I know this is a very subjective question that I need to answer by listening to them myself and seeing what I like, but I only have enough money to build one firstwatt amp and I don't know anybody else who has one that I can listen to. I've read reviews of all of these amps and cruised the forums, but I still can't narrow it down.
This is my current setup: Speakers are home made Austin A166 back loaded horns with Fostex FE166e drivers. I put phase plugs and coated them with modpodge like everybody suggests. They're very efficient and can fill the room with a watt or so per channel. For the preamp I've got a Firstwatt B1 as well as a Transcendent Audio Grounded Grid preamp I built. The source is a Rega P3 turntable, Denon DL-103 needle, and a Cambridge Audio 640p phono stage.
My current amplifier is a TubelabSE, a 45 based SET. This is the only "high end" amplifier I've ever owned (previously used old Marantz integrated and a T-amp). I'm very happy with the Tubelab, but naturally I'm curious about hearing what the a high end solid state amp has to offer.
I like the silky smooth, natural sound of the Tubelab, but I don't want a solid state amp that just simulates the tube sound. I just want the Firstwatt that's best suited for my horns, and to try something different.
Here's what my research has come up with so far:
F1j - Pros: Cool Transconductance amplifier, ideal for fullrangers without crossovers. Has an "analytical" sound that should offer a different flavor than my 45 SET.
Cons: push pull rather than single ended. I can't use it with a conventional speaker if I choose to in the future.
F2j: Pros: Same as the F1j except single ended with a more tubey flavor.
Cons: Might sound too similar to what I already have, both F1 and F2 seem to have been superceded by newer F series amps, can't find anybody saying these sound better than an F3 or F4. Can't use with conventional speaker if I don't like it with my horns.
F3
ros: Reviews say it sounds alot like a 45 SET. Really low distortion. I can use it with "normal" speakers if I don't like it with my horns.
Cons: I don't want something that sounds identical to the 45 SET I already have. Uses negative feedback so I'm afraid it'll overdamp my fullrange drivers.
F4: Pros: Current buffer. Versatile, I can use it as a proper amp, or I can use it with my tube amp to drive a subwoofer. Or I can use it as a headphone amp.
Cons: Seems to reflect the quality of the preamp hooked up to it, so I don't know how it'll sound with my Grounded Grid pre. Might have to build an Aikido or something.
F5: Honestly this one doesn't seem like a good fit for high efficiency horns.
J2: Pros: 6Moons' review makes it sound like this amp supercedes the F3.
Cons: Have to wait until the schematics are published.
With all that in mind, I've narrowed my choices down to the F2, the F3, the F4 or the J2. The J2 and F4 are in the lead now, but the F4 only because I can easily repurpose it if I don't like it as an Amp. Does anybody have any experience with these amps and backloaded horn speakers that might point me in the right direction?
This is my current setup: Speakers are home made Austin A166 back loaded horns with Fostex FE166e drivers. I put phase plugs and coated them with modpodge like everybody suggests. They're very efficient and can fill the room with a watt or so per channel. For the preamp I've got a Firstwatt B1 as well as a Transcendent Audio Grounded Grid preamp I built. The source is a Rega P3 turntable, Denon DL-103 needle, and a Cambridge Audio 640p phono stage.
My current amplifier is a TubelabSE, a 45 based SET. This is the only "high end" amplifier I've ever owned (previously used old Marantz integrated and a T-amp). I'm very happy with the Tubelab, but naturally I'm curious about hearing what the a high end solid state amp has to offer.
I like the silky smooth, natural sound of the Tubelab, but I don't want a solid state amp that just simulates the tube sound. I just want the Firstwatt that's best suited for my horns, and to try something different.
Here's what my research has come up with so far:
F1j - Pros: Cool Transconductance amplifier, ideal for fullrangers without crossovers. Has an "analytical" sound that should offer a different flavor than my 45 SET.
Cons: push pull rather than single ended. I can't use it with a conventional speaker if I choose to in the future.
F2j: Pros: Same as the F1j except single ended with a more tubey flavor.
Cons: Might sound too similar to what I already have, both F1 and F2 seem to have been superceded by newer F series amps, can't find anybody saying these sound better than an F3 or F4. Can't use with conventional speaker if I don't like it with my horns.
F3
ros: Reviews say it sounds alot like a 45 SET. Really low distortion. I can use it with "normal" speakers if I don't like it with my horns.Cons: I don't want something that sounds identical to the 45 SET I already have. Uses negative feedback so I'm afraid it'll overdamp my fullrange drivers.
F4: Pros: Current buffer. Versatile, I can use it as a proper amp, or I can use it with my tube amp to drive a subwoofer. Or I can use it as a headphone amp.
Cons: Seems to reflect the quality of the preamp hooked up to it, so I don't know how it'll sound with my Grounded Grid pre. Might have to build an Aikido or something.
F5: Honestly this one doesn't seem like a good fit for high efficiency horns.
J2: Pros: 6Moons' review makes it sound like this amp supercedes the F3.
Cons: Have to wait until the schematics are published.
With all that in mind, I've narrowed my choices down to the F2, the F3, the F4 or the J2. The J2 and F4 are in the lead now, but the F4 only because I can easily repurpose it if I don't like it as an Amp. Does anybody have any experience with these amps and backloaded horn speakers that might point me in the right direction?
