then try as many preamps you can put your hands on. Eventually you arrive to the point you are totally happy.
Cheers.
I have built the F4, F5, F6, Aleph J and M2x. The F4 is my least favorite amp. It is a bit like distilled water in its lack of character. A lot of people do value the F4 for that quality. The F5 is the most colored of the amps in my opinion. Lots of fun to listen to but not particularly nuanced. The M2x depends on what input stage you choose to use with it. It is a ton of fun to experiment with the different input stages and it has the potential to be the best sounding of the First Watt designs but it wouldn't be my first choice for someone whose "listening experiences are extremely limited". The Aleph J is sonically the equal to many of the M2x input stages and has the advantage of being able to buy the Mosfet/JFET kit from the DIYAudiostore.com site so I would strongly recommend that as your first build. For all of the First Watt builds one of the biggest hurdles is building a power supply for the first time. I found that was one of the least documented and most confusing aspects of my first build but at the end of the day the power supply is quite straightforward, just know that you can safely ignore all the parts called "snubber" in the bill of materials. Also, it is much simpler to use bridge rectifiers rather than build your own from discrete components.
I too find F5 a little sharp, i built three versions with various outputs, with some variations, but maintaining the same character. It needs mellow preamp.
I built two M2, very pleased with both, but unlike ZM who ovulates just by talking about M2, i needed more. Recently made few F1J versions, all very good. For some reason, current drive works for me. Sound i can live with.
Aleph J is perfect all around, and I am building second one, just like F3.
The reason i suggested F4 is just that, to avoid all exploration, since F4 can provide all that.
Neutral is its strength.
You just need to find the pre to match the speakers.
Or build all of the fw amps 🙂
I built two M2, very pleased with both, but unlike ZM who ovulates just by talking about M2, i needed more. Recently made few F1J versions, all very good. For some reason, current drive works for me. Sound i can live with.
Aleph J is perfect all around, and I am building second one, just like F3.
The reason i suggested F4 is just that, to avoid all exploration, since F4 can provide all that.
Neutral is its strength.
You just need to find the pre to match the speakers.
Or build all of the fw amps 🙂
I have found that I like some character, but not over the top. Clean pre + character amp (like my sig), or the opposite.... character pre and clean amp (Impasse + F4, etc.) Always keeping in mind overall gain, input and output impedance, speaker load, listening preferences and environment, and so on when combining things.
Build the Aleph J. Everybody needs an Aleph, it’s a seriously wonderful amp. Will go beautifully with your preamp.
Thanks again everyone, I really appreciate the feedback.
And about the power supply, I’m going through those pains right now. I ordered the boards from the diy store, an Antek AS-4218 transformer and trying to get all the parts together from the BOM and the various build threads. I’m sure I’m going to have questions about acceptable substitutions for the caps and those Panasonic resistors I can’t find.
And about the power supply, I’m going through those pains right now. I ordered the boards from the diy store, an Antek AS-4218 transformer and trying to get all the parts together from the BOM and the various build threads. I’m sure I’m going to have questions about acceptable substitutions for the caps and those Panasonic resistors I can’t find.
Blasphemy!!!
I never said that M2 is best sounding FW amp, but it certainly is best FW amp
it is Swiss Knife FW specimen - build it properly, gave it best preamp you can, you'll not strive for better
though, being Greedy Boy, you'll always strive for more ... or just one more .........
+1 for the Aleph J as a first First Watt build. 😀 You won't need to ever build another amp, but you know you will. 
The blog linked below is a wonderful resource if you have not happened across it yet.
https://diyalephj.blogspot.com/
The boards in the store are currently sold out, and they may be changing configurations. So, if you're chomping at the bit to get started, you may need another option unless you can find someone with spare boards.
re: your resistors / caps. Someone in the Aleph J build guide thread needed alternatives for a few out of stock parts for their PSU. You can look over posts in the last few days.
The blog linked below is a wonderful resource if you have not happened across it yet.
https://diyalephj.blogspot.com/
The boards in the store are currently sold out, and they may be changing configurations. So, if you're chomping at the bit to get started, you may need another option unless you can find someone with spare boards.
re: your resistors / caps. Someone in the Aleph J build guide thread needed alternatives for a few out of stock parts for their PSU. You can look over posts in the last few days.
If you're looking for the Panasonic 0.47 ohm 3W resistors, they are being discontinued. However, for now they are still available
(say at Mouser: https://www.mouser.ca/ProductDetail/Panasonic/ERX-3SJR47V?qs=9gtMhpKs0nFjLCUulW%2BCHg== ,
with more in different packaging coming in a few months) It's a decent part, but not magical, and there are many others you can use.
(say at Mouser: https://www.mouser.ca/ProductDetail/Panasonic/ERX-3SJR47V?qs=9gtMhpKs0nFjLCUulW%2BCHg== ,
with more in different packaging coming in a few months) It's a decent part, but not magical, and there are many others you can use.
Thank you for that link. My search skills must be bad, I could only find one alternative. Even when I use the show similar link it just shows the one.
Go passive if you have adequate gain and do not need impedance matching. There is no value to adding more distortion and excess gain to an already gain adequate system.