I dont think you could go wrong with the F5. It may not suit your taste.
I enjoy it more than an F3 clone with lowther PM5a's. I agree with Nelson however, I have some small FF85K fostex's that sound golden honey sweet with the F3 clone.
The F2 is an easy project to build point to point. The F5 not much more complicated, and there are still options for PCB's for F5 around.
I enjoy it more than an F3 clone with lowther PM5a's. I agree with Nelson however, I have some small FF85K fostex's that sound golden honey sweet with the F3 clone.
The F2 is an easy project to build point to point. The F5 not much more complicated, and there are still options for PCB's for F5 around.
I picked up boards for the f5 about a year ago but I decided against building it. If 1 watts can rupture my eardrums, I doubt I'd ever take the f5 out of first gear. Seems like one more gain stage than I need.
The fostex's I'm using are 6 inches and they're responsible for the entire frequency range (no woofer or tweeter), is there a firstwatt that might squeeze an extra db or two at the top and bottom? Especially the top, the bass is actually pretty good as it is if I use an amp without negative feedback.
The fostex's I'm using are 6 inches and they're responsible for the entire frequency range (no woofer or tweeter), is there a firstwatt that might squeeze an extra db or two at the top and bottom? Especially the top, the bass is actually pretty good as it is if I use an amp without negative feedback.
Just a thought, most of the cost of building a firstwatt amp is in the Case, power supply and heat sinks. Say $300 of a $400 build. Changing could be done by just replacing the circuit.
I would listen to Nelson and Build an F3. No two different design 45 amps sound the same. Let alone a F3 and a Tubelab. Both are likely to have strengths. If you want an F5 later, its a smaller step.
Doug
I would listen to Nelson and Build an F3. No two different design 45 amps sound the same. Let alone a F3 and a Tubelab. Both are likely to have strengths. If you want an F5 later, its a smaller step.
Doug
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Joined 2009
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I'll add my vote to DougL's suggestion. Build the chasis with psu and all the wiring as if it were a test vehicle. It's not just the cost but also a lot of the effort - metal work and wiring that is.
Even if you build and love the F3, you will have been infected with the audio DIY amplifier bug and will want to build something else just for the heck of it. Being able to drop another amp board into an existing chasis will make this easier.
Even if you build and love the F3, you will have been infected with the audio DIY amplifier bug and will want to build something else just for the heck of it. Being able to drop another amp board into an existing chasis will make this easier.
I've used both F3 and F5 clones into a Lowther DX-3 running with a Promitheus Reference TVC passive preamp. Both amps sound excellent, but I think I agree with Nelson on the F3, it just sounds that little bit more special, probably in a valve kind of way. And more relevant seeing you are coming from a SET 45 tube amp, meaning you'll keep a to familiar flavour which may result in longer term satisfaction.
The F3 has an uncanny knack of allowing you to walk-in-and-amongst the performers, with fantastic separation and a real ebb and flow to the music! The F5 is similar, but IMO maybe not as holistic and developed in this way, while perhaps having a slightly sweeter and more extended top end, than the F3.
The only caveat with my F3 vs. F5 comments, is that I have heard the F5 likes to be driven by an active preamp, whereas I am currently using a passive TVC. I have a Supratek Grange triode preamplifier which I normally use and love the sound of, but it is with its maker Mick Maloney getting a circuit upgrade ...I can't wait to see what the Grange does to the F5? Maybe it will take it to another level as described by Srajan Ebaen at 6Moons.com ...
Regards,
Steve M.
The F3 has an uncanny knack of allowing you to walk-in-and-amongst the performers, with fantastic separation and a real ebb and flow to the music! The F5 is similar, but IMO maybe not as holistic and developed in this way, while perhaps having a slightly sweeter and more extended top end, than the F3.
The only caveat with my F3 vs. F5 comments, is that I have heard the F5 likes to be driven by an active preamp, whereas I am currently using a passive TVC. I have a Supratek Grange triode preamplifier which I normally use and love the sound of, but it is with its maker Mick Maloney getting a circuit upgrade ...I can't wait to see what the Grange does to the F5? Maybe it will take it to another level as described by Srajan Ebaen at 6Moons.com ...
Regards,
Steve M.
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The link in the thread doesn't work (http://www.firstwatt.com/downloads/F3-service-manual-sm.pdf) and I can't find it anywhere on the new firstwatt website. But I just found it on another web site. It looks like there's a wealth of build information in other threads that should get me started, so off I go! Thanks everyone for your help.
Just something for you to consider. If you go with the Peter Daniels PCBs, I think they have all the same footprint (ie for F1 to F5) so it would be very easy to swap out the populated PCBs later if you wanted a change.
Although as I type this, something tells me that one of the amps is a bigger board than the others....
Fran
Although as I type this, something tells me that one of the amps is a bigger board than the others....
Fran
F3 FIRST WATT F3 At the bottom of the page is a working link to the manual
Zen Variation 9 is here FIRST WATT ARTICLES was the article on the circuit design of the F3.
Send me an email from the forum as I have a couple LU1014's I can part with
Zen Variation 9 is here FIRST WATT ARTICLES was the article on the circuit design of the F3.
Send me an email from the forum as I have a couple LU1014's I can part with
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